Revised Dam Design

Preliminary Tailings Dam Design Doris North Project, Hope Bay Nunavut, Canada

Prepared for: Miramar Hope Bay Limited Suite 300, 889 Harbourside Drive North Vancouver, BC V7P 3S1 Canada

Prepared by:

SRK Project No. 1CM014.006

October 2005

Preliminary Tailings Dam Design, Doris North Project, Hope Bay Nunavut, Canada Miramar Hope Bay Limited 300 - 889 Harbourside Drive Vancouver, BC, Canada. V7P 3S1

SRK Consulting (Canada) Inc. Suite 800, 1066 West Hastings Street Vancouver, B.C. V6E 3X2 Tel: 604.681.4196 Fax: 604.687.5532 E-mail: [email protected] Web site: www.srk.com SRK Project Number 1CM014.006

October 2005

Authors Michel Noël, M.A.Sc., P.Eng. Senior Geotechnical Engineer Maritz Rykaart, PhD., P.Eng Senior Geotechnical Engineer

Reviewed by Cam Scott, P.Eng. Principal

SRK Consulting (Canada) Inc. Preliminary Tailings Dam Design, Doris North Project, Hope Bay, Nunavut, Canada

Page i

Table of Contents Table of Contents ..........................................................................................................................i List of Tables ............................................................................................................................... iii List of Figures .............................................................................................................................. iii List of Appendices ....................................................................................................................... iii

1 Introduction .................................................................................................................. 1 1.1 Scope of Work..................................................................................................................... 1 1.2 Dam Design Review............................................................................................................ 1 1.3 Report Organisation ............................................................................................................ 2

2 Background Information ............................................................................................. 3 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14

General ............................................................................................................................... 3 Location............................................................................................................................... 3 Topographic Maps and Terrain Model ................................................................................ 3 Site Layout and Logistics .................................................................................................... 3 Dam Locations and Operating Intent .................................................................................. 4 Tailings Discharge............................................................................................................... 5 Tailings Properties .............................................................................................................. 5 Spillway ............................................................................................................................... 6 Tailings Impoundment Closure ........................................................................................... 6 Concept of a Frozen Core Dam .......................................................................................... 7 Meteorological Data ............................................................................................................ 8 Climate Change .................................................................................................................. 8 Subsurface Investigations ................................................................................................. 10 Foundation Conditions ...................................................................................................... 11 2.14.1 North Dam .............................................................................................................................11 2.14.2 South Dam.............................................................................................................................12

2.15 2.16 2.17 2.18 2.19

Ground Temperature and Permafrost ............................................................................... 13 Freezing Temperature....................................................................................................... 13 Unfrozen Water Content ................................................................................................... 14 Strength............................................................................................................................. 14 Seismicity .......................................................................................................................... 15

3 Preliminary Dam Design............................................................................................ 17 3.1 General Layout.................................................................................................................. 17 3.2 Design Criteria .................................................................................................................. 17 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.2.6 3.2.7 3.2.8 3.2.9 3.2.10

Dam Classification.................................................................................................................17 Design Earthquake................................................................................................................18 Design Capacity ....................................................................................................................18 Design Freeboard..................................................................................................................19 Design Flood .........................................................................................................................19 Stability ..................................................................................................................................19 Seepage ................................................................................................................................20 Freezing Temperature...........................................................................................................20 Construction Temperature.....................................................................................................20 Climatic Data and Climate Change .......................................................................................20

3.3 Upset Conditions............................................................................................................... 21 3.3.1 3.3.2 MN/spk

Warm Climate........................................................................................................................21 Over-Topping ........................................................................................................................21 PreliminaryTailingsDamDesign.Report.1CM014.006.emr.20051012.doc, Oct. 21, 05, 3:02 PM

October 2005


3.3.3

Page ii

Extended Duration of Storage ...............................................................................................21

3.4 Settlement ......................................................................................................................... 22 3.5 Dam Section...................................................................................................................... 23 3.5.1 3.5.2 3.5.3

Justification............................................................................................................................23 Description.............................................................................................................................24 Abutments .............................................................................................................................25

3.6 Construction Materials ...................................................................................................... 25 3.6.1 3.6.2 3.6.3 3.6.4 3.6.5

3.7 3.8 3.9 3.10

Material A (20 mm minus) .....................................................................................................25 Material B (150 mm minus) ...................................................................................................25 Material C (run-of-quarry)......................................................................................................26 Impervious Membrane (GCL)................................................................................................26 Thermosyphons.....................................................................................................................26

Spillway ............................................................................................................................. 27 Decant System.................................................................................................................. 27 Quantities .......................................................................................................................... 28 Thermal Analysis............................................................................................................... 28 3.10.1 3.10.2 3.10.3 3.10.4 3.10.5 3.10.6 3.10.7

Scenarios...............................................................................................................................28 Model.....................................................................................................................................29 Soil Properties .......................................................................................................................29 Calibration .............................................................................................................................30 Predictions - Normal Operating Conditions...........................................................................31 Predictions - Upset Condition................................................................................................34 Discussions and Conclusions................................................................................................34

3.11 Seepage............................................................................................................................ 35 3.12 Stability.............................................................................................................................. 35 3.12.1 3.12.2 3.12.3 3.12.4

Failure Modes........................................................................................................................35 Method of Analysis ................................................................................................................35 Geometry and Input Parameters ...........................................................................................36 Results...................................................................................................................................36

4 Implementation .......................................................................................................... 37 4.1 Final Design ...................................................................................................................... 37 4.1.1 4.1.2 4.1.3 4.1.4 4.1.5

Emergency Preparedness Plan ............................................................................................37 Adaptive Management Plan ..................................................................................................38 Engineering Analysis.............................................................................................................39 Additional Field Work ............................................................................................................40 Additional Laboratory Work ...................................................................................................40

4.2 Construction ...................................................................................................................... 40 4.2.1 4.2.2 4.2.3

Methodology..........................................................................................................................40 Equipment .............................................................................................................................41 QA/QC ...................................................................................................................................42

4.3 Post-Construction Activities .............................................................................................. 42 4.3.1 4.3.2 4.3.3

Monitoring..............................................................................................................................42 Site Inspection.......................................................................................................................43 Maintenance ..........................................................................................................................43

5 References.................................................................................................................. 45

MN/spk

PreliminaryTailingsDamDesign.Report.1CM014.006.emr.20051012.doc, Oct. 21, 05, 3:02 PM

October 2005


Page iii

List of Tables Table 1: Table 2: Table 3: Table 4: Table 5: Table 6: Table 7: Table 8: Table 9:

Correlated ambient temperature, average, cold and warm values..................................... 8 Probabilistic seismic ground motion analysis ................................................................... 15 CDA dam classification in terms of consequences of failure............................................ 17 Minimum factors of safety ................................................................................................ 20 Estimated quantities to construct the North and South Dams .......................................... 28 Thermal properties used in the thermal model................................................................. 29 Input parameters used in the stability analyses ............................................................... 36 Summary of critical factors of safety for North Dam......................................................... 36 Checklist of work to be carried out prior to completing detailed design of dams.............. 37

List of Figures Figure 1: Figure 2: Figure 3: Figure 4: Figure 5: Figure 6: Figure 7: Figure 8: Figure 9: Figure 10: Figure 11: Figure 12: Figure 13: Figure 14: Figure 15: Figure 16: Figure 17: Figure 18: Figure19: Figure 20: Figure 21:

Location Map Overall Site Infrastructure Layout Site Plan of Tail Lake North Dam, Layout Plan South Dam, Layout Plan North Dam Alignment, Longitudinal Section A-A’ South Dam Alignment, Longitudinal Section C-C’ Ground Temperature and Permafrost Characteristics Unfrozen Water Content, Laboratory Results North Dam, Section and Details South Dam, Section and Details Recommended Gradation Envelope, Material A (Core) Recommended Gradation Envelope, Material B (Transition) Estimated Unfrozen Water Content Calibrated Ground Temperature Profile Thermal Model Geometry, North Dam Temperature Predictions, North Dam, Average Climate Temperature Predictions, North Dam, Average Climate with Thermosyphons Temperature Predictions, North Dam, Warm Climate with Thermosyphons Temperature Predictions, Comparisons, 40 Year Simulations North and South Dams, Conceptual Instrumentation

List of Appendices Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Appendix G Appendix H MN/spk

EBA Engineering Consultants Letter Report by Mr. Don Hayley, P.Eng. SRK Technical Memorandum re: Water Cover Design for Tail Lake SRK Technical Memorandum re: Doris North Project Tailings Properties Summer 2004 Geotechnical Field Investigation Winter 2005 Geotechnical Field Investigation SRK Technical Memorandum re: Wave Run-up Calculations Larger Scale Drawings of Thermal Modeling Results Detailed Slope Stability Results PreliminaryTailingsDamDesign.Report.1CM014.006.emr.20051012.doc, Oct. 21, 05, 3:02 PM

October 2005


1

Introduction

1.1

Scope of Work

Page 1

SRK Consulting (Canada) (SRK) has been working with Miramar Hope Bay Limited (MHBL) since October 2001, on various aspects of the Hope Bay Doris North Project (from here on referred to as the Doris North Project), including completion of a Preliminary Assessment in February 2002 (SRK 2002a) and a Feasibility Study in February 2003 (SRK 2003a). The Doris North Project is a two year underground mining operation, located in Nunavut Canada. Ore will be extracted and processed on site, requiring an on-site tailings disposal facility. The preferred tailings disposal approach is sub-aqueous tailings disposal in Tail Lake (SRK 2005f). Two earth dams are required to contain Tail Lake during the operational period, and SRK developed a series of technical reports documenting preliminary designs of these dams (SRK 2003b; 2005f). The first preliminary dam design (SRK 2003b) consisted of an unprecedented frozen core design constructed from locally sourced marine clays and silts. Subsequently the design was revised to reflect the more common frozen core dam designs adopted at the Ekati Diamond MineTM. Based on additional field data that has been collected, as well as comments received from interveners during technical discussion in Yellowknife in August 2005, MHBL requested that SRK update and replace the April 2005 (SRK 2005f) Preliminary Dam Design report. This report therefore replaces in its entirety all previous dam designs for the Doris North Project. The report was prepared by Mr. Michel Noël, P.Eng. (BC) and Mr. Maritz Rykaart, Ph.D., P.Eng. (BC, SK, NT/NU, YT). The report was reviewed internally by Mr. Cam Scott, P.Eng. (BC, NT/NU).

1.2

Dam Design Review The preliminary dam designs presented in this report have been reviewed by Mr. Don Hayley, P.Eng., from EBA Engineering. Mr. Hayley is a recognized world expert in the design and construction of dams in the arctic, and played a pivotal role in the design and construction of the Ekati Diamond MineTM frozen core dams. Mr. Hayley is a Registered Professional Engineer in Nunavut Territory. The complete review comments presented by Mr. Hayley are included as Appendix A. In his review, Mr. Hayley confirmed that the Tail Lake dam locations “…have particularly complex permafrost stratigraphy…”, and that “…There is no direct precedent for design and construction of a frozen core dam on saline marine soils such as identified at this site…”. However, Mr. Haley concludes that “A frozen core dam remains the most appropriate structure for the environmental conditions and operating parameters at this location. The level of site characterization and design analysis will need to be elevated in order to deal with uncertainties identified in this review…” Mr. Hayley proceeded to make recommendations as to how the dam design should be modified to accommodate the complex permafrost stratigraphy, and also suggested additional site characterization and analysis which should be conducted prior to the final design stage of the dam.

MN/spk


October 2005


Page 2

The recommendations suggested by Mr. Hayley have all been fully and unconditionally adopted in the preliminary dam designs presented for the Doris North Project (See page 4 through 7 of the attached letter report in Appendix A). This includes an upstream dam side slope of 6:1 and a downstream side slope of 4:1. These flat slopes are specifically intended to address concerns related to potential deformation. This design is significantly more robust than the Ekati Diamond MineTM designs, to specifically accommodate site specific conditions. The additional thermal analysis suggested on Page 8 of the review letter report has been completed and is documented in this report. This report also acknowledges that additional stability analysis calculations will be conducted at the detailed design phase. The additional field characterization suggested by Mr. Hayley has also been carried out and is documented in this report. This program specifically targeted obtaining high quality samples of overburden from the North Dam foundation.

1.3

Report Organisation Following this introduction, Section 2 provides an overview of background information that is relevant for the dam design. Section 3 presents the preliminary dam design, which includes the design criteria, the definition of upset conditions, the estimation of settlement, the description of the dam sections and related components, the thermal, seepage and stability analyses. Section 4 covers the implementation aspects of the dam such as the final design, the construction, and the postconstruction activities.

MN/spk


October 2005


2

Background Information

2.1

General

Page 3

This report relies heavily on background information presented in other reports and documents, and where relevant these reports have been appropriately referenced. The focus of this report is on the preliminary design of the two frozen core dams required to isolate Tail Lake as a tailings impoundment for the Doris North Project. Related components associated with the water management for the facility are not included, other than making brief mention of those aspects that has relevance to the dam design criteria. Where appropriate, sections of the October 2003 Preliminary Tailings Impoundment Design Report (SRK 2003b) have been repeated for completeness.

2.2

Location The Doris North Project is situated approximately 400 km east of Kugluktuk (Coppermine) and 160 km southwest of Ikaluktutiak (Cambridge Bay) in the West Kitikmeot Region of the Territory of Nunavut (Figure 1). The site is approximately 160 km north of the Arctic Circle and 5 km south of the Arctic Ocean, at latitude 67° 30’ N and longitude 107° W. The nearest communities are Umingmaktok, located 65 km to the west and Kingauk (Bathurst Inlet), located 110 km southwest. The site is remote and can only be reached via air (float planes in the summer and ice airstrips in the winter) or sea (using ships or barges during the late summer season).

2.3

Topographic Maps and Terrain Model Topographic contour data for the terrain model was provided by MHBL. The resolution of the contours is 1 m intervals for most of the area and a small portion around Tail Lake has a contour interval of 2 m. The area along both dam alignments were surveyed and incorporated into the terrain model to generate updated topographic contours, which was then used for the dam design. The field survey data was also provided by MHBL and was consistent with the topographic maps. The surveyed elevation was within 0.5 m of the contours shown in the topographic maps.

2.4

Site Layout and Logistics SRK (2005a, b) provides a complete description of the overall site infrastructure layout; however, this will be summarized briefly, to place the proposed dams in perspective. The proposed mill site is located approximately four kilometres from Roberts Bay, which forms part of the Arctic Coastline. This area is accessible via ships and barges for a short period during summer months only. This will become the main re-supply route for equipment and supplies for the Doris North Project. A jetty will be constructed in the bay as a landing facility for the barges. Equipment will be offloaded and stored in a lay-down area close to the shore. Annual fuel supply will be pumped from the barges to a fuel transfer station, from where trucks will transport fuel to a tank farm located at the mill. These

MN/spk


October 2005


Page 4

facilities will be linked to the mill and tailings facilities via all-weather roads. Between the mill and the bay a portion of the road will be widened to act as a permanent airstrip, suitable for mid-sized aircraft that could transport personnel and small freight. The overall site plan is shown in Figure 2. The proposed development has enough reserves to sustain mining for two years (SRK 2003a). Mining will be underground, and the ore will be transported to surface via an adit. The ore will then be crushed and processed in a plant to produce gold bars as final product. Tailings produced during the milling process will be deposited in Tail Lake (Figure 3) about five kilometres from the proposed mill location. Tailings deposition will be sub-aqueous, requiring the construction of two water retaining structures; the North Dam and the South Dam. The North Dam is designed to retain a maximum hydraulic head of 7.5 m and the South Dam 2.0 m. Both dams are designed to operate for a maximum period of 25 years, after which the North Dam will be breached. The South Dam will not require breaching since the dam coincides with a natural watershed boundary with the adjacent Ogama Lake, and after the North Dam is breached, will impound no water, and not impede any natural flow of water. It should be noted that there is no potential for flow from Ogama Lake into Tail Lake. The normal operating water elevation in Tail Lake is 28.3 m, and that in Ogama Lake is 24.3 m. The lowest point in the saddle between Ogama and Tail Lake is 33 m. Therefore leaving the South Dam in place will not disrupt the natural hydrology under normal or extreme events, especially considering the fact that the normal range of water level for these lakes is in the 0.5 m range. All construction equipment and supplies will be shipped (or barged) to site during the short summer navigation season. This equipment will be stored in a temporary lay-down area until the winter season when temporary winter roads will be constructed to relocate construction equipment to the desired construction areas. All other surface infrastructure will be constructed during this season, and through the following spring and summer.

2.5

Dam Locations and Operating Intent The tailings impoundment requires the construction of two dams located at the north and south ends of Tail Lake as indicated in Figure 3. The proposed site layout for the North Dam is shown in Figure 4 and the South Dam in Figure 5. The tailings impoundment is sized to operate as a zero discharge facility during the two years of operation, if necessary. In addition, under the most conservative water balance assumptions (SRK 2005c) Tail Lake would take just over five years to reach the design Full Supply Level (FSL) of 33.5 m. A permanent spillway will be constructed at this elevation, to prevent the possibility of dam overtopping. The tailings water management plan (SRK 2005c) stipulates that the maximum water level in Tail Lake would be about 29.4 m, and that within five years after start of tailings deposition (i.e. three years after mining ceases), the natural inflow in Tail Lake would be equal to the amount of annual discharge that could be allowed. This proposed tailings management strategy requires discharge via

MN/spk


October 2005


Page 5

active pumping during the operational, closure and post-closure phases of the project. Under this scenario, the dams will never reach FSL, and the spillway will never be used. The water management plan is based on a water quality model, and detailed sensitivity analysis has been carried out to address any uncertainties in the model. Based on this analysis, the soonest timeframe within which Tail Lake could reach FSL is five years. Furthermore, the longest period of time that Tail Lake would have to be at FSL would be about 22 years. Therefore, the dams containing Tail Lake has been designed for a minimum operational design life of 25 years; however, as an minimum upset condition, the design has been tested to ensure safe operation for at least 40 years. The design takes into account, that after a maximum of 25 years, the North Dam will be breached, allowing the water level in Tail Lake to return to its pre-mining elevation of 28.3 m. The South Dam will not be breached as it is constructed on the watershed boundary between Tail and Ogama Lakes and is higher than elevation 28.3 m.

2.6

Tailings Discharge Slurried tailings from the mill will be pumped about 5 km to the Tail Lake tailings impoundment. The tailings will be deposited sub-aqueously and the water level in the impoundment will be regulated through the use of recycle water and summer decant to Doris Creek. Tailings deposition locations will be continuously changed to ensure that tailings is evenly spread over the deepest sections of Tail Lake. Winter deposition will also be sub-aqueous, and will be achieved by pipes though the ice. No on-ice tailings deposition will be allowed. Tailings will not be in contact with any of the two dams. Appendix B provides the details of the minimum water cover design thickness for Tail Lake, but also includes figures presenting the final tailings deposition plan view for Tail Lake. Although the intent would be to deposit tailings as level as practical, it is understood that there will be some undulations. An annual bathymetric survey of the tailings surface should be conducted to assist in planning of the tailings deposition. Should there be significant undulations in the tailings surface that would compromise the final water cover design requirements, consideration will be given to levelling the surface through dredging.

2.7

Tailings Properties Since tailings will not be used to structurally or hydraulically enhance the dam design, the tailings properties do not play a role in the dam design; however, for completeness Appendix C contains a detailed description of the tailings properties for the Doris North Project. A complete discussion of the tailings settlement characteristics and tailings geochemistry is presented in SRK (2005c).

MN/spk


October 2005


2.8

Page 6

Spillway A permanent operational spillway is required, and will be provided as protection against overtopping. The soonest that Tail Lake would reach FSL is just after five years of zero discharge, under the most conservative water balance assumptions. A permanent spillway will be constructed at the North Dam, at the FSL of 33.5 m, to allow through flow for a period of up to 25 years. The spillway will be sized to accommodate the 24-hour storm event with a 1:500 year recurrence interval. The spillway is illustrated in Figure 4 and entails a side-spillway across the northeast abutment of the North Dam. Spillway outflow will enter the original Tail Lake outflow channel approximately 100 m downstream of the North Dam toe, and would thus enter Doris Lake immediately upstream of the Doris Lake outflow point into Doris Creek. A spillway is not required at the South Dam as well due to the fact that both dams operate under the same conditions. If the North Dam cannot overtop due to the presence of an operational spillway, the South Dam will not be able to overtop as long as the freeboard requirements are met. Considering the fact that the spillway may never be required or seldom used, an alternative approach would be to design the dams without a permanent spillway but to rely on a decant pumping system and incorporate components in the dam design that would support short term overtopping. Short term overtopping of the dam is however not considered a reasonable alternative and are therefore not recommended as part of this preliminary design. It is however possible to consider delaying the construction of the spillway. Due to the fact that there is up to five years before the FSL is expected to be reached, if at all, it may make sense to delay the construction of the spillway and re-evaluate the situation annually based on actual water level measurements compared to the predicted values. SRK recommends that this alternative be further investigated at the detailed design stage. For the purpose of this report, it has been assumed that the spillway will be constructed at the same time as the dam.

2.9

Tailings Impoundment Closure The final closure for the Tail Lake tailings impoundment is a permanent water cover of at least 3.0 m above the highest tailings elevation in the impoundment. Research has shown that a minimum stagnant water cover of 0.3 m is sufficient to prevent oxidization of tailings. Tailings can however be re-suspended due to wave action induced by environmental factors, and therefore the rule of thumb is to design a water cover of at least 1.0 m thick. Based on the orientation of Tail Lake, the predominant wind direction, maximum wind speeds, and the particle size of the tailings, the actual minimum water cover depth for Tail Lake has been calculated to be at least 2.0 m thick. A 3.0 m thick water cover was subsequently selected as the design criteria to add an additional factor of safety against unforeseen events. Complete details of the minimum water cover thickness calculations are presented in Appendix B. For the full design tailings volume over two years, the tailings surface is expected to be below 24.3 m, which implies that the minimum final water elevation in Tail Lake must be at 27.3 m. In

MN/spk


October 2005


Page 7

actual fact the existing (i.e. pre-mining elevation of Tail Lake is 28.3 m, which implies that once the water quality in Tail Lake return to background concentrations, the North Dam can be breached to allow Tail Lake to return to its pre-mining elevation. Under this condition there will be a 4.0 m water cover over the tailings, which is a two-fold factor of safety.

2.10 Concept of a Frozen Core Dam The concept of frozen core dams is to maintain both the core of a dam and the foundation in a frozen state, which will provide an impervious barrier to water. Frozen core dams thus requires that the foundation be saturated and frozen, and that the core of the dam be constructed with soils containing sufficient fines to retain water and enable the pore water to freeze in a quasi-saturated state. The frozen pore water, once saturated, provides two benefits: strength and an impervious media. The strength is achieved by the frozen pore water that acts as bonding agent to the soil. The frozen pore water will block the pathways for groundwater seepage by filling the air voids, thus enabling impervious conditions over the frozen zone. Additionally, the frozen foundation does not require extensive excavation and grouting because of the rigid and impervious nature of the frozen ground along the foundation. It is however essential that the ground is saturated with pore ice to achieve impervious conditions. The performance of frozen core dams will be dependent on the sustainability of the frozen conditions in the long-term. The long-term performance should also sustain potential upset conditions. This will often translate in additional backfill material to provide the necessary thermal insulation for the frozen core. Frozen core dams, and in particular the core itself, are normally constructed in winter to “lock-in” as much cold temperature as possible within the dam. Frozen core dams often include synthetic liners placed against the upstream face of the core. This relative inexpensive option provides an additional barrier to contain water, thus increasing the margin of safety against potential seepage. Thermosyphons are sometimes installed during the construction of the dam to provide additional cooling within the dam. The benefit of using thermosyphons is to lower the ground temperature in areas where ground temperature may exceed a threshold value, or as an additional precaution to compensate for uncertainties that may be associated with the dam design and the site conditions. Thermosyphons can either be horizontally placed loops or independent vertically placed systems. The horizontal looped systems are placed during the construction and the vertical thermosyphons generally require drilling and are installed after construction of the dam. Most recently, five frozen core dams were successfully constructed at the Ekati Diamond MineTM Mine (Hayley et al. 2004). The configuration of these dams consists of a central frozen core that is encapsulated with a rock fill shell. The material consists of processed crushed rock to obtain the required gradations. The central core was constructed with granular material that was adjusted for water content to achieve the proper level of saturation. The construction was performed in winter which enabled the introduction of cold temperatures in the dam, thus establishing the frozen MN/spk


October 2005


Page 8

condition as the dam was built. Thermosyphons were installed at some locations to target potential taliks or as a preventive measure against possible thermal impact to the warm permafrost that was present at those sites. The construction of the dams is scheduled for winter to benefit from the cold climate, thus achieving the coldest conditions possible. The winter construction is the most economical approach to create a frozen core. It also provides a safeguard against introducing heat into the foundation material and impacting the thermal regime of the existing permafrost.

2.11 Meteorological Data Some climatic data was collected at the Doris North and the Boston Camp sites during exploration (60 km south of the Doris North Project site). The local climatic data was complemented using three regional weather stations operated by Environment Canada, namely Lupin, Ikaluktutiak (Cambridge Bay) and Kugluktuk (Coppermine) (AMEC 2003a, b). The climatic data collected at the Doris North Project and Boston Camp sites was then used to develop correlations for the Doris North site using Environment Canada weather stations. The correlated average ambient temperature from the Environment Canada weather stations over a 30-year period (1974 to 2003 inclusive) is summarised in Table 1. It also shows temperature values representative of extreme cold and warm conditions. These extreme values are based on the three coldest and warmest annual ambient temperatures over the 30-year period. Table 1: Correlated ambient temperature, average, cold and warm values 30 year average

Cold Condition (3 coldest years)

Warm Condition (3 warmest years)

Mean annual air temperature, MAAT (°C):

-12.0

-13.9

-10.0

Ambient temperature annual amplitude of monthly average (°C):

20.2

20.2

19.0

Air freezing index (°C-days):

-5,105

-5,566

-4,461

Air thawing index (°C-days):

754

536

860

The total annual precipitation is in the order of 207 mm, with about 80 mm as rain and 145 mm as snow water equivalent. Wind speed data reported for the Boston area (Rescan 2001) indicates predominant wind directions ranging from northwest to northeast, with wind speed in the order of 5 to 7.5 m/s. Calm conditions (wind speed below 1 m/s) occur about 6 to 9% of the time.

2.12 Climate Change The Department of Indian and Northern Affairs of Canada (INAC) commissioned a technical report on the “Implication of Global Warming and the Precautionary Principle in Northern Mine Design and Closure” (BGC 2003). This report highlights the importance of including the impact of climate changes into the design for mine development. The issue of climate change becomes more critical as the geographical location approaches the southern boundary of continuous permafrost. Although the

MN/spk


October 2005


Page 9

Doris North Project is well within the zone of continuous permafrost, climate change will impact its thermal regime, as discussed below. Many climate change studies have indicated that global warming is expected to be most pronounced in the Polar Regions (e.g. Cohen 1997, Houghton et al. 1996; NRCan 2004). Several papers (e.g. Harvey 1982; Hansen et al. 1984; Smith and Burgess 1998; Kettles et al. 1997; Environment Canada 1998; IPCC 1995, 2001) predict that the mean annual ambient air temperature could rise by 2 to 5 °C in the region covering the Doris North Project over the next century. Historical ambient temperature data between 1895 and 1991 (Environment Canada 1992) from the MacKenzie District shows the highest overall warming in the country, with an increase of 1.7 °C over that 96 year period. The Intergovernmental Panel on Climate Change (IPCC) concluded that the temperature trends indicate that some global climate change has already occurred (IPCC 1995, 2001). They recognised that global climate change is very difficult to predict and contains considerable uncertainties. Their predictions for the year 2100 estimate a global mean temperature increase between 1.5 °C and 4.5 °C, with a “best estimate” of 2.5 °C. The influence of climate change will also be dependent on the latitude of the region. For instance, the Doris North Project, which is situated at a latitude of approximately 67° 30’, could see a more pronounced impact of climate change in the winter, (relative to the global prediction), and lesser but still noticeable effect in the summer. Assuming the “best estimate” global temperature increase of 2.5 °C, the predictions made by IPCC for the latitude at the Doris North Project translate into a predicted increase of up to 5.8 °C in the winter, 4.2 °C in the spring and about 1 °C in the summer and fall. These increases would raise the mean annual ambient temperature by 3.1 °C. If the worst case scenario is assumed (global temperature increase of 4.5 °C), the predicted temperature increase would reach 10.1 °C during the winter, 7.2 °C in the spring and about 2 °C in the summer and fall. This scenario would see the mean annual ambient temperatures increase by 5.3 °C. The predictions advanced by IPCC show that climate change would eventually modify the thermal regime that currently exists at Doris North. The warming trends described herein are consistent with Burn et al. (2004) which presents the anticipated climate change scenarios for the Mackenzie River Valley. There is no clear trend based on the historical precipitation data, although most predictions show lower summer precipitations and larger winter precipitations. Smith (1988) indicated that precipitation would probably increase with global warming, thus increasing the probability of higher snow accumulation. The larger snow accumulation will increase the insulation provided by the snow cover, thus less heat losses during the winter months. Goodrich (1982) showed that a hypothetical doubling of snow accumulation from 0.25 to 0.50 m could increase the minimum ground surface temperature by about 7 °C and the mean annual surface temperature by 3.5 °C. This is consistent with the work presented by Nicholson and Thom (1973), and Nicholson and Granberg (1973). The larger snow accumulations could potentially accelerate the impact of climate change on the permafrost.

MN/spk


October 2005


Page 10

The following is an extract from “Climate Change, Impact and Adaptation: A Canadian Perspective” published by the Climate Change Impacts and Adaptation Directorate, Natural Resources Canada (NRCan 2004, page ix): A recurring issue in the field of climate change impacts and adaptation is uncertainty. There is uncertainty in climate change projections (degree and rate of change in temperature, precipitation and other climate factors), imperfect understanding of how systems would respond, uncertainty concerning how people would adapt, and difficulties involved in predicting future changes in supply and demand. Given the complexity of these systems, uncertainty is unavoidable, and is especially pronounced at the local and regional levels where many adaptation decisions tend to be made. Nonetheless, there are ways to deal with uncertainty in a risk management context, and most experts agree that present uncertainties do not preclude our ability to initiate adaptation. In all sectors, adaptation has the potential to reduce the magnitude of negative impacts and take advantage of possible benefits. Researchers recommend focusing on actions that enhance our capacity to adapt and improve our understanding of key vulnerabilities. These strategies work best when climate change is integrated into larger decision-making frameworks. It is therefore important the design incorporates a risk component for climate change, and as indicated above, it should also provide the ability to adapt to the variability introduced by the climate change.

2.13 Subsurface Investigations Six geotechnical drilling programs have been undertaken at the Doris North Project during 2002, 2003, 2004 and 2005, all of which specifically targeted geotechnical and thermal information at potential dam locations and along the perimeter of Tail Lake. The winter 2002 investigation comprised nine drill holes along three section lines across Tail Lake. The fall 2002 program consisted of five holes at the proposed North Dam location. The winter 2003 and summer 2003 programs involved further drilling at the North (5 holes) and South Dam (6 holes) locations, as well as three deep holes around the Tail Lake perimeter to investigate potential talik development. The summer 2004 program consisted of drilling one hole at the North Dam for the spillway and three more along the perimeter of Tail Lake to assess the shallow thermal regime and slope stability. The 2004 field program also included the installation of a 200 m long thermistor string located in the vicinity of the mill area and Doris Lake. The winter 2005 investigation included 5 boreholes at or adjacent to the North Dam alignment and three additional ones were drilled near the shoreline of Tail Lake. The results from the 2002 and 2003 investigations are compiled in SRK (2003b, 2005a). The 2004 investigation is summarised in SRK (2005d) and the 2005 investigation in SRK (2005e). These two reports are included in Appendices D and E at the end of this report.

MN/spk


October 2005


Page 11

The subsurface investigations included the installation of temperature measuring devices (thermistors) installed in selected holes. Nine thermistor strings were installed along the North Dam alignment, four at the South Dam and six along the perimeter of Tail Lake.

2.14 Foundation Conditions 2.14.1 North Dam The North Dam is located about 200 m downstream of north extremity of Tail Lake as shown in Figure 3. The proposed dam alignment, shown in more detail in Figure 4, is within a relatively narrow valley and is essentially perpendicular to the valley. The valley bottom is about elevation 26 m and consists of a narrow marshy area that drains the flow from Tail Lake. This surface flow then discharges into Doris Lake. The ground surface has generally a vegetative cover, although some areas are clear of vegetation and show the underlying overburden deposits. Rock outcrops are also visible within the valley but are commonly at higher elevations. Ground temperature measurements along this dam alignment indicate that permafrost is present over the entire length of the dam, with mean annual ground temperatures ranging between -9 °C and -7 °C. No talik was encountered under the shallow stream of water that traverses the valley. The geothermal gradient is generally isothermal in the upper 100 m. The ground temperatures measured in the 200 m drillhole near Doris Lake (SRK 2005d) indicate a geothermal gradient of about 11 °C km-1. Based on measured surface conditions, the permafrost depth is estimated to be 550 m. The interpreted stratigraphy at the North Dam that is shown in Figure 6 is characterised by two relatively distinct zones. About two thirds of the dam longitudinal section, on the southwest side, is dominated by a sand deposit with a thickness of 10 to 15 m, which is ice-saturated. The icesaturated condition was confirmed during winter 2005 investigation. The sand deposit is overlain by a silt and clay deposit that does not exceed about 3 m on the southwest side of the valley. Peat was encountered over a short distance in the middle portion of the dam. The remaining one third portion on the northeast side is dominated by marine clayey silt with a thickness reaching a maximum of about 15 m. This deposit is ice-saturated and contains excess ice. A relatively thin layer of granular soils, primarily sand and gravel was encountered overlying the bedrock surface in the upper portions on both sides of the valley. The bedrock consists primarily of basalt and is at a maximum depth of about 20 m in the middle of the valley and become shallower towards the crest of the valley. The bedrock condition is considered good at depth based on the recovery and the rock quality designation (RQD) as measured from recovered rock core. There were some zones at the overburden interface where the bedrock quality was poor, but it is reasonable to assume that this weathered zone was saturated with pore ice. The abutments at the proposed dam will be founded on overburden. Frozen sand forms the foundation material to the southwest, while overburden at the northeast side of the alignment is silt and clay. MN/spk


October 2005


Page 12

Hydraulic conductivity tests conducted within the bedrock formation along this dam alignment show very low values or no flow intake, indicating that the bedrock can be considered impervious, for practical purposes, when frozen. The RQD values were typically high, indicating that the bedrock would remain relatively impervious in the unfrozen state. Regional geology suggests that the Tail Lake Shear Zone intersects immediately south of the proposed dam alignment. While minor fractures were encountered in the recovered drill core, no evidence of the Tail Lake Shear Zone or any major faulting was observed. Salinity measurements on pore water extracted from soil samples indicate that the frozen pore water in the marine deposit (silt and clay) is saline, with salinity similar or slightly higher to that of sea water (salinity of about 30 to 50 ppt).

2.14.2 South Dam The South Dam is located about 400 m south of Tail Lake and is located at the watershed boundary that separates Tail Lake and Ogama Lake to the south (see Figure 3). The proposed dam alignment is along a flat valley section that remains above elevation 33 m (see Figure 5). The ground surface along the dam alignment is covered with hummocky vegetation and is well drained. Bedrock outcrops are present on both sides of the valley. The ground temperature measurements at the South Dam indicate that permafrost is present over the entire dam alignment. The temperature measurements indicate a similar thermal regime to the one present at the North Dam, with mean annual ground temperatures ranging between -9 to -7 °C with similar surface temperatures and being isothermal within the top 100 m. It is also reasonable to assume the same geothermal gradient profile exists as for the North Dam. The stratigraphy along the South Dam alignment is illustrated in Figure 7. It consists of a marine deposit comprised of silt and clay overlying a till deposit. The surficial marine deposit reaches a thickness of about 20 m in the middle of the valley and gradually become thinner towards the valley sides. Zones with silty fine sands were encountered within this upper zone, which may be attributed to lacustrine deposit from the evolution of Tail Lake. As for the North Dam, the fine grained marine deposit is ice-saturated and contains excess ice. The till deposit consists of a fine sand matrix with variable amounts of silts, gravel, cobbles and boulders. Some of the boreholes that encountered this till were limited to recovered coarse particles and did not recover the finer grained matrix. Borehole SRK-43 was the only one that used a polymer based drilling mud and managed to recover intact samples within the till. The recovered samples showed the typical nature of tills, which consisted of a fine grained matrix with unsorted gravel and cobbles. The till deposit, which generally overlays bedrock, has a maximum thickness of about 15 m and is limited to the middle portion of the dam alignment. A shallow pocket of sand and gravel was encountered above the bedrock surface at the east abutment. The bedrock formation beneath the dam alignment consists primarily of basalt along the west and central portions of the valley and argillite near the east abutment. The surrounding bedrock outcrops suggest that the argillite is probably underlain by basalt. The rock core yielded high RQD values, MN/spk


October 2005


Page 13

thus indicating good rock quality. The hydraulic conductivity tests in the bedrock resulted in very low values, thus supporting the good rock quality and the expectation of ice-saturated pore space. The abutments at the proposed dam consist of a thin overburden cover or exposed bedrock. Bedrock is expected to contain minor discontinuities, some of which will be contiguous; nevertheless, the bedrock appears competent overall. Pore water recovered from the marine deposit at the South Dam (borehole SRK-43) had salinities ranging from 30 to 46 ppt. These values encompass or slightly exceed the range for seawater.

2.15 Ground Temperature and Permafrost The Doris North Project site is underlain by continuous permafrost that has been estimated to extend to depths in order of 550 m (SRK 2005e). This permafrost depth was estimated from a 200 m deep drillhole (SRK-50) where the mean surface temperature is about -6.3 °C and the geothermal gradient is 11.4 °C km-1. The geothermal gradient in the upper 100 m appears to be isothermal or slightly negative. For comparison, the deep ground temperature profile measured at the Boston Camp also suggested a similar permafrost depth, about 560 m (EBA 1996; Golder 2001). The mean annual surface temperature is however colder at –10 °C and the geothermal gradient is higher at 18 °C km-1. The difference in the ground temperature profiles at those two sites can be attributed to different surface conditions and the thermal conductivity of the ground at depth. The geothermal gradient measured at the Doris North site is probably representative of the conditions in the vicinity of Tail Lake. Temperature data collected around Tail Lake indicates that the active layer in the marine clay/silt soils appears to be about 0.5 m, while the sand deposit has an active zone no greater than 2 m. The depth of zero annual amplitude varies between 11 and 17 m. The ground temperatures at the depth of zero annual amplitude are generally in the range of -9 to -7 °C. Figure 8 shows the ground temperature and permafrost characteristics present at the site. SRK (2005e), which is included in Appendix E, contains the most recent compilation of the ground temperature data collected by SRK since 2002.

2.16 Freezing Temperature The foundation material is composed in large part with a marine deposit that is saline. Pore water salinity measurements indicated that the pore water in the marine deposit is generally similar to seawater, with a few measurements that are slightly higher. Seawater has a freezing temperature of about -2 °C while the highest salinity measurement (54 ppt) corresponds to a freezing temperature of about -3.1 °C. Given the range of values measured, a freezing temperature of -2.5 °C probably includes most of the marine soils. Salinity levels of 4 ppt or less were measured in the sand deposit that was encountered at various locations around Tail Lake (SRK 2005e). The low salinity values indicate that the sand deposit is not

MN/spk


October 2005


Page 14

saline. Given the relatively high salinity of the fine grained soils, the sand deposit is treated as a saline soil as a precautionary measure for the purpose of design and thermal modelling. The salinity of the pore water from rock core was not measured during the investigation. It was considered as saline like the fine grained soils. Both dams will be constructed using crushed rock that will be amended with fresh water. The pore water in this material will therefore freeze near 0 °C.

2.17 Unfrozen Water Content The unfrozen water content is important for fine grained soils, such as the marine deposit. Such soils will have amounts of unfrozen pore water well below the freezing point, usually characterised by the relationship between the unfrozen water content and the temperature. The unfrozen water content was measured on one sample that was recovered at the surface near the North Dam (SRK 2005d). This sample consisted of shallow sandy clayey silts with some organics and had probably low salinity values due to its shallow depths. The results show that about 20 to 30% of the pore water remained unfrozen at temperatures of -12 to -8 °C (Figure 9). The unfrozen water content was recently measured on three additional samples following the winter 2005 investigation. Two of these three samples showed much higher unfrozen water contents than the previous measurements. They are however similar to data reported by Hivon and Sego (1995) for saline soils (salinity 30 ppt). The results shows 50% of the pore water will remain unfrozen at -8 °C and about 15% will be unfrozen at -20 °C. Although a portion of pore water will remain unfrozen at subzero temperatures, the frozen fraction will still be sufficient to reduce the hydraulic conductivity by probably a few orders of magnitude (Newman and Wilson 1997). The unfrozen water content of the sandy soils has not been measured. Given that sandy soils generally exhibit relatively low unfrozen water content below the freezing temperature, it is reasonable to use data from literature, such as Hivon and Sego (1995). The unfrozen water content of bedrock was also not measured. Bedrock has a similar behaviour to sand in relation to the unfrozen water content, normally exhibiting low unfrozen water content below the freezing point of the pore fluid. Bedrock often has low to very low porosity values, which further reduce the influence of the unfrozen water content. The unfrozen water content is therefore not critical in bedrock and a relationship similar to sand is considered adequate.

2.18 Strength Soil strength was not measured during the investigations for this project. Permafrost soils normally have three states for which the strength will vary considerably, which depends whether the soil is frozen or not. The strength will obviously be greater for frozen soils, due to the inter-particle bonding provided by the frozen pore water. The thawing of permafrost soils often induce very low strengths because of the excess pore pressure caused by the thawing of the pore ice and the often unconsolidated nature of permafrost soils. Finally, thawed frozen soils will eventually consolidate over time, thus gradually gaining strength. MN/spk


October 2005


Page 15

The presence of brine within the soil matrix of saline soils generally decreases the strength of the frozen soil, in particular its resistance against creep deformation (long term deformation). The unfrozen water content will also play a role in reducing the strength (Hivon and Sego 1995). Although fine grained saline soils will have lower strengths amongst frozen soils, they still have greater strengths than their unfrozen counterparts. It can be expected that creep deformation will occur during the life of the dams, but the magnitude of the deformation will likely be small and therefore, have minimal impact on the deformation of the dam. Thawing will occur along the upstream side of the dams, thus creating a talik. This will introduce zones of very low strength during the thawing process, followed by a gain in strength as the excess pore water dissipates and the soils consolidate. The weak zones from the thawing will not sustain the load from the dam and will result in settlements that are generally proportional to the amount of pore ice present in the soil. The rate of settlement will be dependent on the rate at which the talik develops. The talik will likely begin at the toe and gradually progress towards the core of the dam. The design of the dams will therefore have to accommodate possible settlements and longitudinal cracks by using flat slopes. This would however only occur when the talik develops.

2.19 Seismicity A site specific seismic hazard assessment was done by the Geological Survey of Canada, according to the procedures documented in Adams and Halchuck (2003). Peak ground accelerations and velocities for various annual probabilities of exceedence were determined and are listed in Table 2. Table 2: Probabilistic seismic ground motion analysis Annual Probability of Exceedence

Return Period (Years)

Peak Ground Acceleration (g)

Peak Ground Velocity (cm/sec)

0.01

100

0.014

0.033

0.005

200

0.018

0.039

0.0021

475

0.023

0.049

0.0010

1,000

0.028

0.060

0.0004*

2,475

0.059

-

*The 1:2,475 return period data is not site specific to the Doris North Project area, but are for Kugluktuk (Coppermine).

The Doris North Project falls within the “stable” zone of Canada. This region has too few earthquakes to define reliable seismic source zones. However, international experience suggests that large earthquakes can occur anywhere in Canada, although the probability is very low. Within this “stable” zone, the project area falls in acceleration zone 1 (Za = 1) and experiences zonal accelerations of 0.05 g. The velocity zone in which the area falls is zone 0 (Zv = 0) which corresponds to zonal velocities of 0.05 m/s. These zonal classifications are the lowest zones classified on the seismic hazard maps of Canada (Adams and Halchuck 2003). For design purposes, the 1:475 year earthquake for the site is calculated as having a peak horizontal ground acceleration of 0.023 g, with a peak ground velocity of 0.049 m/s. In conjunction with MN/spk


October 2005


Page 16

proposed changes to the National Building Code of Canada, it is indicated that it would be prudent to evaluate the performance of the structures during an earthquake with a 2,475-year return period. Since the site specific seismic hazard calculation did not have a peak ground acceleration for this return period, we have used the closest available data which is at Kugluktuk (Coppermine), and has a reported peak ground acceleration of 0.059 g.

MN/spk


October 2005


3

Preliminary Dam Design

3.1

General Layout

Page 17

The general layout of the tailings impoundment is illustrated in Figure 3. The tailings impoundment consists of two dams to be constructed at both ends of Tail Lake (see Figure 4 for the North Dam layout and Figure 5 for the South Dam layout). A spillway will be constructed immediately east of the North Dam. The invert of the spillway will be constructed at elevation 33.5 m, which correspond to the FSL of the tailings pond. Both dams will rely on permafrost to restrict seepage through the dams.

3.2

Design Criteria The design criteria for the tailings dams that are presented in the subsequent sections follow the guidelines provided in Dam Safety Guidelines (Canadian Dam Association 1999).

3.2.1 Dam Classification The dam classification system recommended in the Canadian Dam Association (1999) guidelines is shown in Table 3. For the dams proposed herein, the potential incremental “life safety” consequence of failure is “no fatalities”, due to the remote nature of the site and the topography and conditions downstream of the dam. “No fatalities” corresponds to a “very low” consequence category. Table 3: CDA dam classification in terms of consequences of failure Consequence Category Very High

a)

b)

c)

MN/spk

Potential Incremental Consequences of Failure[a] Socioeconomic, Financial & Life Safety[b] Environmental[c] Large number of fatalities Extreme damages

High

Some fatalities

Large damages

Low

No fatalities anticipated

Moderate damages

Very Low

No fatalities

Minor damages beyond owner’s property

Incremental to the impacts which would occur under the same natural conditions (flood, earthquake or other event) but without the failure of the dam. The consequence (i.e. loss of life or economic loses) with the higher rating determines which category is assigned to the structure. In the case of tailings dams, consequence categories should be assigned for each stage in the life cycle of the dam. The criteria which define the Consequence Categories should be established between the Owner and the regulatory authorities, consistent with societal expectations. Where regulatory authorities do not exist, or do not provide guidance, the criteria should be set by the owner to be consistent with societal expectations. The criteria may be based on levels of risk which are acceptable or tolerable to society. The Owner may wish to establish separate corporate financial criteria which reflect their ability to absorb or otherwise manage the direct financial loss to their business and their ability to pay for damages to others.


October 2005


Page 18

The potential incremental “socioeconomic, financial and environmental” consequences of failure include environmental impacts associated with the release of contaminated water to the downstream environment and financial impacts related to the cost of mitigation. As indicated by note “b”, stakeholders need to define these consequence categories to be consistent with societal expectations. For purposes of this assessment, we have assumed that the potential incremental consequences of failure of the new dam would be “moderate damages”. Our reasoning is that failure of the new dam would release only contaminated water, not tailings. The uncontrolled release of contaminated water would result in limited adverse environmental effects, but more importantly would discourage the use of the area for subsistence hunting and fishing, which would represent an impact on the people that may want to use the area at the time of the uncontrolled release. For instance, the failure of the dam during extreme flood conditions would likely have very low consequences because of the dilution involved. Additionally, if the dams are exposed to an unforeseen earthquake, the consequence will likely be limited to the release of potentially contaminated water. Based upon the life safety factor and the socioeconomic, financial and environmental aspects, the tailings dams are classified as “low” in terms of consequences of failure. This classification is based on SRK’s best judgement and may differ from the local stakeholders. This needs to be assessed and endorse by the local stakeholders prior to the final design.

3.2.2 Design Earthquake The CDA guidelines indicate that the minimum criterion for the design earthquake for a dam in the “low” consequence category would be an earthquake with an annual exceedence probability of 0.01 to 0.001. These probabilities represent return periods of 100 and 1,000 years, respectively. The Geological Survey of Canada indicated that the 1,000 year event has a peak ground acceleration (PGA) of 0.028 g. However, in relation to upcoming changes to the National Building Code of Canada, Natural Resources Canada has been suggesting that it would be prudent for designers to evaluate the performance of the structures during an earthquake with a 2,475-year return period. Although no estimates are available for the Doris North site for that return period, a peak ground acceleration of 0.06 g was estimated for a 2,475 year return period earthquake based on Kugluktuk data.

3.2.3 Design Capacity A detailed water balance for Tail Lake is documented in SRK (2005c). This water balance was used in conjunction with the water quality model (SRK 2005c) to determine an appropriate design capacity for Tail Lake. An iterative procedure was followed, where storage capacity was balanced with decant requirements, such that a robust water management design could be implemented that would account for all foreseeable uncertainties and upset conditions, whilst keeping the dams as small as practical for reasons of minimising potential shoreline erosion concerns as well as keeping the construction costs down. Based on this evaluation a FSL of 33.5 m was selected as the design capacity. At this capacity, all proposed water management strategies would be able to function

MN/spk


October 2005


Page 19

effectively, whilst still allowing a significant but reasonable margin of safety as deemed appropriate by MHBL.

3.2.4 Design Freeboard The tailings dams have been designed with both North and South Dams at a final crest elevation of 37.0 m. The frozen core of the dams, including the geosynthetic clay liners (GCL) will terminate at an elevation of 34.5 m. The FSL in Tail Lake and the operational spillway will be at 33.5 m. This allows for 3.5 m of freeboard, which constitutes 1.0 m for the core against potential spillway blockages, as well as 2.5 m of thermal protection on top of the frozen core. The design freeboard requirement for wind induced waves was calculated as 0.3 m. Complete details of this calculation are presented in Appendix F. Considering the peak flood depth in the spillway will be about 0.2 m (see next section), this means a total hydraulic freeboard requirement of 0.5 m, which half of the 1.0 m that has been allowed for.

3.2.5 Design Flood The CDA guidelines indicates that the minimum criterion for the inflow design flood (IDF) for a dam which coincides with the “low” consequence category would be a flood with an annual exceedence probability of 0.01 (100-year return period) to 0.001 (1,000-year return period). The freeboard requirement for the Dams is 3.5 m, and far exceeds the requirements based on any possible flood estimates. Therefore, it was deemed appropriate to size the spillway for a 24-hour storm event with a return period of 1:500 years. For the preliminary design calculations, no attenuation of the flood peak within Tail Lake has been accounted for, and it was assumed that 100% of the precipitation event in the catchments will flow over the spillway. Even under this scenario, it is inconceivable that the dams could overtop, even if a complete blockage of the spillway was to occur. The design depth of the water over the spillway crest when it is passing the 1:500 year, 24hour duration flood would be approximately 0.17 m.

3.2.6 Stability The current stability requirements for earth and rock fill dams, advocated by the International Committee on Large Dams (ICOLD) and the Canadian Dam Association (1999), were adopted for preliminary design of the North and South Dams. These requirements are summarized in Table 4. As indicated in this table, the case of rapid drawdown conditions was not examined. Rapid drawdown conditions were considered unlikely for the facility because the dam materials on the upstream face of the dams are coarse; the upstream slope is limited to 6H:1V and the core is frozen.

MN/spk


October 2005


Page 20

Table 4: Minimum factors of safety Minimum Factor of Safety

Slope

1.5

Downstream

Not applicable

Upstream

End of construction before reservoir filling

1.3

Downstream and Upstream

Earthquake (pseudo-static)

1.1

Downstream

Loading Condition Steady state seepage with maximum storage pool Full or partial rapid drawdown

3.2.7 Seepage Seepage through the dam or foundation will not be present because both dams are designed as frozen core dams constructed on frozen foundations. The seepage of properly constructed frozen core dams will be at the lower bound for all types of dams and may, in some cases, approach zero.

3.2.8 Freezing Temperature As a measure to introduce a margin of safety in the design, the interpretation of the frozen conditions was reduced by 2 °C. Such reduction corresponds to a freezing temperature of -2 °C for the dam material and -5 °C for the natural soils and the bedrock. The freezing temperature of the marine deposit was further reduced to -6 °C to account for its salinity and unfrozen water content.

3.2.9 Construction Temperature The dams will be constructed during the winter months to enable the freezing of the core and to introduce cold temperatures into the dam materials as they are being placed. The placement of the dam materials will therefore require that the ambient air temperature is colder than -15 °C. It is important that the snow accumulation be cleared from the dam working surfaces as it being constructed to maximise heat loss.

3.2.10 Climatic Data and Climate Change This preliminary dam design is based on the 30 year average climate (MAAT of -12.0 °C with an amplitude of -20.2 °C) as initial condition. The 30 year average climate is then adjusted over time to reflect the impact of climate change. The daily temperatures were increased at a rate of 0.1 °C per year over half of the year to reflect the winter increase, and by 0.03 °C per year for the remaining half during the warmer period (see Section 2.12). This warming trend equates to increase the MAAT by 6.5 °C over the next century, which is slightly higher than 5.3 °C mentioned in Section 2.12. The difference is due to a simplification in the calculation: the above value is calculated using two six months periods instead of quarterly periods based on seasons. This simplification, which introduces slightly warmer conditions, was selected essentially for the thermal modelling presented later.

MN/spk


October 2005


3.3

Page 21

Upset Conditions Upset events are incorporated in this preliminary design, essentially to assess the robustness of the design that is proposed. These upset events are described in the following sections.

3.3.1 Warm Climate Climate change could potentially initiate exceptionally warm years which could impact the performance of the frozen core dams. An exceptional warm climate scenario was incorporated for this design. The warm condition listed in Table 1, which is based on the warmest three years over the last 30 years, was considered as being the average climate when the dam is constructed. The initial warm climate then incorporates a gradual temperature rise to reflect the impact of climate change. The same approach as described in the previous section was applied for this warm climate scenario: an increase of 0.1 °C per year during the cold half of the year and 0.03 °C for the remaining part of the year. A statistical analysis performed on the 30 year climate data indicate that the above warm climate combined with the climate change effects would exceed the 1/100 Annual Exceedence Probability (AEP) value in about 12 years, and the 1/1000 AEP in about 25 years.

3.3.2 Over-Topping Over-topping of the dam could introduce heat to the dam, especially if this event occurs during the late part of the summer. Overtopping will also expose the dam to erosion, which is addressed with proper material selection and transition zones within the dam. The storage volume in Tail Lake between 33.5 m and 34.5 m is in excess of 1 million cubic meters. Assuming 100% of the 62.8 mm, 1:500 year, 24-hour precipitation event fall on the 450 ha Tail Lake catchment, that only accounts for approximately 300,000 cubic meters, or less than 0.3 m rise in the water level. Conversely, a 24-hour precipitation event in excess of 220 mm would have to occur to allow the water level in Tail Lake to rise 1.0 m, which is more than 3.5 times the magnitude of the design event. Therefore, given the storage capacity of Tail Lake and the magnitude of the precipitation at the site, it is inconceivable that the water level in Tail Lake can rise from 33.5 m to 34.5 m during a single peak storm event, even if a complete blockage of the spillway occurred. Additionally, elevation 34.5 m corresponds to the crest of the frozen core inside the dam, while the dam crest is at elevation 37.0 m. A rise of 1 m above the FSL would still remain within the overall freeboard of the dam. This situation was therefore considered unrealistic and overtopping was not included as a possible upset condition.

3.3.3 Extended Duration of Storage The proposed water balance for the tailings impoundment indicates that, in the worst case scenario, the dams may have to retain water for a period of 22 years. The adopted design criteria were therefore to design the dam to function for at least 25 years. Although it is very unlikely, the storage period was extended to 40 years for the assessment of upset conditions. MN/spk


October 2005


3.4

Page 22

Settlement The dams will be subject to settlement, primarily from the thawing of the frozen ground below the upstream and downstream shells of the dams. The central portion of the dam, where the impervious core is located, will not settle since the foundation and the core are to remain frozen during the entire operating life of the dams. Because the core and the foundation will perform as a rigid block, the potential for crest settlement is practically nil. Therefore, there is no requirement to include a higher height of the core to compensate for settlement. The height of the core is therefore controlled by the hydraulic and thermal freeboard components of the dams. Settlement at the dam toe (upstream and downstream) will be dependent on the state of consolidation of the underlying soils but will be essentially controlled by the amount of excess ice present in the soil formation. The soil will subside by the amount of excess ice once the talik is fully developed. Excess ice mentioned herein corresponds to the volumetric portion of ice that is in excess to the pore volume of a soil when unfrozen. The subsurface investigations encountered soils with excess ice. It was confirmed with the finegrained marine deposit, although the coarser sand deposit is also expected to contain excess ice. Based on visual inspections of the soil samples at the time of recovery, the silty soils contain most of the visible ice. The clayey and sandy soils contain visible ice, but to a lesser extent and mostly intermittently. The gravimetric water content measured in the marine soils ranged from 30.4% to 146% (the second highest value is 82.2%) over 24 samples (see Table 5.1 of SRK 2003b), for an average of 52% (excluding the highest value). The marine soils without excess ice will have lower water contents and a value of 33.5% (second lowest value) was assumed for settlement estimations. Although these average values may represent average conditions over the entire length of the dam, it is important to note the variability in the water content, which suggests that there is a potential of having localised zones of higher ice content. The maximum thickness of the marine deposit varies from about 20 m at the North Dam to 30 m at the South Dam. It is therefore reasonable to assume that 50% of the marine deposit contains excess ice based on field observations. The thickness of soil with excess ice would therefore be in the order of 10 to 15 m. Using the method based on the ratio of bulk densities of the frozen and unfrozen soils, the conditions at the North and South Dams suggest that the talik could potentially induce settlements up to 2.5 m at the North Dam and to 3.7 m at the South Dam. As indicated above, there is also a possibility of having localised pockets where the settlement could exceed these values. These potential settlements will only affect the upstream portion of the dam because the core and foundation will be designed to remain frozen for the entire design life of the dam. It is therefore important that the upstream slopes of the dams be flat enough to compensate for the settlement that will eventually develop over time. However, in reality the magnitude of the talik will be limited since the dam will be operated for a finite time (i.e. 25 years).

MN/spk


October 2005


Page 23

In addition to the above potential differential settlement on the upstream side, the North Dam also has the potential of being subject to differential settlement along the longitudinal axis of the core if the foundation is allowed to thaw. This is due to the discontinuity in the overburden between the sand dominated foundation and the ice-rich clay-silt foundation. The development of the talik along the upstream side of the dams will introduce weak zones that will potentially induce large deformation. Deformation analysis using models based on visco-elastic constitutive relationships will be undertaken at final design to quantify settlement. A model such as the FLAC model will likely be used because of its capacity to accommodate large displacements and strains, non-linear material behaviour, thermally induced deformation and creep deformation. The settlement can be mitigated by selecting sufficiently flat slopes for the dam sections and by providing proper maintenance and care to the dams during their operations. Differential settlement would still occur along the upstream face of the dams caused by the retained water, but the central frozen zone would maintain the integrity of the dam against leakage and deformation. Depressions caused by settlement will require backfill and proper grading. The layout of the dams will therefore have to accommodate for potential large deformation caused by the ingress of the talik against the dam. As mentioned earlier, since it is a design requirement to keep the core and foundation fozen, the crest core of the dam will be subject to practically no deformation. Creep deformation is another possible source of settlement, given that the foundation contains saline pore water. The rate of deformation will however be low to very low and mitigation measures can easily be implemented following annual dam inspections. Also, given the duration for which the dam will be required to retain water (maximum of 25 years), the magnitude of the creep settlement will be much less than the potential settlement caused by the talik along the upstream face of the dams.

3.5

Dam Section

3.5.1 Justification The core of the dams will be processed crushed rock, and a synthetic liner will placed against the upstream face of the core as a secondary containment measure. The entire dam section will be constructed with crushed rock of various gradations. This type of dam configuration eliminates the uncertainties and concerns raised during the review process with the potential use of the natural fine grained material as the frozen core material (SRK 2003b). Those uncertainties and concerns are eliminated because there is no need to develop a borrow source, there is no risk of suspended solids that could potentially originate from the borrow source area, it eliminates the potential variability associated with natural borrow sources, and finally, there are precedents of frozen core dams using crushed rock similar to the configuration proposed herein (EBA 1998; 2003).

MN/spk


October 2005


Page 24

3.5.2 Description The dam configuration will be constructed as a rock fill structure with a geosynthetic clay liner (GCL), filter and transition zones and a frozen key trench founded on non-organic permafrost soils and/or bedrock. The cross-sections for the North Dam are shown in Figure 10 and for the South Dam in Figure 11. The upstream side of the dams will have a slope of 6H:1V (horizontal:vertical), and the downstream side at 4H:1V. These flat slopes are to compensate for the uncertainties associated with the potential deformation induced by the talik along the toe of the dams. Further analysis at the final design stage may lead to some optimization of these slopes. The North Dam will reach a height of about 11 m and will be about 200 m long. The South Dam will be 7 m high and almost 300 m long. The width at the crest will be 10 m for both dams. The outer shell (upstream and downstream) will consist of run-of-quarry rock fill (Material C), which will encapsulate a transition zone consisting of processed crushed rock (Material B – 150 mm material). This transition zone will provide the transition between the outer rock fill shell and the central core. The central core will be fabricated from finer processed crushed rock (Material A – 20 mm material) and will be placed in a wet state. This wet placement will enable the core to become impervious once frozen. The central core will reach an elevation of 34.5 m, which is 1.0 m above FSL. Material A will also be used to backfill the key trench. A GCL (or an equivalent impervious membrane) will be used as secondary containment and will be placed along the upstream face of the central frozen core. The GCL will also extend over the entire crest of the central core and over most of the key trench. The GCL will be overlapped along the upstream face of the dam where the GCL from the key trench intercepts the upper GCL. The GCL will be covered by at least 0.3 m of Material A for protection purposes. Passive looped thermosyphons are incorporated in the preliminary design as necessary components at this stage. The purpose of the looped thermosyphons is to lower the ground temperature of the foundations to overcome the uncertainties associated with salinity and the unfrozen water content of the marine deposit. The thermosyphons will consist of passive horizontal loop evaporators that would be installed at the base of the key trench during the construction of the dams as shown in Figure 10. Four looped thermosyphons are currently planned for the each dam, with two thermosyphons on both sides of the dam. The thermosyphons will each have a single loop evaporator that will cover half of the dam along the longitudinal axis. The looped evaporator will be offset by 1.5 m apart and will cover the entire length of the dam. It is expected that each thermosyphon will consist of a 39 m2 radiator connected to evaporator looped pipes that could be up to 220 m long. The 220 m length includes a 20 m offset between the dam alignment and the location of the radiator, plus two times 90 m for the looped evaporator pipe to reach the mid-point of the dam and return. The vegetation cover will be removed below the entire footprint of the dams. The dam sections will also require the excavation of a key trench that will be at least 4 m deep. The final depth and width of the key trench will be confirmed during construction excavation.

MN/spk


October 2005


Page 25

3.5.3 Abutments The dam abutments will extend to bedrock, which appears competent at shallow depth but have some open and contiguous discontinuities. The slope of the rock should be limited to a 1H:1V slope, thus resulting in some rock excavation. The three-dimensional aspect associated with the active layer at the abutments needs to be considered to provide an adequate seal against water leakage along the core-bedrock interface or in the near-surface fractured bedrock. Slush grouting or similar surface treatment may be required to fill voids in fractures and prepare the key trench. The condition of the abutments will be assessed during construction excavation.

3.6

Construction Materials The construction materials for the dams consist of Materials A, B and C and a geosynthetic clay liner (GCL). All the granular material used to construct the dams will be produced from quarried rock. The locations of the rock quarries are indicated on Figure 2 and consist of predominantly basalt. Complete geological, mineralogical and geochemical details on these quarry sites are documented in Miramar (2003) and AMEC (2003c). Preliminary specifications of the construction materials are described in the following sections. This specification is consistent with the dam’s constructed at the Ekati Diamond MineTM (EBA 1998, 2003).

3.6.1 Material A (20 mm minus) Material A will consist of well graded processed crushed rock with a maximum particle size of 20 mm. Since each lift of this material will have to be frozen prior to the placement of the next lift, it is important that this material contains sufficient fine particles to provide water retaining capabilities for the duration of the freezing process. The recommended gradation is shown in Figure 12. The material will be moisture conditioned to a moisture content representing at least 90% saturation or higher. The material will be placed in winter and require heating capabilities to condition the granular material to the proper water content prior to placement. The placement will require compaction capable of obtaining 90% of its maximum dry density. The thickness of the lifts will be determined in the field prior the beginning of the construction, although it will be in the order of 0.2 to 0.3 m.

3.6.2 Material B (150 mm minus) This material will comprise of well-graded screened crushed rock with a maximum particle size of 150 mm. This material is intended to act as a transition between Materials A and C. The material will be placed in compacted lifts with a thickness prior to compaction of approximately 0.5 m. The recommended gradation for Material B is shown in Figure 13.

MN/spk


October 2005


Page 26

3.6.3 Material C (run-of-quarry) Material C is the material used to construct the outer shell of the dams. It will consist of run-ofquarry and have a maximum size of 500 mm. The fabrication of this material will be dependent on the condition of the rock and the blasting procedure at the quarry. The suitable gradation may require further processing or adjustment to the blasting procedure prior to placement. The placement of Material C as shell material will be in compacted lifts approximately 1 m thick.

3.6.4 Impervious Membrane (GCL) The GCL will consist of sodium bentonite enclosed between two non-woven geotextiles. The three layer assembly will be held together by needle punching. GCL are readily available from several manufacturers. The specification will be determined for the final design but it can be expected that it will be similar to Bentofix NW. Alternate membrane types will be assessed at the final design to determine the best product for the dams. The placement of the GCL will also require some bentonite to seal the overlaps between sheets of GCL. Bentonite would also be used for bedding of the GCL in the key trench.

3.6.5 Thermosyphons Artificial ground freezing can be achieved in cooler climates using thermosyphons. A thermosyphon is a hollow pipe filled with pressurized carbon dioxide (CO2) that evaporates and condensates depending on the ambient air and ground temperatures. They essentially consist of two main components: the evaporator and the condenser/radiator. The evaporator is the portion of the thermosyphons that is buried in the ground where the heat is extracted from the ground, namely where cooling occurs. The radiator is the component that is installed above grade and is generally installed in a vertical position. The section joining the radiator and the evaporator is often called the riser. The radiator will usually be covered with protruded fins that increase the heat exchange between the thermosyphon and the ambient air. Thermosyphons become active only when the ambient air is colder than the evaporators (buried portion). The heat extraction simply ceases over the period where the ambient air temperature is warmer than the ground temperature. A key advantage of thermosyphons is the absence of mechanical assistance, i.e. they operate “passively”. It should be noted that in some instances these thermosyphons can be made “active” by providing a freezing plant actively cool the radiators. This is however only done when thermosyphons are used to freeze a foundation, and is not being considered for the Doris North Project. There are two types of thermosyphons that are sometimes used on dam projects: the single pipe system and the loop system. The North and South Dams will include loop system thermosyphons, with two loops installed on both sides of the dam with some overlap in the middle portion of the dam. Single pipe thermosyphons are usually used where the objective is to provide ground freezing along a vertical or sloped plane such as a cut-off wall. The single pipe thermosyphon consists of a single pipe that is installed in drilled holes, with a short length left to extend above the ground surface. A MN/spk


October 2005


Page 27

radiator is attached to the above-ground portion, which generally consists of a 25 mm coil welded in spiral around the pipe. Any heat in the ground causes the CO2 liquid within the pipe to evaporate and rise upwards to the radiator. When the radiator is cold, as it would be throughout the winter, the CO2 gas condenses and the liquid runs back down the tube, where it can be evaporated again. This causes the internal bi-directional flow: the liquid phase flows downward by gravity along the internal wall of the pipe while the evaporated gas phase flows upwards through the central portion. Loop system thermosyphons are intended to induce ground freezing along horizontal planes, such as the foundation of buildings or the base of dams. The loop system functions the same way as the single pipe system with one difference: the flow in the evaporator (buried portion) is uni-directional. The radiator is the same as the single pipe thermosyphon. The loop system thermosyphons utilise proprietary internal components within the riser to force the working fluid to travel in one direction within the evaporator. As the CO2 fluid absorbs heat, it vaporizes and expands. The expansion helps to push the working fluid around the loop. The working fluid moves around the loop in twophase flow, increasing in velocity as it proceeds around the loop. This allows the loop to be placed on a “relatively” flat plane. The term “relatively” means that there can be some undulations in the vertical profile of the loop. The subgrade can just be graded to a near flat condition within the specifications of the manufacturer and the loops then placed directly on the graded material. Loop lengths of 150 m are not uncommon. (extracted from Yarmak and Long 2002). Thermosyphons would be provided and installed by Arctic Foundations of Canada, the supplier of thermosyphons in Canada.

3.7

Spillway The operational spillway will be located on the right abutment of the North Dam. The spillway has been sized to pass a 24-hour storm event with a 1:500 year recurrence interval. The spillway will be 20 m wide and will have a constant gradient of 2%. The spillway will be excavated in bedrock with no additional finishing. The spillway side slopes will be excavated at a slope of 1H:3V and, where permafrost is encountered, the slopes will be armoured with geotextile and a 300 mm thick layer of rip rap. The construction of this spillway may be delayed to the closure phase of the project due to the time Tail Lake requires to reach FSL. This decision will be made at the final design stage.

3.8

Decant System Decant will be achieved through a system of pumps, which will be synchronized to match the annual Doris Lake outflow hydrograph. Flow measurements at the Doris Lake outflow location will be used to trigger the pump(s) that will transfer the appropriate decant volume from Tail Lake to a discharge point downstream of Doris Lake, but upstream of the 4.5 m high waterfall in Doris Creek (see Figure 2). More details of this system are provided in SRK (2005c).

MN/spk


October 2005


3.9

Page 28

Quantities A preliminary estimate of the quantities for the North and South Dams is summarised in Table 5. Construction of the North Dam will require about 65,350 m3 of material, and the South Dam about 42,020 m3, for a total of 107,365 m3. The key trench will represent 14,834 m3 at the North Dam and 8,335 m3 at the South Dam. These quantities are based on the preliminary design drawings that accompany this report. Table 5: Estimated quantities to construct the North and South Dams North Dam (m3)

South Dam (m3)

Total (m3)

14,834

8,335

23,169

Material A (core)

11,351

3,229

14,580

Material B (transition)

6,437

4,373

10,810

Material C (shell)

32,725

26,081

58,806

Total

65,347

42,018

107,365

Material Excavation (key trench) Backfilled with Material A

3.10 Thermal Analysis 3.10.1 Scenarios The thermal modelling consisted of calibrating the model against field measurements, predicting the thermal regime until the end of the operating life of the dams and to predict the thermal regime under upset conditions. All the thermal simulations are based on transient simulations. Model calibration consisted of reproducing the ground temperature measurements obtained from borehole SRK-33 and SRK-43, both located at the South Dam. The stratigraphy at these two boreholes consists of the marine deposit of about 20 m thick overlying an 8 m thick layer of till and then bedrock. The calibration enabled the estimation of the freezing and thawing indices that are representative of the conditions along Tail Lake. The thermal performance of the dam was assessed by using the current conditions as initial conditions and predicting the ground temperature in the dam and in the foundations over a period of 40 years, although the dam design criteria is for a life of 25 years only. The ambient air temperature was gradually increased over time to reflect the impact of climate change. Thermal simulations were performed to reflect the upset conditions described, including climate change and prolonged storage (see Section 3.3). The specific upset condition consists of using the “warm climate” as the initial climate, applying a warming trend for climate change and running the model for a 40 year period.

MN/spk


October 2005


Page 29

3.10.2 Model Thermal modelling was carried out using the finite element model SVHEAT version 3.09 developed by SoilVision Systems Ltd. and FlexPDE version 4.2 developed by PDE Solutions Inc. SVHEAT models heat transport for both steady-state and time-dependent analyses based on the FlexPDE solver. It incorporates the latent heat associated with phase changes of water. The model can support geometries in 2D or 3D. SVHEAT supports multiple boundary conditions as well as transient boundary conditions. Further details are available in the User’s Manual of SVHEAT (SoilVision Systems 2004). FlexPDE is a general purpose partial differential equation (PDE) solver that is based on the finite element method. FlexPDE can solve a multitude of PDE problems in 1D, 2D and 3D spaces. More information is available in the User’s Manual of FlexPDE (PDE Solutions 2004a, b).

3.10.3 Soil Properties The thermal properties of the existing ground and the dam materials were represented by five material types as listed in Table 6. The marine and till deposits were assigned the same values while the dam materials can be either saturated or unsaturated, depending on the zone relative to the water table. The porosity and the unfrozen thermal conductivity of the marine deposit are based on laboratory results. The thermal conductivity for the sand and the dam materials was estimated using the method by Johansen (1975). The thermal conductivity of the bedrock was estimated from values obtained in the literature. Table 6: Thermal properties used in the thermal model Degree of saturation

Porosity

Marine & till deposits

100%

Sand deposit

Soil types

Thermal conductivity (kJ °C-1 m-1 day-1)

Heat capacity (kJ m-3 day-1)

Unfrozen

Frozen

Unfrozen

Frozen

0.52

104

195

2991

2060

100%

0.30

130

192

2601

1973

Basalt bedrock

100%

0.05

260

260

2238

2133

Dam Materials A, B, C saturated

100%

0.30

163

244

2751

2123

Dam Materials A, B, C unsaturated

60%

0.30

161

178

2230

1916

Figure 14 shows the three unfrozen water content curves that were used to represent the five materials listed in Table 6. The marine and the sand deposits are based on the unfrozen water content curves reported by Hivon and Sego (1995) for saline soils (salinity of 30 ppt). The curve used in the thermal model corresponds to the upper bound of the combined fine silty sand and silty sand as reported in that paper. The saline sand from that same paper was used for the sand deposit in

MN/spk


October 2005


Page 30

the model. The bedrock and the dam materials were assigned an arbitrary unfrozen water content curve representative of non-saline soils. The recent laboratory testing performed for the winter 2005 investigation are not included in the above properties. However, the recent laboratory data were consistent with the parameters listed above and a series of simulations performed using the recent values did not show any significant differences, and therefore the results presented in this report using the values listed in Table 6 are valid an applicable. The final design will however use the most recent dataset to establish the parameters for the thermal analyses.

3.10.4 Calibration The calibration consisted of reproducing the ground temperatures measured at the South Dam inside SRK-33 and SRK-43. This modelling exercise was used to estimate the surface thawing and freezing indices as well as the shallow geothermal gradient. Setup The thermal model was setup as a one-dimensional problem. The ground profile consisted of 20 m of marine sediments overlying 10 m of till and then bedrock. The thermal properties were according to the values presented in the previous section. The boundary condition at the top was a time-dependent temperature oscillation based on average climatic conditions that combined the application of the thawing and freezing indices. The seasonal oscillation was approximated with a time (t) dependent sinusoidal function in the form of:

T A (t ) = MAAT + AT sin( 2π

t ) 365

(1)

where TA(t) is the air temperature at a given time t(°C), MAAT is the mean annual air temperature (°C), AT the annual amplitude of MAAT. The simulations were performed with an MAAT of -12.0 °C and an amplitude of -20.2 °C. In comparison with two years for which measurements were taken from SRK-33 and SRK-43, the 2003 climatic data was slightly warmer while 2004 appear slightly colder. The small variation from the MAAT was considered sufficiently small that the selected MAAT was considered appropriate for this calibration. The above time-dependent air temperature was then converted to a surface temperature by using the thawing and freezing indices. The daily surface temperatures are calculated as:

TS (t ) = ni T A (t )

(2)

where Ts(t) = Surface temperature (°C) Surface index: nt if TA(t) > 0 °C ni = nf if TA(t) < 0 °C

MN/spk


October 2005


Page 31

The surface thawing index (nt) and surface freezing index (nf) are dependent on snow cover and the ground surface conditions. These two parameters were varied until the annual variation of the shallow ground temperature resembled the distribution of ground temperature measurements obtained from SRK-33 and SRK-43. The surface at these two boreholes consists of typical hummocky vegetation. The bottom boundary condition consisted of specifying a no heat flux boundary, which is consistent with the measurements around Tail Lake and more specifically inside SRK-33 and SRK-43. The initial condition consisted of specifying a uniform temperature of -8.5 °C, although this had little impact on the interpretation of the simulations because they were applied for a 50 year period to assure that the pseudo-steady state conditions were achieved. Results The result of the calibration is shown in Figure 15 where the modelled ground temperature is compared with the field measurements. The calibration was achieved by using a surface thawing index of 1.00, a surface freezing index of 0.70, while maintaining a no heat flux boundary at the bottom.

3.10.5 Predictions - Normal Operating Conditions The thermal model was used to predict the performance of the North and South Dams after 25 years of operation. Preliminary thermal simulations showed that the North Dam has the most critical section of the two dams. Consequently, the thermal modelling discussed herein focuses on the North Dam only. The North Dam was first modelled without thermosyphons and two looped thermosyphons were then added to assess their potential benefits of maintaining colder ground temperatures. Setup The geometry of the North Dam that was used in the thermal model is shown in Figure 16, which is according to the dam section shown in Figure 10. Figure 16 also shows the limits of the entire domain. The thickness of the marine deposit is 6 m and the underlying sand deposit is 17 m thick. The remaining bottom portion is represented by bedrock. The dam material is represented by either saturated or unsaturated materials. The central core, the portion upstream the core that is below elevation 33.5 m (FSL) are considered saturated and the remainder unsaturated. The thermal properties are consistent with the values presented earlier. The initial condition consisted of specifying a surface temperature of -8 °C over the original ground surface, including the foundation below the footprint of the dam. The initial surface temperature was increased by 0.5 °C from the calibration value of -8.5 °C simply to introduce some conservatism in the thermal simulations. Since the dam will be constructed during winter under ambient temperature colder than -15 °C, the dam was also set to an initial temperature of -8 °C. MN/spk


October 2005


Page 32

The 30 year average climate was used as the initial climate and climate change was applied over the entire duration of the simulations by increasing the ambient temperature by 0.1 °C per year for half of the year during the cold season and by 0.03 °C for the warm season. The time-dependent ambient air temperature was represented by a sinusoidal function as described in the previous section. The left and right boundaries were considered as no flux boundary. Although the calibration was obtained with a no heat flux boundary at the bottom of the domain, the dam was modelled with a heat flux of 1,560 J day-1, which is based on the geothermal of 18 °C km-1 measured at the Boston Camp. The geothermal gradient of 11.4 °C km-1 measured at the Doris North site would be more representative of the site conditions but the higher value was selected simply to increase the margin of safety in the predictions. The top boundary was represented with a time-dependent surface temperature using the sinusoidal function mentioned above combined with surface indices. The top boundary was divided in three sections: the vegetation cover downstream of the North Dam, the exposed surface of the dam and the submerged zone on the upstream side. The vegetation zone on the downstream side was considered similar to the area used to calibrate the model, although there are some uncertainties associated with potential snow accumulation that could influence the value of the surface freezing index. As a precaution, the calibrated surface freezing index of 0.70 was reduced by 20% for a value of 0.56. The surface thawing index remained at 1.00. The exposed surface of the dam was assigned a surface freezing index of 0.70 over the entire dam that is not submerged. A 6 m dam segment at the downstream toe of the dam was assigned a surface freezing index of 0.56 for potential snow accumulation. The surface thawing index was set to 2.00 for the exposed granular material of the dam. The submerged portion of the top boundary was represented by the sinusoidal ambient air temperature and did not use the surface indices. The temperature was however restricted to remain above +4 °C (i.e. the water remained at +4 °C during the winter and followed the ambient air temperature during the summer). This boundary condition assumes that the dam will be exposed to the FSL at 33.5 m from day 1 and remain at that level for the remainder of the simulation. For comparison, the water balance predicts that it would take approximately five years to reach FSL, and that the FSL may never be reached over the 25 year design life of the dam. The presence of such water body against the dam for the entire simulation contributed to further increase the margin of safety in the thermal predictions. Additional thermal simulations were performed with horizontal thermosyphons present at the bottom of the key trench. The simulations included four evaporator pipes that represented the two horizontal looped systems, each loop being connected at the surface to a vertical radiator with a surface area of 39 m2.

MN/spk


October 2005


Page 33

The rate of heat extraction was simulated using the following expression (Long 2004): Q = (A + B VC)(Tsoil – TA) Q=0

for TA < Tsoil for TA ≥ Tsoil

(3) (4)

Q corresponds to the total heat flux extracted by the thermosyphon (BTU hour-1); V is the wind velocity (mph); Tsoil the temperature of the evaporator in the soil (°F); and TA the ambient air temperature (°F). The parameters A, B and C are fitting coefficients based on measurements and were assigned the following values (Long 2004): A = 200.8 BTU hour-1 °F-1 B = 401 (BTU hour-1 °F-1)(mph)-C C = 0.273 V = 4.47 mph The wind velocity was assumed constant at 2 m/s (4.47 mph). The ambient air temperature was calculated using the sinusoidal relationship described previously and Tsoil was calculated dynamically by the thermal model. The total heat flux was then converted to a heat flux per unit of looped evaporator. The unit heat flux was obtained by dividing the total heat flux by the length of the looped pipe; in this case 220 m. It represents four looped thermosyphons covering a length of about 90 m plus a 20 m offset to connect to the radiator, thus a total loop of 220 m (2 x 110 m). Results The results shown in Figure 17 (larger scale figures are presented in Appendix G) are for the North Dam and correspond to the simulation without any thermosyphon. It indicates that the core of the dam will remain colder than -2 °C over the entire 25 year period, thus sufficiently cold to meet the design criterion. The warmest area of the core is situated along the top surface of the core at elevation 34.5 m where the temperature reaches -2 °C. The -2 °C isotherm remains however above the FSL (elevation 33.5 m). The position of the -2 °C isotherm can easily be raised simply by adding a granular pad along the crest of the dam or by treating the surface to reduce heat penetration during the summer months. This detail will be optimised during the final design. The foundation material remains sufficiently cold for most of the 25 year period but the ground temperature becomes marginal towards the end of the initial 25 year period. At 25 years, the -6 °C isotherm is located just outside the key trench, and therefore, is slightly outside the criterion of maintaining the foundation material colder than -6 °C. The simulations for the South Dam showed similar results. The simulation that incorporates the thermosyphons was able to meet all the criteria over the entire 25 year period as shown in Figure 18. The presence of the thermosyphons provided sufficient heat MN/spk


October 2005


Page 34

extraction to maintain the foundation soils below the threshold value of -6 °C. The results for the South Dam were also similar. Appendix G provides larger scale figures of these simulation results.

3.10.6 Predictions - Upset Condition The upset condition is to simulate unforeseen events that could impact the performance of the dam. It also assesses the robustness of the dam against such unforeseen events. The upset condition is essentially the application of a warm climate over the initial 25 year of operation plus a 15 year extension, thus a total duration of 40 years. The simulation included the presence of two looped thermosyphons that are identical to the ones described in the previous sections. Setup The setup for the upset conditions is identical to the previous scenario with the exception of the MAAT and the amplitude used in the sinusoidal function. In the case of the warm climate, the current climate is considered as having a MAAT of -10 °C and an amplitude of 19 °C. These values were used as the starting climatic conditions and climate change was maintained over the entire duration of the simulation as described in the previous section. Results The results for the upset condition that involves a warm climate are shown in Figure 19. It shows that the North Dam with thermosyphons can sustain a warm climate over the initial 25 years. Similar results were obtained for the South Dam. Figure 20 compares the three cases (average climate with and without thermosyphons, and warm climate with thermosyphons) that were modelled for a 40 year period. It shows that the average climate without thermosyphons will not meet the criterion of -6 °C underneath the core of the dam, although it was “missed” by only 1 °C. The -5 °C isotherm still covers a portion of the footprint of the core of the dam after 40 years. The average and warm climate simulations that incorporated thermosyphons met the -6 °C criterion. The temperature of the dam material was sufficiently cold in all the simulations to meet the -2 °C criterion.

3.10.7 Discussions and Conclusions The thermal simulations indicate that the thermal performance of the North and South Dams could be marginal in meeting the criterion of-6 °C for the foundation soils, without the inclusion of thermosyphons. Alternatively, the thermal simulations show that the dam will meet the set criterion of -6 °C if thermosyphons are used, even under upset conditions such as a warm climate. For the purpose of this preliminary design, the thermal simulations indicate that the dams will require thermosyphons. It also indicates that the final design will have to demonstrate clearly the performance of the dam in meeting the thermal criteria if thermosyphons are to be excluded.

MN/spk


October 2005


Page 35

3.11 Seepage The frozen core dams are expected to have negligible seepage as long as the material in the core and in the foundations is frozen.

3.12 Stability The stability of the North Dam at Tail Lake has been assessed using conventional stability analyses. The results from this dam are applicable to the South Dam at Tail Lake, as the design section is identical with lower heights (6 m vs. 11m), and similar foundation materials and conditions. A summary of these analyses is presented below. The detailed results are contained in Appendix H. Further assessment will require deformation analysis using models based on visco-elastic constitutive relationships. Such assessment would be performed at the final design stage.

3.12.1 Failure Modes The proposed dams will have flat slopes. The outer shell of the dams will consist of granular material while the foundations can be either granular (mainly sand) or fine-grained (marine silt and clay). The central fine-grained core will remain frozen and the foundations are expected to remain frozen on the downstream side of the dams. Data from the drilling programs suggest that, in general, the foundations contain excess ice, in particular in the fine-grained marine deposit. The most likely failure modes therefore comprise: • • •

a failure surface which is relatively shallow and sub-parallel to the slope face, a failure in the surface of the core if thawing occurred, and a failure of the granular material overlying the frozen core, i.e. downward movement of the crushed rock fill on the core interface.

The analyses assume that, in the event there is thawing of the dam or its foundation, the rate of thawing would be sufficiently low that the pore pressure would dissipate at levels that would not affect the stability of the dam. The frozen strength of the soils was not used in the analyses.

3.12.2 Method of Analysis The slope stability analyses were performed using 2-dimensional limit equilibrium analyses and the computer program SLOPE/W, which was developed by GEO-SLOPE International (GEO-SLOPE 1998). Factors of safety for the various stability cases were determined using the Morgenstern-Price method.

MN/spk


October 2005


Page 36

3.12.3 Geometry and Input Parameters The highest slope of the North Dam has been used for analysis. Input parameters have been selected based on judgment and are believed to be at or below typical mean values for the materials considered (Table 7). An earthquake with a 2,475-year return period, coinciding with a peak ground acceleration of 0.06 g, was used for the pseudo–static assessment. Table 7: Input parameters used in the stability analyses Parameter

Moist Unit Weight (kN/m3)

Rock Shell

Effective Strength Parameters c (kPa)

phi (degrees)

20.0

0

40

Transition

21.0

0

35

Core

21.0

0

32

GCL

18.0

0

15

Foundation silt

18.5

0

30

Earthquake for PseudoStatic Assessment

0.06 g

Note: The water tables are assumed to run through the upstream shell at the spillway invert elevation, to downstream face of core, down through the downstream transition zone, then along ground surface downstream of the dam.

3.12.4 Results Table 8 demonstrates that the calculated factors of safety for the North and South Dams meet or exceed the minimum allowable values. Table 8: Summary of critical factors of safety for North Dam Stability Condition

MN/spk

Suggested Minimum Factor Calculated of Safety FOS (FOS)

Comments

Dam Surface End of Construction Steady State

1.3 1.5

2.8 2.8

Dam shell, infinite slope analysis Dam shell, infinite slope analysis

Deep Seated Steady State Steady State Pseudo-static Pseudo-static

1.5 1.5 1.1 1.1

3.2 2.3 2.0 1.8

Circular, upstream face Circular, downstream face Circular, upstream, a = 0.06 g Circular, downstream, a = 0.06 g

Along Core Face Steady State Steady State Pseudo-static Pseudo-static

1.5 1.5 1.1 1.1

2.7 3.0 1.7 2.4

Upstream face (along GCL) Downstream face a = 0.06 g; Upstream face (along GCL) a = 0.06 g; Downstream face


October 2005


4

Implementation

4.1

Final Design

Page 37

The design presented herein is preliminary but confirms that the concept and the constructability are achievable, since it is based on experience (EBA 1998, 2003). The final design will be undertaken based on the information presented in this report supported by additional analysis, data and a more rigorous evaluation of cost optimizations, construction specifications and scheduling. Table 9 provides a summary checklist of work that will be carried out leading up to the detailed design of the dams. The sections that follow provide additional detail related to these checklist items. Table 9: Checklist of work to be carried out prior to completing detailed design of dams Class

Detail

Plans

Engineering Analysis

Field Characterization Laboratory Characterization Design Optimizations

• • • • • • • • • • •

Emergency Preparedness Plan Adaptive Management Plan Monitoring Plan Provide Dam Safety Classification Dam failure assessment Thermal modeling Stability modeling Settlement modeling Continue ground temperature monitoring Climate monitoring Snow-course monitoring

• Select testing as required on stored samples • Opportunity to delay spillway construction • Opportunity to delay construction of South Dam • Investigate alternate secondary liner types

4.1.1 Emergency Preparedness Plan An Emergency Preparedness Plan (EPP) will be prepared upon completion of the Final Design of the North and South Dams. The EPP will be prepared in general accordance with the Dam Safety Guidelines published by the Canadian Dam Association (1999). The purpose of such plan is to identify and evaluate potential emergencies in order to determine adequate preventive or remedial actions. The EPP will contain a notification process in case of an emergency situation and will incorporate preventive measures for situations or conditions that could be repaired or reduce the potential damage. The EPP will describe the actions to be taken in an emergency and will identify the various parties responsible for the actions and the agencies to be MN/spk


October 2005


Page 38

notified. As listed in the Dam Safety Guidelines, the EEP will include the following procedures and information: •

Emergency identification and evaluation

•

Preventive actions

•

Notification procedure

•

Notification flowchart

•

Communication systems

•

Access to site

•

Response during periods of darkness

•

Response during periods of adverse weather

•

Sources of equipment

•

Stockpiling supplies and materials

•

Emergency power sources, if required

•

Inundation maps

•

Warning systems (if used).

Copies of the EPP will be issued to all parties that have responsibilities under the plan or that may be affected by the emergency situation. The EPP will be revised on annual basis to ensure that the site conditions still apply to the plan and that the contact information of the various parties is still valid.

4.1.2 Adaptive Management Plan The performance of the dams will be managed using an adaptive management approach, where performance indicators obtained from field measurements will be used to determine or trigger actions. An Adaptive Management Plan (AMP) will be prepared as part of the final dam design. It will contain a compilation of performance indicators that will reflect the expected performance of the dams. One key objective of the AMP is to insure that the integrity of the dams remains safe, even under unforeseen conditions that may arise in the future. In the event that a performance indicator is not achieved, the AMP will contain measures or actions that would correct the situation and enable the dams to perform according to the original criteria. The AMP is in a sense a looped-back approach: real-time performance of the dams through field measurements is used to manage the dams. The AMP will likely include, but not necessarily limited to, the following typical parameters:

MN/spk

•

ground temperature,

•

settlement,

•

pond level,

•

climate,

•

snow cover,

•

seepage, and

•

erosion. PreliminaryTailingsDamDesign.Report.1CM014.006.emr.20051012.doc, Oct. 21, 05, 3:02 PM

October 2005


Page 39

The above parameters will be measured and compared with expected values. Failure to meet those expected values will trigger predetermined actions depending on the severity of the situation. For example, ground temperatures will be taken at various locations. The occurrence of a deeper active zone could be addressed by adding a granular blanket as insulation. A much warmer foundation temperature could ultimately require the installation of vertical single pipe thermosyphons as a measure to sustain the frozen condition within the foundation and in the dams. This example would probably one of the numerous possibilities that would be incorporated in the AMP.

4.1.3 Engineering Analysis The final design will require more detailed and rigorous analyses to insure that the dams will meet the set criteria once built. The final design will also include optimisation of the various dam components and tentatively minimise the level of uncertainties associated with various design assumptions. These uncertainties will then be incorporated into the Adaptive Management Plan as a measure to manage and reduce the risks. The basis of evaluation for the various analyses will be based primarily on performance but constructability and cost will also be incorporated in the evaluation process. The analyses that will be performed for the final design will have two important aspects of the design, namely thermal and stress-deformation. Another aspect that will be address during the final design is the breaching and decommissioning of the dam. The final design will include thermal analyses that will focus on specific components, such as the cover thickness above the core material, the abutments, the influence of potential snow accumulation, better representation of the pond level over time within the thermal model, optimisation of the geometry, optimisation of the number and layout of thermosyphons (if required), and benefits of treating the dam surface to reduce heat penetration. This is not a final list as other components will likely be added as the final design progresses. The accumulation of water against the upstream face of the dam will create a talik which will likely induce large deformations. These deformations will require sophisticated modelling tools such as models based on visco-elastic constitutive relationships. The final design will require that the stressdeformation aspect of the dam be assessed to determine the optimum geometry that would minimise the deformation and stress on the dam. Such analysis would also provide estimates of settlement that could occur at the dams and help determine the mitigation measures. Model such as the FLAC model will likely be used because of their capacity to accommodate large displacements and strains, nonlinear material behaviour, thermally induced deformation and creep deformation. The water balance will play an important role for the final design. The rate at which the pond will rise has direct impact on the amount of heat that is introduced into the dam by the standing water. It also induces the creation taliks along the upstream face of the dams. A better representation of the pond level will be incorporated into the thermal and stress-deformation models.

MN/spk


October 2005


Page 40

4.1.4 Additional Field Work No additional field investigation will be required to complete the final design. However, it is important to maintain the program to collect ground temperature measurements from the thermistor strings currently installed at the site. The on-going climatic data collection should also be maintained.

4.1.5 Additional Laboratory Work No additional laboratory work is currently required to complete the final design. However, further testing may be performed on currently stored samples if the final design identifies some aspects or properties that could be easily be confirmed by laboratory testing.

4.2

Construction

4.2.1 Methodology Most of the construction activities will occur during the winter months to benefit from the cold temperatures. As mentioned previously, the placement of the dam material will require an ambient air temperature of at least -15 °C. The current schedule is to construct both dams during the same season. However, the water balance shows that the South Dam will not be required during the first year of operations, which allows for an opportunity to delay the construction of the South Dam. This will be re-evaluated at the final design stage. The pre-construction period will include the procurement of the materials that need to be imported to the site, such as the GCL, bentonite, and instrumentation. The production of quarry rock could also be initiated during that period and be processed accordingly to obtain the proper gradation for Materials A, B and C. The granular material would be stockpiled in preparation for the winter construction. The critical aspect for the production of the granular materials is to make sure that the supply can keep up with the rate of placement. In the early part of winter, the construction activities would be initiated with the removal of the vegetation cover within the footprint of the dam, the excavation of the key trench and the preparation of the abutments. A small temporary berm may be required immediately upstream of the North Dam to obtain a dry surface prior to the construction work. The excavation of the key trench is expected to be 4 m deep but it will have to reach competent ground conditions. The key trench will be excavated using drill and blast methods combined with mechanical excavation. Loose frozen soil, boulders and protruding frozen ground would be removed to provide a clean key trench surface. Final cleaning would be carried out with compressed air. The excavated material will be stockpiled in a suitable area for potential future use. Investigative work will be carried out at the bottom of the key trench in the sandy deposit at the North Dam to confirm that the key trench is within ice saturated soils. This may result in a deeper key trench over that section. The abutments will require particular attention to assure a good bond between the core of the dam and the overburden and bedrock. Blasting in the bedrock may be required at the abutments to limit MN/spk


October 2005


Page 41

the slope of the bedrock to 1H:1V and to prepare the bedrock surface to key in the core at the abutments. The three types of crushed and processed material should be stockpiled individually and be of sufficient quantity prior to the beginning of the placement. The stockpiled material should be kept as dry as possible to avoid inter-particle ice-bonding. The placement of Material A, which is the finer crushed rock used for the core, will require the addition of heat and water to achieve a high degree of saturation and to ensure that it is ice-free at the time of placement. The moisture content of the core material will have to be adjusted to prevent excess water that could form free ice lenses while maintaining the degree of saturation as high as possible. The material would then be placed in lifts of 100 to 200 mm. The following lift would only be placed once the previous lift has completely frozen and that the surface is cleared of snow, ice and loose material. Test trials would probably be required to determine the optimum lift thickness and the proper water content. Based on the experience gained from the Ekati Diamond MineTM frozen core dams, sufficient compaction would be achieved by construction traffic. The evaporators of the thermosyphons would be placed on top of the first lift placed at the bottom of the key trench. The radiators would consist of 19 mm (¾ inch) diameter high pressure steel pipes placed as four loops. Each pair of looped pipes would cover opposing halves over the entire length of the dams, as shown in Figure 4. The radiator pipes would be spaced at 1.5 m intervals. Materials B (transition) and C (shell) can be placed using the material directly from the stockpile and in subfreezing conditions. The thickness of the lifts should be limited to 500 mm for Material B and 1,000 mm for Material C. Material B would be compacted using vibratory smooth drum compactors while Material C would be compacted by routing heavy equipment over each lift. It is important that the placement of these materials minimises the segregation or nesting of coarse particles. The surface prior to placing the GCL should be smooth and absent of protrusions and angular particles larger than 20 mm. The placement of the backfill material covering the GCL should not be pushed across the seams to prevent uplifting the GCL. The GCL panels should be orientated perpendicular to the dam axis and should have an overlap of at least 500 mm. The overlaps will require bentonite powder to seal the adjacent GCL panels. The GCL should be protected from moisture prior to its placement.

4.2.2 Equipment Construction of the dams can be achieved, in most part, using conventional earth moving equipment. Trucks, loaders, graders, excavators, smooth roller compactors and track-mounted bulldozers would not require special requirements other than to be capable of operating in extremely cold weather. The production of granular materials, such as the rock fill/crushed rock, the transition material, the filter material and the rip rap would be undertaken with “normal” quarry equipment. This equipment would likely involve track-mounted air drills, crushers and screening equipment. MN/spk


October 2005


Page 42

The handling of the core material will require more effort and attention. Such manipulation could be achieved by using a mobile plant capable of heating the crushed rock and a mobile mixer capable of controlling the proper dosage of water and soils.

4.2.3 QA/QC Quality assurance and quality control (QA/QC) procedures will be followed during the construction of the dams. As mentioned above, the dams will be constructed in winter under potentially extreme climatic conditions. It is essential, therefore, that the construction of the dams be supervised by an engineer familiar with the design and construction of frozen core dams. The QA/QC will involve measurements to characterise the material and the state at which it is being placed. It will be important that the QA/QC program includes suitable coring equipment to core the frozen lifts, which would then provide bulk densities and degree of saturation. Technical staff with facilities for soil testing will therefore be required during the construction of the dams.

4.3

Post-Construction Activities

4.3.1 Monitoring A monitoring program will be included in the final design to monitor the performance of the tailings impoundment, including the dams. The monitoring program will include the thermal regime, deformation, seepage and climate. The level of monitoring will be intensive during the early stages of operations since it is during this period that the dam performance against the design assumptions will be confirmed. Additionally, the monitoring information may identify aspects of the original design predictions that may be too conservative, thus providing opportunities to readjust some of the predictions. The monitoring program described below will be developed in conjunction with the Adaptive Management Plan, which will be detailed during the final design. Given the importance of the frozen core for the performance of the dam, the ground temperature inside the dam will be monitored. The ground temperature measurements will determine the extent of the frozen region in the dam and should provide information on the rate of thawing or freezing fronts. Figure 21 illustrate the zones within the dam section where ground temperature sensors will be installed. Temperature sensors are located in sensitive areas, such as the upstream zone of the dam, the outer shell that will be subject to the fluctuations of the active zone, as well as the abutments. As illustrated in Figure 21, it is expected that temperature sensors will be installed both horizontally and vertically, and as much as possible, will be installed as the dams are being constructed. Monthly readings should be sufficient to depict the thermal regime in the dams but data loggers will be installed to collect continuous data at key locations. This frequency should be maintained until the dam reaches pseudo-steady state conditions. The frequency could then be reduced thereafter but the frequency would have to coincide with the peaks of the annual climatic cycles (i.e. low and high temperatures). MN/spk


October 2005


Page 43

Settlement will be monitored by installing monuments along the crest and sloped faces of the dam as shown in Figure 21. The monuments would be installed during the construction of the dam and would be surveyed on a regular basis to monitor the movement of the dam, both horizontally and vertically. The deformation will be monitored using settlement plates (or similar devices) and, possibly, inclinometers. The frequency of measurements will be higher during the initial stage of the operations and will be based on the rate at which the talik is developing along the upstream side of the dams. The frequency of the measurements may be decreased as the rate of deformation decreases. Climatic data will be collected during the operation of the mine. The climatic data will include ambient air temperature, precipitation (rain and snow), wind speed and wind direction as a minimum. Surveys of snow cover would also be performed to complement the assessment of the thermal regime at the dams. Other parameters such as relative humidity and solar radiation are not essential but would provide useful information, in particular for evapotranspiration estimations. The climatic data will be recorded with an automatic data logger. The dams should be inspected on a regular basis to detect damage, deformation or any other anomalies. It is important that the inspections be frequent during the period the lake level is rising and the talik developing. The water level of Tail Lake should also be monitored as part of those regular inspections. Observations of potential seepage should be incorporated in the dam inspection requirements. The various data collected from the monitoring program should be compiled and assessed as part of the AMP (see Section 4.1). The compiled data should also be made available to the regulatory agencies as well as other parties that may have interest in such data. The frequency of reporting will likely be determined at the licensing stage, but should at least be reported on an annual basis.

4.3.2 Site Inspection The dams and the spillway will be inspected by individuals responsible for routine monitoring activities at the Doris North site. In addition, a suitably qualified professional engineer registered in the Nunavut Territory will make an annual inspection of the tailings dams each summer. The subsequent inspection report will summarize the observations and the review of the available monitoring data (described above). The report will be filed in a timely manner so that, if required, mitigation measures to these structures can be implemented prior to the next freshet.

4.3.3 Maintenance The dams may require maintenance as the talik develops on the upstream face of the dams. As mentioned previously, the talik will induce settlements along the upstream face of the dams. The central frozen core is expected to remain frozen and is unlikely to be subject to significant settlement. The final design may include provisions to reduce or minimise these potential settlements along the upstream faces. Regardless of the outcome of the final design, the maintenance program should include placement of additional fill on the upstream face of the dams as settlement MN/spk


October 2005


Page 44

develop. The frequency of the maintenance should decrease over time as the thermal regime gradually reaches equilibrium. Regular inspection of the dams will identify any other maintenance issues.

This report, 1CM014.006 – Preliminary Tailings Dam Design, Doris North Project, Hope Bay, Nunavut, Canada, was prepared by SRK Consulting (Canada) Inc.

Prepared by

Michel Noël, M.A.Sc., P.Eng. Senior Geotechnical Engineer

Maritz Rykaart, PhD., P.Eng. Senior Geotechnical Engineer

Reviewed by

Cam Scott, P.Eng. Principal

MN/spk


October 2005


5

Page 45

References Adams, J. and Halchuk, S. 2003. Fourth generation seismic hazard maps of Canada: Values for over 650 Canadian localities for the 2005 National Building Code of Canada. Geological Survey of Canada, Open File 4459, 155 p. AMEC. 2003a. Draft Environmental Impact Statement, Doris North Project, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, January 2003. AMEC. 2003b. Meteorology and Hydrology Baseline, Doris North Project, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, August 2003. AMEC. 2003c. ARD and Metal Leaching Characterization Studies in 2003, Doris North Project. Report no. VM00259 submitted to Miramar Hope Bay Ltd. November 2003, 68 pages. BGC Engineering Inc. 2003. Implication of Global Warming and the Precautionary Principle in Northern Mine Design and Closure. Report submitted to Indian and Northern Affairs Canada, Iqaluit, NU. Burn, C.R., Barrow, E., Bonsal, B. 2004. Climate change scenarios for Mackenzie River Valley. Proc. 57th Canadian Geotechnical Conference, Quebec, QC, Session 7A-G35.443. Canadian Dam Association. 1999. Dam Safety Guidelines. Cohen, S.J. (ed.). 1997. Mackenzie Basin Impact Study Final Report, North York, ON: Environment Canada, 372 p. EBA Engineering Consultants Ltd. 1996. Boston Gold Project, Surficial Geology and Permafrost Features. Report submitted to Rescan Environmental Services Ltd. EBA Engineering Consultants Ltd. 1998. Ekati Diamond MineTM Long Lake Outlet Dam As-Built Construction Report. Report submitted to BHP Diamonds Inc. August 1998. EBA Engineering Consultants Ltd. 2003. Ekati Diamond MineTM Bearclaw Diversion Dam As-Built Construction Report. Report submitted to BHP Billiton Diamonds Inc. July 2003. Environment Canada. 1992. A state of Canada’s climate: temperature change in Canada 1895-1991. A State of the Environment Report, 38 pages. Environment Canada. 1998. Climate change impacts on permafrost engineering design. Published by the Environmental Adaptation Research Group, Atmospheric Environment Services, Environment Canada, March 1998.

MN/spk


October 2005


Page 46

GEO-SLOPE International Ltd. 1998. User’s Guide – SLOPE/W for Slope Stability Analysis – Version 4. Golder. 2001. Report on Thermistor Data Review – Hope Bay Project. Letter-report submitted to Miramar Mining Corporation. Goodrich, L.E. 1982. The influence of snow cover on the ground thermal regime. Canadian Geotechnical Journal, vol. 19, pp. 421-432. Hansen, J.E., Lacis, A., Rind, D., Russell, G., Stone, P., Fung, I., Ruedy, R. and Lerner, J. 1984. Climate sensitivity: analysis of feedback mechanisms. In Climate Processes and Climate Sensitivity, J.Hansen and T. Takahashi (eds.), Maurice Ewing Series #5, American Geophysical Union, Washington D.C., pp. 130-163. Harvey, R.C. 1982. The climate of arctic Canada in a 2 x CO2 world. Environment Canada, Atmospheric Environment Service Report 82-5, Ottawa, 21 pages. Hayley, D.W., J.T.C. Seto, C.K. Gräpel, D.C. Cathro and M.A. Valeriote. 2004. Performance of two rockfill dams with thermosyphons on permafrost foundations, Ekati Diamond Mine, NT. Proc. 57th Canadian Geotechnical Conference, Quebec, QC, Session 5F-G15.454. Hivon, E.G. and Sego, D.C. 1995. Strength of frozen saline soils. Canadian Geotechnical Journal, vol. 32, pp. 336-354. Houghton, J.T., Meira Filho, L.G., Callendar, B.A., Harris, N., Kattenbureg, A. and Maskell, K. eds. 1996. Climate Change 1995; the science of climate change. Contribution of Working Group 1 to the second assessment report of the intergovernmental panel on climate change, Cambridge University Press, Great Britain, pp. 572 Intergovernmental Panel on Climate Change (IPCC). 1995. Climate Change 1995: The science of climate change. Technical Summary, Cambridge University Press, Cambridge, UK Intergovernmental Panel on Climate Change. 2001. Climate Change 2001: Synthesis Report; contribution of Working Groups I, II, and III to the Third Assessment Report of the Intergovernmental Panel on Climate Change, (ed.) R.T. Watson and the Core Writing Team, Cambridge University Press, 398 p.; also available on-line at http://www.ipcc.ch/pub/reports.htm (accessed October 2003). Johansen, O. 1975. Thermal conductivity of soils. Ph.D. diss., Norwegian Technical Univ., Trondheim; also, U.S. Army Cold Reg. Res. Eng. Lab. Transl. 637, July 1977. Kettles, I.M., Tarncai, C. and Bauke, S.D. 1997. Predicted permafrost distribution in Canada under a climate warming scenario. In Current Research 1997-E, Geological Survey of Canada, pp. 109119.

MN/spk


October 2005


Page 47

Long, E.L. (Arctic Foundations). 2004. Private communications. Miramar Hope Bay Ltd. 2003. Geological Summary, Proposed Quarry Sites, Doris North Project, Hope Bay, Nunavut, Canada. September 2003, 15 pages. Natural Resources Canada. 2004. Climate Change Impacts and Adaptation: A Canadian Perspective. Climate Change Impacts and Adaptation Directorate of NRCan (http://adaptation.nrcan.gc.ca), 174 pages. Newman, G.P. and Wilson, G.W. 1997. Heat and mass transfer in unsaturated soils during freezing. Canadian Geotechnical Journal, Vol. 34: pp. 63-70. Nicholson, F.H. and Granberg, H.B. 1973. Permafrost and snowcover relationships near Schefferville. Permafrost, Second International Conference (13-28 July 1973, Yakutsk, U.S.S.R.), North American contribution, National Academy of Sciences, Washington, D.C., pp. 151-158. Nicholson, F.H. and Thom, B.G. 1973. Studies at the Timmins 4 permafrost experimental site. Permafrost, Second International Conference (13-28 July 1973, Yakutsk, U.S.S.R.), North American contribution, National Academy of Sciences, Washington, D.C., pp. 159-166. PDE Solutions Inc. 2004a. FlexPDE Reference Manual, version 4. 61 pages. PDE Solutions Inc. 2004b. FlexPDE User Guide, version 4. 49 pages. Rescan. 2001. 2000 Supplemental Environmental Baseline Data Report, Hope Bay Belt Project. Report submitted to Hope Bay Joint Venture. Smith, M.W. 1988. The significance of climate change for the permafrost environment. 5th International Conference on Permafrost, pp. 18-23. Smith, S.L. and Burgess, M.M. 1998. Mapping the response of permafrost in Canada to climate warming. Current Research 1998-E, Geological Survey of Canada, pp. 163-171. SoilVision Systems Ltd. 2004. SVHeat User’s Manual v.2. Saskatoon, SK, Canada. SRK Consulting Inc. 2002a. Hope Bay Doris North Project – Preliminary Assessment, Doris North Trial Operation, Nunavut, Canada. Report submitted to Hope Bay Joint Venture, February 2002. SRK Consulting Inc. 2003a. Hope Bay Doris North Project – Technical Summary of Feasibility Study, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, February 2003. SRK Consulting Inc. 2003b. Hope Bay Doris North Project – Tailings Impoundment Preliminary Design, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2003. SRK Consulting Inc. 2003c. Hope Bay Doris North Project – Surface Infrastructure Preliminary Design, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2003. MN/spk


October 2005


Page 48

SRK Consulting Inc. 2005a. Preliminary Surface Infrastructure Design, Doris North Project, Hope Bay, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2005. SRK Consulting Inc. 2005b. Preliminary Jetty Design, Doris North Project, Hope Bay, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2005. SRK Consulting Inc. 2005c. Water Quality Model, Doris North Project, Hope Bay, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2005. SRK Consulting Inc. 2005d. Hope Bay Doris North Project – Summer 2004 Geotechnical Field Investigation at Tail Lake, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, 2005. SRK Consulting Inc. 2005e. Hope Bay Doris North Project – Winter 2005 Geotechnical Field Investigation at Tail Lake, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, 2005. SRK Consulting Inc. 2005f. Revised Dam Design Preliminary Engineering, Hope Bay Doris North Project, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, April 2005. SRK Consulting Inc. 2005g. Tailings Alternatives Assessment, Doris North Project, Hope Bay, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2005. Yarmak, E. and Long, E.L. 2002. Recent Developments in Thermosyphon Technology. Proceedings, Eleventh International Specialty Conference on Cold Regions Engineering; Anchorage, Alaska; May 20-22, 2002.

MN/spk


October 2005

Figures

DORIS NORTH PROJECT

x Kingauk

DORIS NORTH PROJECT Preliminary Tailings Dam Design

Location Map

MIRAMAR HOPE BAY LIMITED

PROJECT

DATE

1CM014.006 Sept. 2005 File Ref.: 1CM014.006_Fig 1.1_20051003.ppt

APPROVED

EMR

FIGURE

1

North Dam

South Dam

FILE REF: fig_inside_title_block_mn02_20051011.xls/Fig 8_Oct2005

Temperature Frozen

Unfrozen

-9 to -7 °C

Ground surface Active layer

0.5 to 2.5 m

Depth of zero annual amplitude 11 to 17 m

Permafrost layer 560 m

dZ dT

Geothermal gradient (dT/dZ) Z < 100 m, dT/dZ ≈ 0 °C/km Z ≥ 100 m, dT/dZ ≈ 11 to 18 °C/km

Unfrozen Depth



Ground temperature and permafrost characteristics PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MMN

FIGURE

8

FILE REF: fig_inside_title_block_mn02_20051011.xls/Fig 9-Oct2005a

1 SRK-51-4D: Silt & clay CL (Winter 2005 Program)

Volumetric Fraction of Unfrozen Pore Water

0.9

SRK-58-4D: Silt & clay CL (Winter 2005 Program) SRK-62-6E: Silt & clay CL (Winter 2005 Program)

0.8

Clayey, sandy silt (2004 Summer Program) From gravimetric

0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -20

-18

-16

-14

-12

-10

-8

-6

-4

-2

0

Temperature (°C)



Unfrozen water content laboratory results PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MMN

FIGURE

9

FILE REF:Hope Bay SPEC Grain Size Distribution_20051011.XLS/Fig 12_20mm

100 90 80

PERCENT PASSING

70 60 50 40 30 20 10 0 0.01

0.1

1

SIEVE SIZE (mm) 10

100

1000


Recommended Gradation Envelope Material A (Core)


PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MMN

FIGURE

12

FILE REF: Hope Bay SPEC Grain Size Distribution_20051011.XLS/Fig 13_150mm

100 90 80

PERCENT PASSING

70 60 50 40 30 20 10 0 0.01

0.1

1

10

100

1000

SIEVE SIZE (mm) DORIS NORTH PROJECT Preliminary Tailings Dam Design

Recommended Gradation Envelope Material B (Transition)


PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MMN

FIGURE

13


Volumetric fraction of unfrozen pore water

1 0.9 0.8

M arine fine soils deposit S and deposit D am material & bedrock Average Lab - Clayey sandy silt

0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -30

-25

-20

-15

-10

-5

0

5

Temperature (°C)


Estimated unfrozen water content MIRAMAR HOPE BAY LIMITED

PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MMN

FIGURE

14


0

Depth (m)

10

20

30

nF = 0.70 nT = 1.00

40

M odel SRK-33 SRK-43

50 -25

-20

-15

-10

-5

0

5

10

Temperature (°C) DORIS NORTH PROJECT Preliminary Tailings Dam Design

Calibrated ground temperature profile MIRAMAR HOPE BAY LIMITED

PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MMN

FIGURE

15

Elevation (m)

ENTIRE DOMAIN

50

FSL = 33.5 m

0

-50

-100

-50

0

50

100

150

200

Horizontal distance (m)

DAM DETAILS

70

60

50

Material C saturated

Elevation (m)

40

Material B unsaturated

Material B saturated

Material C unsaturated

FSL = 33.5 m 30

Material A saturated Marine deposit

20

Sand deposit 10

0

Bedrock -10 0

20

40

60

80

100

120

Horizontal distance (m)


Thermal model geometry, North Dam

MIRAMAR HOPE BAY LIMITED fig_inside_title_block_mn02_20051011.xls/Fig.16_Oct2005

PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MNN

FIGURE

16

TIME: YEAR 5 September

Te = Ground temperature °C

50

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-7 0

3 -1 -6 -2

-9-6

0

-10 -2

-4

1

- 2 -3

1

-6

-7

-8-1 1

-3

-6

-5

-4

-2

-5

3

20 -4

10

-1 2 -9-6 -3

-6-6

3

-5

2

-4 -1 4

30

-5

Elevation (m)

40

-7

-5

0

0

20

40

60 Horizontal distance (m)

80

100

120

TIME: YEAR 15 September 50

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 -6-3 1 -10 -7 -2

--11 3

3

30

-2

2

1

0

1

2

3

-14

-1

-8 -1 2 -9 -2

-3

-5

-1 1 -4

-5

-1 -5 3

-1-12 0 -9

-1

20 -5

Elevation (m)

40

10

-4 -7

0

0

20

40


80

100

120


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

40

-7 -6 0

30 -1

20

1

2

3

-12 -2

-1 -4

-1

-140 -9-4 -1 1 -3 1 -8 -2

-5

-3

0

2

0

-2

-7 -5

-3

-6 -5

3

-4

Elevation (m)

-1 3

-2 -3

10

-6

0

0

20

40


80

100

120


Temperature predictions, North Dam Average climate

MIRAMAR HOPE BAY LIMITED fig_inside_title_block_mn02_20051011.xls/Fig.17_heat_avgClim

PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MNN

FIGURE

17



50

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-1 -14 2

30

-1 4 -5

-8 -4-9 -2 -3

-4

-4 -4

-7

3

1

2

3

-12 0-6-11 -8-13

-11

-9

20

0

-9 -3

-5

-7

Elevation (m)

40

-8

-6

10 -7 -8

0

-8

0

20

40


80

100

120


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

10

30

-5

-1

-14

-12

1

-9 -6

-12

-2

3

- 10

-8

-3

-5 -6

-9

0

20

2

-1-83-1 -2 -3 1

-5 -4

-9

-7

-7

-8

-8

-5

10

0

-9

Elevation (m)

40

-4 -6

0

0

20

40


80

100

120


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

3

2

-2

1

20

-4

-2

-1

-1

-2

2

3

-1-7 0 -8 -9-1 3 -3 -5

-5

-8 -9

2 0

1

-11 -9

3

-6

0

-1 2 -1 4 -1 -2 -3 -5 -1

-3

30

-7

-9 -4 0 -1

-11

-8

Elevation (m)

40

-4 -5

-6

-3

10

-7

0

0

20

40


80

100

120


Temperature predictions, North Dam Average climate with thermosyphons

MIRAMAR HOPE BAY LIMITED fig_inside_title_block_mn02_20051011.xls/Fig.18_heat_avgClimThermo

PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MNN

FIGURE

18



50

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

30

-11 -9 0

1

2

3

-4 -7 -2 -4 -3

-2

-5

-1 -3

2

-1

-1 -3 -29 -8

-7

-4

-3

-8

-1-31 4 -4

20

-10

-9

1

0

-10

-1

-3

-4 -4

-6

Elevation (m)

40

-5 -7

-7

-8

10

0

0

20

40


80

100

120


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

2

-4-3

1

30

-12 -5

-8 -1

-6

-5

0

-

20

0

1

2

3

-1-50 -1 3 -6 -1 -3 -4

-5

-1

-8

Elevation (m)

40

11

-9-1 1 -7

-2

-3

-5

-6

-3

-6

-7

-4

-5

-5

0

-7

10

0

20

40


-7

80

100

120


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-2

-2

-4

-1

0

-5

-3 -5

-1 0 -2

-2

-5

20

40

-9

-1-6

-3 -4

-7

-4

0

-1 3

-5

0

-3

-1 1

-6

10

3

-7 -9

20

2

-7

2

1

-2

0

0

30

0

-8

-5

2 -7 -1 -4

-1

Elevation (m)

40


80

100

120


Temperature predictions, North Dam Warm climate with thermosyphons

MIRAMAR HOPE BAY LIMITED fig_inside_title_block_mn02_20051011.xls/Fig.19_WarmClimThermo

PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MNN

FIGURE

19

Te = Ground temperature °C AVERAGE CLIMATE, NO THERMOSYPHON

TIME: YEAR 40 50

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 -1 1 -7-8

-9 3-1 0 -1

-2 32

30

-5

0

1

2

3

-1

-1-142

-2

20

-2

-4 -1

3

-3

-5

-9-1 3 -6

-5

-4

-3

-2

-3 -5

-4

Elevation (m)

40

10

0

0

20

TIME: YEAR 40

-5

40


80

100

120

AVERAGE CLIMATE, WITH THERMOSYPHONS

50

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

30

1

2

-1

-7 -5 -2

3

-10 -4

-3

-13-14

-5

-4 -3

-1 1

-5

-3

-7

1

-8

-6

-4

20

-5

-3

0

2

3

-1 1

-1 2 -4

-1 1-9 -1 -1

0

-8

Elevation (m)

40

-5

-3

10

-6

-7

-7

0

0

TIME: YEAR 40

20

40


80

100

120

WARM CLIMATE, WITH THERMOSYPHONS

50

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 -1 -4-3

-6 0

3

30

-12 0 -1 -3

-7

3

0-5 -2

-5

0

-3

-4

0

-7

-1

-1 -1 -2

-3

-6 -5

-3

-5

-6

10

0

-11-9 -3-1-8

2

-6

20

1

-4

1

2

0

-4

-5

Elevation (m)

40

-6

0

20

40


80

100

120


Temperature predictions, North Dam Comparison, 40 year simulations

MIRAMAR HOPE BAY LIMITED fig_inside_title_block_mn02_20051011.xls/Fig.20_Year40Compare

PROJECT

DATE

1CM014.006

Sept. 2005

APPROVED MNN

FIGURE

20

Appendix A EBA Engineering Consultants Letter Report by Mr. Don Hayley, P.Eng.

EBA Engineering Consultants Ltd. Creating and Delivering Better Solutions

February 28, 2005 EBA File: 1100074 SRK Vancouver Suite 800 1066 West Hastings Street Vancouver, BC V6E 3X2 Attention:

M. Rykaart, P.Eng

Subject:

Review of Alternate Dam Design, Hope Bay Doris North Project

Dear Maritz: This letter-report summarizes my comments following a review of your draft report on an alternate dam design for the Doris North Project. The review was requested in December 2004, and my comments were discussed with Michel Noel and Cam Scott at a meeting in Edmonton on January 27th. We reviewed the meeting notes transmitted to you from Michel on the telephone on February 2nd. Scope of Review The review specifically addressed the preliminary design of two dams required to contain process water in a lake selected for tailings disposal just East of Doris Lake (Tail Lake). The dam at the North end (North Dam) of the proposed impoundment is configured to sustain a differential head of water of 7.5 m with a design life of 25 years. The South Dam is higher on the natural terrain and would have a maximum head of only about 1 m. It is understood that examination of an alternate dam design was triggered by concerns raised by the Nunavut Impact Review Board during their review of the Environmental Impact Statement. Miramar Hope Bay Ltd. have requested SRK to evaluate other options for dam design and construction that have established precedent for an arctic mine site. Technology for design and construction of frozen core dams, based on experience developed at EKATI Diamond Mine over the past 10 years, offers the best experience basis for an alternative to the originally proposed earthfill dam. The conceptual design section adopted for the report is drawn from the EBA EKATI experience and is consistent with comments provided by this reviewer at our brief meeting in Calgary last November (2004). L01 SRK Dam Design Feb 28 05.doc

#255, 1715 Dickson Avenue, Kelowna, British Columbia V1Y 6K7 - Tel: (250) 862-4832 Fax: (250) 862-2941 Email: [email protected] - Web Site: www.eba.ca

1100074

-2-

February 28, 2005

This review examines the site conditions as defined by SRK in the Appendix Volume (Volume II) of the report entitled “Tailings Impoundment Preliminary Design, Doris North Project” dated October 2003. The adaptation of frozen core dam technology to the Doris North Site has been documented in the Draft report entitled “Alternate Dam Design. Preliminary Engineering”, dated December 2004. The review has been based on information included in these two reports together with comments provided by Michel Noel and Cam Scott at the review meeting on January 27th. Frozen Core Dam Fundamentals A frozen core dam is comprised of a perennially frozen granular fill on a permafrost foundation. The principle function of limiting seepage loss is achieved by an ice-saturated granular core matrix bonded to natural permafrost foundation soils. The application is only suited to arctic environments where continuous permafrost soils are sustained naturally. Planning, design, construction and operation of a frozen core dam at any site must meet the following broad objectives: Continuous permafrost foundation soils or bedrock are present with ground temperatures typically less than -5°C; A winter construction schedule is feasible; Well graded natural granular materials or processed (crushed) rock is available; A period of thermal embankment stability, typically one year, is available between completion of construction and achieving full water head; There is a defined operational life followed by decommissioning; Analyses must demonstrate acceptable geothermal response in both the embankment and the foundation soils; Knowledge of the behaviour of the frozen foundation soils and their sensitivity to changes in temperature has been gained from careful site evaluation; and A program is in place to monitor both ground temperatures and deformations during the period of operation. The advantages of a frozen core dam are generally related to the benefits of using the longer winter construction schedule and non-dependency on natural soils that are invariably in a permafrost condition. An important secondary benefit is that embankments can be constructed on permafrost overburden rather than attempting excavation to a bedrock foundation. Bedrock foundations in a permafrost condition are not a panacea for earth dam foundation because fractures are often filled with ice that can render the foundation pervious if it is allowed to thaw. L01 SRK Dam Design Feb 28 05.doc

1100074

-3-

February 28, 2005

North Dam Site Conditions The focus of this review has been the more critical North Dam. Geotechnical conditions for the foundation of the North Dam are shown in the longitudinal section, SRK Figure 7. There have been three or more phases of geotechnical drilling that provided substantial information on site conditions. In spite of the extensive information brought together on Figure 7, the foundation conditions at this site must be considered very complex with uncertainties remaining that will affect the final design. The geotechnical conditions that are of concern when evaluating the proposed frozen core design concept at this site are as follows: Ground temperatures at depth are well into the continuous permafrost range at -8 to -9°C but there is minimal ground temperature data within the upper 2 m from which the active layer can be well defined. The active layer in the marine silty clay soils appears to be about 0.5 m (based on reinterpretation of SRK 43). The active layer in the sand profile appears to be not greater than 2.0 m (based on reinterpretation of SRK 41). The geothermal gradient within the upper 100 m appears to be isothermal with some installations suggesting a negative gradient. These initial conditions differ somewhat from the generalized assumptions shown in Figure 6, a factor that may affect calibration of the geothermal model for initial ground temperature conditions. The deep thermistor data reported from SRK 50 shows an interesting inflection point at a depth of 100 m. The upper portion of the curve is near isothermal whereas the lower 100 m to the full depth of 200 m is consistent with the estimated geothermal gradient of 0.018C°/m. This type of ground temperature response has been linked to long term climatic warming trends when similar data was reported from the Alaska North Slope. It would be helpful to confirm these data with additional readings if the installation remains functional. Half the dam foundation is on permafrost sand, probably of marine beach origin. The drilling into the deep sand has noted loss of circulation fluid and has not been able to produce sufficient intact sample to characterize the extent of ice saturation of this deposit. In situ falling head permeability tests suggest greater hydraulic conductivity (10-6 cm/sec) than would be expected for frozen, ice saturated sand. There are portions of the underlying bedrock where core recovery was poor. It is prudent to assume that the upper bedrock below the overburden is fractured and that the fractures are ice-filled. There is not a clear benefit to installing a positive cut-off to the bedrock surface. The bedrock at depth should remain frozen at this site. The east half of the site is underlain by marine silty clays characteristic of the surrounding marine lowland. These soils have highly variable ground ice and zones of massive ice have been identified. More importantly, the marine clays are saline. L01 SRK Dam Design Feb 28 05.doc

1100074

-4-

February 28, 2005

Borehole SRK 42 has a salinity profile within the permafrost zone ranging from 30 to 46 ppt. These values are in excess of seawater (32 ppt). The borehole is located at the South Dam but the data must be assumed to be characteristic of the marine clay in the region. These reported salinities are consistent with drilling results from marine clays carried out by EBA at a proposed port site further north in Roberts Bay in 1997. The soils overlying the marine clay at the centre of the valley are described as interbedded layers of sand, peat and silty clay. These highly variable layered surface soils extend to a depth of about 3.5 m. South Dam Site Conditions Geotechnical conditions at the South Dam Site are more uniform than at the North Dam. The valley at this location has been infilled with marine and possibly lacustrine soils. The upper 6 m is identified on Figure 8 as “silt/clay” but logged on Borehole log SRK 43 as silty sand to sand. Below this surface layer is the regional marine clay with similar properties to that identified at the North Dam Site. Below the clay is a layer logged as cobbles, boulders and gravel and described on the section as “till”. This geomorphic descriptor seems unlikely at this site as it was well below the marine limit during the glacial period. The visual description of the granular soils suggests it is either a buried beach deposit or alluvium. Bedrock at this site is deep, as it was not encountered until 34 m below surface. The surficial silty sand identified at this site is probably of lacustrine origin, deposited in brackish water when Tail Lake was much higher. This surface soil has a somewhat lower salinity than the underlying marine clay. The surficial geology report (Thurber, 2002) identifies ice wedge polygons in the valley, indicative of abundant natural ground ice in surficial soils. Design Issues It is the opinion of this reviewer that there is not a viable alternative to a frozen core dam for either site. A frozen core dam will meet the operating objectives set out in the draft report but the design and construction process may be more involved than identified to date. Information currently available from the site is considered sufficient to support a preliminary design for Environmental Assessment purposes. The following discussion focuses primarily on enhancements that are suggested to address the complex site conditions for purposes of final design of both water retention structures. The final design submitted for full regulatory approval (Water License) will require more comprehensive analyses that include the following:

L01 SRK Dam Design Feb 28 05.doc

1100074

-5-

February 28, 2005

The thermal analyses should assume that the in situ salinity of the permafrost marine clay is in the order of 40 ppt. The implication of that assumption is shown in Figure 13, which relates the unfrozen water content to temperature of a marine soil with similar salinity. Ground temperatures must be less then -6°C in order to have 50% of the water in the soil frozen. The significance is that the foundation soils must be sustained at near in situ values of -6 to -8°C in order to reasonably ensure the foundation is impermeable and that creep displacements won’t be excessive. The maximum allowable foundation temperature criterion adopted for the preliminary design of -4°C (Subsection 3.2.7) will probably not satisfy performance objectives. Installation of thermosyphons into the foundation key trench of North Dam will likely be required to achieve the revised maximum temperature criteria in the foundation. This hypothesis should be tested by rerunning the thermal analyses for a revised preliminary design with the modifications suggested in this review. The saline clay soils at this site are subject to creep displacement. This can result in a significant stability risk that could lead to longitudinal cracks within the embankment caused by lateral spreading of the foundation soils. Lateral displacements that could result in progressive failure of the slopes have not been addressed to date in the analyses. Our past experience suggests that this failure mode will probably dominate the design process for this structure, necessitating substantial flattening of sideslopes on both the upstream and downstream rockfill shell. The impact of progressive thaw under the upstream slope once the reservoir is at or near full supply level must be carefully evaluated. The key trench currently shown to be approximately 2 m at North Dam should be deepened to allow removal of the interbedded peat and sand at that site. The key trench excavation at South Dam should ensure that no wedge ice remains in the dam foundation. Construction Considerations The site must be prepared by removing surface boulders and organic soils over the footprint of the dam. The key trench can be excavated by drill and blast techniques. Dental work is required where massive ice is encountered. The key trench must be left clean and all materials damaged by overblasting removed. Final cleaning can be achieved with compressed air. A pad of prepared core material is necessary over the rough excavation in order to prepare a bed for the Geocomposite Clay Liner (GCL) contingency liner.


1100074

-6-

February 28, 2005

The materials chosen for embankment construction are appropriate. The core material designated as a 20 mm minus crushed rock will need to be dry and processed on site to add sufficient water to achieve saturation. The fines content from the crushed material needs to be sufficient (greater than 10 % fines) in order that the granular material retains water during mixing, transporting and placement. Past practice on large projects has been to set up a gravel moisture conditioning enclosure and run the gravel through a pugmill or kiln. This procedure has been developed by Nuna Logistics and has worked well at EKATI. The core material must be placed in finite lifts, generally about 30 cm thick, and left to freeze as described in your report. Placement of one lift every day will normally meet these objectives. Attempts to compact the material with a roller have not been practical in the past. Vibration causes the thin saturated lift to liquefy. Generally, compaction by construction traffic is satisfactory. A conventional concrete coring rig is used to core the frozen lift for Quality Control testing. Bulk density and degree of saturation can be determined in a field laboratory. Ice saturation should be greater than 90% and no readings should be less than 85%. Continuous field supervision by an experienced Engineer and Technologist is essential as your report states. The GCL is a contingency addition to the design to reduce the risk that cracking of the core could leading to progressive failure by piping. This material is relatively easy to work with in winter and does not need a dedicated liner installation crew. The GCL has proven to be both satisfactory and cost effective on other winter-constructed projects such as the EKATI dams. It is also important that the transition zones be properly designed to act as filters in the remote possibility of thaw within the core. The material gradations identified in the report are appropriate. Transition material thicknesses need to be generous, as you have shown, because there is little control over the size of the run-of-quarry shell rock. It will be important to integrate the internal monitoring system into the construction plan. The most recent EBA experience suggests that it is better to install foundation thermistor cables as the fill is placed, rather than drill through the embankment afterwards. Modifications to the Preliminary Design The comments above pertaining to design and construction of the North and South Dams suggest certain modifications to the preliminary dam section shown in Figures 9 and 10. The design at its current stage should recognize all of the site-related issues that could affect performance. It should also be sufficiently robust to deal with uncertainties in the site conditions. The design can be optimized as more information becomes available and further analyses are carried out. At this stage, however, it is important to demonstrate that allowance for all possible uncertainties have been considered. The following modifications are recommended to the preliminary design before it is submitted for environmental review: L01 SRK Dam Design Feb 28 05.doc

1100074

-7-

February 28, 2005

Increase the expected depth of the cutoff trench for the North Dam from 2 m to 3.5 m while retaining the flexibility to adjust the depth locally (include a note on the sketch) based on site surveillance during construction. The South Dam cutoff trench can remain at 2 m with selective subexcavation of ground ice. Flatten the upstream slope of both dams to 6/1 (hor/vert). Although this seems excessive, there are concerns about lateral spreading by displacements along the advancing thaw plane within the foundation soils. This failure mechanism is difficult to consider in conventional limit equilibrium stability analyses. Flatten the downstream slope of both dams to 4/1 (hor/vert). The flatter slopes will reduce the risk of creep displacements initiating progressive failure of the downstream slope. Identify installation of a looped thermosyphon system at the base of the key trench as a component of the design of the North Dam. The system can be deleted if subsequent analyses indicate it is not required. The purpose of the thermosyphons is to lower foundation temperatures to offset the effect of salinity in the permafrost clay. Reconsider the necessity for inclusion of a spillway and when it would be constructed. If the probability that the spillway will ever be used is very remote, consider relying on the decant pumping system and modifying the dam to allow short term overtopping. If the spillway is indeed required, the design should be enhanced to determine the nature of the rock that will be exposed upon excavation and provide assurances that overburden where it is encountered can be protected from erosion and thaw subsidence. Provide a schedule identifying when the structures will be constructed. Can the South dam and spillway be deferred, allowing information collected during construction of the North Dam to be used to improve the designs? A revised preliminary design will result from inclusion of the above comments. That design should be tested by further ground thermal analyses to establish that basic requirements of sustaining an acceptable core and foundation temperature can be achieved. This design can then be submitted for environmental assessment with reasonable confidence that basic objectives have been addressed and that details will be more fully evaluated for final design. Requirements for Final Design Final design and preparation of drawings for construction purposes (required for final approvals and issuance of a Water License) will require supplemental analyses that draw on additional site data that addresses certain data gaps identified in this review. These include the following components of the design.


1100074

-8-

February 28, 2005

Future thermal analyses should address the temperature distribution within the foundation soils more precisely and how it varies with time over the 25 year operating period. The projected rate of thaw under the upstream shell slope and its effect on the core should be investigated further. Test the design for abnormal climatic conditions such as successive warm years (1/100AEP) and a global warming trend that is consistent with the Environment Canada (PERD) report of 1998 possibly with a judgmental correction to indicate that more recent information has been considered. Develop a maximum design ground temperature criteria for the foundation soils that better reflects behaviour of the saline marine soils and confirm the benefits that thermosyphons could add to the project, particularly the North Dam. The foundation stability and embankment slopes will be driven by creep displacements and possibly progressive failure along any receding permafrost boundary. A finite element deformation analysis that uses a visco-elastic constitutive relationship to model soil behaviour is recommended. A commercially available program such as FLAC is capable of addressing this component of the design. Plan and execute one more phase of geotechnical drilling for the site in order to supplement the geotechnical database and reduce uncertainties for the new analyses. The supplemental drilling program should focus on obtaining high quality samples of the overburden at this site as the permafrost soil will determine foundation performance. A minimum of three holes are recommended at the North Dam Site as follows: o The thick marine clay foundation o The thick sand foundation o The spillway excavation A dry auger core barrel (CRREL-Type) should be available to sample the fine frozen sand and clay deposits within the upper metre of permafrost. Thermistor cables should be configured and installed to supplement the ground temperature data within the active layer and upper 2 m of permafrost. Samples of the marine clays and sands should be carefully preserved and transported in a frozen condition to the laboratory for determination of frozen bulk density, salinity and unfrozen water content-temperature relationship. Overall Conclusions and Recommendations The site chosen for the Tail Lake containment dams have particularly complex permafrost stratigraphy. There is no direct precedent for design and construction of a frozen core dam on saline marine soils such as identified at this site. There are not obvious opportunities to shift the site to one with improved geotechnical conditions nor are there design options to a frozen core dam that eliminate the performance risks identified. L01 SRK Dam Design Feb 28 05.doc

1100074

-9-

February 28, 2005

A frozen core dam remains the most appropriate structure for the environmental conditions and operating parameters at this location. The level of site characterization and design analyses will need to be elevated in order to deal with uncertainties identified in this review. Consequently, the cost of design, construction and monitoring will increase for these structures. I trust these comments are helpful. Please contact me if you require clarification or expansion of any of the topics discussed. Yours truly, EBA Engineering Consultants Ltd.

D.W. Hayley, P.Eng. Principal Engineer (Direct Line: (250) 767-9033) (e-mail: [email protected])

DWH:ln cc:

Michel Noel, SRK


Appendix B SRK Technical Memorandum Re: Water Cover Design for Tail Lake

SRK Consulting (Canada) Inc. Suite 800 – 1066 West Hastings Street Vancouver, B.C. V6E 3X2 Canada [email protected] www.srk.com

Tel: 604.681.4196 Fax: 604.687.5532

Technical Memorandum To:

Brian Labadie

Date:

September 16, 2005

cc:

Project File

From:

Maritz Rykaart, Ben Wickland

Subject:

Water Cover Design for Tail Lake

Project #:

1CM014.006

1

Introduction This technical memorandum documents the design procedure, calculations and assumptions for the minimum water cover thickness of Tail Lake. Tail Lake will be used to sub-aqueously deposit tailings from the Doris North Project, and upon final closure there will be a permanent water cover over the tailings of 4.0 m. The calculations documented in this memorandum provide justification that this water cover is adequate. The primary purpose of a water cover is to ensure that the covered mine waste, in this case tailings, is kept from oxidizing. Oxidizing will result in geochemical changes to the tailings, which in turn will result in poor quality water. It is generally understood that a stagnant water column of 0.3 m is sufficient to prevent oxidization of the underlying waste; however, in nature the water column cannot be stagnant, and as a result the tailings bed stability is affected through physical processes such as wave action, seiching, seasonal lake turnover, currents, and ice entrainment. The general rule of thumb is therefore to ensure a water cover of at least 1.0 m, to counter these processes. Such rules of thumb are however only a guideline, and cannot be used for an actual water cover design. According to the MEND 1998 guidelines (MEND 1998), the objective of water cover design is: “…to provide an adequate depth of water to ensure the consolidated bed of tailings is not entrained or remobilized during operation and after closure of the pond.” The water cover must be deep enough that the tailings do not become re-suspended due to wind generated waves and currents. Resuspension occurs when the resistance of the bed of tailings is overcome by action of overlying water. The resistance of the bed is dependent on particle size, density, and cohesion. The action of the overlying water-wave action is dependent on: • • •

fetch length, the maximum distance of water over which waves may be generated, wind speed, for a maximum return period, and wind direction, duration.

This technical memorandum presents the design calculations for a minimum water cover thickness to prevent re-suspension from occurring.

2

Water Cover Design Approach The current state-of-the art in water cover design is the procedure documented in MEND (1998). According to this guideline, there are five processes that affect bed stability; seiching, seasonal lake turnover, currents, wave action and ice entrainment. The guideline suggest that for small tailings impoundments (less than 5 km2 water body area), and a water depth of 0 to 10 m, that only wave action and ice entrainment need to be accounted for in the design. Since the Tail Lake water body

Authors Initials/typist initials

TechMemoWaterCoverDesign-EMR.doc, 2:10 PM, Sep. 9, 05

SRK Consulting

Page 2 of 10

will vary in size between 81 and 130 ha (0.8 to 1.3 km2), and its depth is between 4.0 and 9.2 m (this is based on the water level in Tail Lake ranging between 28.3 m and 33.5 m, with the tailings at an elevation of 24.3 m), it clearly falls within this category. Note that the surface areas quoted for Tail Lake in this technical memorandum is based on the engineering stage curve for Tail Lake which includes the areas leading up to the North and South Dams. The actual body of water in Tail Lake at the normal water elevation of 28.3 m is 76.6 ha (as reported in the NNLP) in size; however, if the surface area leading up to the dams are included, the area increases to about 81 ha. For re-suspension due to wave action, the MEND (1998) guideline uses the method proposed by Lawrence et al. (1991) to determine minimum water cover depth, but couples his approach with a critical bed velocity computation derived from the work of Komar and Miller (1975a,b). Since the modification adopted by MEND (1998) is less conservative than the original Lawrence et al. (1991) method, SRK have selected to use both methods in calculating a safe water cover thickness for Tail Lake. Both of these methods provide a way of calculating the minimum water cover depth at which no tailings re-suspension will occur, i.e. if the minimum water cover depth requirement is satisfied, then there will be no re-suspension of tailings. Mian and Yanful (2001) and Bennet and Yanful (2001) has been documenting their research on water covers, and suggest that the procedures for water cover design, such as those proposed by Lawrence et al. (1991) and MEND (1998) are perhaps too conservative, and that water cover design should be based on an allowable re-suspension value, i.e. the water cover can be designed to allow some re-suspension provided that that amount of re-suspension would not result in exceedence of water quality criteria. This research has culminated in the development of a proposed new design methodology for selecting an optimum water cover depth (Samad and Yanful 2005). This method calculates the bed erosion for any specific water cover depth, using a similar wave theory approach as Lawrence et al. (1991), but refines it to account for shallow water waves and counter current flow. Furthermore, Samad and Yanful (2005) suggest that the tailings impoundment should be divided into a grid, and a minimum water cover depth requirement at each grid point should be calculated. This refinement accounts for changes in fetch distance and bathymetry at each grid point, and generally results in a reduced minimum water cover depth requirement. The grid method proposed by Samad and Yanful (2005) is less conservative than the methods described by MEND (1998) and Lawrence et al. (1991) and was therefore not applied to Tail Lake.



SRK Consulting

Page 3 of 10

3

Minimum Water Cover Design

3.1

Primary Design Assumptions and Input Data The primary design variables required for the water cover design using the MEND (1998) and Lawrence et al. (1991) methods are summarized in Table 1. Table 1. Values of water cover design variables Parameter

3.2

Possible Range

Fetch Distance [F]

Baseline Design Value 1,350 m

Wind Speed [U, Uw]

11.1 m/s

6.1 to 22.2 m/s

Threshold Velocity [Ut] Wave Height Ratio [R]

0.04 m/s 1

0.005 to 0.1 m/sec Constant

Median Particle Size [D50] Sediment Density

0.06 mm 1,230 kg/m3

0.0001 to 0.08 mm Constant

500 to 3,500

Source

Topographical maps of Tail Lake Cambridge Bay hourly wind speed data Lawrence et al. (1991) Lawrence et al. (1991) & MEND (1998) SRK 2005 SRK 2005

Results Results of the water cover design calculations are presented in Figures 1, 2, 3 and 4. Each of these figures show the minimum water cover as calculated using both the conservative Lawrence et al. (1991) and the less conservative MEND (1998) methods. Figure 1 demonstrates the sensitivity of the calculation to fetch distance. As the fetch distance increases, the minimum water cover depth increases, with the MEND (1998) method suggesting that the water cover should be between 0.4 and 1.6 m over the likely range of fetch distances applicable at Tail Lake. Similarly, according the Lawrence et al. (1991) method, the range in water cover should be between 0.8 and 3.3 m. The effect of wind speed on the water cover is illustrated in Figure 2. With increasing wind speed, the minimum water cover increases. According to the MEND (1998) method, the water cover should be between 0.5 and 1.7 m, whilst the equivalent water cover according to the Lawrence et al. (1991) method, should be between 1.0 and 3.0 m. The MEND (1998) method uses the median particle size as a variable to account for bed shear stress, whilst the Lawrence et al. (1991) method uses the particle threshold velocity to account for bed shear stress. Figures 3 and 4 present the effect that different values of these properties have on the minimum water cover. As can be seen in Figure 3, as the median particle size increase, the required water cover decreases. For the range of likely particle sizes in the Doris North Project this will result in a range in water cover between 0.8 and 2.0 m. Similarly, as the threshold velocity increases, the water cover reduces for a likely range of 1.2 to 2.8 m of water cover, as illustrated in Figure 4. For the chosen design parameters as listed in Table 1, the minimum water cover, depending on the calculation method used, ranges between 0.8 and 1.7 m. Using the values in the range of design parameters for each variable that would result in the most significant water cover, i.e. the maximum fetch distance, the maximum wind speed, the smallest median particle size and the lowest threshold velocity, results in a minimum water cover requirement of between 2.2 and 3.6 m, depending on which method is used. This is however a worst case scenario, included to demonstrate sensitivity of the calculation methods.



SRK Consulting

Page 4 of 10

4.0 (U = 11.1 m/sec, D50 = 0.06 mm) 3.5 MEND (1998)

Lawrence et al. (1991)

Min. water cover (m)

3.0 2.5 Design Value 1.350 km 2.0 1.5 1.0 0.5 0.0 0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Fetch (km)

Figure 1. Water cover versus fetch distance 4.0 (F = 1.35 km, D50 = 0.06 mm or Ut = 0.04 m/sec) 3.5 MEND (1998)

Lawrence et al. (1991)


3.0 2.5 Design Value 11.1 m/s 2.0 1.5 1.0 0.5 0.0 0

5

10

15

Wind velocity (m/sec)

Figure 3. Water cover versus wind velocity



20

25

SRK Consulting

Page 5 of 10

4.0 (F = 1.35 km, U = 11.11 m/sec) 3.5


3.0 MEND (1998) 2.5 Design Value 0.06 mm 2.0 1.5 1.0 0.5 0.0 0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

Median particle size (mm)

Figure 3. Water cover versus median particle size 4.0 (F = 1.35 km, U = 11.1 m/sec) 3.5 Lawrence et al. (1991) Min. water cover (m)

3.0 2.5 Design Value 0.04 m/sec 2.0 1.5 1.0 0.5 0.0 0

0.01

0.02

0.03

0.04

0.05

0.06

Threshold velocity (m/sec)

Figure 4. Water cover versus threshold velocity



0.07

0.08

0.09

0.1

SRK Consulting

3.3

Page 6 of 10

Validity of Lawrence et al. (1991) and MEND (1998) Results The water covers determined using the Lawrence et al. (1991) and MEND (1998) procedures assumes that wave development is consistent with deep water wave theory. Deep water wave theory applies when the ratio of water depth over wavelength is less than 0.5, which is a condition which is typically not met for shallow water covers (typically less than 5 m deep). Under such circumstances, shallow water wave theory must be applied, which results in calculating smaller significant wave heights and shorter significant wave periods. Both the Lawrence et al. (1991) and MEND (1998) design procedures suggest that the water cover design does not apply if the deep water wave condition cannot be met; however, they do not propose a solution to overcome this problem. Samad and Yanful (2005) does provide a procedure to calculate the significant wave height and period using shallow wave theory, and SRK conducted a sensitivity analysis on the range of input parameters evaluated for Tail Lake to determine how much the significant wave height and significant wave period would vary if the appropriate wave theory was applied. The results of this sensitivity analysis are presented in Figures 5 and 6. SRK then substituted the appropriate shallow water wave theory significant wave height and wave period values into the Lawrence et al. (1991) and MEND (1998) design procedures and concluded that there was an overall variance in the design water cover of 4%, which only applied to shallow covers of less than 1 m thick. Therefore, SRK is satisfied that the design water covers are appropriate. To summarize, the minimum water covers, based on wave action for the Doris North Project will be between 0.83 and 1.7 m, depending on which calculation method is used (this assumes a correction for the shallow wave theory). However, since the MEND (1998) method is considered the current state-of-the art method in calculating minimum water covers, the overall recommended minimum water cover due to wave action is 0.83 m.

Significant wave period (sec)

2.5

2.0

1.5

1.0

0.5

0.0 0

1

2

3

4

5

6

Water Depth (m) Deep Water Wave - MIN Deep Water Wave - MAX

Shallow Water Wave - MIN Shallow Water Wave - MAX

Figure 5. Variation of the significant wave period over different water covers using both shallow and deep water wave theory Authors Initials/typist initials


SRK Consulting

Page 7 of 10

0.40

Significant wave height (m)

0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0

1

2

3

4

5

6

Water depth (m) Deep Water Wave - MIN Deep Water Wave - MAX

Shallow Water Wave - MIN Shallow Water Wave - MAX

Figure 6. Variation of the significant wave height over different water covers using both shallow and deep water wave theory 3.4

Ice Entrainment The MEND (1998) guideline recommends that the minimum water cover should be at least 10% greater than the maximum lake ice thickness that the pond might incur. A detailed study of lake ice thickness has not been conducted at Tail Lake; however, select ice thickness measurements during water sample and drilling programs suggest that the maximum lake ice thickness varies between 1.9 m and 2.2 m. Regional studies on lake ice thickness confirm that a reasonable maximum ice thickness at Tail Lake is probably around 2.2 m. Therefore, the minimum water cover to prevent tailings re-suspension through ice entrainment is 2.2 m + 10% = 2.42 m. This value is greater than the selected design criteria for minimum water cover due to wave action, and therefore the specified minimum water cover for Tail Lake will be dominated by ice the ice entrainment value of 2.42 m. Furthermore, since the operating water cover would be 4.0 m, there is a significant factor of safety against ice entrainment. Conversely, the tailings surface could be up to 1.58 m above the design elevation of 24.3 m before ice entrainment would start to contribute towards tailings re-suspension. Providing a 1.0 m allowance for an uneven final tailings deposition surface, would result in the minimum water cover depth being reduced to 3.0 m, which in turn implies that the factor of safety against ice entrainment reduces slightly, but still remain significant. Figure 7 presents a schematic of Tail Lake, including the deposition zones of tailings, confirming that at any given time, assuming level tailings surface, the minimum water cover depth of Tail Lake would be 4.0 m.



SRK Consulting

Page 8 of 10

FSL 33.5 m

Tail Lake 28.3 m

Tailings 24.3 m Minimum Water Cover 4.0 m

Figure 7. Schematic of tailings deposition location in Tail Lake

3.5

Extreme Drought Conditions The design guideline by MEND (1998) states that the water cover should be designed taking into account standard water balance principles; however, it does not provide any procedure for taking into account drought conditions. Yanful (2005) documents a detailed procedure to account for drought conditions in the evaluation of a minimum water cover design. Due to the substantial factor of safety available for the minimum water cover at Tail Lake, SRK opted to consider the effect of a severe drought on the water cover using a simplified procedure. The basic assumptions of this analysis can be summarized as follows: • • • •

Tail Lake elevation at start of drought = 28.3 m (i.e. the post closure scenario) 5-year long drought Zero precipitation for entire duration (no rain or snow) 20% above average lake evaporation (i.e. 220 mm + 20% = 264 mm)

Applying these conditions, would result in a final lake water elevation in Tail Lake after the drought of 27.0 m. At this time, the minimum water cover depth over the tailings (at elevation 24.3 m) would be 2.7 m. Furthermore, it should be noted that the total volume of water lost during this simulated drought is just under 1.0 million m3, or 48% of the total volume of free water in Tail Lake (i.e. the volume excluding tailings). Under average climatic conditions it would take two years before the water level will reach the natural outflow elevation of 28.3 m, providing ample time for settlement, should any particles be re-suspended in any way. This evaluation of a drought is extremely conservative, but still the minimum design water cover criteria are upheld, for wave action and ice entrainment. As before, providing a 1.0 m allowance for an uneven final tailings deposition surface would result in the minimum water cover depth during an Authors Initials/typist initials


SRK Consulting

Page 9 of 10

extreme drought being reduced to 1.7 m. Under such a scenario, the minimum water cover requirement against wave action would still be upheld; however, ice entrainment can occur. This is however not a significant concern, since as described above under such severe drought conditions, Tail Lake water cannot flow out of the basin, since the natural outflow elevation is at 28.3 m. Considering the fact that it would take two years before outflow would start again ice entrainment during drought conditions is not considered a concern. 3.6

Minimum Water Depth Requirement for Bed Stability Table 2 summarizes the minimum water cover requirements to ensure bed stability as described in the preceding sections. It is clear that the dominating process in determining the water cover is ice entrainment. Therefore, the minimum water cover for Tail Lake should be 2.42 m. This implies that the tailings surface can have undulations up to 1.58 m high, allowing a substantial safety margin. Furthermore, as demonstrated in the preceding sections, using the most conservative calculation method, and the worst case input variables, the maximum water cover would have to be 3.6 m, which still leaves a safety margin of 0.4 m. There is therefore no doubt that the 4.0 m water cover is sufficient to prevent tailings re-suspension in Tail Lake. Table 2. Summary of minimum water cover requirements for Tail Lake Condition Planned final tailings surface Final water level in Tail Lake Planned water cover thickness Possible loss in water cover thickness due to uneven tailings deposition Possible loss in water cover thickness due to drought conditions Possible loss in water cover thickness due to uneven tailings deposition and drought conditions simultaneously Minimum water cover due to wave action (deep water wave theory) Minimum water cover due to wave action (shallow water wave theory) Minimum water cover due to ice plucking

4

Design Value 24.3 m 28.3 m 4.0 m 1.0 m (remaining water cover = 3.0 m) 1.3 m (remaining water cover = 2.7 m) 2.3 m (remaining water cover = 1.7 m) 0.80 m 0.83 m 2.42 m

References Bennett, C.V., and Yanful, E.K. 2001. Investigation of tailings re-suspension under a shallow water cover. In: Proceedings Canadian Geotechnical Society. 2001 an Earth Odyssey. Calgary AB. pp. 1596-1603. Milan, M.H., and Yanful, E.K. 2001. Wind induced wave sand re-suspension in two mine tailings ponds. In: Proceedings Canadian Geotechnical Society. 2001 an Earth Odyssey. Calgary AB. pp. 1604-1611. Lawrence, G.A., Ward, P.R.B., MacKinnon, M.D. 1991. Wind-wave-induced suspension of mine tailings in disposal ponds – a case study. Canadian Journal of Civil Engineering. 18. pp. 1047-1053. MEND 1998. Design guide for the subaqueous disposal of reactive tailings in constructed impoundments. Project 2.11.9. Samad, M.A., and Yanful, E.K. 2005. A design approach for selecting the optimum water cover depth for subaqueous disposal of sulfide mine tailings. Canadian Geotechnical Journal. 42: pp. 207228.



SRK Consulting

Page 10 of 10

SRK Consulting (Canada) Inc. 2005. Preliminary Tailings Dam Design, Doris North Project, Hope Bay, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October. Yanful, E.K. 2005. Short Course Notes: Design and management of water covers for mitigating acid generation from reactive sulphide mine wastes. Securing the future. International Conference on Mining and the Environment, Metals, and Energy Recovery. 27 June – 1 July 2005, Skelleftea, Sweden.



Appendix C SRK Technical Memorandum Re: Doris North Project Tailings Properties


Tel: 604.681.4196 Fax: 604.687.5532


Brian Labadie

Date:

July 15, 2005

cc:

Project File

From:

Maritz Rykaart

Subject:

Doris North Project Tailings Properties

Project #:

1CM014.006

The tailings physical characteristics are documented in the following two reports; SRK Consulting (Canada) Inc. (2003). Tailings Impoundment Preliminary Design, Doris North Project, Nunavut, Canada – Volume I, Report. Technical Report prepared for Miramar Hope Bay Limited. Project No. 1CM014.01, October 2003. SRK Consulting (Canada) Inc. (2003). Tailings Impoundment Preliminary Design, Doris North Project, Nunavut, Canada – Volume II, Appendixes. Technical Report prepared for Miramar Hope Bay Limited. Project No. 1CM014.01, October 2003. This technical memorandum contains an extract of the relevant sections of the above two reports relating to tailings properties. Please note that we have retained the original report numbering of the source report. 6.3

Tailings Properties A sample of total combined mill tailings from a pilot metallurgical tests conducted by Bateman Engineering was sent to AMEC Earth Engineering Pty Limited in Perth Australia (AMEC 2003). Representative samples of the tailings were extracted for determination of the tests listed in Table 6.1. The Australian Standards listed in Table 6.1 all have similar or equivalent ASTM procedures. The complete laboratory data sheets for all these tests are presented in Appendixes 6A through 6F. Table 6.1: Laboratory Tests Conducted on Final Combined Mill Tailings Test

EMR

Test Method (Australian Standards)

Number of Tests

Grain Size Distribution

Sieve and Hydrometer (AS 1289.3.6.2)

1

Plastic Properties

Casagrande Method (AS 1289.3.1.1,.3.2.1,.3.3.1,.3.4.1,.2.1.1)

1

Particle Density

AS 1289.3.5.1

1

Triaxial Test

Consolidated Undrained Triaxial Test with Pore Pressure Measurement (AS 1289.6.4.2)

1

Consolidation Test

One-Dimensional Consolidation (AS 1289.6.6.1)

1

Undrained Settling Test

SRC-WI-4.8.3

1

Drained Settling Test

SRC-WI-4.8.2

1

App 6 - Tailings Properties Extracted.doc, 3:04 PM, Oct. 11, 05

SRK Consulting

6.3.1

Page 2 of 4

Index Properties The total tailings are composed of sandy fine to coarse silt with 56% passing the No. 200 sieve (75 micron). The percent by weight of clay sized particles (less than 2 microns) in the tailings sample was approximately 11%. The tailings were found to be non-plastic and the measured tailings particle density was 2.74 g/cm3.

6.3.2

Deposited Tailings Densities The deposited tailings density is dependent on both the specific gravity of the particles and the void ratio of the resulting deposited material. Representative tailings densities deposited by different methods are given in Table 6.2. Void ratios for each method are conservatively estimated from SRK’s experience at other mines. The measured dry density for the Doris North Project is summarized in Table 6.3. Table 6.2: Typical In-Place Dry Densities for Tailings Deposition Method

Void Ratio e

Dry Density (tonnes/m3)

Tailings hydraulically deposited above water

1.0

1.50

Tailings hydraulically deposited underwater

1.2

1.36

Table 6.3: Measured Void Ratio & Dry-Density for the Doris North Project Tailings Void Ratio e


Triaxial Test

0.839

1.49

Consolidation Test - Initial

0.839

1.49

Consolidation Test – Final

0.797

1.54

Undrained Settling Test @ 33.8% solids

-

1.19

Drained Settling Test @ 33.8% solids

-

1.43

Data Source

The most realistic design value to use for the subaqueous tailings deposition in Tail Lake is 1.19 tonnes/m3, based on the measured properties. For the preliminary design presented in this report, we have assumed a tailings solids specific gravity of 2.7 and an in-place void ratio of 1.2, which results in an in-situ dry density of 1.23 tonnes/m3. 6.3.3

Permeability and Strength Parameters The permeability of the total tailings was measured in the laboratory by using one triaxial and one consolidation test. The results of these tests are summarized in Tables 6.4 and 6.5 respectively. Table 6.4: Summary of Triaxial Compression Test Data Stage Confining Stress, σ3 (kPa)

Coefficient of Consolidation, Cv (m2/year)

Coeff. of Volume Compressibility, Mv, (m2/kN)

Hydraulic Conductivity, K (cm/sec)

Cohesion, c (kPa)

1 (250 kPa)

113,890

0.153

5.4 x 10-5

0.825

0.108

1.1 x 10

-5

0.010

2.2 x 10

-6

0.007

2 (300 kPa) 3 (400 kPa)

EMR

3,388 1,822

0.040


SRK Consulting

Page 3 of 4

Table 6.5: Summary of One-Dimensional Consolidation Properties of Tailings Pressure (kPa)

Void Ratio e

Coefficient of Consolidation, Cv (m2/year)

Coeff. of Volume Compressibility, Mv, (m2/kN)

Hydraulic Conductivity, K (cm/sec)

0

0.839

-

-

-5

1.69 x 10-9

20

0.836

0.648

8.170 x 10

40

0.830

0.529

8.183 x 10-5

1.37 x 10-9

100

0.833

0.488

2.732 x 10-5

0.42 x 10-9

200

0.824

0.455

3.289 x 10-5

0.47 x 10-9

300

0.811

0.439

7.178 x 10-5

9.98 x 10-10

400

0.797

0.441

7.791 x 10-5

1.11 x 10-10

200

0.798

-

-

-

40

0.803

-

-

-

Following the measurement of the hydraulic conductivity at 400 kPa confining stress, the tailings sample in the triaxial cell was axially loaded to failure under undrained conditions to measure the frictional strength. The results of this test are summarized in Table 6.6. A value of 43.2° was obtained for the angle of internal friction, which is considered high for tailings. This value may have to be confirmed with further testing if it is required for the final design. Table 6.6: Summary of Shear Strength Properties for Tailings Parameter

Stage 1

Stage 2

Stage 3

Confining Stress, σ3 (kPa)

250

300

400

Porewater Pressure, U (kPa)

222

137

134

Effective Confining Stress, (σ3 – U) (kPa)

28

163

266

Deviator Stress, (σ1 - σ3) (kPa)

128

706

1,163

Shear Stress (σ1 - σ3)/2 (kPa)

64

353

582

Internal Friction, Ф (degrees)

43.2

Cohesion, c (kPa)

6.3.4

1

Tailings Settling Properties The tailings settling tests results are summarized in Table 6.7. These results confirm that due to the coarse nature of the tailings they settle out quickly and the recovery of clarified water should, therefore, be relatively simple. The bench scale tests suggest that under undrained conditions, similar to subaqueous deposition in Tail Lake, the maximum settling time is in the order of 2 hours.

EMR


SRK Consulting

Page 4 of 4

Table 6.7: Tailings Settlement Time Test

Supernatant Suspension (%)


Elapsed Time (minutes)

Undrained

74.44

1.112 (1.190 maximum)

120

Drained

84.16

1.412 (1.430 maximum)

The Appendixes referred to in the text above are appended.

EMR


(2,880 minutes to reach maximum dry density) 75 (150 minutes to reach maximum dry density)

Appendix D Summer 2004 Geotechnical Field Investigation

Summer 2004 Geotechnical Field Investigation at Tail Lake, Doris North Project, Nunavut, Canada Miramar Hope Bay Limited Suite 300, 889 Harbourside Drive North Vancouver, B.C. V7P 3S1

SRK Consulting (Canada) Inc. Suite 800, 1066 West Hastings Street Vancouver, B.C. V6E 3X2 Tel: 604.681.4196 Fax: 604.687.5532 Email: [email protected] Web site: www.srk.com

SRK Project Number 1CM014.04-050

April 2005

Authors Michel Noël, M.A.Sc., P.Eng. Quinn Jordan-Knox, M.Sc., G.I.T.

Reviewed by Maritz Rykaart, Ph.D., P.Eng.

SRK Consulting (Canada) Inc. Summer 2004 Geotechnical Field Investigation at Tail Lake

Page i

Table of Contents 1 Introduction .................................................................................................................. 1 1.1 General ............................................................................................................................... 1 1.2 Background ......................................................................................................................... 2 1.3 Methods .............................................................................................................................. 2

2 Field Program............................................................................................................... 4 2.1 Introduction ......................................................................................................................... 4 2.2 Drilling ................................................................................................................................. 4 2.2.1 2.2.2

2.3 2.4 2.5 2.6 2.7

Drill Holes ................................................................................................................................4 Drill Method .............................................................................................................................4

Thermistor String Installations............................................................................................. 5 Thermistor Data .................................................................................................................. 5 Sample Collection and Laboratory Testing ......................................................................... 5 Bulk Sampling ..................................................................................................................... 6 Topographic Cross-Section Surveys................................................................................... 6

3 Results of Drilling Program......................................................................................... 8 3.1 Summary of Drill Hole Profiles ............................................................................................ 8 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5

SRK-50 ....................................................................................................................................8 SRK-61 ....................................................................................................................................8 SRK-54 ....................................................................................................................................8 SRK-55 ....................................................................................................................................9 SRK-56 ....................................................................................................................................9

3.2 Field Bulk Density Testing................................................................................................... 9 3.3 Laboratory Testing ............................................................................................................ 10 3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6 3.3.7 3.3.8

Water Content and Atterberg Limits......................................................................................10 Particle Size Distribution .......................................................................................................11 Bulk Density...........................................................................................................................12 Specific Gravity .....................................................................................................................12 Pore Water Salinity................................................................................................................12 Thermal Conductivity.............................................................................................................13 Unfrozen Water Content........................................................................................................13 X-Ray Diffraction Analysis.....................................................................................................16

4 References.................................................................................................................. 18

MN//qjk/spk

TailLake2004Drilling.Report.1CM014.04.20050503.doc, May. 3, 05, 10:25 AM

April 2005


Page ii

List of Tables Table 1: Details of Completed Drill Holes Table 2: Details of Thermistor String Installations Table 3: Samples Collected and Laboratory Testing Program Table 4: Field Bulk Density from Intact Cored Soil Samples Table 5: Water Contents, Atterberg Limits and Intact Bulk Densities Table 6: Salinity of Pore Water Table 7: Bulk Sample Thermal Conductivity Test Results

List of Figures Figure 1: Drill hole and Topographic Survey Locations Figure 2: Drill hole Location North Dam Figure 3: Tail Lake Shore Investigation Site 1 Figure 4: Tail Lake Shore Investigation Site 2 Figure 5: Tail Lake Shore Investigation Site 3 Figure 6: Tail Lake Shore Investigation Site 4 Figure 7: Plasticity Chart from Atterberg Testing Figure 8: Unfrozen Volumetric Water Fraction vs. Temperature

List of Appendices Appendix 1: Drill Hole Logs Appendix 2: Ground Temperature Measurements Appendix 2-A: Thermistor Calibration Data Sheets Appendix 2-B: Thermistor Data (Graphical) Appendix 2-C: Thermistor Data (Tabular) Appendix 3: Topographic Survey Data Appendix 4: Laboratory Testing Appendix 4-A: Gravimetric Moisture Content Appendix 4-B: Atterberg Limits Appendix 4-C: Particle Size Distribution Appendix 4-D: Specific Gravity & Bulk Density Appendix 4-E: Pore Water Salinity Appendix 4-F: Thermal Conductivity Appendix 4-G: Unfrozen Water Content Appendix 4-H: X-Ray Diffraction Analysis

MN//qjk/spk


April 2005


1

Introduction

1.1

General

Page 1

Miramar Hope Bay Limited (MHBL) is currently preparing a revised Environmental Impact Statement Report (EIS) in support of the Hope Bay Doris North Project (from here on referred to as the Doris North Project), located near Roberts Bay in Nunavut Territory, Canada. SRK Consulting (Canada) Inc. (SRK) has been working with MHBL since October 2001, on various aspects of this project including a Preliminary Assessment in February 2002 (SRK 2002a), a Feasibility Study in February 2003 (SRK 2003a), and a number of engineering documents in support of preliminary infrastructure designs for the project (SRK 2002b; SRK 2002c; SRK 2003c), the tailings water management strategies (SRK 2003d) and preliminary tailings dam design (SRK 2003b). As part of the ongoing process of obtaining background field data upon which the engineering designs can be based, MHBL contracted SRK to undertake a field program during August and September 2004. The primary objectives of this field program can be summarized as follows: •

Installation of one deep (200 m) thermistor string to monitor the geothermal gradient at the Doris North site.

•

Characterize foundation conditions at the proposed spillway location of the North Dam at Tail Lake.

•

Characterize permafrost conditions along the perimeter of Tail Lake, and install shallow thermistors.

•

Conduct detailed strip surveys along sections of the Tail Lake shoreline, for the purpose of providing a pre-flooding benchmark.

•

Recover bulk samples from the North Dam alignment for laboratory determination of bulk density.

•

Monitoring and maintenance of all historic thermistor installations at the Doris North site.

This report presents the results of the field work as described. This report is complete with all the relevant drill logs, laboratory data sheets and thermistor calibration data sheets. The data in this report should be read in conjunction with the documented field data presented in SRK (2003b) and SRK (2003c).

MN/qjk/spk


April 2005


1.2

Page 2

Background The proposed Doris North Project will be a small conventional underground gold mine. Ore will be transported to surface via an access ramp, before being processed on site to produce gold bars. Tailings produced during the milling process will be sub-aqueously deposited into Tail Lake, which will be impounded through the construction of two frozen core dams; the North Dam and the South Dam. The locations of these dams are illustrated on Figure 1. To date there has been a series of field investigations to characterize foundation conditions for the dams and other site infrastructure (SRK 2003b; 2003c). A recent regulatory review of the project, has suggested that there are some gaps in the background geotechnical information that would have to be addressed if MHBL would like to adequately asses the project impacts. These data gaps were specifically linked to: •

Providing site specific evidence of the geothermal gradient, as opposed to solely relying on data from the Boston site which is 60 km to the south.

•

Characterizing the foundation conditions at the proposed spillway location for the North Dam.

•

Characterizing the permafrost conditions around Tail Lake, such that more informed statements can be made as to the amount of thaw induced sediment release that may be triggered as the water level in Tail Lake rises.

•

Determining site specific bulk density for the ice rich marine sediments, to better define the dam foundation conditions.

MHBL subsequently contracted SRK to initiate a field program to address these background data gaps, the results of which are documented in this report.

1.3

Methods This field program involved a great number companies and individuals, as detailed below:

MN/qjk/spk

•

Drilling was conducted by Major Drilling Group International Inc. (Yellowknife), under a standing contract managed by MHBL.

•

Field drill supervision for the deep drill hole was by MHBL geologist, Stacey Lopston. All other holes were logged by SRK Staff Engineers Dylan MacGregor, Mauro Prado and Quinn Jordan-Knox.

•

Field bulk sample collection at the North Dam site was by MHBL staff.


April 2005


Page 3

•

All laboratory testing was conducted by EBA Engineering, out of their Yellowknife, Edmonton and Calgary offices.

•

Thermistors and PVC tubing was supplied by RST Instruments, and installed by SRK Staff Engineers.

•

Detailed strip surveys, and drill hole collar surveys was conducted by MHBL surveyor Jay Hallmann.

•

Thermistor maintenance and data recording was conducted by SRK Staff Engineers.

All of the individual tasks described above were completed with the support and supervision of a Senior Geotechnical Engineer, Michel Noel, M.A.Sc., P.Eng., with overall project management and review completed by SRK Project Manager, Maritz Rykaart, Ph.D., P.Eng.

MN/qjk/spk


April 2005


2

Field Program

2.1

Introduction

Page 4

The details of the field program are listed in the following sections. The program consisted of five drill holes, sample recovery (core and bulk), instrument (thermistors) installation, ground temperature measurements and detailed topographic cross-section surveys.

2.2

Drilling

2.2.1 Drill Holes Five drill holes, as listed in Table 1 were completed between August 19 and September 27, 2004. The prolonged timeframe of this program was as a result of mechanical drill equipment failure, and does not reflect the actual time for completion of the holes. The drill hole locations are shown on Figure 1, and the complete logs are included as Appendix 1. SRK-50 was logged by MHBL geologist Stacey Lopston. SRK-54, SRK-55 and SRK-56 were logged by SRK Staff Engineer Quinn Jordan-Knox and SRK Staff Engineers Dylan MacGregor and Mauro Prado logged SRK-61.

Table 1: Details of Completed Drill Holes Location

Hole No.

Collar Elevation1 (m)

Nothing2

Easting2

Depth (m)

North-west shore of Doris Lake

SRK-50

38.00

7,559,177

433,807

205

South-east shore of Tail Lake

SRK-54

28.56

7,556,467

435,632

12.2

North-west shore of Tail Lake

SRK-55

30.68

7,558,400

434,638

9.5

North-east shore of Tail Lake

SRK-56

28.75

7,558,258

435,334

6.7

North Dam spillway

SRK-61

33.50

7,559,231

434,384

6.4

1. 2.

Collar elevation refers to ground elevation at drill hole location. Northing and easting are based on the UTM NAD 83, Zone 13 co-ordinate system.

2.2.2 Drill Method Drilling was conducted with a JT2000 diamond core drill rig, equipped with a NQ size (47.6 mm core, 76 mm hole diameter) triple tube wire line core barrel. Lake water from Doris or Tail Lake was used as drilling fluid, without addition of polymeric mud or salt (brine). Although the plan was to drill using chilled brine, the chiller was not functional, and no attempt was made to cool the drilling fluid by any other means. Since the drilling fluid was not chilled, the adopted drilling method attempted to minimise core loss by slowing down the drilling, minimizing the use of water and conducting short core recovery runs, in particular with coarser grained materials. The recovery within the fine grained material was MN/qjk/spk


April 2005


Page 5

generally good, but less successful with the coarser material. Selected recovered soil samples were later shipped to the laboratories of EBA Engineering in Yellowknife, Edmonton and Calgary for geotechnical and thermal property characterisation testing. The recovered rock core samples were transported to the on-site geology laboratory for further logging by MHBL personnel and remained on-site. The overburden in SRK-50 was not sampled.

2.3

Thermistor String Installations Table 2 list the details of the instrument (thermistors string) installations. Appendix 2-A contains the supplier calibration data sheets and wiring diagram for each of these thermistors strings. The strings was installed inside a 1-inch diameter PVC tube, which was pushed into the drill hole, though the drill rods prior to pulling out the drill rods. This was done to ensure access to the hole during the period of drill shutdown. Each installation was finished by driving a section of old drill rod into the ground over the PVC and mounting the readout box on the top of the rod.

Table 2: Details of Thermistor String Installations Location

Drill Hole

Cable Serial Number

Stickup Height (m)

Thermistor Bead Installation Depths (m)1

North-west shore of Doris Lake

SRK-50

TS 1618

0.0

5, 10, 20, 30, 50, 70, 90, 110, 130, 150, 170, 190, 200

South-east shore of Tail Lake

SRK-54

TS 1626

1.0

1, 2, 3, 5, 7. 5, 10

North-west shore of Tail Lake

SRK-55

TS 1624

1.2

0.8, 1.8, 2.8, 4.8, 7.3, 9.8

North-east shore of Tail Lake

SRK-56

TS 1621

5.2

0, 0, 0, 0.8, 3.3, 5.8

1. A bead depth of 0 m indicates a bead that is above natural ground.

2.4

Thermistor Data SRK Staff Engineers visited all 31 thermistors that have been installed at the Doris North Site since 2002, to collect data, as well as to conduct maintenance and repair as needed. A complete compilation of all data is included as Appendix 2-B in graphical format, and as Appendix 2-C in tabular format. Only one string, SRK-13, has been permanently damaged and has not been collecting data since August 2003.

2.5

Sample Collection and Laboratory Testing Representative disturbed overburden core samples were collected from each material type encountered in SRK-54, SRK-55 and SRK-56. A list of the samples collected is included in Table 3. These samples were shipped to the geotechnical and thermal testing laboratories of EBA Engineering in Yellowknife, Edmonton or Calgary. The samples were not preserved other than being sealed in

MN/qjk/spk

TailLake2004Drilling.Report.1CM014.04.20050503.doc, May. 3, 05, 1:33 PM

April 2005


Page 6

plastic bags to retain any water and ice within the sample. The complete list of laboratory tests that was carried out on each of these samples is included in Table 3.

2.6

Bulk Sampling Two bulk soil samples were collected in the vicinity of the North Dam (Figure 2). The bulk samples were collected immediately below the surficial thin organic cover. One sample consisted of sand with some gravel and the other sample was predominantly composed of silt with sand and clay, with a small fraction of gravel. Both samples contained some visible organic matter. These bulk samples were collected by MHBL staff and subsequently preserved and shipped to the laboratory of EBA Engineering in Edmonton for thermal characterisation testing.

2.7

Topographic Cross-Section Surveys Detailed topographic cross-sections were surveyed on four sections along the shoreline of Tail Lake by MHBL staff. Three of those four sections were drilled and instrumented for ground temperature measurements, which consisted of drill hole SRK-54, SRK-55 and SRK-56. This detailed topographic survey provides a reference in time of the geometry of the shore embankment and will provide valuable information in assessing potential deformation of the slope as the level of Tail Lake is raised and lowered. Figure 1 shows the location of the four topographic cross-sections around Tail Lake and Figures 3 to 6 show in more detail the location of the survey points as well as longitudinal and transversal cross-sections. The cross-sections show both the section based on the topographic map and the survey points. The survey data points are all tabulated in Appendix 3.

MN/qjk/spk


April 2005


Page 7

Table 3: Samples Collected and Laboratory Testing Program Drill Hole

Sample No.

Sample Depth

Moisture Content2

Liquid Limit

Plastic Limit

Plasticity Index

Specific Gravity

Intact Bulk Density

Intact Bulk Dry Density

Particle Size Distribution

Salinity2

X

X

X

X

X

X

X

X

X

(m)

SRK-54

SRK-55

SRK-56

S-1

0.46 - 0.61

X

X

X

X

S-2

2.79 - 2.95

X

X

X

X

X

X

X

S-3

3.18 - 3.34

X

S-4

4.12 - 4.32

X

S-5

5.33 - 5.49

X

S-6

6.10 - 6.17

X

S-7

8.26 - 8.41

X

S-8

9.40 - 9.55

X

S-9

10.11-10.26

X

X

X

X

0.10 - 0.20

X

X

X

X

X

X

X

X

S-3

5.95 - 6.10

X

S-1

0.14 - 0.20

X

X

X

X

S-2

0.30 - 0.40

X

X

X

X

S-3

0.50 - 0.60

X

X

X

X

0 – 0.3

X

X

X

X

X X

0.35 - 0.45

No. 2 Bulk Sample Clayey 1 Silt

X-Ray Diffraction3

X

S-2

0 – 0.3

Unfrozen Water Content

X

S-1

No. 1 Bulk Sample 1 Sand

Thermal Conductivity

X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X

X

X

X

X

X

X - Test conducted on sample at EBA Yellowknife, unless otherwise noted. 1. Samples tested at EBA Edmonton. 2. Testing conducted in EBA Edmonton. 3. Testing conducted in EBA Calgary.

MN/qjk/spk


April 2005


3

Results of Drilling Program

3.1

Summary of Drill Hole Profiles

Page 8

3.1.1 SRK-50 Drill hole SRK-50 was drilled in the vicinity of the proposed mine site and adjacent to Doris Lake for deep ground temperature monitoring, as shown in Figure 1. Drill hole SRK-50 is a vertical drill hole that extends to a depth of 205 m and was drilled between August 19 and 21, 2004. A thermistor string with 13 temperature measuring points was put down this drill hole, with the bottom thermistor located at a depth of 200 m. The drilling supervision and logging of this drill hole was performed by MHBL personnel. Overburden (not characterized and sampled) was encountered to a depth of 3.14 m and the bedrock consisted primarily of fine to medium grained basalt with intermittent thin dyke layers. Upon completion of the drill hole, the fluid inside the drill hole cavity was amended with CaCl2 salt to raise the salt content to 25% by weight as a preventive measure to prevent freezing of the drill rods inside the drill hole, while waiting for the installation of the thermistor string. The thermistor string was installed inside a 1 inch PVC rigid threaded pipe. Once the thermistor string was installed, the fluid inside the drill hole was flushed out with fresh water until the salt content was about 5% by weight. The positions of the individual thermistors are listed in Table 2, and Appendix 2 provides more details on the thermistor installation and also contains the ground temperature measurements recovered at the site.

3.1.2 SRK-61 Drill hole SRK-61 was put down along the proposed alignment of the spillway to determine the depth to bedrock. Its location is shown in Figure 2. This drill hole was terminated at a depth of 6.4 m and was drilled between September 2 and 3, 2004. Overburden was encountered over a thickness of 3.65 m and the bedrock consisted of fine grained basalt. The top 1.2 m of overburden was lost; although the returned drilling fluid indicated that it consisted mostly of a sandy soil intermixed with some organic matters. A clayey silt layer mixed with some sand lenses was encountered between 1.2 and 3.65 m and overlaid the bedrock surface. The horizon between 1.2 and 2.7 m deep contained visible ice up to 25 mm thick and estimated ice content in the order of 50%. The zone between 2.7 and 3.65 m contained less ice, usually 1 mm or less in size, for an estimated ice content of about 5%. No thermistor string was installed in this drill hole.

3.1.3 SRK-54 Drill hole SRK-54 was completed on September 27, 2004 and is located on the east side of Tail Lake, at the south end. Unfrozen soils were present to a depth of 0.3 m, while bedrock was encountered at a depth of 10.7 m. The drill hole was terminated at 12.2 m, 1.5 m into the bedrock. Sample recovery varied from 0 to 100% and averaged 76% over 7 runs. The overburden consisted of a thin organic cover over 0.3 m of silty fine sand. A layer of clayey silt was then encountered

MN/qjk/spk


April 2005


Page 9

between 0.3 and 0.5 m, followed by massive ice interbedded with silt layers down to a depth of 2.74 m. This massive ice layer had an estimated ice content of about 80%. Clayey silt was present between 2.74 and 9.14 m, with visible ice lenses decreasing in size and frequency with depth. A 1.56 m thick sand layer with few ice lenses was encountered overlying the bedrock surface. Bedrock was inferred based on returned rock chips and drilling efforts. A thermistor string with six measurement points was installed down to a depth of 10.0 m. Table 2 provides the positions of the thermistors relative to the surface.

3.1.4 SRK-55 Drill hole SRK-55 was completed on September 26, 2004 and is located on the west side of Tail Lake towards the north end. The overburden is 9.14 m thick, with the top surficial 0.3 m being unfrozen. The drill hole was terminated at a depth of 9.5 m and penetrated bedrock by about 0.35 m. A thin organic silt layer of a few centimetres thickness was present at the surface and overlaid a 3.05 m thick clayey silt layer. A massive ice layer was present within this stratum between 0.55 and 1.3 m. Silty fine to medium sand was encountered below the clayey silt from a depth of 3.05 to 3.94 m and from 4.4 to 9.14 m. Another clayey silt layer was present within that sandy zone between 3.94 and 4.4 m. Recovery was relatively good for most of the drill hole, with the exception of the bottom portion of the sand deposit overlying the bedrock surface. A thermistor string was installed upon completion, with six measuring points distributed over 9.8 m as indicated in Table 2.

3.1.5 SRK-56 Drill hole SRK-56 was drilled on September 27, 2004 and is located on the east side of Tail Lake, opposite to drill hole SRK-55. This drill hole encountered inferred bedrock at a depth of 6.1 m and was terminated at a depth of 6.7 m. The top 1.6 m consists mainly of silt intermixed with a 0.2 m thick layer of massive ice and two zones of sand of 0.1 and 0.15 m thick. Another massive ice layer was encountered between 1.6 and 1.9 m. The very poor recovery between 1.9 and 6.1 m suggests the presence of granular soils as observed from the returned cuttings. Recovery was excellent within the clayey silt but was practically nil over the granular deposit. A thermistor string was installed to a depth of 5.8 m. This shallow depth resulted in having only three thermistors located below the ground surface as listed in Table 2. The drill hole was originally planned as a 10 m deep drill hole, which explains the three thermistor strings positioned on the ground surface.

3.2

Field Bulk Density Testing The bulk density of six intact cored soil samples from drill holes SRK-55 and SRK-56 was measured in the field and the results are listed in Table 4. Samples were wrapped with cellophane for protection then weighed with an electronic scale. Sample volumes were then determined with a graduated cylinder and a 2.4 L can. Cellophane weight and volume were within sample measurement error (1 mg, 10 ml). These measurements show bulk densities varying from 1,190 to 2,380 kg/m3 for the five samples recovered from within the marine deposit and the sample from the glacio-fluvial deposit gave a value of 1,980 kg/m3.

MN/qjk/spk


April 2005


Page 10

Table 4: Field Bulk Density from Intact Cored Soil Samples Drill Hole

Sample No.

Sample Depth

Deposit

(kg/m3)

(m) SRK-55

SRK-56

3.3

Bulk Density

1

0.10 – 0.20

Marine

2,380

2

0.35 – 0.45

Marine

1190

3

5.95 – 6.10

Glacio-fluvial

1,980

1

0.14 – 0.20

Marine

1,960

2

0.30 – 0.40

Marine

1,640

3

0.50 – 0.60

Marine

1,820

Laboratory Testing Laboratory testing was performed on selected samples for characterisation purposes. The following sections summarise the results from the laboratory testing and the individual laboratory report sheets are all included in Appendix 4.

3.3.1 Water Content and Atterberg Limits Gravimetric water content (Appendix 4-A) was measured on 15 samples, of which nine were tested for Atterberg Limits (Appendix 4-B). The Atterberg Limits were also measured on one of the bulk samples that contained fine grained soils. The results are summarised in Table 5 and the Atterberg Limits are plotted in the plasticity chart shown in Figure 7.

MN/qjk/spk


April 2005


Page 11

Table 3: Water Contents, Atterberg Limits and Intact Bulk Densities Drill Hole

Sample No.

Sample Depth (m)

Gravimetric Moisture Content

Liquid Limit

Plastic Limit

Plasticity Index

(%)

(%)

(%)

Specific Gravity

Intact Bulk Density (kg/m3)

(kg/m3)

(%) SRK-54

SRK-55

SRK-56

S-1

0.46 - 0.61

21.9

29

17

12

2.69

2,111

1,731

S-2

2.79 - 2.95

84.1

39

24

15

-

-

-

S-3

3.18 - 3.34

47.4

36

21

15

-

1,744

1,183

S-4

4.12 - 4.32

56.0

-

-

-

-

-

-

S-5

5.33 - 5.49

52.3

40

24

16

2.72

1,706

1,120

S-6

6.10 - 6.17

54.3

-

-

-

-

-

-

S-7

8.26 - 8.41

23.8

-

-

-

-

-

-

S-8

9.40 - 9.55

23.7

-

-

-

-

-

-

S-9

10.11-10.26

16.0

-

-

-

-

-

-

S-1

0.10 - 0.20

27.6

28

20

8

2.60

2,157

1,691

S-2

0.35 - 0.45

76.4

43

37

6

-

-

-

S-3

5.95 - 6.10

29.7

-

-

-

-

-

-

S-1

0.14 - 0.20

53.5

34

21

13

-

-

-

S-2

0.30 - 0.40

63.3

33

21

12

-

1,564

958

0.50 - 0.60

46.4

34

20

14

-

-

-

0.00 – 0.30

-

41

28

13

-

-

-

S-3 No 2 Bulk Sample Silt


The moisture content (gravimetric water content) results varied from 16.0 and 84.1%, while the liquid limit ranged from 28 to 43%, the plastic limit from 17 to 37% and the plasticity index from 6 to 16%. The corresponding averages are 45.1% for water content, 35.7% for the liquid limit, 23.3% for the plastic limit and 12.4% for the plasticity index. The high volumetric water content values are indicative of ice lenses present in the overburden. The plasticity chart shown in Figure 7 indicates that the fine grained soils present in the marine deposit, with the exception of two test results, are above the “A” Line, which usually delimits organic and inorganic soils. The soils with results above the “A” Line would essentially be classified as inorganic clays with low to medium plasticity. Sample S-2 from drill hole SRK-55 contained high amounts of organic material and does not follow the same trend as the other samples on the plasticity chart. The fine grained bulk sample was also below the “A” Line but closer to the other test results. Both of these samples contained organic matters and are classified as organic silts with medium compressibility.

3.3.2 Particle Size Distribution The particle size distribution (Appendix 4-C) was measured on 11 soil samples. Nine of those samples had their fine fraction (smaller than 75 µm) determined by sedimentation process using a

MN/qjk/spk


April 2005


Page 12

hydrometer. The laboratory procedure was performed according to ASTM D422-63(2002) “Standard Test Method for Particle-Size Analysis of Soils”. The fine grained samples, which represented nine samples, were generally composed of clayey silt with some sand. The clay content varied from 12 to 37% with an average of 22.8%; the silt from 48 to 78% with an average of 66.6%; the sand from 3 to 23% with an average of 10%, and gravel was present only in one sample with a 6% gravel content. These results are consistent with the CL and OL classifications obtained with the Atterberg Limits and the plasticity chart. The remaining two samples consisted of sandy soils. One sample was composed of poorly graded sand (84%) with some gravel (14%) and traces of silt (2%). This sample is classified as SP according to the Unified Soil Classification System (USCS). The other sample consisted of 57.5% sand with 42.5% silt and clay, and was classified as SM according to the USCS.

3.3.3 Bulk Density The bulk density (Appendix 4-D) was measured on five intact soil samples and the results are listed in Table 5. The values ranged from 1,564 to 2,157 kg/m3 for an average of 1,856 kg/m3. The corresponding dry bulk density varied from 958 to 1,731 kg/m3 and averaged 1,337 kg/m3. The lower values reflect the presence of pore ice and organic material. The bulk density was also measured in the field as indicated in Section 2.7. Two samples were tested both in the field and in the laboratory for comparison. The field values are slightly higher but still similar to the laboratory values. The field measured bulk densities are 2,380 and 1,640 kg/m3 and the corresponding laboratory values are 2,157 and 1,564 kg/m3.

3.3.4 Specific Gravity The specific gravity (Appendix 4-D) was measured on three samples, giving values of 2.69, 2.72 and 2.60, for an average of 2.67. The values are also listed in Table 5.

3.3.5 Pore Water Salinity The salinity of the pore water (Appendix 4-E) was measured on seven samples, with values ranging from 0.5 to 11 parts per thousand (ppt), as listed in Table 6. The results show that the salinity of the pore water increases with depth, generally due to the salts being flushed out from the freeze/thaw cycles within the active zone. The salinity measurements were performed according to ASTM D4542-95(2001) “Standard Test Method for Pore Water Extraction and Determination of the Soluble Salt Content of Soils by Refractometer”.

MN/qjk/spk


April 2005


Page 13

Table 6: Salinity of Pore Water Drill Hole No.

Sample No.

Depth (m)

Salinity (ppt)

SRK-54

S-1

0.46 - 0.61

1.0

S-3

2.79 - 2.95

6.0

S-5

5.33 - 5.49

9.0

SRK-55

S-1

0.10 - 0.20

0.5

SRK-56

S-1

0.14 - 0.20

0.0

S-2

0.30 - 0.40

5.0

S-3

0.50 - 0.60

11.0

3.3.6 Thermal Conductivity Thermal conductivity (Appendix 4-F) was measured on the two bulk samples that were recovered near the alignment of the North Dam. The results are summarised in Table 7, which includes the state at which the samples were tested. It should be noted that these two bulk samples contained some organic matter that will influence the thermal properties. Thermal conductivity tests were performed according to ASTM D5334-00 (2004) “Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure”. The clayey silt sample was tested at two temperatures for unfrozen and frozen conditions. The unfrozen thermal conductivity gave a value of 1.20 W m-1 °C-1 and the frozen one was 1.52 W m-1 °C-1. The sand sample was tested four times under unfrozen conditions, giving an average value of 1.13 W m-1 °C-1. The sand sample was tested for frozen conditions but gave unreliable results. The organic matter present in the sample may have contributed to give unreliable results.

3.3.7 Unfrozen Water Content Unfrozen water content (Appendix 4-G) as a function of temperature was measured on one specimen taken from the bulk clayey silt sample. The tested specimen had the following properties:

MN/qjk/spk

•

bulk density: 1,733 kg/m3

•

bulk dry density: 1,257 kg/m3

•

gravimetric water content: 37.9%

•

volumetric water content: 47.6%

•

assumed specific gravity of solids: 2.65

•

porosity: 0.52

•

degree of saturation: 90.6%


April 2005


Page 14

The unfrozen water content curves are shown in Figure 8. The two curves differ by the method to calculate the volumetric water content from time domain reflectometry (TDR) measurements. The results show, for example, that about 40% of the pore water will remain unfrozen at -2 °C, and 20 to 30% will still be unfrozen at a temperature of -8 °C.

MN/qjk/spk


April 2005


Page 15

Table 7: Bulk Sample Thermal Conductivity Test Results Bulk Sample

No. 1

Volumetric Water Content

Dry Bulk Density

(kg/m3)

Gravimetric Water Content

1,849

8.0%

13.8%

1711

Bulk Density

Void Ratio

Porosity

Degree of Saturation

0.58

63.4%

37.6%

Sand

1,757

37.9%

48.3%

Average Test Temperature



(°C)

(W m-1 °C-1)

(kJ Day-1 m-1 °C-1)

1

30.5

0.94

81.2

2

42.0

1.32

114.0

3

27.3

1.12

96.8

4

26.7

1.12

96.8

1

23.2

1.20

103.7

2

-15.3

1.52

131.3

(kg/m3)

Bulk

No 2

Test No.

1274

1.12

52.8%

91.5%

Bulk Clayey Silt

MN/qjk/spk


April 2005


Page 16

3.3.8 X-Ray Diffraction Analysis X-ray diffraction analysis (Appendix 4-H) was performed by Core Lab in Calgary, and affiliate of EBA Engineering, on two samples recovered from drill hole SRK-54. The samples consisted of clayey silt from the marine deposit. The purpose of this test was to characterise the clay fraction of the deposit to assess the sedimentation potential of the fine particles following the erosion of the lake shoreline during the operation of the tailings disposal facility in Tail Lake. The test results include the composition of clay fraction and a description of the mineral content for the bulk sample. The two results indicate clay fractions of 23 and 24%, which contained the following clay types: •

smectite: none

•

illite/smectite mixed-layer clay: 12 and 13%

•

illite and mica: 58 and 54%

•

kaolinite: none

•

chlorite: 30 and 33%

The clay types composing the clay fraction provides information on the susceptibility of the soil to settle in water. For instance, smectite has the characteristic of remaining in suspension in water for long periods while the other components will settle at a higher rate. According to the test results, the clay fraction contains up to 13% of illite/smectite, thus representing about 3% of the bulk sample. The analysis also indicated that the bulk soil samples contained 43 to 45% of quartz. The quartz has a higher thermal conductivity than other soil particles, which increases the overall thermal conductivity of soils.

MN/qjk/spk


April 2005


Page 17

This report, 1CM014.04-050 – Summer 2004 Geotechnical Field Investigation at Tail Lake, Doris North Project, Nunavut, Canada, was prepared by SRK Consulting (Canada) Inc.

Michel Noël, M.A.Sc., P.Eng. Senior Geotechnical Engineer

Quinn Jordan-Knox, M.Sc., G.I.T. Staff Engineer

Reviewed by

Maritz Rykaart, Ph.D., P.Eng. Senior Geotechnical Engineer

MN/qjk/spk


April 2005


4

Page 18

References SRK Consulting Inc. 2002a. Hope Bay Doris North Project - Preliminary Assessment, Doris North Trial Operation, Nunavut, Canada. Report submitted to Hope Bay Joint Venture, February 2002. SRK Consulting Inc. 2002b. Hope Bay Doris North Project - Surface Infrastructure Feasibility Study Inputs, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, December 2002. SRK Consulting Inc. 2002c. Hope Bay Doris North Project, Tail Lake Dam Site Geotechnical Investigation and Conceptual Design Report, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, December 2002. SRK Consulting Inc. 2003a. Hope Bay Doris North Project - Technical Summary of Feasibility Study, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, February 2003. SRK Consulting Inc. 2003b Hope Bay Doris North Project - Tailings Impoundment Preliminary Design, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2003. SRK Consulting Inc. 2003c. Hope Bay Doris North Project - Surface Infrastructure Preliminary Design, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2003. SRK Consulting Inc. 2003d. Hope Bay Doris North Project - Predictive Water Quality Modelling, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2003.

MN/qjk/spk


April 2005

Figures

SITE 1

South Dam

SITE 2

South Dam

SITE 3

South Dam

SITE 4

South Dam

File Ref: Fig_7_2004 summer drill rpt_20050419.ppt

60% SRK-54 SRK-55 SRK-56 Bulk Sample - Silt

50%

"A" Line = 0.73(wL-20)

Plasticity Index, PI

CH 40%

30% CL OH or MH 20% CL 10% OH-MH

ML 0% 0%

10%

20%

OL or ML

30%

OI or MI 40%

50%

60%

70%

80%

90%

100%

Liquid Limit, wL DORIS NORTH PROJECT Summer 2004 Geotechnical Field Investigation

Sample Plasticity From Atterberg Testing MIRAMAR HOPE BAY LIMITED

PROJECT

DATE

APPROVED

1CM014.04

March 2005

MNN

FIGURE

7

File Ref: Fig_8_2004 summer drill rpt_20050419.ppt

Volumetric fraction of unfrozen pore water

1.0 Clayey sandy silt From gravimetric

0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 -12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

Temperature (°C) DORIS NORTH PROJECT Summer 2004 Geotechnical Field Investigation

Unfrozen Volumetric Water Fraction vs. Temperature MIRAMAR HOPE BAY LIMITED

PROJECT No.

DATE

APPROVED

1CM014.04

March 2005

MNN

FIGURE

8

Appendix 1 Borehole Logs

Borehole Log SRK-50

HOLE NO: SRK 50

PROJECT: HOPE BAY DORIS NORTH - SUMMER 2004 PROJECT NO: 1CM014.04

HOLE DIAMETER: 76 mm (NQ)

LOCATION: NW of Doris Lake

DATE AND TIME STARTED: Aug. 19, 2004

SURFACE (COLLAR) ELEVATION: 38.0 m

DATE AND TIME FINISHED: Aug. 21, 2004 DRILL CONTRACTOR: Major Drilling

EASTING: 433807

Installations

DIP vertical steep medium shallow horizontal

Sample

Recovery

DISCONTINUITY SEPARATION closed v. narrow narrow wide v. wide

Run

Dip (degrees)

Separation

ROUGHNESS smooth sl. rough medium rough v. rough

Roughness

Hardness

0.6

Weathering

0.2

FABRIC v. fine fine medium coarse v. coarse

Fabric

ROCK MASS HARDNESS v. hard hard medium soft v.soft

Fracture Spacing

Contact (m)

Material Description

WEATHERING unweathered slightly medium highly completely

Lithology

GRADE 1 2 3 4 5

RQD ROCK QUALITY(%) 100 x core lengths 100 mm and longer length of run

Depth (m)

DRILLING METHOD: Diamond Drill Core

RQD

LOGGED BY: Stacey Loptson (Miramar)

Soil Class

NORTHING: 7559177

OVERBURDEN

1

2

3 3.14

4

Dark green with lilac-grey bands fine grained BASALT. Moderate to strong foliation throughout. Small arrowhead fold structures. Moderate dolomite with moderate to strong sericite (ranging in colour from lilac to metallic blue grey). Small quartz/dolomite veins, mainly following/stretching with the foliation. Abundant quartz eyes and recrystallized dolomite. Trace to 0.1% pyrite occasionally forming small veinlets along the foliation.

5

6

7 7.4 7.5

8

Small pale green fine to medium grained speckled intermediate dyke with iron staining along the fractures at the upper contact. Mostly massive, except for the fractured contacts at either end of the unit. Weak dolomite alteration with weak to moderate chlorite. No veins. Trace to no pyrite. Dark green with lilac-grey bands fine grained BASALT. (Similar to interval from 3.14-7.4 m)

9

10

9.84 9.87

Sheet 1 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

Small pale green fine to medium grained speckled intermediate dyke. (Similar to interval from 7.4-7.5 m) Dark green with lilac-grey bands fine grained BASALT. (Similar to interval from 3.14-7.4 m) 11

12

13

14

15

16

16.64 17

18

16.98

Rosy coloured fine to medium grained massive intermediate dyke. Sharp contacts on either end of the unit with finer grained chill margins around the edges. Weak dolomite alteration with moderate sericite (possibly leading to the rosy colour of the interval). Very small mm scale stringer veins. Trace to 0.1% pyrite. Dark green with lilac-grey bands fine grained BASALT. (Similar to interval from 3.14-7.4 m)

19

20

Sheet 2 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)

Depth (m) 21



Lithology

GRADE 1 2 3 4 5


20.1


RQD


Soil Class

NORTHING: 7559177

Dark green fine grained BASALT flow. Weak to moderate foliation throughout. Moderate to strong chlorite alteration. Abundant quartz eyes. Weak dolomite. Many extensional veins cross cutting the core; few small pink calcite veins; and other quartz/dolomite veins that follow foliation as in previous units. 0.1% pyrite.

22

23

24

25 25.32

26

Dark green fine to medium grained magnetic BASALT. Iron tholeite? Weakly foliated. Weak dolomite; moderate to strong chlorite alteration. Similar veining as in previous unit. Quartz/dolomite/calcite. Extensional cross veins cutting the core; random anastamosing; and others following foliation. 0.1% pyrite fine grained and disseminated through the matrix.

27

28

29

30

Sheet 3 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

31

32

33

34

35

36

37

38

39

40

Sheet 4 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

41

42

43

44

45

46

47

48

49

50

Sheet 5 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

51

52

53

54

55

56

57

58

59

60

Sheet 6 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)

Depth (m)

60.77



Lithology

GRADE 1 2 3 4 5


61


RQD


Soil Class

NORTHING: 7559177

Dark green fine grained BASALT flow. (Similar to interval from 20.10-25.32 m)

62

63

64

65

66

67

68

69

69.66 70

Dark green fine to medium grained magnetic BASALT. (Similar to interval from 25.32-60.77 m)

Sheet 7 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

71

72

73

74

75

76

77

77.55

Dark green fine grained BASALT flow. (Similar to interval from 20.10-25.32 m)

78

79

80

Sheet 8 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

81

82

83

84

85 85.3

Dark green with lilac-grey bands fine grained BASALT. (Similar to interval from 3.14-7.4 m)

86

87

88

89

90

Sheet 9 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

91

92

93

94

95

96

97

98

99

100

Sheet 10 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

101

102

103

104

105

106

107

108

109

110

Sheet 11 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

111

112

113

114

115

116

117

118

119

120

Sheet 12 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

121

122

123

124

125

126

127

128

129

130

Sheet 13 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

131

132

133

134

135

136

137

138

139

140

Sheet 14 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

141

142

143

144

145

146

147

148

149

149.1

Dark green fine to medium grained magnetic BASALT. (Similar to interval from 25.32-60.77 m, but with quickly alternating weak to very strong magnetite alteration)

150

Sheet 15 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

151

152

153

154

155

156

157

158

159

160

Sheet 16 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

161

162

163

164

165

166

167

168

169

170

Sheet 17 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

171

172

173

174

175

176

177

178

179

180

Sheet 18 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177

181

182

183

183.8 184

184.56

185

Dark medium to coarse grained magnetic diabase dyke. Mostly massive with fractures. Chill margins on either end (mm scale). Very weak dolomite and strong magnetite alteration. No veins. Trace to no pyrite mineralization. Dark green fine to medium grained magnetic BASALT. (Similar to interval from 149.10-183.80 m)

185.07

Dark medium to coarse grained magnetic diabase dyke. (Similar to interval from 183.80-184.56 m)

186

187

188

188.76 189

Dark green fine to medium grained magnetic BASALT. (Similar to interval from 149.10-183.80 m)

189.8 190

Sheet 19 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177


191

192

193

194

195

196

197

198

199

200

Sheet 20 of 21

HOLE NO: SRK 50







EASTING: 433807

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD


Soil Class

NORTHING: 7559177


201

202

203

204

205

205 EOH

206

207

208

209

210

Sheet 21 of 21

Borehole Log SRK-54

HOLE NO: SRK 54


HOLE DIAMETER: 76mm (NQ)

LOCATION: Tail Lake Perimeter

DATE AND TIME STARTED: 1:00 pm, Sept. 27, 2004


DATE AND TIME FINISHED: 4:30 pm, Sept. 27, 2004 DRILL CONTRACTOR: Major Drilling

EASTING: 435632

1.1 1.5

Thin silt laminae within ice matrix. 80% ice content. Pure ice at depth 0.91 - 0.95 m. LOSS

2

100%

Installations

70%

Sample

Dip (degrees)

Separation

Roughness

Fabric

Hardness

Weathering

1


SP MH ICE + MH

SRK 54-1 0.46-0.61m

Loss

ICE + MH 2.74


ICE with interbeded silt. Ice lenses up to 1.5 cm thick.

2

3

0.6


Recovery

1

0.2


Run

0.8

Organic - roots, muskeg, and mucky fines. Silty fine SAND Grey clayey SILT with stratified ice. Vs from 0.7 - 0.8 m.


Fracture Spacing

Contact (m)

Depth (m)

0.3



Lithology

GRADE 1 2 3 4 5


0.076

DRILLING METHOD: Triple Tube Diamond Drill Core

RQD

LOGGED BY: Quinn Jordan Knox

Soil Class

NORTHING: 7556467

Frozen fine grained soil, grey clayey SILT. Visible ice, lenses up to 1.5 cm thick. Stratified ice laminae up to 3 mm, Vs.

SRK 54-2 2.79-2.95m SRK 54-3 3.18-3.34m

3

100%

4 SRK 54-4 4.17-4.32m

MH 5

SRK 54-5 5.33-5.49m

6 6.2

Frozen fine grained soil, grey clayey SILT, with some coarse sand and fine gravel from 6.17 - 6.48 m, MH-SP. Visible ice. Irregular fine cracks with few horizonal ice lenses,Vs/Vr.

4

88%

5

100% SRK 54-7 8.26-8.41m

SRK 54-6 6.1-6.17m

MH

7

7.44 7.6 8

LOSS Frozen fine grained soil, grey clayey SILT with poorly graded sand from 8.13 - 8.51 m. Visible stratified ice, Vs.

Loss

MH

9 9.14

10

Frozen light baige well graded SANDwith few ice lenses from 9.14 - 10.06 m. Coarsen to well graded gravel from 10.06 - 10.3 m.

SRK 54-8 9.4-9.55m

SW 6

75%

Sheet 1 of 2

HOLE NO: SRK 54




DATE AND TIME STARTED: 1:00 pm, Sept. 27, 2004



EASTING: 435632

11

LOSS

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)

Depth (m)

10.7



Lithology

GRADE 1 2 3 4 5


10.3


RQD


Soil Class

NORTHING: 7556467

SRK 54-9 10.11 10.26m

Loss

Bedrock - dark green BASALT (inferred from returned rock chips and drill efforts). 7

0%

12 12.2 EOH

13

14

15

16

17

18

19

20

Sheet 2 of 2

Borehole Log SRK-55

HOLE NO: SRK 55




DATE AND TIME STARTED: 8:30 am, Sept. 26, 2004



EASTING: 434638

1.3 1.52

2

3

4

2.9 3.06

3.94

4.4 4.57

5

Organics with olive brown silt Fine grained soil, grey to light baige clayey SILT, medium plasticity, trace fine sand from 0.025 - 0.3 m. Unfrozen from 0.025 - 0.3 m. Non-visible ice from 0.3 - 0.35 m. Vr from 0.35 - 0.55 m. ICE + soil, grey clayey silt lenses from 0.55 - 0.68 m. Pure cloudy ice from 0.68 - 0.8 m. Silty clay blocks suspended in ice matrix from 0.8 - 1.3 m. LOSS Frozen fine grained soil, grey clayey SILT, medium plasticity, Nbn. Ice with angular to subrounded gravel, up to 3 mm, set ice matrix from 2.7 - 2.73 m.

LOSS Frozen fine to medium grained soil, silty fine SAND with minor gravel, Nbn. (not frozen at depth 3.29 to 3.4m)

Frozen fine grained soil, clayey SILT, medium plasticity, Nbn. LOSS Frozen medium grained soil, pink granite rich (K-spar), well graded SAND minor gravel, Nbn.

Installations

SRK 55-1 0.10-0.20m SRK 55-2 0.35-0.45m

MH ICE + MH


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)

Depth (m) 1



Lithology

GRADE 1 2 3 4 5


0.55


RQD


Soil Class

NORTHING: 7558400

1

80%

2

90%

3

90%

4

100

Loss

MH

Loss SP

MH Loss

6

SRK 55-3 5.95-6.10m

SW 5

100%

6

40%

7

70%

7

8 8.25

LOSS Loss

9 9.14

Bedrock - BASALT

9.5 EOH 10

Sheet 1 of 1

Borehole Log SRK-56

HOLE NO: SRK 56




DATE AND TIME STARTED: 8:30 am, Sept. 27, 2004



EASTING: 435334

2

1.9 2.1 2.2

Rock chips SAND LOSS, sand and rock chips washed up in return cuttings.

MH


100%

2

100%

3

45%

Installations

1


Sample

Dip (degrees)

Separation

Roughness

Fabric

Hardness

Weathering

0.6


Recovery

1.6

SAND Vs/Vr. SILT ICE + soil. Pure ice from 1.8 - 1.9 m.

SW MH ICE + ML SP

0.2


Run

1

Organic SAND Fine grained soil, MH traces fine sand from 0.15 - 0.24 m. ICE + SOIL. Pure ice from 0.33 - 0.66 m. Vs and silt from 0.51 - 0.58 m


Fracture Spacing

Contact (m)

Depth (m)

0.58 0.74



Lithology

GRADE 1 2 3 4 5


0.05 0.15 0.33


RQD

LOGGED BY: Quinn Jordan-Knox

Soil Class

NORTHING: 7558258

SRK56-1 0.14-0.20m SRK56-2 0.30-0.40m SRK56-3 0.50-0.60m

ICE + ML Rock SW

3

4 4

Loss

5

5 6

6.1

Bedrock (inferred)

6.7 7

EOH

8

9

10

Sheet 1 of 1

Borehole Log SRK-61

HOLE NO: SRK 61


HOLE DIAMETER: 83 mm (PQ)

LOCATION: North Dam NE Abutment

DATE AND TIME STARTED: Sept 2, 2004 20:15


DATE AND TIME FINISHED: Sept 3, 2004 17:50 DRILL CONTRACTOR: Major Drilling

EASTING: 434384

Installations


Sample

Recovery


Run

Dip (degrees)

Separation


Roughness

Hardness

0.6

Weathering

0.2


Fabric


Fracture Spacing

Contact (m)



Lithology

GRADE 1 2 3 4 5


Depth (m)


RQD

LOGGED BY: Mauro Prado, Dylan MacGregor

Soil Class

NORTHING: 7559231

No Recovery 1 1 1.2

Fine grained soil, low to medium plasticity, gray clayey silt, with traces of fine to coarse sand, MH. Visible ICE, clear to cloudy, lenses between <1.0 cm and 2.5 cm thick, approx. ice content 50%, Vr.

2

2.7 3

3.65 4

5

Fine grained soil, medium to high plasticity, dary gray, friable, clayey SILT (high clay content), MH. Thin (<0.5 cm) sand lenses intercalated between 3.45 and 4.0 m. Visible ice, clear, granular (crystals 1 mm diam.), ice content 5%. 3.0 - 3.1 m: thawed zone, no visible ice. 3.3 - 3.6 m: isolated ice lenses, <1.0 cm thick. Bedrock - medium green fine grained BASALT.

2

ICE + MH

3

MH

4

6 6.4 EOH 7

8

9

10

Sheet 1 of 1

Appendix 2 Ground Temperature Measurements

Appendix 2-A Calibration Sheets

Appendix 2-B Figures

-20.0 0.0

Soil Temperature (oC) -10.0 -5.0

-15.0

0.0

5.0

2.0

4.0

Thermistor depth below ground (m)

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2002/09/14

2002/09/14

2002/09/15

2002/09/19

2003/03/29

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/26

HOPE BAY DORIS NORTH PROJECT

SRK11 Thermistor Data PROJECT

DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

1

Soil Temperature (oC) -30.0 0.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2002/09/14

2002/09/14

2002/09/15

2002/09/19

2003/02/16

2003/03/17

2003/03/24

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

2

-20.0 0.0


-15.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0 Steel casing installed after readings on April 15, 2003

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/26



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

3


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/28



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

4


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2002/09/14

2002/09/15

2002/09/19

2003/03/18

2003/03/24

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/26



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

5


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

Initial readings on installation. Beads prob not equilibrated

10.0

12.0 2003/04/14

2003/04/16

2004/08/26

2004/09/28

2003/05/17

2003/08/25

2003/09/21

2004/04/16



DATE

1CM014.04

Nov. 2004

APPROVED

M.M.N.

FIGURE

6


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0

Steel casing installed after readings on April 13, 2003

2003/04/13

2003/04/14

2003/04/16

2004/04/16

2004/08/26

2004/09/28

2003/05/17

2003/08/25

2003/09/21



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

7


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0 2003/04/13

2003/04/14

2003/04/15

2003/04/16

2003/05/17

2003/09/21

2004/04/16

2004/05/17

2004/08/27

2004/09/28

2003/08/25



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

8


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0


12.0

2003/04/14

2003/04/15

2003/04/16

2003/05/17

2004/04/16

2004/05/17

2004/08/27

2004/09/28

2003/08/25

2003/09/21



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

9


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0


2003/04/13

2003/04/14

2003/04/15

2003/04/16

2003/05/17

2003/09/21

2004/04/16

2004/05/17

2004/08/27

2004/09/28

2003/08/25



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

10


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0


2003/04/13

2003/04/14

2003/04/16

2004/04/16

2004/05/17

2004/08/27

2003/05/17

2003/08/25

2003/09/21



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

11


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0


2003/04/13

2003/04/14

2003/04/16

2003/05/17

2004/04/16

2004/05/17

2004/08/27

2004/09/28

2003/08/25

2003/09/21



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

12


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2003/04/06

2003/04/09

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/28

2003/05/16



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

13


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2003/04/06

2003/04/09

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/28

2003/05/16



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

14


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2003/04/06

2003/04/09

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/28

2003/05/16


SRK34A Thermistor Data PROJECT

DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

15


-15.0

-10.0

-5.0

0.0

5.0


2.0

4.0

6.0

8.0

10.0

12.0


2003/04/08

2003/04/13

2003/04/14

2003/04/16

2003/05/17

2003/09/21

2004/04/11

2004/05/17

2004/08/23

2004/09/26

2003/08/25



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

16


-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0 2003/04/06

2003/04/09

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/26

2003/05/16



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

17


-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/26



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

18


-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/28



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

19


-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/26



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

20


-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/26



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

21


-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0 2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/28



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

22


-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/28



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

23


-15.0

-10.0

-5.0

0.0

5.0


50.0

100.0

150.0

200.0

250.0

2004/08/31

2004/09/26



DATE

APPROVED

1CM014.01

Nov. 2004

M.M.N.

FIGURE

24


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0

2004/09/28



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

25


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0

2004/09/26

2004/09/28



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

26


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0

14.0

16.0

2004/09/28



DATE

APPROVED

1CM014.04

Nov. 2004

M.M.N.

FIGURE

27

Appendix 2-C Tables

Read By

5.0 6.0 7.0 8.5 10.0

-5.7 -6.3 -6.3 -6.2 -6.1

2002/09/14

1.2

Thermistor installation 9/14/02

Pipe blocked at 10.0 m on 9/13/02

Drill hole completed and pipe installed pipe installed to 23.0 m on 9/10/02

Thermistor installed in 25 mm internal diameter polyethylene pipe

Stick up of lead is 1.1 m (thus actually 1.2 m)

-6.5 -7.3 -7.4 -7.3 -7.0

2002/09/14

-6.8 -7.4 -7.5 -7.4 -7.3

2002/09/15

Andrew Doe Andrew Doe Andrew Doe (SRK) (SRK) (SRK)

Total string length = 10.0 m (includes 0.1 m inside connector box)

3.8 4.8 5.8 7.3 8.8

Date Bead Bead Location Depth (m) from Top (m)

String Serial No. = 00577-2

Bead 1 Bead 2 Bead 3 Bead 4 Bead 5

Bead No.

SRK-11

-7.5 -7.8 -7.9 -7.9 -7.8

Dwayne Winsor (Miramar) 2002/09/19

Maritz Rykaart (SRK) 2003/03/17

Thermistor Thermistor chewed off by chewed off by animals animals


-8.1 -7.7 -7.7 -7.4 -7.6

Dylan MacGregor (SRK) 2003/03/29

-8.4 -7.9 -7.6 -7.4 -7.5

2003/04/06

-8.7 -8.1 -7.7 -7.5 -7.5

2003/04/13

Dan Mackie (SRK) 2003/04/16

Dan Mackie (SRK)

-8.8 -8.5 -7.8 -7.6 -7.6

-8.8 -8.2 -7.8 -7.5 -7.5

Temperature (Celsius)

2003/04/15

Dan Mackie (SRK)

THERMISTOR DATA Sebastian Fortin (SRK)

-8.9 -8.2 -7.8 -7.5 -7.5

2003/04/20

Dan Mackie (SRK)

-9.5 -8.9 -8.4 -7.9 -7.7

2003/05/16

Jay Hallman (Miramar)

-8.3 -8.4 -8.4 -8.1 -8.1


0.8 -8.0 -8.1 -8.0 -8.1

2003/09/21

Mike Cripps (Miramar)

-8.7 -8.1 -7.8 -7.4 -7.5


-9.9 -9.2 -8.6 -7.9 -7.8

2004/05/17

Thorpe/Lindsay

-8.7 -8.8 -8.8 -8.5 -8.4


-8.1 -8.3 -8.3 -8.3 -8.3

Quinn Jordan-Knox (SRK) 2004/09/26

3.9

-1.1 -3.7 -5.6 -7.5 -8.0

Pipe blocked at 6.2 m on 9/13/02 Thermistor installation 9/14/02

-1.2 -3.9 -5.8 -7.5 -8.1

-1.2 -4.2 -6.3 -7.6 -8.1

Andrew Dwayne Andrew Doe Doe Winsor (SRK) (SRK) (Miramar) 2002/09/14 2002/09/15 2002/09/19





1.1 2.1 3.1 4.6 6.1

0.0 -1.5 -2.8 -4.3 -7.6

2002/09/14

Bead Depth (m)

Date

Bead Location from Top (m) 5.0 6.0 7.0 8.5 10.0



Bead No.

SRK-13

Andrew Doe (SRK)

Read By

-26.5 -16.9 -11.9 -7.4 -7.1


-21.5 -19.6 -14.8 -9.4 -8.1

Maritz Rykaart (SRK) 2003/03/17

-23.5 -18.1 -14.9 -9.9 -8.4

-17.4 -17.6 -14.8 -10.5 -9.0

-18.8 -16.8 -14.7 -10.8 -9.3

2003/04/13


Dan Mackie (SRK)

-21.7 -16.7 -14.7 -10.9 -9.4

-13.1 -17.0 -14.9 -11.2 -9.5


2003/04/15

Dan Mackie (SRK)

THERMISTOR DATA Dylan Sebastian MacGregor Fortin (SRK) (SRK) 2003/03/24 2003/04/06

-13.3 -16.4 -14.8 -11.3 -9.6

2003/04/20

Dan Mackie (SRK)

-3.3 -12.1 -12.6 -11.4 -10.1

2003/05/16


16.4 1.0 -3.4 -7.4 -8.3


BROKEN

BROKEN

Dylan Mike Cripps MacGregor (Miramar) (SRK) 2003/09/21 2004/04/11

No Readings

2004/05/17

Thorpe/Lindsay

No Readings


No Readings


2.0 3.0 4.0 6.0 8.5 11.0

-11.8 -11.1 -9.7 -7.6 -7.8 -8.3

0.77

-13.6 -12.6 -11.3 -9.3 -8.5 -8.6

Bead depth changed when steel casing was installed as thermistor protection

Thermistor installation 4/1/03 2:45pm

Drill hole completed and pipe installed to 19.5 m on April 1, 2003



2003/04/13

Dan Mackie (SRK)

-13.8 -12.8 -11.6 -9.6 -8.6 -8.6

2003/04/15

Dan Mackie (SRK)


2003/04/06


1.2 2.2 3.2 5.2 7.7 10.2

Date Bead Location Bead from Top Depth (m) (m)

Read By

String Serial No. = 690014

Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6

Bead No.

SRK-14

Sebastian Fortin (SRK)

1.2 2.2 3.2 5.2 7.7 10.2

Bead Depth (m) -14.6 -13.7 -12.7 -10.5 -8.7 -8.6

2003/04/16

-14.7 -13.9 -12.8 -10.8 -9.0 -8.7

2003/04/20

Dan Mackie (SRK)

-10.8 -12.4 -12.5 -11.5 -9.8 -9.1

2003/05/16


THERMISTOR DATA Dan Mackie (SRK)

-0.1 -2.6 -4.9 -7.6 -9.2 -9.4

-0.1 -2.1 -4.1 -6.8 -8.6 -9.2

-17.8 -16.3 -12.8 -9.8 -8.9 -14.7 -14.9 -13.2 -10.8 -9.6

-13.8

Dylan Mike Cripps MacGregor Thorpe/Lindsay (Miramar) (SRK) 2003/09/21 2004/04/11 2004/05/17



-0.5 -2.8 -5.5 -8.5 -9.9 -9.9


-0.6 -2.3 -4.5 -7.3 -9.2 -9.6


Read By

Date Bead Inclined Vert. Location Bead Bead from Top Depth (m) Depth (m) (m) 6.0 2.6 1.8 11.0 7.6 5.4 13.5 10.1 7.1 16.0 12.6 8.9 18.5 15.1 10.7 21.0 17.6 12.4 23.5 20.1 14.2 26.0 22.6 16.0 28.5 25.1 17.7 31.0 27.6 19.5

Vert. bead depth corrected for inclined drill hole

Thermistor installation 3/24/03 11:40am

Drill hole completed and pipe installed to 21.9 m vert. depth on 3/24/03



-13.2 -8.3 -8.0 -8.1 -8.1 -7.8 -8.1 -8.2 -8.1 -8.1

2003/04/06



Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 Bead 7 Bead 8 Bead 9 Bead 10

Bead No.

SRK-15


3.4

-13.5 -8.4 -8.2 -8.3 -8.2 -7.9 -8.2 -8.2 -8.2 -8.2

2003/04/13

Dan Mackie (SRK)

-13.6 -8.4 -8.4 -8.3 -8.3 -8.0 -8.2 -8.2 -8.2 -8.2

2003/04/15

Dan Mackie (SRK)

-13.6 -8.4 -8.2 -8.3 -8.3 -8.0 -8.2 -8.2 -8.2 -8.1

2003/04/16

-13.6 -8.4 -8.2 -8.3 -8.3 -8.0 -8.2 -8.2 -8.2 -8.2

2003/04/20

Dan Mackie (SRK)


-11.4 -8.6 -8.4 -8.4 -8.4 -8.2 -8.2 -8.3 -8.2 -8.2

-4.6 -8.9 -8.6 -8.5 -8.4 -8.3 -8.3 -8.3 -8.2 -8.2


2003/05/16



-4.1 -8.8 -8.6 -8.5 -8.4 -8.3 -8.3 -8.2 -8.1 -8.2

2003/09/21


-17.4 -8.4 -8.9 -8.5 -8.5 -8.3 -8.2 -8.3 -8 -8.1

-13.6 -8.8 -8.5 -8.4 -8.5 -8.3 -8.2 -8.3 -8 -8

-4.9 -9.5 -8.9 -8.4 -8.4 -8.2 -8.1 -8.2 -8.0 -8.0

-4.3 -9.4 -9 -8.5 -8.4 -8.2 -8.1 -8.2 -8 -8

Dylan Quinn Dylan MacGregor Thorpe/Lindsay MacGregor Jordan-Knox (SRK) (SRK) (SRK) 2004/04/11 2004/05/17 2004/08/27 2004/09/28

Date Bead Bead Location from Top Depth (m) (m) 5.0 3.3 6.0 4.3 7.0 5.3 8.5 6.8 10.0 8.3

-0.6 -1.4 -1.6 -2.0 -1.6

2002/09/14

1.7

Thermistor installation 9/14/02 4:30pm Thermistor repaired on 3/18/03 - cable position unchanged




-2.1 -2.4 -2.5 -3.1 -2.8

2002/09/15

Andrew Doe Andrew Doe (SRK) (SRK)




Bead No.

SRK-16

Read By

-5.0 -6.5 -7.4 -7.9 -6.9


Thermistor Thermistor chewed off chewed off by animals by animals

-13.6 -11.8 -10.5 -9.3 -8.9

Dwayne Maritz Dylan Winsor Rykaart MacGregor (Miramar) (SRK) (SRK) 2003/02/16 2003/03/17 2003/03/18

-13.9 -12.2 -10.8 -9.5 -9.0


-14.3 -12.7 -11.4 -9.9 -9.2

2003/04/06

-14.5 -13.0 -11.6 -10.2 -9.4

2003/04/13


Dan Mackie (SRK)

-14.5 -13.0 -11.7 -10.2 -9.5

-14.5 -13.0 -11.7 -10.3 -9.5


2003/04/15

Dan Mackie (SRK)

THERMISTOR DATA Sebastian Fontin (SRK)

-14.5 -13.1 -11.8 -10.4 -9.5

2003/04/20

Dan Mackie (SRK)

-13.6 -13.0 -12.1 -10.9 -10.0

2003/05/16


-7.4 -8.4 -9.0 -9.6 -9.8


-6.5 -7.6 -8.3 -9.0 -9.4

-16.7 -13.7 -13 -11 -9.8

-15.3 -14.4 -13.5 -11.9 -10.7

Dylan Mike Cripps MacGregor Thorpe/Lindsay (Miramar) (SRK) 2003/09/21 2004/04/11 2004/05/17

-7.9 -8.9 -9.7 -10.2 -10.4


-6.8 -7.9 -8.3 -9.4 -9.8


Read By

Date Bead Bead Location from Top Depth (m) (m) 2.0 1.0 3.0 2.0 4.0 3.0 6.0 5.0 8.5 7.5 11.0 10.0 -13.4 -11.8 -9.2 -7.9 -7.9 -8.0

1.05








Bead No.

SRK-19

THERMISTOR DATA

-13.9 -11.5 -9.0 -7.0 -7.3 -7.6

-9.7 -10.1 -9.3 -7.1 -7.3 -7.6

-0.9 -4.2 -6.2 -7.4 -7.5 -7.6 -0.7 -3.7 -5.7 -7.3 -7.4 -7.6

-15.5 -13.4 -10.5 -6.7 -7.3 -7.5


No Readings

-1.0 -4.3 -6.6 -7.7 -7.5 -7.5

-0.9 -3.7 -5.9 -7.4 -7.6 -7.5

Dylan Dan Dan Jay Dylan Mike Dylan Quinn Mackie Mackie Hallman MacGregor Cripps MacGregor Thorpe/Lindsay MacGregor Jordan-Knox (SRK) (SRK) (Miramar) (SRK) (Miramar) (SRK) (SRK) (SRK) 2003/04/14 2003/04/16 2003/05/17 2003/08/25 2003/09/21 2004/04/16 2004/05/17 2004/08/26 2004/09/28

Dan Mackie (SRK)

Date 2003/04/13 Bead Bead Location Bead Depth Temp (C) (m) Depth (m) from Top (m) 2.0 0.8 -12.0 0.8 3.0 1.8 -10.2 1.8 4.0 2.8 -8.2 2.8 6.0 4.8 -6.7 4.8 8.5 7.3 -7.1 7.3 11.0 9.8 -7.4 9.8

1.23









Bead No.

SRK-20

Read By

-11.8 -11.1 -9.3 -7.0 -7.1 -7.4

-12.7 -11.0 -9.4 -6.9 -7.0 -7.4

Dan Mackie Dan Mackie (SRK) (SRK)

-9.3 -9.9 -9.3 -7.1 -7.1 -7.4

0.3 -3.0 -5.3 -7.2 -7.2 -7.4 0.0 -2.7 -4.9 -7.0 -7.2 -7.3

-15.1 -13.4 -11 -6.9 -7.1 -7.2


Dylan Mike Dylan Jay MacGregor Cripps MacGregor Hallman (Miramar) (SRK) (Miramar) (SRK) 2003/04/14 2003/04/16 2003/05/17 2003/08/25 2003/09/21 2004/04/16

THERMISTOR DATA

No Readings

2004/05/17

Thorpe/Lindsay

0.0 -3.3 -5.8 -7.7 -7.3 -7.1

-0.2 -2.8 -5.1 -7.4 -7.3 -7.1

Quinn Dylan MacGregor Jordan-Knox (SRK) (SRK) 2004/08/26 2004/09/28

Read By









Bead No.

SRK-22

THERMISTOR DATA

1.32

-11.8 -11.4 -9.5 -7.3 -7.6 -7.9

-12.3 -11.3 -9.5 -7.3 -7.6 -7.9

-12.7 -11.4 -9.5 -7.3 -7.6 -7.9

-10.3 -10.5 -9.7 -7.7 -7.7 -7.9

-2.4 -5.6 -7.4 -7.9 -7.9 -8.0 -2.1 -5.1 -6.9 -7.8 -7.9 -8.0

Temperature (Celsius) -14.4 -12 -9.3 -7.4 -7.7 -7.8 -12.8 -11.7 -9.9 -7.7 -7.7 -7.8

-2.8 -6.0 -7.8 -8.2 -7.8 -7.8

-2.6 -5.3 -7.2 -8.1 -7.9 -7.8

Dylan Dylan Mike Dylan Quinn Dan Jay Dan Mackie Dan Mackie Dan Mackie Cripps MacGregor Thorpe/Lindsay MacGregor Jordan-Knox Mackie Hallman MacGregor (SRK) (SRK) (SRK) (SRK) (Miramar) (SRK) (Miramar) (SRK) (SRK) (SRK) 2003/04/13 2003/04/14 2003/04/15 2003/04/16 2003/05/17 2003/08/25 2003/09/21 2004/04/16 2004/05/17 2004/08/27 2004/09/28

Read By

Dan Mackie (SRK) Dan Mackie (SRK)


Dylan MacGregor (SRK)


1.08






-12.9 -12.6 -11.1 -8 -7.6 -7.8

2004/05/17

-1.7 -4.8 -7.2 -8.3 -7.8 -7.8

-1.5 -4.2 -6.6 -8.1 -7.9 -7.8

Quinn JordanKnox (SRK) 2004/08/27 2004/09/28

Dylan Dylan MacGregor Thorpe/Lindsay MacGregor (SRK) (SRK)

Date 2003/04/14 2003/04/15 2003/04/16 2003/05/17 2003/08/25 2003/09/21 2004/04/16 Bead Location Bead Depth Temperature (Celsius) from Top (m) (m) 2.0 0.9 -13.2 -13.0 -13.2 -10.5 -1.5 -16.2 -1.3 3.0 1.9 -11.9 -11.6 -11.6 -10.5 -4.4 -13.9 -4.0 4.0 2.9 -9.7 -9.3 -9.3 -9.5 -6.7 -10.8 -6.2 6.0 4.9 -8.0 -7.1 -7.1 -7.6 -7.8 -7.5 -7.7 8.5 7.4 -8.0 -7.5 -7.5 -7.5 -7.7 -7.6 -7.8 11.0 9.9 -8.3 -7.8 -7.8 -7.8 -7.8 -7.9 -7.8



Bead No.

SRK-23

Dan Mackie (SRK)

THERMISTOR DATA

1.32


Thermistor installation April 9, 2003

Drill hole completed and pipe installed to 12 m on April 9, 2003




-1.4 -4.5 -6.6 -8.1 -8.0 -8.0 -1.2 -4.2 -6.2 -7.6 -7.6 -7.6

-16 -14 -11.3 -7.6 -7.4 -7.5

-13.3 -13 -11.4 -8.2 -7.4 -7.5

2004/05/17

-1.7 -5.2 -7.3 -8.3 -7.7 -7.4

-1.6 -4.6 -6.6 -8 -7.8 -7.4

Quinn JordanKnox (SRK) 2004/08/27 2004/09/28

Dylan Dylan MacGregor Thorpe/Lindsay MacGregor (SRK) (SRK)

2003/09/21 2004/04/16



2003/08/25

Dan Mackie Dan Mackie Dan Mackie (SRK) (SRK) (SRK)

Date 2003/04/13 2003/04/14 2003/04/15 2003/04/16 2003/05/17 Bead Location Bead Bead Temp (C) from Top Depth (m) Depth (m) (m) 2.0 0.7 -11.1 0.7 -10.0 -10.4 -10.9 -10.0 3.0 1.7 -9.9 1.7 -11.0 -10.9 -10.8 -10.1 4.0 2.7 -8.0 2.7 -9.4 -9.5 -9.5 -9.4 6.0 4.7 -7.1 4.7 -7.2 -7.4 -7.3 -7.7 8.5 7.2 -7.3 7.2 -7.3 -7.3 -7.4 -7.5 11.0 9.7 -7.4 9.7 -7.4 -7.4 -7.4 -7.6



Bead No.

SRK-24

Dan Mackie (SRK)


Read By


THERMISTOR DATA



Thermistor installation on April 8, 2003



Stick up of lead after steel installed is 1.13 m (thus actually 1.23 m)


1.23

Date 2003/04/13 2003/04/14 Bead Location Bead Bead Temperature (Celsius) from Top Depth (m) Depth (m) (m) 2.0 0.8 -14.0 -13.9 0.8 3.0 1.8 -13.1 -13.1 1.8 4.0 2.8 -11.0 -11.0 2.8 6.0 4.8 -8.5 -8.6 4.8 8.5 7.3 -8.4 -8.4 7.3 11.0 9.8 -8.7 -8.7 9.8



Bead No.

SRK-26

Read By

-14.8 -13.7 -12.3 -9.0 -8.4 -8.7

Dan Mackie (SRK)

-11.7 -12.2 -11.7 -9.6 -8.5 -8.7

-1.6 -4.6 -6.8 -9.0 -8.9 -8.7 -1.2 -4.0 -6.0 -7.8 -8.0 -8.0

-18.8 -17.4 -15 -10 -8.5 -8.7

Temperature (Celsius) -14.3 -15.1 -14.3 -10.8 -8.7 -8.7

Dylan Mike Dylan Jay Cripps MacGregor Thorpe/Lindsay Hallman MacGregor (Miramar) (SRK) (Miramar) (SRK) 2003/04/16 2003/05/17 2003/08/25 2003/09/21 2004/04/16 2004/05/17

THERMISTOR DATA

-1.9 -4.8 -7.5 -9.8 -9.2 -8.8









1.23

Date 2003/04/13 2003/04/14 Bead Bead Bead Location Temperature (Celsius) Depth (m) from Top Depth (m) (m) 2.0 0.8 -12.1 -12.0 0.8 3.0 1.8 -10.5 -10.5 1.8 4.0 2.8 -8.6 -8.6 2.8 6.0 4.8 -7.4 -7.5 4.8 8.5 7.3 -7.8 -7.8 7.3 11.0 9.8 -7.9 -8.0 9.8



Bead No.

SRK-28

Read By

-13.3 -11.8 -10.2 -7.6 -7.7 -7.9

Dan Mackie (SRK)

-9.8 -10.6 -10.0 -8.2 -7.7 -8.0

-1.5 -4.5 -6.6 -8.1 -8.0 -8.0 -1.3 -4.1 -6.2 -8.7 -8.9 -8.8

-16.7 -14.7 -12 -8.1 -7.7 -8

Temperature (Celsius) -12.9 -13.2 -11.9 -8.8 -7.7 -7.9

Dylan Mike Dylan Jay Cripps MacGregor Thorpe/Lindsay Hallman McGreggor (Miramar) (SRK) (Miramar) (SRK) 2003/04/16 2003/05/17 2003/08/25 2003/09/21 2004/04/16 2004/05/17

THERMISTOR DATA

-1.9 -5.0 -7.1 -8.6 -8.1 -8.0


-1.7 -4.3 -6.4 -8.3 -8.2 -8


Read By

Date Bead Location Bead from Top Depth (m) (m) 2.0 0.9 3.0 1.9 4.0 2.9 6.0 4.9 8.5 7.4 11.0 9.9 -11.5 -9.7 -8.9 -8.7 -8.7 -8.1


Drill hole completed and pipe installed to 18 m on April 2, 2003






Bead No.

SRK-32

1.1

-12.0 -11.0 -8.8 -8.6 -8.5 -8.2

Dylan Sebastian MacGregor Fortin (SRK) (SRK) 2003/04/06 2003/04/09

-12.4 -11.9 -10.1 -8.6 -8.5 -8.3

2003/04/13

Dan Mackie (SRK)

-12.7 -11.9 -10.2 -8.6 -8.5 -8.3

2003/04/15

Dan Mackie (SRK)

-12.9 -11.9 -10.3 -8.5 -8.4 -8.3

2003/04/16

-13.2 -12.0 -10.4 -8.6 -8.4 -8.3

2003/04/20

2003/05/16


-11.4 -11.4 -10.7 -8.7 -8.3 -8.3

0.4 -3.2 -5.6 -8.3 -8.6 -8.4



Dan Mackie (SRK)


-0.1 -2.8 -5.0 -7.4 -8.6 -8.4

2003/09/21


-18.3 -16.8 -14.3 -9.3 -8 -8.3 -13.5 -14.2 -13.5 -10.2 -8.3 -8.3

Dylan MacGregor Thorpe/Lindsay (SRK) 2004/04/11 2004/05/17

0.0 -3.6 -6.1 -8.9 -8.9 -8.4


-0.5 -3.2 -5.4 -8.3 -8.8 -8.5


Read By

Date Bead Location Bead from Top Depth (m) (m) 2.0 0.9 3.0 1.9 4.0 2.9 6.0 4.9 8.5 7.4 11.0 9.9

-10.7 -6.9 -6.4 -5.3 -5.2 -5.0

2003/04/06








Bead No.

SRK-33


1.1

-13.1 -12.0 -10.0 -7.3 -7.1 -7.2


-12.4 -13.0 -12.5 -9.3 -7.8 -7.9

2003/04/13

Dan Mackie (SRK)

-13.1 -13.1 -12.5 -9.6 -8.0 -8.1

2003/04/15

Dan Mackie (SRK)

-13.4 -13.1 -12.5 -9.7 -8.0 -8.2

2003/04/16

-13.5 -13.3 -12.5 -9.9 -8.1 -8.3

2003/05/16


-10.7 -11.7 -11.8 -10.4 -8.5 -8.6

-3.4 -5.4 -7.0 -8.9 -9.5 -8.8



2003/04/20

Dan Mackie (SRK)


-2.3 -4.7 -6.4 -8.5 -8.9 -8.8

2003/09/21


-19.1 -16.8 -14.3 -9.9 -8.6 -8.8 -15.3 -15 -13.9 -10.7 -8.7 -8.7


-3.8 -6.0 -7.8 -9.6 -9.1 -8.8


-3.2 -5.1 -6.8 -9 -9.1 -8.8


Read By

Date Bead Location Bead from Top Depth (m) (m) 2.0 0.9 3.0 1.9 4.0 2.9 6.0 4.9 8.5 7.4 11.0 9.9

-10.3 -7.4 -7.4 -7.1 -6.1 -7.2








Bead No.

SRK-34A

Sebastian Fortin (SRK) 2003/04/06

1.1

-13.1 -12.0 -10.0 -7.3 -7.1 -7.2


-12.4 -13.0 -12.5 -9.3 -7.8 -7.9

2003/04/13

Dan Mackie (SRK)

-13.1 -13.1 -12.5 -9.6 -8.0 -8.1

2003/04/15

Dan Mackie (SRK)

-13.4 -13.1 -12.5 -9.7 -8.0 -8.2

2003/04/16

-13.5 -13.3 -12.5 -9.9 -8.1 -8.3

2003/04/20

Dan Mackie (SRK)


-10.5 -10.8 -10.3 -8.5 -7.5 -7.7

-1.8 -4.2 -6.1 -8.0 -8.1 -8.0


2003/05/16



-1.5 -3.7 -5.5 -7.7 -8.0 -8.1

2003/09/21


-17.6 -15.3 -12.2 -8.8 -7.4 -7.6 -13.8 -13.6 -12 -9.2 -7.7 -7.7


-2.2 -4.8 -6.4 -8.7 -8.5 -8.3


-1.9 -4.2 -5.6 -8.3 -8.4 -8.3






-7.4 -6.1 -4.5 -5.4 -6.0 -6.3



2003/04/13

Dan Mackie (SRK)

1.61

-7.5 -6.2 -4.6 -5.4 -6.0 -6.3

2003/04/14

Dan Mackie (SRK)


2003/04/08




Bead No.

SRK-35

Read By


0.4 1.4 2.4 4.4 6.9 9.4

Bead Depth (m) -10.3 -7.5 -6.0 -5.0 -5.9 -6.2

2003/04/16

-6.4 -7.0 -6.4 -5.3 -5.9 -6.3

2003/05/17



-0.4 -3.1 -4.8 -5.6 -6.0 -6.3


-0.4 -2.7 -4.4 -5.5 -6.0 -6.3

-13.5 -11 -8 -5.4 -6 -6.2 -10.6 -10 -8.4 -5.7 -5.9 -6



2003/09/21


-0.5 -3.6 -5.6 -6.0 -5.9 -6.1


-0.5 -3.1 -5 -6 -6.1 -6.1


Date Bead Vert. Inclined Location Bead Bead from Top Depth (m) Depth (m) (m) 6.0 0.0 0.0 11.0 4.6 3.3 13.5 7.1 5.0 16.0 9.6 6.8 18.5 12.1 8.6 21.0 14.6 10.4 23.5 17.1 12.1 26.0 19.6 13.9 28.5 22.1 15.7 31.0 24.6 17.4

Vert. Bead Depth corrected for drill hole angle

Thermistor installation March 26, 2003

Drill hole completed and pipe installed to 21.2 m vert. depth on March 25, 2003


First bead is above ground surface


-14.7 -14.0 -12.2 -10.5 -9.3 -8.6 -8.2 -8.2 -8.4 -8.2

2003/04/06




Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 Bead 7 Bead 8 Bead 9 Bead 10

Bead No.

SRK-37

Read By

6.36

-20.9 -13.1 -11.1 -9.6 -8.8 -8.7 -8.1 -8.2 -8.3 -8.0

2003/04/09


-23.0 -14.2 -12.4 -10.7 -9.5 -8.8 -8.3 -8.3 -8.4 -8.2

2003/04/13

Dan Mackie (SRK)

-20.9 -14.3 -12.5 -10.8 -9.6 -8.8 -8.3 -8.2 -8.3 -8.2

2003/04/15

Dan Mackie (SRK)

-13.3 -14.2 -12.5 -10.8 -9.6 -8.8 -8.3 -8.2 -8.3 -8.2

2003/04/16

-10.3 -14.3 -12.6 -10.9 -9.7 -8.9 -8.4 -8.2 -8.3 -8.2

2003/04/20



-1.8 -13.4 -12.5 -11.3 -10.1 -9.3 -8.6 -8.3 -8.2 -8.2

13.0 -6.9 -7.9 -8.7 -9.1 -9.2 -8.9 -8.7 -8.4 -8.2


2003/05/16



-5.2 -6.1 -7.1 -7.9 -8.6 -8.8 -8.8 -8.6 -8.5 -8.3

2003/09/21


-19.9 -17 -14.6 -12 -10.1 -9 -8.9 -8.1 -8.1 -8.1

2004/04/11


-3.2 -15.5 -14.4 -12.6 -11 -9.8 -9 -8.3 -8.2 -8

2004/05/17

Thorpe/Lindsay

4.7 -7.4 -8.6 -9.4 -9.8 -9.7 -9.3 -8.9 -8.5 -8.2

2004/08/27


-1.4 -6.6 -7.5 -8.4 -9 -9.2 -9.1 -8.9 -8.6 -8.3


6.0 11.0 16.0 21.0 31.0 41.0 51.0

Drill hole completed and pipe installed to 50 m

Total string length = 51.0 m

1.0 6.0 11.0 16.0 26.0 36.0 46.0

Date Bead Bead Location from Top Depth (m) (m)

String Serial No. = TS0015

Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 Bead 7 Bead 8

Bead No.

SRK-38

Read By

1.5 -7.9 -7.7 -8.1 -8.1 -8.0 -8.1


0.2 -7.9 -8.0 -8.2 -8.2 -8.1 -8.1

2003/09/21


-17.6 -8 -8.2 -8.3 -8.2 -8.1 -8.1 -13.4 -8.4 -8.2 -8.2 -8.2 -8.1 -8.1


0.3 -9.0 -8.2 -8.2 -8.2 -8.1 -8.1

-0.5 -8.8 -8.2 -8.2 -8.2 -8.1 -8.1

Dylan Quinn Dylan MacGregor Thorpe/Lindsay MacGregor Jordan-Knox (SRK) (SRK) (SRK) 2004/04/11 2004/05/17 2004/08/27 2004/09/26

THERMISTOR DATA

Date Bead Bead Location from Top Depth (m) (m) 21.0 4.6 26.6 10.2 32.1 15.7 43.1 26.7 54.1 37.7 66.0 49.6





Bead No.

SRK-39

Read By

-1.2 -3.8 -1.1 -1.8 -1.9 -7.5

-6.3 -7.7 -7.8 -8.0 N/A -8.2

-15.8 -16 -7.1 -7.6 -7.8 -8 -11.8 -12.3 -7.8 -7.6 -7.8 -8

Temperature (Celsius) 4.5 4.2 -8.2 -7.9 -7.8 -8.0

-2.7 -2.5 -8 -7.9 -7.8 -8

Dylan Dylan Quinn Dylan Mike Cripps MacGregor MacGregor Thorpe/Lindsay MacGregor Jordan-Knox (Miramar) (SRK) (SRK) (SRK) (SRK) 2003/08/25 2003/09/21 2004/04/11 2004/05/17 2004/08/27 2004/09/28

THERMISTOR DATA

6.0 11.0 16.0 21.0 31.0 41.0 51.0



0.9 5.9 10.9 15.9 25.9 35.9 45.9




Bead No.

SRK-40

Read By

3.1 -8.2 -8.7 -8.5 -8.7 -8.8 -8.8 1 -7.8 -8.7 -8.6 -8.7 -8.8 -8.9

-18.2 -10 -8.2 -8.5 -8.8 -8.9 -8.9 -14.7 -10.9 -8.5 -8.5 -8.8 -8.9 -8.9


Dylan Dylan Mike Cripps McGreggor MacGregor Thorpe/Lindsay (Miramar) (SRK) (SRK) 2003/08/25 2003/09/21 2004/04/11 2004/05/17

THERMISTOR DATA

-0.1 -9.2 -9.0 -8.7 -8.7 -8.8 -8.8


-1.1 -8.4 -9 -8.7 -8.7 -8.7 -8.8


Date Bead Bead Location from Top Depth (m) (m) 3.5 1.4 6.0 3.9 8.5 6.4 11.0 8.9 13.5 11.4 16.0 13.9 18.5 16.4 21.0 18.9 -16 N/A -4.9 -6.2 -6.5 -6.5 -6.8 -7 -15.4 -10.8 -10 -6.3 -6.7 -6.8 -7 -7.8

-18.5 error -9.3 -6.6 -6.5 -6.8 -7.1 -7.2 -2.1 -109 -9.9 -7.3 -6.7 -6.8 -7 -7.2


Dylan Dylan Mike Cripps MacGregor MacGregor Thorpe/Lindsay (Miramar) (SRK) (SRK) 2003/08/25 2003/09/21 2004/04/11 2004/05/17

Drill hole completed and pipe installed to 30.6 m




Bead No.

SRK-41

Read By

THERMISTOR DATA

6.2 error -6.5 -7.3 -7.2 -7.1 -7.1 -7.1


-1.3 -109 -5.8 -7 -7.2 -7.1 -7.1 -7.2


11.0 16.0 21.0 31.0 41.0 51.0



0.2 5.2 10.2 20.2 30.2 40.2



Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 Bead 7 Bead 8

Bead 1

Bead No.

SRK-42

Read By

6 -6.3 -7.1 -7.8 -8 -8.1 0.8 -6.3 -7.3 -7.9 -8.1 -8.1

-17.4 -7.6 -7.4 -8 -8.1 -8.1 -11.3 -8.6 -7.4 -8 -8.1 -8.1


Dylan Dylan Mike Cripps McGreggor MacGregor Thorpe/Lindsay (Miramar) (SRK) (SRK) 2003/08/25 2003/09/21 2004/04/11 2004/05/17

THERMISTOR DATA

1.6 -7.7 -7.6 -8.0 -8.1 -8.1


-0.1 -7.2 -7 -8 -8.1 -8.1


15.5 21.0 26.6 32.1 43.1 54.1 66.0

-2.3 -7.7 -7.8 -7.6 -8.2 -8.5 -8.5 -2.6 -8.2 -8.3 -8.2 -8.5 -8.6 -8.5

-16.4 -8.2 -8.6 -8.7 -8.7 -8.6 -8.9 -14.5 -8.4 -8.6 -8.8 -8.7 -8.6 -8.5


Dylan Dylan Mike Cripps MacGregor MacGregor Thorpe/Lindsay (Miramar) (SRK) (SRK) 2003/08/25 2003/09/21 2004/04/11 2004/05/17

Drill hole completed and pipe installed to 51.5 m


0.5 6.0 11.6 17.1 28.1 39.1 51.0




Bead No.

SRK-43

Read By

THERMISTOR DATA

-5.2 -9.0 -8.6 -8.7 -8.7 -8.7 -8.5


-4.5 -9 -8.6 -8.8 -8.7 -8.6 -8.5


202.5 m m

Drill hole completed to (m b.g.s.) 205

PVC installed to (m b.g.s.):

Instrumentation installed August 8, 2004

Estimated stickup: (assume no stickup)

TS1618

Date Bead Bead Location from Top Depth (m) (m) 5.0 5.0 10.0 10.0 20.0 20.0 30.0 30.0 50.0 50.0 70.0 70.0 90.0 90.0 110.0 110.0 130.0 130.0 150.0 150.0 170.0 170.0 190.0 190.0 200.0 200.0

Total string length =

String Serial No. =

Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 Bead 7 Bead 8 Bead 9 Bead 10 Bead 11 Bead 12 Bead 13

Bead No.

SRK-50

Read By


-5.4 -6.4 -5.7 -5.4 -5.3 -5.3 -5.1 -5 -4.7 -4.5 -4.3 -3.9 -3.8

finalized by QJK- check field notes for final stickup

-5.4 -6 -5.1 -4.9 -4.9 -5 -4.8 -4.7 -4.4 -4.3 -4.1 -3.8 -3.7



THERMISTOR DATA

Date Bead Bead Location from Top Depth (m) (m) 2.0 1.0 3.0 2.0 4.0 3.0 6.0 5.0 8.5 7.5 11.0 10.0 -0.1 0 -0.6 -4.3 -5.7 -6



Drill hole completed and pipe installed to

Approximate Stick up above ground (visual estimation from photo) : meter

Total string length =

String Serial No. =


Bead No.

SRK-54

Read By

THERMISTOR DATA

1

Date Bead Bead Location from Top Depth (m) (m) 2.0 0.8 3.0 1.8 4.0 2.8 6.0 4.8 8.5 7.3 11.0 9.8 0 -0.01 -3.9 -6.2 -7.4 -6.9


-0.1 -1.1 -5.7 -7.2 -7.7 -7.5


Quinn Quinn Jordan-Knox Jordan-Knox (SRK) (SRK) 2004/09/26 2004/09/28

Total string length = Approximate Stick up above ground (visual estimation from photo) : meter thermistor box located right on top of the casing (from Quinn's field notes)

String Serial No. =


Bead No.

SRK-55

Read By

THERMISTOR DATA

1.2

Date Bead Bead Location from Top Depth (m) (m) 2.0 3.0 4.0 6.0 0.8 8.5 3.3 11.0 5.8 -2.9 -2.9 -2.6 0 -0.3 -3.6




Total string length = Approximate Stick up above ground (visual estimation from photo) : meter top three beads are above casing (from Quinn's field notes)

String Serial No. =


Bead No.

SRK-56

Read By

THERMISTOR DATA

5.2

Appendix 3 Topographic Survey Sheets

Site: Survey_SRK54

Note: The prismpole was pushed into the ground so that the whole tip was inserted. The elevation of the ground surface resulted using pole height of 1.36, not 1.435 (height to tip). Shots were taken on the ground between hummocks. Point 260 324 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305

2005-03-17

North 7556490.225 7556493.036 7556496.15 7556494.87 7556492.89 7556491.33 7556489.70 7556488.47 7556486.93 7556485.36 7556484.28 7556482.77 7556481.16 7556479.60 7556477.81 7556476.12 7556474.66 7556472.28 7556470.55 7556469.19 7556468.44 7556466.87 7556465.33 7556460.42 7556461.87 7556463.62 7556464.97 7556466.66 7556467.38 7556468.66 7556470.50 7556472.04 7556473.50 7556474.56 7556476.38 7556477.98 7556479.19 7556480.56 7556482.47 7556483.51 7556485.24 7556486.85 7556488.14 7556489.80 7556491.17 7556486.09 7556484.83

East 435669.120 435679.818 435724.21 435718.22 435711.37 435705.15 435698.95 435693.74 435687.82 435681.94 435676.56 435670.54 435664.26 435657.35 435651.36 435644.34 435638.52 435630.74 435624.32 435618.71 435616.07 435611.01 435604.37 435605.08 435610.91 435617.24 435622.99 435628.59 435631.95 435638.04 435644.82 435650.59 435656.58 435661.75 435666.59 435672.35 435677.68 435684.49 435690.89 435696.24 435701.96 435707.50 435713.16 435719.52 435724.80 435725.48 435720.04

Elevation 29.608 30.171 34.48 33.80 32.82 32.14 31.44 30.83 30.53 30.10 29.82 29.57 29.30 28.76 28.64 28.60 28.52 28.37 28.13 28.06 28.28 28.11 28.10 27.97 28.00 28.19 28.14 28.35 28.56 28.52 28.68 28.77 28.72 28.97 29.30 29.66 29.88 30.11 30.64 31.15 31.88 32.53 33.08 33.64 34.65 34.79 33.61

Page 1 of 8

Description 54N spike BM54 high point on rock N STK N N N N N N N N N N N N N N N STK N N N STK N N C C C STK C C C STK C C C C C C C C C C C C C C C C STK S STK S

Survey_TailLake_Summer2004.xls

Site: Survey_SRK54

306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 346 347 348 349 350 351

2005-03-17

7556482.81 7556480.78 7556480.78 7556479.09 7556477.29 7556475.45 7556473.47 7556472.64 7556470.75 7556468.70 7556466.99 7556465.16 7556464.03 7556462.32 7556460.71 7556458.94 7556457.15 7556455.42 7556450.36 7556455.65 7556460.45 7556455.04 7556449.26 7556445.28

435713.85 435708.17 435701.27 435694.71 435689.40 435683.49 435676.97 435670.47 435663.23 435656.77 435650.77 435644.58 435638.83 435632.32 435626.47 435619.40 435614.26 435609.60 435586.21 435585.73 435585.18 435562.58 435565.70 435567.06

32.97 32.56 31.69 31.02 30.61 30.09 29.73 29.36 28.92 28.76 28.65 28.64 28.59 28.59 28.30 28.20 27.99 28.01 27.99 28.03 28.00 27.95 27.96 27.93

Page 2 of 8

S S S S S S S S S S S S S S STK S S STK S S S C N N LK C LK S LK


Site: Survey_SRK55


2005-03-17

North 7558414.940 7558436.309 7558471.043 7558392.26 7558392.51 7558394.11 7558396.41 7558398.33 7558400.38 7558403.05 7558404.90 7558407.02 7558408.48 7558410.45 7558412.59 7558415.29 7558410.51 7558408.53 7558406.12 7558403.65 7558401.72 7558400.14 7558397.99 7558396.06 7558393.90 7558392.54 7558392.54 7558390.25 7558386.44 7558385.65 7558382.62 7558383.21 7558384.95 7558387.72 7558389.80 7558391.40 7558393.06 7558395.29 7558396.97 7558398.75 7558400.49 7558402.30 7558404.38 7558405.60 7558436.309 7558415.28 7558413.33

East 434628.509 434596.424 434669.009 434701.74 434700.85 434691.58 434681.66 434671.37 434660.88 434651.24 434639.65 434629.13 434622.10 434612.22 434602.39 434588.99 434587.65 434597.94 434607.86 434620.87 434631.32 434638.05 434648.33 434657.87 434667.33 434675.33 434675.33 434686.17 434699.17 434700.33 434698.24 434695.93 434686.84 434674.02 434664.14 434654.64 434644.07 434636.87 434628.47 434619.79 434610.57 434599.94 434590.00 434586.24 434596.423 434588.98 434597.96

Elevation 31.462 33.691 30.078 28.176 28.250 28.707 28.985 29.144 29.526 29.994 30.584 31.309 31.973 32.467 33.157 33.868 33.925 33.281 32.646 31.820 31.158 30.680 30.161 29.653 29.348 29.130 29.118 28.806 28.331 28.167 28.174 28.243 28.516 28.888 29.249 29.843 30.525 31.002 31.276 31.853 32.476 33.099 33.589 33.855 33.690 33.876 33.283

Description 55N spike 55N2 spike BM55 N LK N N N N N N N STK N N STK N N N STK C STK C C C STK C C STK C C C C STK C STK C C C LK S LK S S S S S S S S S STK S S S S STK 55N2(spike) NSTK N

Page 3 of 8


Site: Survey_SRK55

109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146

2005-03-17

7558411.25 7558409.50 7558408.47 7558406.45 7558404.89 7558402.60 7558400.47 7558398.43 7558397.34 7558394.99 7558391.13 7558387.44 7558389.25 7558391.48 7558392.54 7558394.08 7558396.23 7558397.98 7558400.12 7558402.03 7558403.63 7558405.43 7558407.63 7558409.66 7558410.50 7558405.59 7558403.49 7558401.64 7558399.71 7558398.78 7558396.64 7558395.31 7558393.13 7558389.93 7558388.32 7558387.72 7558385.49 7558383.25

434607.57 434617.25 434622.09 434631.90 434639.65 434649.86 434660.73 434670.52 434676.72 434686.79 434700.02 434699.27 434689.85 434679.68 434675.33 434664.98 434654.90 434644.41 434638.06 434628.48 434620.88 434611.13 434601.17 434593.00 434587.68 434586.24 434594.82 434605.08 434614.37 434619.77 434629.64 434636.84 434647.27 434657.82 434668.17 434674.01 434684.78 434695.94

32.738 32.224 31.978 31.109 30.585 30.027 29.532 29.201 29.228 28.748 28.331 28.336 28.710 28.908 29.109 29.332 29.920 30.473 30.680 31.342 31.819 32.454 33.042 33.532 33.924 33.857 33.459 32.847 32.208 31.841 31.193 31.009 30.275 29.517 29.117 28.883 28.600 28.255

Page 4 of 8

N N N STK N N STK N N N N STK N N C C C C STK C C C C STK C C STK C C C C STK S STK S S S S S S STK S S S S STK S S


Site: Survey_SRK56


2005-03-17

North 7558283.249 7558275.877 7558388.597 7558266.33 7558266.21 7558265.98 7558265.99 7558265.19 7558265.23 7558264.62 7558264.34 7558263.89 7558263.76 7558263.51 7558263.10 7558262.56 7558262.48 7558262.13 7558261.63 7558261.49 7558260.87 7558260.15 7558255.84 7558256.24 7558256.49 7558256.69 7558256.57 7558256.72 7558256.99 7558258.07 7558258.31 7558258.82 7558258.98 7558258.86 7558259.71 7558259.86 7558260.17 7558260.35 7558260.34 7558260.63 7558261.34 7558256.35 7558255.76 7558255.70 7558255.34 7558255.00 7558254.68

East 435319.650 435365.639 435267.947 435399.90 435394.06 435388.02 435381.97 435375.66 435368.88 435362.60 435355.49 435348.86 435342.67 435337.45 435333.76 435327.31 435321.03 435314.84 435308.60 435301.95 435296.16 435290.06 435292.01 435298.37 435302.38 435307.99 435314.58 435320.47 435326.15 435334.02 435341.11 435347.37 435354.08 435360.62 435366.09 435372.14 435377.14 435383.35 435390.30 435396.39 435399.77 435399.68 435394.35 435388.52 435382.70 435377.13 435372.01

Elevation 28.957 31.330 29.398 34.21 33.71 33.00 32.41 31.93 31.13 30.20 29.67 29.18 29.05 28.98 28.90 28.89 28.75 28.59 28.40 28.39 28.44 28.14 28.08 28.43 28.51 28.47 28.62 28.74 28.70 28.75 28.94 29.04 29.43 30.05 30.57 31.30 32.35 32.58 33.28 33.89 34.07 34.13 33.61 33.02 32.51 31.96 31.22

Description 56N spike BM56 high point on rock BM56A N STK N N N N N N N N N N N STK N N N N N STK N N LK C LK C C STK C C C C C STK C C C C C C C C C C C STK S STK S S S S S

Page 5 of 8


Site: Survey_SRK56

244 245 246 247 248 249 250 251 252 253 254 255 256

2005-03-17

7558254.48 7558253.96 7558253.35 7558253.58 7558253.46 7558253.13 7558252.55 7558252.28 7558251.83 7558251.86 7558251.51 7558250.34 7558249.91

435365.75 435360.04 435354.11 435347.39 435341.68 435334.30 435328.21 435322.30 435316.48 435310.27 435302.84 435297.01 435290.26

30.59 30.01 29.61 29.09 29.05 28.88 28.72 28.67 28.62 28.46 28.35 28.18 28.12

Page 6 of 8

S S S S S S STK S S S S S STK S S


Site: Survey_Site4


2005-03-17

North 7557795.255 7557781.430 7557775.107 7557763.94 7557767.22 7557772.84 7557779.26 7557785.71 7557792.05 7557798.10 7557803.93 7557810.71 7557817.05 7557822.62 7557827.43 7557832.61 7557838.67 7557841.72 7557846.73 7557847.10 7557847.72 7557842.97 7557838.13 7557833.36 7557830.06 7557826.47 7557821.53 7557816.49 7557812.20 7557806.29 7557799.88 7557794.85 7557789.41 7557783.49 7557777.69 7557771.16 7557766.05 7557768.07 7557773.78 7557779.22 7557785.42 7557790.70 7557796.02 7557802.12 7557808.34 7557813.83 7557818.42

East 434947.085 434963.564 435000.379 434928.95 434930.52 434931.87 434933.70 434935.69 434937.67 434939.24 434941.25 434943.34 434945.15 434946.91 434948.36 434950.05 434951.82 434952.91 434954.16 434957.68 434949.56 434948.10 434946.63 434944.95 434943.63 434942.86 434941.24 434939.80 434938.55 434936.89 434934.98 434932.91 434930.79 434929.26 434927.96 434925.98 434924.34 434919.87 434921.29 434923.30 434924.99 434926.29 434928.06 434929.91 434931.66 434933.87 434935.07

Elevation 31.870 32.584 33.520 34.27 33.73 33.46 33.11 32.80 32.49 32.10 31.39 30.91 30.49 30.07 29.72 29.02 28.41 28.34 28.22 28.11 28.16 28.34 28.52 28.89 29.18 30.15 30.35 30.57 31.01 31.34 31.77 31.98 32.53 32.86 33.29 33.66 34.59 35.04 33.95 33.04 32.77 32.58 32.26 31.72 31.48 31.15 30.82

Description 57N spike 57N2 spike BM57 high point on rock S STK S S S S S S S S STK S S S S S S STK S S LK C C STK C C C C C C C STK C C C C C C C C STK N STK N N N N N N N N STK N

Page 7 of 8


Site: Survey_Site4

194 195 196 197 198 199

2005-03-17

7557824.64 7557828.86 7557834.85 7557840.24 7557844.06 7557848.18

434937.00 434938.35 434940.19 434941.77 434943.20 434944.73

30.35 29.41 28.80 28.29 28.24 28.17

Page 8 of 8

N N N N N STK N


Appendix 4 Laboratory Testing

Appendix 4-A Moisture Content

EBA Engineering Consultants Ltd. MOISTURE CONTENT TEST RESULTS

Project: Project No.:

SRK 2004 Testing Services

BH No:

SRK-54, SRK-55, SRK-56

1780108

Location:

Hope Bay, NU

Date Tested: October 12 - October 13, 2004

Client:

SRK Consulting

By:

VG

Test No.

Sample Number

Depth (m)

Moisture Content %

Specific Gravity

Bulk Density, kg/m3

Bulk Density (dry), kg/m3

3763-1

SRK-54, S-1

0.46 - 0.61

21.9

2.69

2.111

1.731

3763-2

SRK-54, S-2

2.79 - 2.95

84.1

3763-3 3763-4 3763-5 3763-6 3763-7 3763-8 3763-9

SRK-54, S-3 3.18 - 3.34 SRK-54, S-4 4.12 - 4.32 SRK-54, S-5 5.33 - 5.49 SRK-54, S-6 6.10 - 6.17 SRK-54, S-7 8.26 - 8.41 SRK-54, S-8 9.40 - 9.55 SRK-54, S-9 10.11 - 10.26

47.4 56.0 52.3 54.3 23.8 23.7 16.0

1.744

1.183

2.72

1.706

1.120

3763-10 3763-11 3763-12

SRK-55, S-1 SRK-55, S-2 SRK-55, S-3

0.10 - 0.20 0.35 - 0.45 5.95 - 6.10

27.6 76.4 29.7

2.60

2.157

1.691

3763-13 3763-14 3763-15

SRK-56, S-1 SRK-56, S-2 SRK-56, S-3

0.14 - 0.20 0.30 - 0.40 0.50 - 0.60

53.5 63.3 46.4

1.564

0.958

Data presented hereon are for the sole use of the

The testing services reported herein have been performed by an EBA technician to recognized

stipulated client. EBA is not responsible, nor can

industry standards., unless otherwise noted. No other warranty is made. These data do not

be held liable, for use made of this report by any

include or represent any interpretation or opinion of specification compliance or material

other party, with or without the knowledge of EBA.

suitability. Should engineering interpretation be required, EBA will provide it upon written request.

EBA Engineering Consultants Ltd. MOISTURE CONTENT TEST RESULTS

Project:

SRK 2004 Testing Services

BH No:

Hope Bay, Summer 2004


Project No.:

1780108

Location:

Hope Bay, NU

Client:

SRK Consulting

By:

SRK 54, SRK 55, SRK 56 NR

BH No.

Sample Number

Depth (m)

LL, %

PL, %

PI, %

SRK 54

3763 - 1

0.46 - 0.61

29

17

12

SRK 54

3763 - 2

2.79 - 2.95

39

24

15

SRK 54

3763 - 3

3.18 - 3.34

36

21

15

SRK 54 SRK 55 SRK 55 SRK 56 SRK 56 SRK 56

3763 - 5 3763 - 10 3763 - 11 3763 - 13 3763 - 14 3763 - 15

5.33 - 5.49 0.1 - 0.2 0.35 - 0.45 0.14 - 0.20 0.30 - 0.40 0.50 - 0.60

40 28 43 34 33 34

24 20 37 21 21 20

16 8 6 13 12 14









`

Appendix 4-B Atterberg Limits

Atterberg Limits Date Received: Job Number: 1780108 Sample #: 3763-1 Source: SRK 54, 0.46m - 0.61 m ASTM D-2487, Unified Soils Classification System Liquid Limit Determination #1 29.20 23.50 3.80 19.70 5.70 28.9 % 29

Liquid Limit @ 25 Blows: Plastic Limit: Plasticity Index, IP:

#2 30.50 24.50 3.80 20.70 6.00 29.0 % 24

#3 32.40 25.80 3.90 21.90 6.60 30.1 % 15

#4

#5

#6 35%

30%

25%

20%

29.1 % 17.2 %

15%

11.9 %

Plastic Limit Determination Weight of Wet Soils + Pan: Weight of Dry Soils + Pan: Weight of Pan: Weight of Dry Soils: Weight of Moisture: % Moisture:

#1 13.90 12.40 3.80 8.60 1.50 17.4 %

Liquid Limit

% Moisture

Weight of Wet Soils + Pan: Weight of Dry Soils + Pan: Weight of Pan: Weight of Dry Soils: Weight of Moisture: % Moisture: N:

10% #2 14.90 13.30 3.90 9.40 1.60 17.0 %

#3

#4

#5

#6 5%

0% 10

Number of Blows, "N"

100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index

"A" Line 50.0 % CH or OH

40.0 %

30.0 % MH or OH 20.0 % CL or OL 10.0 % CL-ML 0.0 % 0.0 %

10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %

Atterberg Limits Date Received: Job Number: 1780108 Sample #: 3763-2 Source: SRK 54, 2.79 - 2.95 m ASTM D-2487, Unified Soils Classification System Liquid Limit Determination Weight of Wet Soils + Pan: Weight of Dry Soils + Pan: Weight of Pan: Weight of Dry Soils: Weight of Moisture: % Moisture: N:

#1 32.90 24.80 4.00 20.80 8.10 38.9 % 33

#2 38.50 28.70 3.80 24.90 9.80 39.4 % 26

#3 30.20 22.70 3.90 18.80 7.50 39.9 % 18

#4

#5

#6

Liquid Limit 45% 40% 35%


% Moisture

30% 25%

39.4 % 23.9 %

20%

15.5 %

15%


#1 15.30 13.10 3.90 9.20 2.20 23.9 %

#2 15.10 12.90 3.70 9.20 2.20 23.9 %

#3

#4

#5

#6

10% 5% 0% 10


100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index


40.0 %


10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %


#1 31.30 24.20 4.00 20.20 7.10 35.2 % 36

#2 31.80 24.40 3.80 20.60 7.40 35.9 % 27

#3 30.70 23.60 4.30 19.30 7.10 36.8 % 19

#4

#5

#6



% Moisture

25% 36.2 % 21.4 %

20%

14.8 %

15% Plastic Limit Determination Weight of Wet Soils + Pan: Weight of Dry Soils + Pan: Weight of Pan: Weight of Dry Soils: Weight of Moisture: % Moisture:

#1 13.30 11.60 3.70 7.90 1.70 21.5 %

#2 14.10 12.30 3.80 8.50 1.80 21.2 %

#3

#4

#5

#6

10% 5% 0% 10


100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index


40.0 %


10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %


#1 31.00 23.60 4.00 19.60 7.40 37.8 % 40

#2 31.80 23.80 4.00 19.80 8.00 40.4 % 25

#3 30.80 23.00 4.00 19.00 7.80 41.1 % 19

#4

#5

#6



% Moisture

30% 25%

40.2 % 24.5 %

20%

15.8 %

15%


#1 15.90 13.50 3.70 9.80 2.40 24.5 %

#2 14.90 12.70 3.70 9.00 2.20 24.4 %

#3

#4

#5

#6

10% 5% 0% 10


100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index


40.0 %


10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %

Atterberg Limits Date Received: Job Number: 1780108 Sample #: 3763-10 Source: SRK 55, 0.1m- 0.2 m ASTM D-2487, Unified Soils Classification System Liquid Limit Determination Weight of Wet Soils + Pan: Weight of Dry Soils + Pan: Weight of Pan: Weight of Dry Soils: Weight of Moisture: % Moisture: N:

#1 36.30 29.40 3.80 25.60 6.90 27.0 % 35

#2 30.60 24.80 4.10 20.70 5.80 28.0 % 22

#3 29.70 24.00 4.00 20.00 5.70 28.5 % 15

#4

#5

#6

Liquid Limit 30%

25%


% Moisture

20%

27.7 % 19.6 %

15%

8.2 %

10%


#1 19.50 16.90 3.90 13.00 2.60 20.0 %

#2 18.20 15.90 3.90 12.00 2.30 19.2 %

#3

#4

#5

#6 5%

0% 10


100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index


40.0 %


10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %


#1 13.00 10.40 4.10 6.30 2.60 41.3 % 29

#2 14.00 11.00 4.00 7.00 3.00 42.9 % 26

#3 17.00 13.00 4.00 9.00 4.00 44.4 % 18

#4

#5

#6

Liquid Limit 50% 45% 40% 35% % Moisture

30%


42.7 % 37.1 %

25%

5.6 %

20%


#1 15.30 12.20 3.90 8.30 3.10 37.4 %

15% #2 15.20 12.10 3.70 8.40 3.10 36.9 %

#3

#4

#5

#6 10% 5% 0% 10


100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index


40.0 %


10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %


#1 30.70 24.10 3.70 20.40 6.60 32.4 % 35

#2 31.80 24.90 4.00 20.90 6.90 33.0 % 28

#3 31.80 24.70 3.90 20.80 7.10 34.1 % 22

#4

#5

#6



% Moisture

25% 33.6 % 20.7 %

20%

12.9 %


#1 13.00 11.40 3.80 7.60 1.60 21.1 %

#2 15.90 13.90 4.10 9.80 2.00 20.4 %

#3

#4

#5

#6

10% 5% 0% 10


100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index


40.0 %


10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %


#1 33.10 25.80 3.80 22.00 7.30 33.2 % 28

#2 30.50 23.80 3.80 20.00 6.70 33.5 % 23

#3 34.70 26.70 3.80 22.90 8.00 34.9 % 14

#4

#5

#6



% Moisture

25% 33.4 % 21.4 %

20%

12.0 %


#1 13.20 11.50 3.70 7.80 1.70 21.8 %

#2 16.10 14.00 4.00 10.00 2.10 21.0 %

#3

#4

#5

#6

10% 5% 0% 10


100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index


40.0 %


10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %


#1 27.20 21.50 3.90 17.60 5.70 32.4 % 39

#2 30.00 23.60 4.10 19.50 6.40 32.8 % 30

#3 28.70 22.40 4.00 18.40 6.30 34.2 % 19

#4

#5

#6



% Moisture

25% 33.6 % 19.5 %

20%

14.0 %


#1 13.00 11.50 3.70 7.80 1.50 19.2 %

#2 16.50 14.40 3.80 10.60 2.10 19.8 %

#3

#4

#5

#6

10% 5% 0% 10


100

Plasticity Chart

80.0 %

70.0 %

60.0 %

"U" Line

Plasticity Index


40.0 %


10.0 %

20.0 %

30.0 %

40.0 %

50.0 %

60.0 %

Liquid Limit

Page 1

70.0 %

80.0 %

90.0 %

100.0 %

110.0 %

Appendix 4-C Grain Size Distribution

EBA Engineering Consultants Ltd. GRAIN SIZE DISTRIBUTION PERCENTAGE PASSING

SIEVE

Project: SRK 2004 Testing Services

40

Project Number: 1780108

25

Client: SRK Consulting

20

Attention: Mr. Dylan MacGregor, Project Manager

16


12.5

Borehole Number: SRK 54

10

Depth:

5

0.46m - 0.61 m

Sample Number: 1

2.5

Lab Number:

3763-1

1.25

100

Soil Description:

SILT, clayey, some sand, CL

0.63

99

Natural Moisture Content: 21.9%

0.315

99

Remarks:

0.16

97

0.08

86.6

LL=29%, PL=17%, PI=12%

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10

GRAIN SIZE (millimeters)

Reviewed By: Data presented hereon is for the sole use of the stipulated client. EBA is not responsible, nor can be held liable, for use made of this report by any other party, with or without the knowledge of EBA

P.Eng.

The testing services reported herein have been performed by an EBA technician to recognized Industry standards, unless otherwise noted, No other warranty is made. These data do not include or represent any interpretation or opinion of specification compliance or material suitability. Should engineering interoperation be required, EBA will provide it upon written request.

20

50

3


SIEVE


40


25


20


16


12.5


10

Depth:

5

3.18m - 3.34 m

Sample Number: 3

2.5

Lab Number:

3763-3

1.25

Soil Description:

SILT and CLAY, trace sand, CL

0.63


0.315

Remarks:

0.16

100

0.08

96.8

LL=36%, PL=21%, PI=15%

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10



P.Eng.


20

50

3


SIEVE


40


25


20


16


12.5


10

Depth:

5

5.33m - 5.49 m

Sample Number: 5

2.5

Lab Number:

3763-5

1.25

Soil Description:

SILT, clayey, trace sand, CL

0.63

100


0.315

99

Remarks:

0.16

98

0.08

96.8

LL=40%, PL=24%, PI=16%

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10



P.Eng.


20

50

3


SIEVE


40


25


20


16

Date Tested: October 18, 2004

12.5


10

Depth:

5

100

2.5

99

8.26m - 8.41 m

Sample Number: 7 Lab Number:

3763-7

1.25

95

Soil Description:

SAND and SILT

0.63

88


0.315

73

Remarks:

0.16

54

0.08

42.5

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10



P.Eng.


20

50

3


SIEVE


40


25


20


16


12.5


10

Depth:

5

0.1m - 0.2 m

Sample Number: 1

2.5

3763-10

Lab Number:

1.25

100

0.63

99


0.315

97

Remarks:

0.16

94

0.08

87.8

Soil Description:

SILT, some clay, some sand, CL

LL=28%, PL=20%, PI=8%

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10



P.Eng.


20

50

3


SIEVE


40


25


20


16


12.5


10

Depth:

5

0.35m - 0.45 m

Sample Number: 2

2.5

100

1.25

99

0.63

98


0.315

96

Remarks:

0.16

92

0.08

84.0

3763-11

Lab Number: Soil Description:

SILT, some clay,some sand, high am. of org. material, OL

LL=43%, PL=37%, PI=6%

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10



P.Eng.


20

50

3


SIEVE


40


25


20


16


12.5


10

100

Depth:

5

99

2.5

99

1.25

99

0.63

98


0.315

97

Remarks:

0.16

96

0.08

94.0

0.14m - 0.20 m

Sample Number: 1 3763-13


SILT, clayey, trace sand, trace gravel, CL

LL=34%, PL=21%, PI=13%

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10



P.Eng.


20

50

3


SIEVE


40


25


20


16


12.5


10

Depth:

5

0.30m - 0.40 m

Sample Number: 2

2.5

3763-14

Lab Number:

1.25

100

0.63

99


0.315

98

Remarks:

0.16

98

0.08

96.6

Soil Description:

SILT, some clay, trace sand, CL

LL=33%, PL=21%, PI=12%

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10



P.Eng.


20

50

3


SIEVE


40


25


20


16


12.5


10

100

Depth:

5

98

2.5

98

1.25

98

0.63

98


0.315

98

Remarks:

0.16

98

0.08

90.5

0.50m - 0.60 m

Sample Number: 3 3763-15


SILT, clayey, trace sand, trace gravel, CL

LL=34%, PL=20%, PI=14%

CLAY

SAND

SILT FINE

GRAVEL

MEDIUM

COARSE

FINE

COARSE

SIEVE SIZES 200

100

100

60

40 30

20 16

10 8

.5

1

2

4

3/8 1/2 3/4 1

11/2 2

90 80

PERCENT SMALLER

70 60 50 40 30 20 10 0 .0005

.001

.002

.005

.01

.02

.05

.1

.2

5

10



P.Eng.


20

50

3

Appendix 4-D Specific Gravity and Density

EBA Engineering Consultants Ltd. RELATIVE DENSITY AND ABSORPTION OF AGGREGATE Project:

SRK 2004 Testing Services.

Location:

Hope Bay, NU

Hope Bay. Summer 2004.

BH No:

SRK-54, SRK-5T-1, T-3, T-4

Date Tested:

October 12 - October 13, 2004 July 15 - July 16

Project No.: 1780108 Client:

SRK Consulting

Attention:

Mr. Dylan MacGregor

Sample #

SRK-54-01

SRK-54-05

SRK-55-01

3

2

1

Mass oven dry

166.0

153.8

99.4

Temperature

21.5

21

21

Mass pycnometer & Water

674.1

663.8

689.0

Mass Pycno. & Sample & water

778.5

761.1

750.2

2.695

2.722

2.602

Sample #

SRK-54-01

SRK-54-03

SRK-54-05

SRK-55-01

SRK-56-02

Trial No.

1

2

3

4

5

236.4

211

194.5

192

165.8

112

121

114

89

106

2.111

1.744

1.706

2.157

1.564

Trial No. Pycnometer No. Mass SSD

Bulk Sp Gravity Bulk Sp Gr (SSD) Apparent Sp. Gravity Absorption

Mass in air Mass in water Bulk Sp Gravity (wet)









Appendix 4-E Pore Water Salinity

Appendix 4-F Thermal Conductivity

Appendix 4-G Unfrozen Water Content

Appendix 4-H X-Ray Diffraction Analysis

EBA Engineering Consultants Ltd. Creating and Delivering Better Solutions

December 22, 2004

EBA File: 1780108

SRK Consulting Suite 800, 580 Hornby Street Vancouver BC V6C 3B6 Attention:

Mr. Dylan MacGregor

Dear Sir: Subject:

X-Ray Diffraction Analysis (XRD) Clay Minerals Identification

Please find enclosed the results of XRD analysis conducted on two samples of soil delivered to our laboratory. In order to identify clay minerals in the samples, after XRD on the bulk samples was conducted, the clay fraction was separated and followed by two XRD analyses on the clay fraction. Core Lab conducted XRD analysis and the results identify minerals present in the bulk sample and in the separated clay fraction. Mixed- layer clays and some illites and chlorites have a potential for the soil volume changes. If the material is used for the road construction, swelling potential has to be determined. It should be noted that increased soil density through compaction or natural depositional history leads to greater amounts of swell and higher swell pressure. We trust that the enclosed meets with your present requirements. However, should you have any questions, please contact our office. Respectfully submitted, EBA Engineering Consultants Ltd.

Bozena Czarnecki, M.Sc., P.Eng. Senior Project Engineer BC: Enclosure M:\1CM014.04\Lab\XRD Testing 1780108xrd.doc

6111 - 36 Street SE, Calgary, Alberta T2C 3W2 - Tel: (403) 236-9700 - Fax: (403) 236-7033 Email: [email protected] - Web Site: www.eba.ca

Appendix E Winter 2005 Geotechnical Field Investigation

Winter 2005 Geotechnical Field Investigation at Tail Lake, Doris North Project, Nunavut, Canada

Miramar Hope Bay Limited Suite 300, 889 Harbourside Drive North Vancouver, B.C. V7P 3S1

SRK Consulting (Canada) Inc. Suite 800, 1066 West Hastings Street Vancouver, B.C. V6E 3X2 Tel: 604.681.4196 Fax: 604.687.5532 Email: [email protected] Web site: www.srk.com

SRK Project Number 1CM014.04-0110

October 2005

Authors Dylan MacGregor Peter Mikes Reviewed by Michel Noël Maritz Rykaart

SRK Consulting (Canada) Inc. Winter 2005 Geotechnical Field Investigation

Page i

Table of Contents 1 Introduction .................................................................................................................. 3 1.1 General ............................................................................................................................... 3 1.2 Background ......................................................................................................................... 3 1.3 Methods .............................................................................................................................. 4

2 Field Program............................................................................................................... 5 2.1 Introduction ......................................................................................................................... 5 2.2 Drilling ................................................................................................................................. 5 2.2.1 2.2.2

Drill Holes ................................................................................................................................5 Drilling Method ........................................................................................................................5

2.3 Thermistor String Installations............................................................................................. 6 2.3.1 2.3.2 2.3.3

North Dam thermistor strings ..................................................................................................6 Tail Lake thermistor strings .....................................................................................................6 Thermistor string completion ...................................................................................................6

2.4 Thermistor Data .................................................................................................................. 7 2.5 Sample Collection and Laboratory Testing ......................................................................... 7

3 Results of Drilling Program......................................................................................... 9 3.1 Summary of Drill Hole Profiles ............................................................................................ 9 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5 3.1.6 3.1.7 3.1.8

3.2 3.3 3.4 3.5 3.6 3.7 3.8

SRK-51 ....................................................................................................................................9 SRK-52 ....................................................................................................................................9 SRK-62 ....................................................................................................................................9 SRK-59 ..................................................................................................................................10 SRK-60 ..................................................................................................................................10 SRK-53 ..................................................................................................................................10 SRK-57 ..................................................................................................................................10 SRK-58 ..................................................................................................................................11

Laboratory Testing ............................................................................................................ 11 Water Content and Atterberg Limits .................................................................................. 11 Particle Size Distribution ................................................................................................... 13 Bulk Density ...................................................................................................................... 13 Specific Gravity ................................................................................................................. 13 Salinity............................................................................................................................... 13 Unfrozen Water Content ................................................................................................... 14

4 References.................................................................................................................. 16

MN//qjk/spk

Winter2005Drilling.Report.1CM014.04.dbm.20051011, Oct. 11, 05, 4:55 PM

October 2005


Page ii

List of Tables Table 1: Winter 2005 drillhole details ................................................................................................ 5 Table 2: Details of Thermistor String Installations............................................................................. 7 Table 3: Samples Collected and Laboratory Testing Program.......................................................... 8 Table 4: Water Contents, Atterberg Limits and Intact Bulk Densities.............................................. 12 Table 5: Salinity of Pore Water........................................................................................................ 14 Table 6: Unfrozen Water Content Sample Properties ..................................................................... 14

List of Figures Figure 1: Winter 2005 Drillhole Locations Figure 2: Frozen core, Sand, Ice Saturated, SRK-52 Figure 3: Sample Plasticity from Atterberg Testing Figure 4: Unfrozen Volumetric Water Fraction versus Temperature

List of Appendices Appendix 1: Borehole Logs, Winter 2005 Program Appendix 2: Ground Temperature Data Appendix 3: Laboratory Testing

MN//qjk/spk


October 2005


1

Introduction

1.1

General

Page 3

As part of the ongoing process of obtaining background field data upon which the engineering designs can be based, MHBL contracted SRK to undertake a field program during April 2005. The primary objectives of this field program can be summarized as follows: •

Further characterize foundation conditions at the proposed North Dam site through three drill holes and install three detailed thermistor strings to better characterize the near-surface ground thermal regime.

•

Characterize foundation conditions at the proposed North Dam spillway location through two drill holes.

•

Characterize permafrost conditions along the perimeter of Tail Lake through three drill holes, and install three shallow thermistors.

•

Monitoring and maintenance of all historic thermistor installations at the Doris North site.

This report presents the results of the field work as described. This report includes drill logs for holes drilled in April 2005, laboratory data sheets from 2005 soil testing, and calibration data sheets for thermistors strings installed as part of the April 2005 program. The data in this report should be read in conjunction with the documented field data presented in SRK (2003a), SRK (2003b), and SRK (2005).

1.2

Background The proposed Doris North Project will be a small conventional underground gold mine. Ore will be transported to surface via an access ramp, before being processed on site to produce gold bars. Tailings produced during the milling process will be sub-aqueous deposition into Tail Lake, which will be impounded through the construction of two frozen core dams referred to as the North Dam and the South Dam. The locations of these dams are illustrated on Figure 1. To date there has been a series of field investigations to characterize foundation conditions for the dams and other site infrastructure (SRK 2003a; 2003b; 2005). A recent regulatory review of the project, has suggested that there are some gaps in the background geotechnical information that would have to be addressed if MHBL is to adequately assess the project impacts. These data gaps were specifically linked to: •

MN/spk

Providing site specific evidence of the geothermal gradient, as opposed to solely relying on data from the Boston site which is 60 km to the south.


October 2005


Page 4

•

Characterizing the foundation conditions at the proposed spillway location for the North Dam.

•

Further characterise the condition of the granular material at the west abutment of the North Dam.

•

Characterizing the permafrost conditions around Tail Lake, such that more informed statements can be made as to the amount of thaw induced sediment release that may be triggered as the water level in Tail Lake rises.

•

Determining site specific bulk density for the ice rich marine sediments, to better define the dam foundation conditions.

MHBL subsequently contracted SRK to initiate a field program to address these background data gaps, the results of which are documented in this report.

1.3

Methods This field program involved a number of parties, as detailed below: •

Drilling was conducted by Major Drilling Group International Inc. (Yellowknife), under a standing contract managed by MHBL.

•

Field drill supervision and material logging were carried out by SRK staff Dylan MacGregor and Peter Mikes.

•

All laboratory testing was conducted by EBA Engineering, out of their Yellowknife and Edmonton offices.

•

Thermistors and PVC tubing were supplied by RST Instruments, and installed by SRK staff.

•

Drill hole collar surveys were conducted by MHBL surveyor Jay Hallmann.

•

Thermistor maintenance and data recording was conducted by SRK and MHBL staff.

All of the individual tasks described above were completed with the support and supervision of a Senior Geotechnical Engineer, Michel Noel, M.A.Sc., P.Eng., with overall project management and review completed by SRK Project Manager, Maritz Rykaart, Ph.D., P.Eng.

MN/spk


October 2005


Page 5

2

Field Program

2.1

Introduction The field program included drilling and sampling eight boreholes, with thermistor string installation in six boreholes, and monitoring and maintenance of existing thermistor installations. The following sections summarize the field work completed in April 2005.

2.2

Drilling

2.2.1 Drill Holes Eight boreholes were drilled between April 20 and April 25, 2005 (Table 1). Boreholes SRK-51 and SRK-52 were drilled along the alignment of the proposed North Dam, on the east and west abutments, respectively. An additional borehole, SRK-62, was drilled 200 m south of the proposed North Dam alignment to support an assessment of the benefits of an alternative dam alignment. Two boreholes, SRK-59 and SRK-60, were drilled near the eastern extent of the proposed North Dam alignment to characterize foundation conditions in the vicinity of the proposed spillway. The three remaining boreholes (SRK-53, SRK-57, and SRK-58) were drilled near the shoreline of Tail Lake to assess overburden and thermal conditions, and to provide for monitoring of changes to these conditions which may result from using Tail Lake as a tailings management facility. Figure 1 shows a site plan of Doris and Tail Lakes with the locations of the eight boreholes drilled in April 2005. Borehole logs are included in Appendix 1. Table 1: Winter 2005 drillhole details

Drill Hole

Collar Elevation (m)

Northing

Easting

Depth

(UTM NAD 83)

(UTM NAD 83)

(m)

SRK-51

30.42

7559165.54

434390.7

14.7

SRK-52

35.74

7559082.73

434316.33

14.3

SRK-53

31.39

7556906.93

435184.24

10.4

SRK-57

31.19

7557812.13

434937.72

9.5

SRK-58

31.29

7557704.54

435284.89

10.7

SRK-59

36.49

7559217.29

434437.46

5.6

SRK-60

33.24

7559172.16

434437.54

4.2

SRK-62

28.14

7558994.93

434500.74

15.3

2.2.2 Drilling Method The boreholes were drilled using the HQ3 (61 mm core, 96 mm hole diameter) triple tube diamond coring system with a Boyles 17 hydraulic drill rig. Lake water from Doris or Tail Lake was mixed with sodium chloride or calcium chloride, chilled to below 0° C through ambient cooling and snow addition, and then used as drilling fluid. A maximum run length of 1.5 m was drilled prior to

MN/spk


October 2005


Page 6

extraction of core, and shorter runs were used where dictated by ground conditions. Core recovery was performed on a continuous basis. Selected soil samples were shipped to EBA Engineering’s soil testing laboratories in Yellowknife and Edmonton for material characterisation, and bulk density, pore water salinity, and unfrozen water content determinations. Field bulk density testing was undertaken at the drill site by SRK staff. Rock core was logged by Miramar geologists at the on-site geology facilities. All rock core and remaining soil core is stored in core boxes outside under ambient conditions at Windy Camp.

2.3

Thermistor String Installations Table 2 lists the details of the instrument (thermistor strings) installations. Appendix 2-A contains the supplier calibration data sheets and a wiring diagram for each thermistor string. In all cases, the thermistor strings were installed immediately following the completion of drilling. In preparation for instrument installation, all boreholes were flushed of saline drilling fluid by pumping a minimum of 800 L of fresh water down each drillhole prior to the final extraction of drill rods.

2.3.1 North Dam thermistor strings The three thermistor strings were installed in boreholes SRK-51, SRK-52, and SRK-62 to monitor the near-surface ground thermal regime at the proposed North Dam location. These instruments were installed following the removal of the drill rods from the borehole, but prior to the drill rig moving off of the setup. These thermistor strings were pushed to depth using 1” diameter PVC, which was subsequently removed from the borehole. This method of installation allowed the precise positioning of the thermistor beads relative to the ground surface, as required by the objective to monitor near-surface ground temperatures.

2.3.2 Tail Lake thermistor strings Thermal instruments installed in SRK-53, SRK-57, and SRK-58 were installed inside 1-inch diameter PVC tubes, similar to related installations completed in September 2004. For each installation, a conduit of PVC was fixed with a bottom end cap and inserted into the drillhole to allow the thermistor string to be installed inside a dry conduit. This was attempted in an effort to avoid the potential for instrument damage due to frost jacking (as discussed for SRK-55 in Section 2.4). This attempt was unsuccessful at SRK-57, where the PVC experienced leakage and the instrument was installed inside saturated PVC conduit. At SRK-53 and SRK-58, the PVC conduit remained dry following installation.

2.3.3 Thermistor string completion All six thermistor strings installed in April 2005 were completed at surface as follows. A 0.6 to 0.75 m length of 3” diameter ABS pipe was inserted into the drillhole, over top of the instrument

MN/spk


October 2005


Page 7

cable, and fixed in position with wire until freezing secured the pipe. The ABS was extended 0.75 to 1 m above ground surface to provide an above-grade fixture to support the instrument’s terminal box. The terminal box was rested on top of the vertical ABS pipe such that the thermistor cable exited the bottom of the box and entered directly into the ABS pipe. The terminal box was secured to a wooden 2x4 with wire, and the 2x4 was in turn secured to the ABS pipe, to ultimately provide a stable completion for the instrument. ABS pipe was selected over steel drill rod due to the low thermal conductivity of ABS. Table 2: Details of Thermistor String Installations

2.4

Location

Drill Hole

Cable Serial Number

Thermistor String Stickup Height (m)

Thermistor Bead Position (m below ground surface)

North Dam

SRK-51

TS 2048

1.00

-0.75, 0.25, 0.50, 0.75, 1.00, 1.50, 2.00, 2.50, 3.00, 3.50, 4.00, 5.00

North Dam

SRK-52

TS 2047

1.00

-0.75, 0.25, 0.50, 0.75, 1.00, 1.50, 2.00, 2.50, 3.00, 3.50, 4.00, 5.00

North Dam

SRK-62

TS 2046

1.00

-0.75, 0.25, 0.50, 0.75, 1.00, 1.50, 2.00, 2.50, 3.00, 3.50, 4.00, 5.00

Tail Lake

SRK-53

TS 1625

1.40

0.60, 1.60, 2.60, 4.60, 7.10, 9.60

Tail Lake

SRK-57

TS 1623

2.67

-0.67, 0.33, 1.33, 3.33, 5.83, 8.33

Tail Lake

SRK-58

TS 1622

0.93

1.07, 2.07, 3.07, 5.07, 7.57, 10.07

Thermistor Data SRK staff visited all 34 thermistors that have been installed at the Doris North Site since 2002, to collect data and to conduct maintenance and repairs as necessary. Initial readings were also taken from the six new instruments installed in April 2005. A complete compilation of all data is included as Appendix 2-B in graphical format, and as Appendix 2-C in tabular format. Three thermistor strings have been damaged and are no longer providing data. SRK-13 has been permanently damaged, apparently by wildlife, and has not been collecting data since August 2003. SRK-55 has been permanently damaged, apparently by frost-jacking, and collected data only during September 2004. Similarly, SRK-56 appears to have been damaged by frost action and only a single bead positioned below the ground surface continues to function.

2.5

Sample Collection and Laboratory Testing Representative disturbed overburden core samples were collected from each material type encountered. A list of the samples collected is included in Table 3.

MN/spk


October 2005


Page 8

Table 3: Samples Collected and Laboratory Testing Program Drill Hole

Sample No.

Lab Sample No.

Sample Depth (m)

Moisture 1 Content

SRK-51

2C 2D 2E 3C 3D 4C 4D 8A 9F

1L 2L 3L 4L 5L 6L 7L 9L 8L

1.87 - 2.00 2.00 - 2.12 2.12 - 2.60 3.38 - 3.52 3.58 - 3.68 4.10 - 4.44 4.44 - 6.14 10.64 - 11.11 11.11 - 11.21

X X X X X X X X

1F

3L

1.54 - 1.87

X

1G

2L

1.87 - 1.97

X

1H

1L

1.97 - 2.07

X

4C

6L

5.24 - 5.60

X

4D

5L

5.60 - 5.78

X

4E

4L

5.78 - 5.86

X

5A

7L

6.38 - 6.46

X

5C

9L

6.64 - 6.99

X

6D

12L

7.80 - 8.20

X

6E

11L

8.20 - 8.34

X

6F

10L

8.34 - 8.45

X

9G 2G 2H 2I 2L 2K 3C 3D 3E 6B

12.74 - 12.83 2.10 - 2.85 2.32 - 2.45 2.45 - 2.57 3.02 - 3.12 2.92 - 3.02 4.28 - 4.68 4.68 - 4.80 4.80 - 4.95 8.40 - 8.50

X X X X X X X X X X

2F

14L 3L 2L 1L 5L 4L 8L 6L 7L 1L 4L

2.10 - 3.40

X

3D

2L

4.00 - 4.10

X

3E

3L

4.10 - 4.40

X

3F

1L

4.55 - 4.67

X

5E 3D 1F 4C 4D 4E 5D 6D 6E 7B 9F

5L 1L 1L 8L 9L 5L 7L 6L 10L 4L 3L

7.56 - 7.68 2.36 - 2.57 2.42 - 2.81 5.15 - 5.28 5.28 - 5.38 6.20 - 6.57 8.06 - 8.15 8.15 - 8.27 8.43 - 11.20 10.65 - 11.00 13.07 - 13.17

X X X X X X

SRK-52

SRK-53

SRK-57

SRK-58

SRK-59 SRK-60 SRK-62

Atterberg Limits

Specific Gravity

Intact Bulk Density


Particle Size Distribution

Salinity


Unfrozen Water Content

X

X

X

X

X

X

X X

X X X

X X

X

X

X

X X

X X

X

X X X X X

X X X

X

X X X

X

X X X X

X

X

X

X

X

X

X

X

X X

X

X

X X X

X

X X

X X X X

X

X

X

X

X

X X

Note: 1 Gravimetric water content X - Test conducted on sample

MN/spk


October 2005


Page 9

3

Results of Drilling Program

3.1

Summary of Drill Hole Profiles

3.1.1 SRK-51 Borehole SRK-51 was drilled on the east abutment of the proposed North Dam, along the dam centreline, as shown in Figure 1. SRK-51 is a vertical hole that extends to a depth of 14.7 m and was drilled April 21, 2005. Sample recovery from SRK-51 was 100% over the entire length of the drillhole, and all samples were observed to be frozen. Soils at SRK-51 consisted of a 0.4 m of surface organics and peat overlying 1.7 m of silt with some clay. A 10.2 m thick ice-rich silt and clay unit was encountered below the silt layer. Below the silt and clay, a thin unit of silty sand with gravel (possibly till) was found immediately above the bedrock interface. Bedrock was encountered at a depth of 12.9 m and consisted of dark green foliated fine grained basalt with calcite veinlets. A detailed log of the material recovered from SRK-51 is included in Appendix 1.

3.1.2 SRK-52 Borehole SRK-52 was drilled on the west abutment of the proposed North Dam, along the dam centreline, as shown in Figure 1. SRK-52 is a vertical hole that extends to a depth of 14.3 m and was drilled April 22, 2005. Sample recovery was generally 100%, with poor recovery immediately above the bedrock interface. All recovered intact core was observed to be frozen and saturated, and a minimum of 0.05 cm of frozen saturated material was recovered from each drill run. Figure 2 shows a picture of intact and ice saturated core sections recovered from within the sand zone. Soils at SRK-52 consisted of a 0.1 m organic cover over 2.7 m of ice-rich silt and clay overlying 10.2 m of bedded fine to coarse sand with gravel. Gravel content increased with depth, and where gravel content was high core recovery tended to be poor. Dark green foliated basalt bedrock was intersected at a depth of 13 m, and was highly fractured, with RQD of zero, from 13 m to end of hole at 14.25 m. A detailed log of the material recovered from SRK-52 is included in Appendix 1.

3.1.3 SRK-62 Borehole SRK-62 was drilled east of Tail Creek 200 m south of the proposed North Dam alignment, as shown in Figure 1. SRK-62 is a vertical hole that extends to a depth of 15.3 m and was drilled on April 23, 2005. Sample recovery from SRK-51 was 100% over the entire length of the drillhole, and all samples were observed to be frozen. Soils at SRK-62 consisted of a 0.3 m peat and organic cover over 2.0 m of poorly graded sand overlying 11 m of ice-rich silt and clay, similar to material encountered in SRK-51. Dark green

MN/spk


October 2005


Page 10

foliated basalt bedrock was intersected at a depth of 13.4 m. A detailed log of the material recovered from SRK-62 is included in Appendix 1.

3.1.4 SRK-59 Borehole SRK-59 was drilled on the alignment of the spillway to characterize foundation conditions east of the proposed dam. The location is shown in Figure 1. SRK-59 is a vertical hole that extends to a depth of 5.6 m and was drilled on April 20, 2005. Sample recovery from SRK-59 was variable due to the shallow depth of overburden and the difficulty of recovering material using only the drill’s starter barrel. All recovered samples were observed to be frozen. Soils at SRK-59 consisted of a 0.1 m thick organic cover over 2.5 m of silty sand and underlain by bedrock. Dark green foliated basalt bedrock was intersected at a depth of 2.6 m. A detailed log of the material recovered from SRK-59 is included in Appendix 1.

3.1.5 SRK-60 Borehole SRK-60 was drilled on the alignment of the spillway to characterize foundation conditions east of the proposed dam. The location is shown in Figure 1. This borehole was drilled April 22, 2005 and was terminated at a depth of 4.2 m. Sample recovery from SRK-60 varied from 60 to 100% due to the shallow depth of overburden and the difficulty of recovering material using only the drill’s starter barrel. All recovered samples were observed to be frozen. Soil at SRK-60 consisted of a 0.15 m thick organic cover overlying 2.0 m poorly graded sand to silty sand containing 10 to 30% ice as discrete random veins. Top of bedrock was intersected at a depth of 2.2 m. Bedrock was dark green pillow basalt with minor calcite veinlets and fracture fillings, and had RQD of 65%. A detailed log of the material recovered from SRK-60 is included in Appendix 1.

3.1.6 SRK-53 Borehole SRK-53 was completed on April 25, 2005 and is located on the west side of Tail Lake, near the south end of the lake as shown in Figure 1. This borehole was drilled to a depth of 10.4 m. Sample recovery from SRK-53 was 100%. All recovered samples were observed to be frozen. Soil at SRK-53 consisted of a 0.2 m organic cover underlain by 4.0 m of ice-rich silt to clayey silt, containing 10 to 90% ice as massive veins and random veinlets. This was underlain by 0.6 m of fine to medium grained bedded sand with silt lenses. Top of bedrock was intersected at a depth of 4.9 m. Bedrock was dark fine grained basalt with calcite fracture fillings, and had RQD of 100%. A detailed log of the material recovered from SRK-53 is included in Appendix 1.

3.1.7 SRK-57 Borehole SRK-57 was drilled on the west side of Tail Lake, near the midpoint of the lake, as shown in Figure 1. Drilling was completed on April 24, 2005, with a final depth of 9.5 m. Core recovery ranged from 32 to 91%, with all recovered samples observed to be frozen. MN/spk


October 2005


Page 11

Soil at SRK-57 consisted of a 0.2 m organic cover underlain by 0.9 m of ice-rich silt containing 5 to 100% ice as massive veins and stratified lenses. Beneath the silt was 8.4 m of bedded fine to coarse clean sand and gravel. Bedrock was not intersected in SRK-57. A detailed log of the material recovered from SRK-57 is included in Appendix 1.

3.1.8 SRK-58 Borehole SRK-58 was drilled on the east side of Tail Lake, near the midpoint of the lake, as shown in Figure 1. Drilling was completed on April 24, 2005 to a depth of 10.7 m. Core recovery ranged from 73 to 100%, with all recovered samples observed to be frozen. Soil at SRK-58 consisted of a 0.15 m organic cover over 4.85 m of ice-rich silt to silt and clay containing 0 to 70% ice as stratified lenses and random veinlets. A layer of poorly to well graded fine to coarse sand with occasional gravel was then encountered over 4.9 m thick. Dark green basalt bedrock was intersected at a depth of 10 m. A detailed log of core from SRK-58 is included in Appendix 1.

3.2

Laboratory Testing Laboratory testing was performed on selected samples for characterisation purposes. The following sections summarise the results from the laboratory testing and the individual laboratory report sheets are all included in Appendix 3.

3.3

Water Content and Atterberg Limits Water content was measured on 43 samples, of which 9 were tested for Atterberg Limits. The results are summarised in Table 4 and the Atterberg Limits are plotted in plasticity chart shown in Figure 3. The moisture content (gravimetric water content) results varied from 13.7 and 137.5%, while the liquid limit ranged from 33 to 43%, the plastic limit from 16 to 22% and the plasticity index from 17 to 21%. The corresponding averages are 43.1% for water content, 39.2% for the liquid limit, 20.3% for the plastic limit and 18.9% for the plasticity index. The high volumetric water content values are indicative of ice lenses present in the overburden. The plasticity chart shown in Figure 3 indicates that the fine grained soils present in the marine deposit are all above the “A” Line, classifying the soils as inorganic clays with low to medium plasticity. The “A” Line delimits organic and inorganic soils.

MN/spk


October 2005


Page 12

Table 4: Water Contents, Atterberg Limits and Intact Bulk Densities Drill Hole

Sample No.

Lab Sample No.

Sample Depth (m)

Gravimetric Moisture Content (%)

SRK-51

2C

1L

1.87 - 2.00

73.4

2E

3L

2.12 - 2.60

36.1

3C

4L

3.38 - 3.52

49.7

3D

5L

3.58 - 3.68

42.3

4C

6L

4.10 - 4.44

42.4

4D

7L

4.44 - 6.14

53.8

43

22

21

8A

9L

10.64 - 11.11

52

40

21

19

9F

8L

11.11 - 11.21

42.2

1F

3L

1.54 - 1.87

55.4

42

22

20

1G

2L

1.87 - 1.97

107.8

1H

1L

1.97 - 2.07

137.5

4C

6L

5.24 - 5.60

19.6

4D

5L

5.60 - 5.78

23.5

4E

4L

5.78 - 5.86

20.5

5A

7L

6.38 - 6.46

17.7

5C

9L

6.64 - 6.99

14.5

6D

12L

7.80 - 8.20

23.1

6E

11L

8.20 - 8.34

23.6

6F

10L

8.34 - 8.45

22.5

SRK-52

9G

14L

12.74 - 12.83

23.3

2G

3L

2.10 - 2.85

66

2H

2L

2.32 - 2.45

132

2I

1L

2.45 - 2.57

63.2

2L

5L

3.02 - 3.12

24.6

2K

4L

2.92 - 3.02

21.9

3C

8L

4.28 - 4.68

26.5

3D

6L

4.68 - 4.80

25.6

3E

7L

4.80 - 4.95

25

6B

1L

8.40 - 8.50

17.2

2F

4L

2.10 - 3.40

53.8

3D

2L

4.00 - 4.10

50.4

3E

3L

4.10 - 4.40

49.1

3F

1L

4.55 - 4.67

50.8

5E

5L

7.56 - 7.68

24.2

3D

1L

2.36 - 2.57

13.7

SRK-60

1F

1L

2.42 - 2.81

20.7

SRK-62

4C

8L

5.15 - 5.28

50.4

4D

9L

5.28 - 5.38

47.3

4E

5L

6.20 - 6.57

51.2

6D

6L

8.15 - 8.27

36.3

6E

10L

8.43 - 11.20

43.9

7B

4L

10.65 - 11.00

40.8

9F

3L

13.07 - 13.17

38.2

SRK-53

SRK-57

SRK-58

SRK-59

MN/spk

Liquid Limit (%)

Plastic Limit (%)

Plasticity Index (%)

42

21

21

Specific Gravity

Intact Bulk Density 3 (kg/m )

Intact Bulk Dry Density 3 (kg/m )

1645

2.78

1694

1101

1981

1947

36

19

17

2.68 1265 2.68

1913

39

20

19

1630

33

16

17

40

22

18

2.68

1596

38

20

18

2.76

1834

1028

1653


1274

October 2005


3.4

Page 13

Particle Size Distribution The particle size distribution was measured on 13 soil samples. Nine of those samples had their fine fraction (smaller than 75 µm) determined by sedimentation process using a hydrometer. The laboratory procedure was performed according to ASTM D422-63(2002) “Standard Test Method for Particle-Size Analysis of Soils”. The fine grained samples, which represented nine samples, were generally composed of clayey silt with some sand. The clay content varied from 16 to 51% with an average of 37.0%; the silt from 40 to 82% with an average of 54.9%; the sand from 2 to 16% with an average of 8%, and gravel was present only in one sample with a 1% gravel content. These results are consistent with the CL classification obtained with the Atterberg Limits and the plasticity chart. The remaining four samples consisted of sandy soils. Two samples were composed of poorly graded sands, one sample with 97% sand and the other sample with 96% sand with traces of gravel (2%) and silt (2%). This sample is classified as SP according to the Unified Soil Classification System (USCS). The remaining two samples were composed of well-graded sands, one sample with 43% sand, 26% gravel, and 31% fines, and the other with 54% sand, 25% gravel and 21% fines.

3.5

Bulk Density The bulk density was measured on ten intact soil samples and the results are listed in Table 4. The values ranged from 1 265 to 1 947 kg/m3 and for an average of 1 716 kg/m3. Dry bulk densities varied between 1 028 to 1 274 kg/m3 and averaged 1 134 kg/m3. The lower values reflect the presence of pore ice and organic material.

3.6

Specific Gravity The specific gravity was measured on five samples. The values are also listed in Table 4. The values ranged from 2.68 to 2.78, for an average of 2.72.

3.7

Salinity The salinity of the pore water was measured on 16 samples, with values ranging from 2 to 162 parts per thousand (ppt) as listed in Table 5. With the exception of samples SRK-51-3D and SRK-52-1H, the results suggest that the salinity of the pore water increases with depth, generally due to the salts being flushed out from the freeze/thaw cycles within the active zone. The 162ppt salinity of sample SRK-51-3D most likely tested high due to contamination from brine used during the drilling process. The salinity measurements were performed according to ASTM D4542-95(2001) “Standard Test Method for Pore Water Extraction and Determination of the Soluble Salt Content of Soils by Refractometer”.

MN/spk


October 2005


Page 14

Table 5: Salinity of Pore Water Drill Hole No. SRK-51

SRK-52

SRK-53 SRK-57 SRK-58 SRK-62

3.8

Sample No.

Depth (m)

Salinity (ppt)

2D 3D 4D 9F 1H 5A 6F 2I 2K 3D 2F 3F 4D 5D 6E 9F

2.00 - 2.12 3.58 - 3.68 4.44 - 6.14 11.11 - 11.21 1.97 - 2.07 6.38 - 6.46 8.34 - 8.45 2.45 - 2.57 2.92 - 3.02 4.68 - 4.80 2.10 - 3.40 4.55 - 4.67 5.28 - 5.38 8.06 - 8.15 8.43 - 11.20 13.07 - 13.17

33.0 162.0 47.0 54.0 23.0 4.0 4.0 7.0 2.0 3.0 47.0 47.0 18.0 22.0 25.0 39.0

Unfrozen Water Content Unfrozen water content as a function of temperature was measured on three samples. The tested specimens had the following properties: Table 6: Unfrozen Water Content Sample Properties SRK-51-4D Bulk Density (kg/m3) Bulk Dry Density (kg/m3) Gravimetric water content (%) Volumetric Water Content (%) Assumed Specific Gravity of Solids Porosity Degree of Saturation

1694 1101 53.8 59.2 2.78 0.60 98.1

SRK-58-2F

SRK-62-6E

1630 1028 58.5 60.2 2.75 0.63 96.1

1834 1274 43.9 55.9 2.76 0.54 104.2

The unfrozen water content curves for the winter 2005 drill program as well as the sample from the summer 2004 drill program are shown in Figure 4. The range of the error bars represent the method to calculate the volumetric water content from time domain reflectometry (TDR) measurements, with the curve points passing through the average.

MN/spk


October 2005


Page 15

This report, “Winter 2005 Geotechnical Field Investigations at Tail Lake, Doris North Project, Nunavut, Canada”, has been prepared by SRK Consulting (Canada) Inc.

Dylan MacGregor, M.A.Sc.

Peter Mikes, B.A.Sc.

Reviewed by

Michel Noël, P.Eng.

Maritz Rykaart, Ph.D., P.Eng.

MN/spk


October 2005


4

Page 16

References SRK Consulting Inc. 2003a Hope Bay Doris North Project - Tailings Impoundment Preliminary Design, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2003. SRK Consulting Inc. 2003b. Hope Bay Doris North Project - Surface Infrastructure Preliminary Design, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2003. SRK Consulting Inc. 2005. Summer 2004 Geotechnical Field Investigation at Tail Lake, Doris North Project, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, April 2005.

MN/spk


October 2005

Figures

DORIS NORTH PROJECT Winter 2005 Geotechnical Field Investigation

Frozen core, SAND, ice saturated SRK-52 MIRAMAR HOPE BAY LIMITED

PROJECT No.

DATE

1CM014.04

Sept 2005

APPROVED

FIGURE

2

File Ref: Fig_7_2005 Winter drill rpt.ppt


Sample Plasticity From Atterberg Testing MIRAMAR HOPE BAY LIMITED

PROJECT

DATE

1CM014.04

Sept 2005

APPROVED

FIGURE

3

File Ref: Fig_8_2005 Winter drill rpt.ppt


Unfrozen Volumetric Water Fraction vs. Temperature MIRAMAR HOPE BAY LIMITED

PROJECT No.

DATE

1CM014.04

Sept 2005

APPROVED

FIGURE

4

Appendices

Appendix 1 Borehole Logs - Winter 2005 Program

PROJECT: Doris North - Detailed Infrastructure Design

BOREHOLE: SRK-51

LOCATION: East side of Tail Creek. adjacent to SRK-15

BORING DATE: 2005-04-21

BOREHOLE LOG

DIP:

2005-04-21

DRILL:

DATUM: NAD83

LABORATORY AND IN SITU TESTS C Consolidation

Ku

Thermal conductivity Unfrozen (W / m°C)

Undisturbed

GS Grab sample

D

Bulk density (kg/m3)

Kf

Thermal conductivity Frozen (W / m°C)

Lost

SS Split spoon

Dr

Specific gravity

PS

Particle size analysis

Ksat

Saturated hydraulic cond. (cm/s)

30.01 0.41

1

5

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY

ELEVATION - m DEPTH - m

DEPTH - m

WELL DETAILS & WATER LEVEL - m

30.42 0.00

LABORATORY and IN SITU TESTS

SILT, some clay, trace of sand, some organic, ice-rich Vs over 0.1 m, ~40% ice Ice layers over 0.2 m, ~60% Vr over 0.04 m, ~25% ice Ice layers over 0.3 m, ~80% ice Vr over 1.0 m, ~5 to 30% ice, averaging ~10% ice

DC-1

100

DC-2

100

28.29 2.13

Salinity= 33 ppt

SILT and CLAY, trace of sand Vr over 1.5 m, ~10 to 20% ice DC-3

100 D = 1645 Salinity= 162 ppt

3

Vr over 2.1 m, ~20 to 30% ice 4

DC-4

100

PS Dr = 2.777 Salinity= 47 ppt Unfrozen Water Content Kf = 1.92 Ku = 1.35

F:\geotec.log\templates\loglog_SRK_m23_HopeBay.sty PLOTTED: 2005-10-02 16:45hrs

15

5

DC-5

100

DC-6

100

Vr over 5.0 m, ~40 to 50% ice 6

7

25

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

Peat and organic soil Nbn

PS

2

20

Boyles 17

CASING: None

AZIMUTH: 0.00

COORDINATES: 7559015.52 N 434381.79 E

Core

10

2

DRILL TYPE: Triple tube (HQ)

TYPE OF SAMPLER DC Diamond core barrel

SAMPLE CONDITION Remoulded

DEPTH - ft

90.00

TO

OF

PAGE: 1

HOPE BAY (1CM014.004)

FILE No:


BOREHOLE: SRK-51

LOCATION: East side of Tail Creek. adjacent to SRK-15


BOREHOLE LOG

DIP:

90.00

2005-04-21

DRILL:

DATUM: NAD83


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


DC-7

100

DC-8

100

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m



9

10 PS Salinity= 54 ppt 35 Vr over 0.3 m, ~20% ice 11

DC-9

100

DC-10

100

DC-11

100

Ice layers over 0.3 m, ~80 to 90% ice Vr over 0.2 m, ~20% ice Vr over 0.8 m, less than 10% ice

12 40 18.06 12.36

13

17.54 12.88

Silty SAND with some Gravel Vs over 0.4 m, ~10% ice Nbn over 0.15 m Basalt Dark green foliated fine grained basalt with calcite veinlets

45 14

15

16.49 13.93

END OF BOREHOLE

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

30


Boyles 17

CASING: None

AZIMUTH: 0.00

COORDINATES: 7559015.52 N 434381.79 E

Core

50

2




DEPTH - ft

TO

OF

PAGE: 2


FILE No:


BOREHOLE: SRK-52

LOCATION: West abutment of the North Dam on Tail Lake


BOREHOLE LOG

DIP:

90.00

2005-04-22

DRILL:

DATUM: NAD83


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


Organic soil SILT and CLAY with trace of sand, ice-rich Nbn over 0.15 m Vs over 0.2 m, ~30% ice Vr over 2.2 m, ~10 to 30% ice

DC-1

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


35.74 0.00 35.67 0.07


95

PS 5

Salinity= 23 ppt

2

32.94 2.80 3

DC-2

100

DC-3

100

DC-4

100

Nbn Fine to coarse SAND with gravel, trace of silt Nbn

4


15 PS

5

D = 1981

Salinity= 4 ppt

6 DC-5

100

DC-6

100

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

1

20

Boyles 17

CASING: None

AZIMUTH: 0.00

COORDINATES: 7559082.73 N 434316.33 E

Core

10

2




DEPTH - ft

TO

OF

PAGE: 1


FILE No:

PS Dr = 2.691

7

25 D = 1947 Salinity= 4 ppt


BOREHOLE: SRK-52

LOCATION: West abutment of the North Dam on Tail Lake


BOREHOLE LOG

DIP:

2005-04-22

Boyles 17

CASING: None DATUM: NAD83


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


9 DC-7

49

DC-8

10

DC-9

70

DC-10

44

DC-11

100

0

DC-12

100

100

10

35 11

12 40

13

22.74 13.00

Basalt Dark green foliated basalt

45 14 21.49 14.25

15

END OF BOREHOLE


and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

30


DRILL:

AZIMUTH: 0.00

COORDINATES: 7559082.73 N 434316.33 E

Core

50

2




DEPTH - ft

90.00

TO

OF

PAGE: 2


FILE No:


BOREHOLE: SRK-53

LOCATION: South end of Tail Lake


BOREHOLE LOG

DIP:

90.00

2005-04-25

DRILL:

DATUM: NAD83


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


Organic soil Nbe SILT to Clayey SILT, trace of Sand, ice-rich with 10 to 90% ice as massive veins and random veinlets Vs over 1.35 m, ~15 to 40% ice

DC-1

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


31.39 0.00 31.39 0.20


5

100

Ice layers over 0.45 m, ~60% ice

2

Vs over 0.17 m, ~10% ice

D = 1265

Ice layers over 0.5 m, ~60 to 90% ice DC-2

100

DC-3

100

DC-4

100

DC-5

100

PS Dr = 2.681 Salinity= 7 ppt

Nbe over 0.2 m Vs over 0.15 m, ~15% ice Nbe over 0.5 m

3

Vs over 0.6 m 4 27.17 4.22


15

5

Fine to medium grained SAND with silt lenses Nbn BASALT Dark fine grained basalt with calcite fracture fillings

6

7

25

26.54 4.85

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

1

20

Boyles 17

CASING: None

AZIMUTH: 0.00

COORDINATES: 7556906.93 N 435184.24 E

Core

DEPTH - ft

TO

2




10

OF

PAGE: 1


FILE No:

100


BOREHOLE: SRK-53

LOCATION: South end of Tail Lake


BOREHOLE LOG

DIP:

TO

2005-04-25

Boyles 17



Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


SAMPLES

N or RQD

100

100

DC-7

100

100

CONDITION

RECOVERY %

WATER CONTENT

DC-6

TYPE AND NUMBER

DESCRIPTION

SYMBOL

STRATIGRAPHY


DEPTH - m


9

10 21.04 10.35 35 11

12 40

13

45 14

15

END OF BOREHOLE


and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

30


DRILL:

AZIMUTH: 0.00

COORDINATES: 7556906.93 N 435184.24 E

Core

50

2




DEPTH - ft

90.00

OF

PAGE: 2


FILE No:


BOREHOLE: SRK-57

LOCATION: West side of Tail Lake.


BOREHOLE LOG

DIP:

90.00

2005-04-24

DRILL:

DATUM: NAD83


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


1

30.12 1.07

Peat with organic soil Nbn SILT, ice-rich with 5 to 100% ice as massive veins and stratified lenses Vs over 0.1 m, less than 5% ice Nbn over 0.22 Vs over 0.4 m, ~5% ice Ice layers over 0.75 m, ~40 to 75% ice Fine to coarse SAND with some gravel, trace of silt

DC-1

86

DC-2

77

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


31.19 0.00 30.99 0.20


Vs-Vr over 0.3 m, ~10 to 20% ice 2

Nbn over 1.65 m

Salinity= 2 ppt D = 1913 Dr = 2.684

3

Vs over 1.0 m, less than 5% ice DC-3 4 PS Salinity= 3 ppt F:\geotec.log\templates\loglog_SRK_m23_HopeBay.sty PLOTTED: 2005-10-02 16:45hrs

15 Nbn over 4.8 m 5

32

DC-5

33

6

7

25

DC-4

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

5

20

Boyles 17

CASING: None

AZIMUTH: 0.00

COORDINATES: 7557812.13 N 434937.73 E

Core

DEPTH - ft

TO

2




10

OF

PAGE: 1


FILE No:


BOREHOLE: SRK-57

LOCATION: West side of Tail Lake.


BOREHOLE LOG

DIP:

TO

2005-04-24

Boyles 17



Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


DC-6

91

DC-7

57

9

21.72 9.47

10

35 11

12 40

13

45 14

15

END OF BOREHOLE

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


30


DRILL:

AZIMUTH: 0.00

COORDINATES: 7557812.13 N 434937.73 E

Core

50

2




DEPTH - ft

90.00

OF

PAGE: 2


FILE No:


and LIMITS (%) W

P

W

W

L

20 40 60 80 100120


BOREHOLE: SRK-58

LOCATION: East side of Tail Lake.


BOREHOLE LOG

DIP:

TO

2005-04-24

DRILL:

DATUM: NAD83


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


Peat and organic soil SILT to SILT and CLAY, ice-rich with 0 to 70% ice as stratified lenses and random veinlets Nbe over 0.1 m Vs over 0.65 m, ~50 to 70% ice

1

Vr over 0.9 m, ~5 to 20% ice

2

Nbn over 0.1 m Vr over 0.4 m, up to ~10% ice

DC-1

93

DC-2

100

DC-3

100

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


31.29 0.00 31.14 0.15


Vr over 0.9 m, ~25% ice

3

PS Salinity= 47 ppt Unfrozen Water Content Kf = 1.87 Ku = 1.05

Vs over 1.6 m, ~10 to 15% ice

D = 1653 4

PS Salinity= 47 ppt


15

5

6

7

25

26.19 5.10

Vr over 0.2 m, ~5% ice Fine to coarse SAND with occasional Gravel, poorly to well graded Vs over 0.6 m, less than 10%

DC-4

100

DC-5

100

Nbn over 4.1 m

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

5

20

Boyles 17

CASING: None

AZIMUTH: 0.00

COORDINATES: 7557704.54 N 435284.89 E

Core

10

2




DEPTH - ft

90.00

OF

PAGE: 1


FILE No:


BOREHOLE: SRK-58

LOCATION: East side of Tail Lake.


BOREHOLE LOG

DIP:

TO

2005-04-24

Boyles 17



Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


DC-6

100

DC-7

73

DC-8

100

9

10

21.32 9.97

20.59 10.70

35 11

12 40

13

45 14

15

BASALT Dark green basalt

END OF BOREHOLE

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


30


DRILL:

AZIMUTH: 0.00

COORDINATES: 7557704.54 N 435284.89 E

Core

50

2




DEPTH - ft

90.00

OF

PAGE: 2


FILE No:


and LIMITS (%) W

P

W

W

L

20 40 60 80 100120


BOREHOLE: SRK-59

LOCATION: North Dam spillway hole along Dam alignment


BOREHOLE LOG

DIP:

2005-04-19

DRILL:

DATUM: NAD83


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


36.49 0.00 36.39 0.10


DC-1

30

5

DC-2

10

DC-3

58

2

33.92 2.57

PS Basalt Dark green foliated basalt

3 DC-4

100

100

DC-5

100

100

4


15

5

30.89 5.60 6

7

25

END OF BOREHOLE

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

Organic soil Silty SAND with some gravel Nbn

1

20

Boyles 17

CASING: None

AZIMUTH: 0.00

COORDINATES: 7559217.29 N 434437.46 E

Core

10

1




DEPTH - ft

90.00

TO

OF

PAGE: 1


FILE No:


BOREHOLE: SRK-60

LOCATION: North Dam Spillway, east side of creek, south of dam HOPE BAY (1CM014.004)

FILE No:


BOREHOLE LOG

DIP:

90.00

2005-04-22

DRILL:

DATUM: NAD83


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


33.24 0.00 33.09 0.15


DC-1

58

Vr over 0.85 m, ~10 to 30% 5

2 31.03 2.21

BASALT Dark green pillow basalt with minor calcite veinlets and fracture fillings

29.04 4.20 15 F:\geotec.log\templates\loglog_SRK_m23_HopeBay.sty PLOTTED: 2005-10-02 16:46hrs

100

DC-3

100

3

4

5

6

7

25

PS DC-2

END OF BOREHOLE

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

Organic soil SAND to Silty SAND, some gravel, poorly graded with 10 to 30% ice as discrete random veins Nbn over 1.2 m

1

20

Boyles 17

CASING: None

AZIMUTH: 0.00

COORDINATES: 7559172.16 N 434437.54 E

Core

10

1



DEPTH - ft

TO

OF

PAGE: 1


65


BOREHOLE: SRK-62

LOCATION: Tail Lake, upstream of the proposed North Dam


BOREHOLE LOG

DIP:

90.00

2005-04-23

DRILL:

CASING: None

AZIMUTH: 0.00


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


27.80 0.34

1

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m


28.14 0.00


Fine grained SAND, poorly-graded Ice layers over 0.15 m Vr over 0.25 m, ~10% ice Ice layers over 0.26 m, ~60% ice

DC-1

92

DC-2

100

DC-3

100


2 25.79 2.35

SILT and CLAY, ice-rich Vs over 0.5 m, ~10 to 20% ice Nx over 0.26 m

3 Vr over 1.65 m, up to 5% ice

4


15 Vs over 2.8 m, ~5 to 10% ice 5

PS D = 1596 Dr = 2.682 Salinity= 18 ppt DC-4

100

DC-5

100

6

7

25

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120

PEAT with organic soil Nbn to Nbe

5

20

Boyles 17

COORDINATES: 7558994.93 N 4345000.74 E DATUM: NAD83

Core

10

2




DEPTH - ft

TO

OF

PAGE: 1


FILE No:

Vr over 1.1 m, ~5% ice Salinity= 22 ppt


BOREHOLE: SRK-62

LOCATION: Tail Lake, upstream of the proposed North Dam


BOREHOLE LOG

DIP:

2005-04-23

DRILL:

CASING: None

AZIMUTH: 0.00


Ku


Undisturbed

GS Grab sample

D


Kf


Lost

SS Split spoon

Dr

Specific gravity

PS


Ksat


DC-6

WATER CONTENT

N or RQD

RECOVERY %

TYPE AND NUMBER

SYMBOL

DESCRIPTION

CONDITION

SAMPLES

STRATIGRAPHY


DEPTH - m



100

9 30

10

DC-7

100

DC-8

100

DC-9

100

DC-10

100

PS Dr = 2.758 Salinity= 25 ppt Unfrozen Water Content Kf = 2 Ku = 1.63

35 11

12 40

Salinity= 39 ppt

13

14.70 13.44 45

BASALT Dark green foliated basalt

14

15 12.84 15.30

END OF BOREHOLE

and LIMITS (%) W

P

W

W

L

20 40 60 80 100120



Boyles 17

COORDINATES: 7558994.93 N 4345000.74 E DATUM: NAD83

Core

50

2




DEPTH - ft

90.00

TO

OF

PAGE: 2


FILE No:

100

Appendix 2 Ground Temperature Data

Appendix 2A Calibration Data Sheets

Appendix 2B Temperature Data - Figures

-20.0 0.0


-15.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0 2002/09/14

2002/09/14

2002/09/15

2002/09/19

2003/03/29

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2004/09/26

2005/07/18

2005/07/18

2005/05/16

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

1


-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2002/09/14

2002/09/14

2002/09/15

2002/09/19

2003/02/16

2003/03/17

2003/03/24

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

2

o

-20.0 0.0

Soil Temperature ( C) -10.0 -5.0

-15.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0


2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2005/04/16

2005/05/16

2005/07/18

2005/09/08

2005/09/26


SRK-14 Thermistor Data PROJECT

DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

3


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2005/04/16

2005/05/16

2005/07/18

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

4


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2002/09/14

2002/09/15

2002/09/19

2003/03/18

2003/03/24

2003/04/06

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2005/04/16

2005/04/16

2005/07/18

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2004

L.W.

FIGURE

5

o

Soil Temperature ( C) -20.0 0.0

-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0


10.0

12.0 2003/04/14

2003/04/16

2003/05/17

2003/08/25

2003/09/21

2004/04/16

2004/08/26

2005/04/16

2005/05/16

2005/07/17

2005/09/08

2005/09/26



DATE

1CM014.04

Oct. 2005

APPROVED

L.W.

FIGURE

6


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0


2003/04/13

2003/04/14

2003/04/16

2003/05/17

2003/08/25

2003/09/21

2004/08/26

2005/04/16

2005/05/16

2005/07/17

2005/09/08

2005/09/26

2004/04/16



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

7


-15.0

-10.0

-5.0

0.0

5.0


2.0

4.0

6.0

8.0

10.0

12.0 2003/04/13

2003/04/14

2003/04/15

2003/04/16

2003/05/17

2003/08/25

2003/09/21

2004/04/16

2004/05/17

2004/08/27

2005/04/16

2005/04/16

2005/07/17

2005/09/08

2005/09/26

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

8


-15.0

-10.0

-5.0

0.0

5.0


2.0

4.0

6.0

8.0

10.0 Initial readings on installation. Beads prob not equilibrated

12.0 2003/04/14

2003/04/15

2003/04/16

2003/05/17

2003/08/25

2003/09/21

2004/04/16

2004/05/17

2004/08/27

2005/04/16

2005/05/16

2005/07/17

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

9


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0


2003/04/13

2003/04/14

2003/04/15

2003/04/16

2003/05/17

2003/08/25

2003/09/21

2004/04/16

2004/05/17

2004/08/27

2005/04/16

2005/05/16

2005/07/18

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

10

o


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0


2003/04/13

2003/04/14

2003/04/16

2003/05/17

2003/08/25

2003/09/21

2004/05/17

2005/04/19

2005/05/16

2005/07/17

2005/09/08

2005/09/26

2004/04/16



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

11

o


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0


2003/04/13

2003/04/14

2003/04/16

2003/05/17

2003/08/25

2003/09/21

2004/04/16

2004/05/17

2004/08/27

2005/04/19

2005/05/16

2005/07/17

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

12


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0 2003/04/06

2003/04/09

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2005/04/16

2005/05/16

2005/07/18

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

13

o


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2003/04/06

2003/04/09

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2005/04/16

2005/05/16

2005/07/18

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

14


-15.0

-10.0

-5.0

0.0

5.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

2003/04/06

2003/04/09

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2005/04/16

2005/05/16

2005/07/18

2005/09/08

2005/09/26


SRK34A Thermistor Data PROJECT

DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

15


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0


2003/04/08

2003/04/13

2003/04/14

2003/04/16

2003/05/17

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/23

2005/04/16

2005/05/16

2005/07/18

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

L.W.

FIGURE

16

o


-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0 2003/04/06

2003/04/09

2003/04/13

2003/04/15

2003/04/16

2003/04/20

2003/05/16

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2004/08/27

2005/04/16

2005/05/16

2005/07/18

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

17

o Soil Temperature ( C)

-20.0 0.0

-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0 2003/08/25

2003/09/21

2004/04/11

2004/05/17

2005/05/16

2005/07/18

2005/09/08

2005/09/26

2004/08/27

2005/04/16



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

18


-20.0 0.0

-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

2003/08/25

2003/09/21

2004/04/11

2004/05/17

2005/05/16

2005/07/18

2005/09/08

2005/09/26

2004/08/27

2005/04/16



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

19

o


-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0

15.0


20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0 2003/08/25

2003/09/21

2004/04/11

2004/05/17

2005/05/16

2005/07/18

2005/09/08

2005/09/26

2004/08/27

2005/04/16



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

20


-30.0 0.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

2.0

4.0


6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0 2003/08/25

2003/09/21

2004/04/11

2004/05/17

2005/05/16

2005/07/18

2005/09/08

2005/09/26

2004/08/27

2005/04/16



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

21


-20.0 0.0

-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0 2003/08/25

2003/09/21

2004/04/11

2004/05/17

2005/05/16

2005/07/18

2005/09/08

2005/09/26

2004/08/27

2005/04/16



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

22


-20.0 0.0

-15.0

-10.0

-5.0

0.0

5.0

5.0

10.0


15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0 2003/08/25

2003/09/21

2004/04/11

2004/05/17

2005/05/16

2005/07/18

2005/09/08

2005/09/26

2004/08/27

2005/04/16



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

23


-20.0 0.0

-15.0

-10.0

-5.0

0.0

5.0


50.0

100.0

150.0

200.0

250.0

2004/08/31

2004/09/26

2005/04/25

2005/05/16

2005/07/18

2005/09/08

2005/09/26



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

24


-15.0

-10.0

-5.0

0.0

5.0

1.0


2.0

3.0

4.0

5.0

6.0

2005/04/26

05/16/2005

07/18/2005

09/08/2005

09/26/2005



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

25


-15.0

-10.0

-5.0

0.0

5.0

10.0

1.0


2.0

3.0

4.0

5.0

6.0 2005/04/25

04/26/2005

05/16/2005

07/18/2005

09/08/2005

09/26/2005



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

26


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0 2005/04/26

05/16/2005

07/18/2005

09/08/2005

09/26/2005



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

27


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0

2004/09/28

04/21/2005

05/16/2005

07/18/2005

09/08/2005

09/26/2005



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

28


-20.0 0.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

2.0


4.0

6.0

8.0

10.0

12.0

14.0

16.0

2004/09/28

04/21/2005

4/24/2005

05/16/2005

07/18/2005

09/08/2005

09/26/2005



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

29

Soil Temperature (oC) -2.0

-20.0 0.0

-15.0

-10.0

-5.0

0.0

5.0


2.0

4.0

6.0

8.0

10.0

12.0 2005/04/26

05/16/2005

07/18/2005

09/08/2005

09/26/2005



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

30


-15.0

-10.0

-5.0

0.0

5.0

2.0


4.0

6.0

8.0

10.0

12.0 2005/04/25

04/26/2005

05/16/2005

07/18/2005

09/08/2005

09/26/2005



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

31


-15.0

-10.0

-5.0

0.0

5.0

10.0

1.0


2.0

3.0

4.0

5.0

6.0 04/25/2005

04/26/2005

05/16/2005

07/18/2005

09/08/2005

09/26/2005



DATE

APPROVED

1CM014.04

Oct. 2005

M.M.N.

FIGURE

32

Appendix 2C Temperature Data - Tables

THERMISTOR DATA

SRK-11

Bead No.


Bead Location from Top (m)

5.0

6.0

7.0

8.5

10.0

Bead Depth (m)

3.8

4.8

5.8

7.3

8.8

2002/09/14 2002/09/14 2002/09/15

-5.7 -6.5 -6.8

-6.3 -7.3 -7.4

-6.3 -7.4 -7.5

-6.2 -7.3 -7.4

-6.1 -7.0 -7.3


-7.5

-7.8

-7.9

-7.9

-7.8

Read By

Andrew Doe Andrew Doe Andrew Doe

Date

(SRK) (SRK) (SRK)

Thermistor chewed off by animals

Maritz Rykaart (SRK) Dylan McGreggor (SRK) Dylan MacGregor (SRK) Sebastian Fortin (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D. Kary (Miramar) E Ballent (Miramar) Notes:

2003/03/17 2003/03/24 2003/03/29 2003/04/06 2003/04/13 2003/04/15 2003/04/16 2003/04/20 2003/05/16 2003/08/25 2003/09/21 2004/04/11 2004/05/17



Thermistor chewed off by animals -7.9 -7.4 -21.8 -20.3 -15.5 -8.1 -7.7 -7.7 -7.4 -7.6 -8.4 -7.9 -7.6 -7.4 -7.5 -8.7 -8.1 -7.7 -7.5 -7.5 -8.8 -8.5 -7.8 -7.6 -7.6 -8.8 -8.2 -7.8 -7.5 -7.5 -8.9 -8.2 -7.8 -7.5 -7.5 -9.5 -8.9 -8.4 -7.9 -7.7 -8.3 -8.4 -8.4 -8.1 -8.1 0.8 -8.0 -8.1 -8.0 -8.1 -8.7 -8.1 -7.8 -7.4 -7.5 -9.9 -9.2 -8.6 -7.9 -7.8

2004/08/27

-8.7

-8.8

-8.8

-8.5

-8.4

2004/09/26

-8.1

-8.3

-8.3

-8.3

-8.3

2005/04/16

-9.9

-9.1

-8.6

-7.9

-7.9

2005/05/16

-10.5

-9.8

-9.1

-8.4

-8.1

2005/07/18 2005/09/08 2005/09/26

-9.8 -8.5 -0.4

-9.6 -8.7 -2.1

-9.3 -8.8 -4.4

-8.8 -8.5 -8.4

-8.5 -8.5 -8.4

String Serial No. = 00577-2 Total string length = 10.0 m (includes 0.1 m inside connector box) Stick up of lead is 1.1 m (thus actually 1.2 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed pipe installed to 23.0 m on 9/10/02 Pipe blocked at 10.0 m on 9/13/02 Thermistor installation 9/14/02

SRK-13

Read By

Date

Bead No. Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead Location from Top 5.0 6.0 7.0 8.5 10.0 (m)

Andrew Doe (SRK) Andrew Doe (SRK) Andrew Doe (SRK) Dwayne Winsor (Miramar) Dwayne Winsor (Miramar) Maritz Rykaart (SRK) Dylan MacGregor (SRK) Sebastian Fortin (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) E Ballent (Mirarmar) Notes:

2002/09/14 2002/09/14 2002/09/15 2002/09/19 2003/02/16 2003/03/17 2003/03/24 2003/04/06 2003/04/13 2003/04/15 2003/04/16 2003/04/20 2003/05/16 2003/08/25 2003/09/21 2004/04/11


Bead Depth (m)

1.1 0.0 -1.1 -1.2 -1.2 -26.5 -21.5 -23.5 -17.4 -18.8 -21.7 -13.1 -13.3 -3.3 16.4

2.1 -1.5 -3.7 -3.9 -4.2 -16.9 -19.6 -18.1 -17.6 -16.8 -16.7 -17.0 -16.4 -12.1 1.0

3.1 -2.8 -5.6 -5.8 -6.3 -11.9 -14.8 -14.9 -14.8 -14.7 -14.7 -14.9 -14.8 -12.6 -3.4 BROKEN

4.6 -4.3 -7.5 -7.5 -7.6 -7.4 -9.4 -9.9 -10.5 -10.8 -10.9 -11.2 -11.3 -11.4 -7.4

BROKEN

2004/05/17

No Readings

2004/08/27

No Readings

2004/09/26

No Readings

2004/09/26

No Readings

String Serial No. = 00577-1 Total string length = 10.0 m (includes 0.1 m inside connector box) Stick up of lead is 3.8 m (thus actually 3.9 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed pipe installed to 10.05 m on 9/11/02 Pipe blocked at 6.2 m on 9/13/02 Thermistor installation 9/14/02

6.1 -7.6 -8.0 -8.1 -8.1 -7.1 -8.1 -8.4 -9.0 -9.3 -9.4 -9.5 -9.6 -10.1 -8.3

THERMISTOR DATA

SRK-14

Read By

Date

Bead No. Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 Bead Location from Top 2.0 3.0 4.0 6.0 8.5 11.0 (m)


2003/04/06


2003/04/13 2003/04/15


2003/04/16 2003/04/20


2003/05/16


2003/08/25


2003/09/21

Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar)

2004/04/11 2004/05/17 2004/08/27


Bead Depth (m)

1.2

2.2

3.2

5.2

7.7

10.2

-11.8 -13.6 -13.8 1.2 -14.6 -14.7

-11.1 -12.6 -12.8 2.2 -13.7 -13.9

-9.7 -11.3 -11.6 3.2 -12.7 -12.8

-7.6 -9.3 -9.6 5.2 -10.5 -10.8

-7.8 -8.5 -8.6 7.7 -8.7 -9.0

-8.3 -8.6 -8.6 10.2 -8.6 -8.7

-10.8

-12.4

-12.5

-11.5

-9.8

-9.1

-0.1

-2.6

-4.9

-7.6

-9.2

-9.4

-0.1

-2.1

-4.1

-6.8

-8.6

-9.2

-17.8 -13.8

-16.3 -14.7

-12.8 -14.9

-9.8 -13.2

-8.9 -10.8

-9.6

-0.5

-2.8

-5.5

-8.5

-9.9

-9.9

-0.6

-2.3

-4.5

-7.3

-9.2

-9.6

-16.9

-17

-16.4

-13.8

-16.9

-9.6

-13.1

-13.9

-14.3

-13.5

-11.5

-10.1

-1.4 -0.3 -0.4

-4.7 -2.5 -2.1

-7.7 -5 -4.4

-10.6 -8.1 -7.4

-11.1 -9.8 -9.3

-10.5 -10.1 -9.9

2004/09/26 2005/04/16 2005/05/16


2005/07/18

D Kary (Miramar) E Ballent (Miramar) Notes:

2005/09/08 2005/09/26 String Serial No. = 690014

Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 0.67 m (thus actually 0.77 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 19.5 m on April 1, 2003 Thermistor installation 4/1/03 2:45pm Bead depth changed when steel casing was installed as thermistor protection

THERMISTOR DATA Bead No.

SRK-15

Bead Location from Top (m) Read By

Date

Inclined Bead Depth (m) Vert. Bead Depth (m)

Bead 1

Bead Bead Bead Bead Bead Bead Bead Bead 2 3 4 5 6 7 Bead 8 9 10

6.0

11.0

13.5

16.0

18.5

21.0

23.5

26.0

28.5

31.0

2.6

7.6

10.1

12.6

15.1

17.6

20.1

22.6

25.1

27.6

1.8

5.4

7.1

8.9

10.7

12.4

14.2

16.0

17.7

19.5

2003/04/06

-13.2

-8.3

-8.0

-8.1

-8.1

-7.8

-8.1

-8.2

-8.1

-8.1

Dan Mackie (SRK)

2003/04/13

-13.5

-8.4

-8.2

-8.3

-8.2

-7.9

-8.2

-8.2

-8.2

-8.2

Dan Mackie (SRK)

2003/04/15

-13.6

-8.4

-8.4

-8.3

-8.3

-8.0

-8.2

-8.2

-8.2

-8.2

Dan Mackie (SRK)

2003/04/16

-13.6

-8.4

-8.2

-8.3

-8.3

-8.0

-8.2

-8.2

-8.2

-8.1

Dan Mackie (SRK)

2003/04/20

-13.6

-8.4

-8.2

-8.3

-8.3

-8.0

-8.2

-8.2

-8.2

-8.2


2003/05/16

-11.4

-8.6

-8.4

-8.4

-8.4

-8.2

-8.2

-8.3

-8.2

-8.2


2003/08/25

-4.6

-8.9

-8.6

-8.5

-8.4

-8.3

-8.3

-8.3

-8.2

-8.2


2003/09/21

-4.1

-8.8

-8.6

-8.5

-8.4

-8.3

-8.3

-8.2

-8.1

-8.2


2004/04/11

-17.4

-8.4

-8.9

-8.5

-8.5

-8.3

-8.2

-8.3

-8

-8.1

-13.6

-8.8

-8.5

-8.4

-8.5

-8.3

-8.2

-8.3

-8

-8

-4.9

-9.5

-8.9

-8.4

-8.4

-8.2

-8.1

-8.2

-8.0

-8.0

-4.3

-9.4

-9.0

-8.5

-8.4

-8.2

-8.1

-8.2

-8.0

-8.0



Thorpe/Lindsay

2004/05/17


2004/08/27

Quinn Jordan-Knox (SRK)

2004/09/28


2005/04/16

-15.2

-9.2

-8.8

-8.6

-8.5

-8.3

-8.2

-8.2

-8.0

-8.0

D Kary (Miramar)

2005/05/16

-12.8

-9.7

-8.9

-8.6

-8.5

-8.3

-8.2

-8.2

-8.0

-8.0


2005/07/18

-6.1

-10

-9.2

-8.6

-8.5

-8.3

-8.1

-8.2

-8

-8

D Kary (Miramar)

2005/09/08

-4.5

-9.7

-9.3

-8.7

-8.5

-8.3

-8.1

-8.2

-7.9

-8

E Ballent (Miramar)

2005/09/26

4.2

-9.6

-9.3

-8.8

-8.6

-8.3

-8.2

-8.2

-8

-8

Notes: String Serial No. = 690012 Total string length = 31.0 m (includes 0.1 m inside connector box) Stick up of lead is 3.3 m (thus actually 3.4 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 21.9 m vert. depth on 3/24/03 Thermistor installation 3/24/03 11:40am Vert. bead depth corrected for inclined drill hole

THERMISTOR DATA

SRK-16

Read By

Date

Bead No.

Bead 1

Bead 2

Bead 3

Bead 4

Bead 5


5.0

6.0

7.0

8.5

10.0

3.3 -0.6 -2.1

4.3 -1.4 -2.4

5.3 -1.6 -2.5

6.8 -2.0 -3.1

8.3 -1.6 -2.8

-5.0

-6.5

-7.4

-7.9

-6.9

Bead Depth (m) Andrew Doe Andrew Doe

(SRK) (SRK)

2002/09/14 2002/09/15


Thermistor chewed off by animals

Maritz Rykaart (SRK) Dylan MacGregor (SRK) Dylan MacGregor (SRK) Sebastian Fontin (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar) E Ballent (Miramar) Notes:

2003/03/17 2003/03/18 2003/03/24 2003/04/06 2003/04/13 2003/04/15 2003/04/16 2003/04/20 2003/05/16 2003/08/25 2003/09/21 2004/04/11 2004/05/17 2004/08/27


Dwayne Winsor (Miramar) 2003/02/16 -13.6 -13.9 -14.3 -14.5 -14.5 -14.5 -14.5 -13.6 -7.4 -6.5 -16.7 -15.3 -7.9

Thermistor chewed off by animals -11.8 -10.5 -9.3 -12.2 -10.8 -9.5 -12.7 -11.4 -9.9 -13.0 -11.6 -10.2 -13.0 -11.7 -10.2 -13.0 -11.7 -10.3 -13.1 -11.8 -10.4 -13.0 -12.1 -10.9 -8.4 -9.0 -9.6 -7.6 -8.3 -9.0 -13.7 -13 -11 -14.4 -13.5 -11.9 -8.9 -9.7 -10.2

-8.9 -9.0 -9.2 -9.4 -9.5 -9.5 -9.5 -10.0 -9.8 -9.4 -9.8 -10.7 -10.4

2004/09/26 2005/04/16 2005/05/16 2005/07/18 2005/09/08 2005/09/26

-6.8 -16.3

-7.9 -14.8

-8.3 -13.5

-9.4 -11.7

-9.8 -10.6

-14.5 -9.7 -7.4 -6.7

-14.0 -10.6 -8.5 -7.8

-13.4 -11.2 -9.3 -8.7

-12.2 -11.3 -10 -9.5

-11.1 -11.1 -10.3 -9.9

String Serial No. = 00577-3 Total string length = 10.0 m (includes 0.1 m inside connector box) Stick up of lead is 1.6 m (thus actually 1.7 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed pipe installed to 20.9 m on 9/14/02 Thermistor installation 9/14/02 4:30pm Thermistor repaired on 3/18/03 - cable position unchanged

THERMISTOR DATA

SRK-19 Read By

Bead No.

Date



2.0

3.0

4.0

6.0

8.5

11.0

Bead Depth (m)

1.0

2.0

3.0

5.0

7.5

10.0

2003/04/14

-13.4

-11.8

-9.2

-7.9

-7.9

-8.0

Dan Mackie (SRK)

2003/04/16

-13.9

-11.5

-9.0

-7.0

-7.3

-7.6

2003/05/17

-9.7

-10.1

-9.3

-7.1

-7.3

-7.6

2003/08/25

-0.9

-4.2

-6.2

-7.4

-7.5

-7.6

2003/09/21

-0.7

-3.7

-5.7

-7.3

-7.4

-7.6

-15.5

-13.4

-10.5

-6.7

-7.3

-7.5

Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar)

2004/04/16 2004/05/17


Dan Mackie (SRK)

No Readings -1.0

-4.3

-6.6

-7.7

-7.5

-7.5

-0.9

-3.7

-5.9

-7.4

-7.6

-7.5

2005/04/16

-14.6

-13.5

-11.7

-7.6

-7.5

-7.6

2005/05/16

-12.4

-11.9

-11.2

-8.2

-7.5

-7.6

Gabrielle (Miramar) 2005/07/17

-1.9

-5.1

-8

-8.5

-7.7

-7.6

2005/09/08

-0.7

-4

-6.4

-8

-7.9

-7.6

E Ballent (Miramar) 2005/09/26

-0.7

-3.7

-6.1

-7.8

-7.9

-7.6

D Kary (Miramar)

2004/08/26 2004/09/28

Notes: String Serial No. = 690014 Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 0.95 m (thus actually 1.05 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 14.7 m on April 11, 2003 Thermistor installation 4/14/03 1:00pm

THERMISTOR DATA

SRK-20 Read By

Dan Mackie (SRK)

Bead No.

Date

2003/04/13

Bead Location from Top (m) Bead Depth (m) Temp (C) Bead Depth (m)

Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 2.0

3.0

4.0

6.0

8.5

11.0

0.8

1.8

2.8

4.8

7.3

9.8

-12.0

-10.2

-8.2

-6.7

-7.1

-7.4

0.8

1.8

2.8

4.8

7.3

9.8

2003/04/14 2003/04/16

-11.8 -12.7

-11.1 -11.0

-9.3 -9.4

-7.0 -6.9

-7.1 -7.0

-7.4 -7.4

2003/05/17

-9.3

-9.9

-9.3

-7.1

-7.1

-7.4

2003/08/25

0.3

-3.0

-5.3

-7.2

-7.2

-7.4

2003/09/21

0.0

-2.7

-4.9

-7.0

-7.2

-7.3

-15.1

-13.4

-11

-6.9

-7.1

-7.2

2004/04/16 2004/05/17


Dan Mackie (SRK) Dan Mackie (SRK) Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar)

No Readings 0.0

-3.3

-5.8

-7.7

-7.3

-7.1

-0.2

-2.8

-5.1

-7.4

-7.3

-7.1

-13.5

-12.6

-11.1

-7.6

-7.2

-7.2

2005/05/16

-11.8

-11.4

-10.6

-8.1

-7.2

-7.2

Gabrielle (Miramar)

2005/07/17

-0.7

-4.4

-7

-8.3

-7.4

-7.2

D Kary (Miramar)

2005/09/08

0.3

-3

-5.4

-7.7

-7.5

-7.2

E Ballent (Miramar)

2005/09/26

-0.1

-2.7

-5.1

-7.5

-7.5

-7.2

2004/08/26 2004/09/28 2005/04/16

Notes: String Serial No. = 690009 Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 1.13 m (thus actually 1.23 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 10.5 m on April 11, 2003 Thermistor installation 4/14/03 1:00pm Bead depth changed when steel casing was installed as thermistor protection

THERMISTOR DATA

SRK-22 Read By

Bead No.

Date



2.0

3.0

4.0

6.0

8.5

11.0

Bead Depth (m)

0.7

1.7

2.7

4.7

7.2

9.7

2003/04/13

-11.6

-11.5

-9.3

-7.3

-7.5

-7.8

Dan Mackie (SRK)

2003/04/14

-11.8

-11.4

-9.5

-7.3

-7.6

-7.9

Dan Mackie (SRK)

2003/04/15

-12.3

-11.3

-9.5

-7.3

-7.6

-7.9

Dan Mackie (SRK)

2003/04/16

-12.7

-11.4

-9.5

-7.3

-7.6

-7.9

2003/05/17

-10.3

-10.5

-9.7

-7.7

-7.7

-7.9

2003/08/25

-2.4

-5.6

-7.4

-7.9

-7.9

-8.0

-2.1

-5.1

-6.9

-7.8

-7.9

-8.0

-14.4

-12

-9.3

-7.4

-7.7

-7.8

-12.8

-11.7

-9.9

-7.7

-7.7

-7.8

-2.8

-6.0

-7.8

-8.2

-7.8

-7.8

2004/09/28

-2.6

-5.3

-7.2

-8.1

-7.9

-7.8

2005/04/16

-13.6

-12

-9.9

-7.8

-7.9

-7.9

2005/05/16

-11.9

-11.2

-10.1

-8.2

-7.9

-7.9

Gabrielle (Miramar)

2005/07/17

-4

-7.3

-8.8

-8.6

-8

-7.9

D Kary (Miramar)

2005/09/08

-2.4

-5.6

-7.6

-8.4

-8.1

-7.9

E Ballent (Miramar)

2005/09/26

-2.3

-5.3

-7.2

-8.2

-8.1

-7.9

Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar)

2003/09/21 2004/04/16 2004/05/17 2004/08/27


Dan Mackie (SRK)

Notes: String Serial No. = 690003 Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 1.22 m (thus actually 1.32 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 14.7 m on April 10, 2003 Thermistor installation 4/12/03 6:30pm

THERMISTOR DATA

SRK-23

Bead No.



2.0

3.0

4.0

6.0

8.5

11.0

Bead Depth (m)

0.9

1.9

2.9

4.9

7.4

9.9


-13.2

-11.9

-9.7

-8.0

-8.0

-8.3


-13.0

-11.6

-9.3

-7.1

-7.5

-7.8


-13.2

-11.6

-9.3

-7.1

-7.5

-7.8

Read By

Date

2003/05/17

-10.5

-10.5

-9.5

-7.6

-7.5

-7.8


2003/08/25

-1.5

-4.4

-6.7

-7.8

-7.7

-7.8


2003/09/21

-1.3

-4.0

-6.2

-7.7

-7.8

-7.8


2004/04/16

-16.2

-13.9

-10.8

-7.5

-7.6

-7.9

Thorpe/Lindsay

2004/05/17

-12.9

-12.6

-11.1

-8

-7.6

-7.8


2004/08/27

-1.7

-4.8

-7.2

-8.3

-7.8

-7.8


2004/09/28

-1.5

-4.2

-6.6

-8.1

-7.9

-7.8


2005/04/16

-14

-12.9

-9.9

-7.8

-7.8

-7.9

2005/05/16

-12.2

-11.7

-10.6

-8.4

-7.8

-7.9

2005/07/17

-2.6

-6

-8.4

-8.7

-7.9

-7.9

2005/09/08

-1.4

-4.4

-6.9

-8.3

-8.1

-7.9

2005/09/26

-1.3

-4.1

-6.5

-8.2

-8.1

-7.9

D Kary (Miramar) Gabrielle (Miramar) D Kary (Miramar) E Ballent (Miramar) Notes:



String Serial No. = 690008 Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 0.98 m (thus actually 1.08 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 14.7 m on April 10, 2003 Thermistor installation 4/14/03 2:11pm

THERMISTOR DATA

SRK-24

Dan Mackie (SRK)

Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar) E Ballent (Miramar) Notes:



3.0

4.0

6.0

8.5

11.0

0.7

1.7

2.7

4.7

7.2

9.7

-11.1

-9.9

-8.0

-7.1

-7.3

-7.4

0.7

1.7

2.7

4.7

7.2

9.7

-10.0 -10.4 -10.9 -10.0 -1.4 -1.2 -16 -13.3 -1.7

-11.0 -10.9 -10.8 -10.1 -4.5 -4.2 -14 -13 -5.2

-9.4 -9.5 -9.5 -9.4 -6.6 -6.2 -11.3 -11.4 -7.3

-7.2 -7.4 -7.3 -7.7 -8.1 -7.6 -7.6 -8.2 -8.3

-7.3 -7.3 -7.4 -7.5 -8.0 -7.6 -7.4 -7.4 -7.7

-7.4 -7.4 -7.4 -7.6 -8.0 -7.6 -7.5 -7.5 -7.4

-1.6

-4.6

-6.6

-8.0

-7.8

-7.4

-14.1

-13.2

-11.1

-8.1

-7.7

-7.5

2005/05/16

-13.9

-13.8

-13.5

-11.0

-9.1

-8.8

2005/07/18 2005/09/08 2005/09/26

-2.5 -1.3 -1.3

-6.3 -4.8 -4.4

-8.3 -6.9 -6.5

-8.7 -8.3 -8.1

-7.9 -8 -8

-7.5 -7.5 -7.5

Date

2003/04/13

Bead Depth (m) Temp (C) Bead Depth (m)

2003/04/14 2003/04/15 2003/04/16 2003/05/17 2003/08/25 2003/09/21 2004/04/16 2004/05/17 2004/08/27 2004/09/28 2005/04/16


Read By

Bead No.

String Serial No. = 690001 Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 1.22 m (thus actually 1.32 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 12 m on April 9, 2003 Thermistor installation April 9, 2003 Bead depth changed when steel casing was installed as thermistor protection

THERMISTOR DATA

SRK-26 Date

Dan Mackie (SRK)

2003/04/13

Dan Mackie (SRK)

2003/04/14

Bead Location from Top (m) Bead Depth (m) Temperature (Celsius)

Read By

Bead No.

Bead Depth (m)


3.0

4.0

6.0

8.5

11.0

0.8

1.8

2.8

4.8

7.3

9.8

-14.0

-13.1

-11.0

-8.5

-8.4

-8.7

-13.9

-13.1

-11.0

-8.6

-8.4

-8.7

0.8

1.8

2.8

4.8

7.3

9.8

2003/04/16

-14.8

-13.7

-12.3

-9.0

-8.4

-8.7


2003/05/17

-11.7

-12.2

-11.7

-9.6

-8.5

-8.7


2003/08/25

-1.6

-4.6

-6.8

-9.0

-8.9

-8.7


2003/09/21

-1.2

-4.0

-6.0

-7.8

-8.0

-8.0


2004/04/16

-18.8

-17.4

-15

-10

-8.5

-8.7

Thorpe/Lindsay

2004/05/17

-14.3

-15.1

-14.3

-10.8

-8.7

-8.7


2004/08/27

-1.9

-4.8

-7.5

-9.8

-9.2

-8.8


2005/04/19

-16.4

-15.6

-14.5

-10.6

-8.9

-8.9

2005/05/16

-13.9

-13.8

-13.5

-11

-9.1

-8.8

2005/07/17

-3.1

-6.5

-9.1

-10.6

-9.5

-8.9

2005/09/08

-1.6

-4.5

-7.1

-9.6

-9.5

-9

2005/09/26

-1.5

-4.1

-6.6

-9.3

-9.5

-9.1

D Kary (Miramar) Gabrielle (Miramar) D Kary (Miramar) E Ballent (Miramar) Notes:


Dan Mackie (SRK)

String Serial No. = 690002 Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead after steel installed is 1.13 m (thus actually 1.23 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 14.7 m on April 7, 2003 Thermistor installation on April 8, 2003 Bead depth changed when steel casing was installed as thermistor protection

THERMISTOR DATA

SRK-28

Bead No.


3.0

4.0

6.0

8.5

11.0

Bead Depth (m)

0.8

1.8

2.8

4.8

7.3

9.8

-12.1

-10.5

-8.6

-7.4

-7.8

-7.9

-12.0

-10.5

-8.6

-7.5

-7.8

-8.0

0.8

1.8

2.8

4.8

7.3

9.8

-13.3

-11.8

-10.2

-7.6

-7.7

-7.9

2003/05/17

-9.8

-10.6

-10.0

-8.2

-7.7

-8.0

2003/08/25

-1.5

-4.5

-6.6

-8.1

-8.0

-8.0

2003/09/21

-1.3

-4.1

-6.2

-8.7

-8.9

-8.8

-16.7

-14.7

-12

-8.1

-7.7

-8

-12.9

-13.2

-11.9

-8.8

-7.7

-7.9

-1.9

-5.0

-7.1

-8.6

-8.1

-8.0

-1.7

-4.3

-6.4

-8.3

-8.2

-8.0

-14.6

-13.8

-12.2

-8.9

-8.0

-8.0

2005/05/16

-12.2

-12.2

-11.6

-9.3

-8.1

-8.0

Gabrielle (Miramar) 2005/07/17

-2.8

-6.2

-8.4

-9.3

-8.3

-8

2005/09/08

-1.5

-4.6

-6.9

-8.7

-8.4

-8.1


-1.4

-4.2

-6.4

-8.4

-8.4

-8.1

Read By

Date

Dan Mackie (SRK) 2003/04/13 Dan Mackie (SRK) 2003/04/14



Bead Depth (m)

Jay Hallman (Miramar) Dylan McGreggor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar)

D Kary (Miramar)

2004/04/16 2004/05/17 2004/08/27 2004/09/28 2005/04/19



Notes: String Serial No. = 690011 Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead after steel installed is 1.13 m (thus actually 1.23 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 13.5 m on April 8, 2003 Thermistor installation April 8, 2003 Bead depth changed when steel casing was installed as thermistor protection

THERMISTOR DATA

SRK-32

Read By

Bead No.

Date



2.0

3.0

4.0

6.0

8.5

11.0

0.9

1.9

2.9

4.9

7.4

9.9

-11.5

-9.7

-8.9

-8.7

-8.7

-8.1

-12.0 -12.4 -12.7 -12.9 -13.2

-11.0 -11.9 -11.9 -11.9 -12.0

-8.8 -10.1 -10.2 -10.3 -10.4

-8.6 -8.6 -8.6 -8.5 -8.6

-8.5 -8.5 -8.5 -8.4 -8.4

-8.2 -8.3 -8.3 -8.3 -8.3

-11.4

-11.4

-10.7

-8.7

-8.3

-8.3

0.4 -0.1

-3.2 -2.8

-5.6 -5.0

-8.3 -7.4

-8.6 -8.6

-8.4 -8.4

-18.3 -13.5

-16.8 -14.2

-14.3 -13.5

-9.3 -10.2

-8 -8.3

-8.3 -8.3

0.0

-3.6

-6.1

-8.9

-8.9

-8.4

-0.5

-3.2

-5.4

-8.3

-8.8

-8.5

-15.2

-14.7

-13.3

-9.7

-8.4

-8.4

-13.0

-13.0

-12.4

-10.2

-8.6

-8.4

0.1 0.8 -0.2

-4.9 -3.2 -3

-7.5 -5.7 -5.3

-9.6 -8.6 -8.2

-9 -9 -9

-8.5 -8.6 -8.7

Bead Depth (m) Sebastian Fortin (SRK) 2003/04/06

Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK)

2003/04/13 2003/04/15 2003/04/16 2003/04/20


2003/05/16

Dylan MacGregor (SRK) 2003/08/25 Mike Cripps (Miramar)

2003/09/21

Dylan MacGregor (SRK) 2004/04/11 Thorpe/Lindsay

2004/05/17

Dylan MacGregor (SRK) 2004/08/27 Quinn Jordan-Knox (SRK)



2004/09/28

Dylan MacGregor (SRK) 2005/04/16 D Kary (Miramar)

2005/05/16


2005/07/18

2005/09/08 D Kary (Miramar) 2005/09/26 E Ballent (Miramar) Notes: String Serial No. = 690010

Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 1.0 m (thus actually 1.1 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 18 m on April 2, 2003 Thermistor installation April 5, 2003

THERMISTOR DATA

SRK-33

Read By

Date

Bead No. Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 Bead Location from Top 2.0 3.0 4.0 6.0 8.5 11.0 (m) Bead Depth (m)

Sebastian Fortin (SRK) 2003/04/06 Dylan MacGregor (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK)

2003/04/09 2003/04/13 2003/04/15 2003/04/16 2003/04/20


2003/08/25

Mike Cripps (Miramar) 2003/09/21 Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar)

2004/04/11 2004/05/17 2004/08/27


Jay Hallman (Miramar) 2003/05/16

0.9

1.9

2.9

4.9

7.4

9.9

-10.7

-6.9

-6.4

-5.3

-5.2

-5.0

-13.1 -12.4 -13.1 -13.4 -13.5

-12.0 -13.0 -13.1 -13.1 -13.3

-10.0 -12.5 -12.5 -12.5 -12.5

-7.3 -9.3 -9.6 -9.7 -9.9

-7.1 -7.8 -8.0 -8.0 -8.1

-7.2 -7.9 -8.1 -8.2 -8.3

-10.7

-11.7

-11.8

-10.4

-8.5

-8.6

-3.4

-5.4

-7.0

-8.9

-9.5

-8.8

-2.3

-4.7

-6.4

-8.5

-8.9

-8.8

-19.1 -15.3

-16.8 -15

-14.3 -13.9

-9.9 -10.7

-8.6 -8.7

-8.8 -8.7

-3.8

-6.0

-7.8

-9.6

-9.1

-8.8

-3.2

-5.1

-6.8

-9.0

-9.1

-8.8

-17.1

-15.7

-14.0

-10.4

-8.8

-8.8

-14.4

-14.0

-13.3

-10.9

-8.9

-8.8

-5.7 -3.4 -3

-8 -5.5 -5

-9.6 -7.4 -6.8

-10.4 -9.5 -9.1

-8.8 -9.3 -9.3

-8.8 -8.9 -9

2004/09/28 2005/04/16 2005/05/16

Jay Hallman (Miramar) 2005/07/18 2005/09/08 D Kary (Miramar) 2005/09/26 E Ballent (Miramar) Notes: String Serial No. = 690005

Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 1.0 m (thus actually 1.1 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 36.2 m on April 4, 2003 Thermistor installation April 5, 2003

THERMISTOR DATA

SRK-34A

Read By

Date


2003/04/06 2003/04/09 2003/04/13 2003/04/15 2003/04/16 2003/04/20 2003/05/16 2003/08/25 2003/09/21 2004/04/11 2004/05/17 2004/08/27


Sebastian Fortin (SRK) Dylan MacGregor (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Dan Mackie (SRK) Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar)

0.9

1.9

2.9

4.9

7.4

9.9

-10.3

-7.4

-7.4

-7.1

-6.1

-7.2

-13.1 -12.4 -13.1 -13.4 -13.5

-12.0 -13.0 -13.1 -13.1 -13.3

-10.0 -12.5 -12.5 -12.5 -12.5

-7.3 -9.3 -9.6 -9.7 -9.9

-7.1 -7.8 -8.0 -8.0 -8.1

-7.2 -7.9 -8.1 -8.2 -8.3

-10.5

-10.8

-10.3

-8.5

-7.5

-7.7

-1.8

-4.2

-6.1

-8.0

-8.1

-8.0

-1.5

-3.7

-5.5

-7.7

-8.0

-8.1

-17.6 -13.8

-15.3 -13.6

-12.2 -12

-8.8 -9.2

-7.4 -7.7

-7.6 -7.7

-2.2

-4.8

-6.4

-8.7

-8.5

-8.3

-1.9

-4.2

-5.6

-8.3

-8.4

-8.3

-14.8

-13.6

-11.4

-8.6

-7.8

-7.9

-12.6

-12.2

-11.0

-9.2

-8.0

-8.0

-3.4 -1.9

-6.2 -4.4

-7.6 -6

-9.2 -8.5

-8.5 -8.5

-8.3 -8.4

-1.7

-4

-5.5

-8.2

-8.4

-8.4

2004/09/28 2005/04/16 2005/05/16 2005/07/18 2005/09/08

E Ballent (Miramar) 2005/09/26 Notes: String Serial No. = 690004

Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead is 1.0 m (thus actually 1.1 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 11.2 m on April 5, 2003 Thermistor installation April 5, 2003

THERMISTOR DATA

SRK-35


Bead Location from Top (m) Bead Depth (m)

3.0

4.0

6.0

8.5

11.0

0.4

1.4

2.4

4.4

6.9

9.4

-6.8

-3.7

-2.9

-4.3

-5.1

-5.0

-7.4

-6.1

-4.5

-5.4

-6.0

-6.3

-7.5

-6.2

-4.6

-5.4

-6.0

-6.3

0.4

1.4

2.4

4.4

6.9

9.4

-10.3

-7.5

-6.0

-5.0

-5.9

-6.2

2003/05/17

-6.4

-7.0

-6.4

-5.3

-5.9

-6.3

2003/08/25

-0.4

-3.1

-4.8

-5.6

-6.0

-6.3

2003/09/21

-0.4

-2.7

-4.4

-5.5

-6.0

-6.3

-13.5

-11

-8

-5.4

-6

-6.2

-10.6

-10

-8.4

-5.7

-5.9

-6

-0.5

-3.6

-5.6

-6.0

-5.9

-6.1

-0.5

-3.1

-5.0

-6.0

-6.1

-6.1

-10.9

-9.9

-8.2

-5.9

-6.0

-6.1

2005/05/16

-9.7

-9.1

-8.2

-6.1

-6.0

-6.1

2005/07/18

-1.3

-4.5

-6.4

-6.4

-6.1

-6.1

2005/09/08

-0.1

-3.3

-5.3

-6.3

-6.1

-6.1

2005/09/26

-0.4

-3

-5

-6.2

-6.1

-6.1

2003/04/08

Dan Mackie (SRK) 2003/04/13 Dan Mackie (SRK) 2003/04/14

Bead Depth (m)

2004/04/11 2004/05/17 2004/08/23 2004/09/26 2005/04/16


Dan Mackie (SRK) 2003/04/16 Jay Hallman (Miramar) Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar) E Ballent (Miramar) Notes:


Date


Read By

Bead No.

String Serial No. = 690000 Total string length = 11.0 m (includes 0.1 m inside connector box) Stick up of lead after steel installed is 1.51 m (thus actually 1.61 m) Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 11.7 m on April 6, 2003 Thermistor installation April 7, 2003 Bead depth changed when steel casing was installed as thermistor protection

THERMISTOR DATA SRK-37

Bead No. Bead Location from Top (m) Inclined Bead Depth (m) Vert. Bead Depth (m)

Bead Bead Bead Bead Bead Bead 1 Bead 2 3 4 5 6 7

Bead Bead Bead 8 9 10

6.0

11.0

13.5

16.0

18.5

21.0

23.5

26.0

28.5

31.0

0.0

4.6

7.1

9.6

12.1

14.6

17.1

19.6

22.1

24.6

5.0

6.8

Date

0.0

3.3

8.6

10.4

12.1

13.9

15.7

17.4


2003/04/06

-14.7

-14.0

-12.2 -10.5

-9.3

-8.6

-8.2

-8.2

-8.4

-8.2


2003/04/09

-20.9

-13.1

-11.1

-9.6

-8.8

-8.7

-8.1

-8.2

-8.3

-8.0

Dan Mackie (SRK)

2003/04/13

-23.0

-14.2

-12.4 -10.7

-9.5

-8.8

-8.3

-8.3

-8.4

-8.2

Dan Mackie (SRK)

2003/04/15

-20.9

-14.3

-12.5 -10.8

-9.6

-8.8

-8.3

-8.2

-8.3

-8.2

Dan Mackie (SRK)

2003/04/16

-13.3

-14.2

-12.5 -10.8

-9.6

-8.8

-8.3

-8.2

-8.3

-8.2

Dan Mackie (SRK)

2003/04/20

-10.3

-14.3

-12.6 -10.9

-9.7

-8.9

-8.4

-8.2

-8.3

-8.2


2003/05/16

-1.8

-13.4

-12.5 -11.3 -10.1

-9.3

-8.6

-8.3

-8.2

-8.2


2003/08/25


2003/09/21

13.0 -5.2

-6.9 -6.1

-7.9 -7.1

-9.1 -8.6

-9.2 -8.8

-8.9 -8.8

-8.7 -8.6

-8.4 -8.5

-8.2 -8.3


2004/04/11

Thorpe/Lindsay

2004/05/17

-19.9 -3.2

-17 -15.5

-14.6 -12 -10.1 -14.4 -12.6 -11

-9 -9.8

-8.9 -9

-8.1 -8.3

-8.1 -8.2

-8.1 -8


2004/08/27

4.7

-7.4

-8.6

-9.4

-9.8

-9.7

-9.3

-8.9

-8.5

-8.2


2004/09/26

-8.4


2005/04/16

D Kary (Miramar)

2005/05/16


2005/07/18

D Kary (Miramar)

2005/09/08

E Ballent (Miramar)

2005/09/26


Read By

-8.7 -7.9

-1.4

-6.6

-7.5

-9.0

-9.2

-9.1

-8.9

-8.6

-8.3

-13.8

-16.5

-14.6 -12.3 -10.6

-9.5

-8.8

-8.4

-8.3

-8.2

-4.1

-14.6

-13.9 -12.5 -11.1 -10.0

-9.1

-8.6

-8.3

-8.2

11.9

-9.3

-10.3 -10.8 -10.7 -10.2

-9.5

-9

-8.6

-8.3

15.6

-6.9

-8.1

-9

-9.5

-9.6

-9.4

-9

-8.7

-8.4

-1.7

-6.3

-7.4

-8.4

-9.1

-9.3

-9.2

-9

-8.7

-8.4

Notes: String Serial No. = 690004 Total string length = 31.0 m (includes 0.1 m inside connector box) Stick up of lead is 6.26 m (thus actually 6.36 m) First bead is above ground surface Thermistor installed in 25 mm internal diameter polyethylene pipe Drill hole completed and pipe installed to 21.2 m vert. depth on March 25, 2003 Thermistor installation March 26, 2003 Vert. Bead Depth corrected for drill hole angle

SRK-38

Read By

Date

THERMISTOR DATA Bead Bead Bead Bead Bead Bead Bead Bead Bead No. 1 2 3 4 5 6 7 8 Bead Location from Top 6.0 11.0 16.0 21.0 31.0 41.0 51.0 (m) Bead Depth (m)

Dylan MacGregor 2003/08/25 (SRK) Mike Cripps (Miramar)

2003/09/21

Thorpe/Lindsay

2004/05/17

Dylan MacGregor 2004/08/27 (SRK) Quinn Jordan-Knox (SRK)

2004/09/26

Dylan MacGregor 2005/04/16 (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar)


Dylan MacGregor 2004/04/11 (SRK)

2005/05/16 2005/07/18 2005/09/08

E Ballent 2005/09/26 (Miramar) Notes:

-2.1

1.0

6.0

11.0 16.0 26.0 36.0

46.0

1.5

-7.9

-7.7

-8.1

-8.1

-8.0

-8.1

0.2

-7.9

-8.0

-8.2

-8.2

-8.1

-8.1

-17.6 -8 -13.4 -8.4

-8.2 -8.2

-8.3 -8.2

-8.2 -8.2

-8.1 -8.1

-8.1 -8.1

0.3

-9.0

-8.2

-8.2

-8.2

-8.1

-8.1

-0.5

-8.8

-8.2

-8.2

-8.2

-8.1

-8.1

-15.1 -8.5

-8.3

-8.3

-8.2

-8.1

-8.1

-12.4 -8.9

-8.3

-8.2

-8.2

-8.0

-8.1

0.9

-9.3

-8.3

-8.2

-8.2

-8

-8

0.9

-9

-8.3

-8.2

-8.2

-8

-8

-0.3

-8.9

-8.3

-8.3

-8.2

-8

-8

String Serial No. = TS0015 Total string length = 51.0 m Drill hole completed and pipe installed to 50 m

THERMISTOR DATA

SRK-39

Read By

Date


4.6

10.2

15.7

26.7

37.7

49.6

-1.2

-3.8

-1.1

-1.8

-1.9

-7.5

-6.3

-7.7

-7.8

-8.0

N/A

-8.2

-15.8 -11.8

-16 -12.3

-7.1 -7.8

-7.6 -7.6

-7.8 -7.8

-8 -8

4.5

4.2

-8.2

-7.9

-7.8

-8.0

-2.7

-2.5

-8.0

-7.9

-7.8

-8.0

-13.9

-12.9

-7.9

-7.8

-7.9

-8.0

-8.3

-7.8

-7.8

-8.0

-8.1

-8.6

-8

-7.8

-8

-8.1

-8.2

-8.1

-7.9

-8

-8.1

-8.1

-8.2

-7.9

-8

-8.1

2003/08/25 2003/09/21 2004/04/11 2004/05/17 2004/08/27

2004/09/28

2005/04/16


Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar)

2005/05/16 2005/07/18

D Kary (Miramar) 2005/09/08 E Ballent 2005/09/26 (Miramar) Notes: String Serial No. = TS0011 Total string length = 66.0 m


SRK-40

Read By

Date


2003/08/25 2003/09/21 2004/04/11 2004/05/17 2004/08/27 2004/09/26 2005/04/16 2005/05/16


Dylan McGreggor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar)

2005/07/18 2005/09/08


0.9

5.9

10.9

15.9

25.9

35.9

45.9

3.1

-8.2

-8.7

-8.5

-8.7

-8.8

-8.8

1

-7.8

-8.7

-8.6

-8.7

-8.8

-8.9

-18.2 -10 -14.7 -10.9

-8.2 -8.5

-8.5 -8.5

-8.8 -8.8

-8.9 -8.9

-8.9 -8.9

-0.1

-9.2

-9.0

-8.7

-8.7

-8.8

-8.8

-1.1

-8.4

-9.0

-8.7

-8.7

-8.7

-8.8

-15.9 -10.5

-8.6

-8.7

-8.8

-8.8

-8.9

-13.6 -10.9

-8.8

-8.7

-8.7

-8.8

-8.8

-0.5 0.5

-14.2 -8.8

-9.2 -9.2

-8.7 -8.7

-8.7 -8.7

-8.8 -8.6

-8.8 -8.6

-0.5

-8.3

-9.1

-8.7

-8.5

-8.3

-8.4

Notes: String Serial No. = TS0014 Total string length = 51.0 m Drill hole completed and pipe installed to 50 m

SRK-41

Read By

Date

THERMISTOR DATA Bead Bead Bead Bead Bead Bead Bead Bead Bead No. 1 2 3 4 5 6 7 8 Bead Location from Top 3.5 6.0 8.5 11.0 13.5 16.0 18.5 21.0 (m) Bead Depth (m)

E Ballent (Miramar)

2003/08/25 2003/09/21 2004/04/11 2004/05/17 2004/08/27 2004/09/26 2005/04/16 2005/05/16


Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar)

2005/07/18 2005/09/08 2005/09/26

1.4

3.9

6.4

8.9

11.4

13.9

16.4

18.9

-16

N/A

-4.9

-6.2

-6.5

-6.5

-6.8

-7

-15.4 -10.8

-10

-6.3

-6.7

-6.8

-7

-7.8

-18.5 -2.1

error -109

-9.3 -9.9

-6.6 -7.3

-6.5 -6.7

-6.8 -6.8

-7.1 -7

-7.2 -7.2

6.2

error

-6.5

-7.3

-7.2

-7.1

-7.1

-7.1

-1.3 -109.0

-5.8

-7.0

-7.2

-7.1

-7.1

-7.2

-13.5

-7.8

-6.5

-6.6

-7.0

-7.1

-7.2

-9.4

-8.2

-6.9

-6.8

-7.0

-7.1

-7.2

19 23.6

-6.9 -5.8

-7.2 -6.9

-7 -7

-7 -7.1

-7.1 -7.1

-7.2 -7.2

-1

-5.5

-6.7

-7

-7.1

-7.1

-7.2

error

Notes: String Serial No. = TS0012 Total string length = 21.0 m Drill hole completed and pipe installed to 30.6 m

SRK-42

Read By

Date

THERMISTOR DATA Bead Bead Bead Bead Bead Bead Bead Bead Bead No. 1 2 3 4 5 6 7 8 Bead Location from Top 11.0 16.0 21.0 31.0 41.0 51.0 (m) Bead Depth (m)

2003/08/25 2003/09/21 2004/04/11 2004/05/17 2004/08/27 2004/09/28 2005/04/16 2005/05/16


Dylan McGreggor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar)

2005/07/18 2005/09/08

E Ballent (Miramar) 2005/09/26 Notes: String Serial No. = TS0013 Total string length = 51.0 m Drill hole completed and pipe installed to 51 m

0.2

5.2

10.2

20.2

30.2

40.2

6

-6.3

-7.1

-7.8

-8

-8.1

0.8

-6.3

-7.3

-7.9

-8.1

-8.1

-17.4 -7.6 -11.3 -8.6

-7.4 -7.4

-8 -8

-8.1 -8.1

-8.1 -8.1

1.6

-7.7

-7.6

-8.0

-8.1

-8.1

-0.1

-7.2

-7.0

-8.0

-8.1

-8.1

-14.1 -7.7

-7.6

-8.0

-8.1

-8.1

-11.4 -8.2

-7.5

-8.0

-8.1

-8.1

2.9 1.2

-8 -7.2

-7.6 -7.6

-8 -8

-8.1 -8

-8.1 -8.1

-0.1

-7

-7.6

-8

-8.1

-8.1

SRK-43

Read By

Date


E Ballent (Miramar)

2003/08/25 2003/09/21 2004/04/11 2004/05/17 2004/08/27 2004/09/28 2005/04/16 2005/05/16


Dylan MacGregor (SRK) Mike Cripps (Miramar) Dylan MacGregor (SRK) Thorpe/Lindsay Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar)

2005/07/18 2005/09/08 2005/09/26

0.5

6.0

11.6

17.1

28.1

39.1

51.0

-2.3

-7.7

-7.8

-7.6

-8.2

-8.5

-8.5

-2.6

-8.2

-8.3

-8.2

-8.5

-8.6

-8.5

-16.4 -14.5

-8.2 -8.4

-8.6 -8.6

-8.7 -8.8

-8.7 -8.7

-8.6 -8.6

-8.9 -8.5

-5.2

-9.0

-8.6

-8.7

-8.7

-8.7

-8.5

-4.5

-9.0

-8.6

-8.8

-8.7

-8.6

-8.5

-15.1

-8.6

-8.7

-8.8

-8.8

-8.6

-8.5

-13.3

-8.8

-8.7

-8.8

-8.7

-8.6

-8.5

-6.4 -4.6

-9.1 -9.2

-8.7 -8.7

-8.8 -8.7

-8.7 -8.7

-8.6 -8.5

-8.5 -8.4

-4.1

-9.1

-8.7

-8.8

-8.7

-8.6

-8.5

Notes: String Serial No. = TS0010 Total string length = 66.0 m Drill hole completed and pipe installed to 51.5 m

THERMISTOR DATA Bead Bead Bead Bead Bead Bead Bead Bead Bead Bead Bead No. 1 2 Bead 3 4 5 Bead 6 7 Bead 8 9 10 11 12 13 Bead Location from Top 5.0 10.0 20.0 30.0 50.0 70.0 90.0 110.0 130.0 150.0 170.0 190.0 200.0 (m)

SRK-50

Read By

Date

Bead Depth (m)

E Ballent (Miramar)

2004/08/31 2004/09/26 2005/04/25 2005/05/16 2005/07/18 2005/09/08


Dylan MacGregor (SRK) Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar)

2005/09/26

5.0

10.0

20.0

30.0

50.0

70.0

90.0

110.0 130.0 150.0 170.0 190.0 200.0

-5.4

-6

-5.1

-4.9

-4.9

-5

-4.8

-4.7

-4.4

-4.3

-4.1

-3.8

-3.7

-5.4

-6.4

-5.7

-5.4

-5.3

-5.3

-5.1

-5

-4.7

-4.5

-4.3

-3.9

-3.8

-10.3

-7.2

-5.9

-5.65 -5.55

-5.45

-5.3

-5

-4.8

-4.6

-4.4

-4.05

-3.95

-10.1

-7.5

-5.9

-5.7

-5.4

-5.4

-5.3

-5

-4.8

-4.6

-4.4

-4

-4

-7.9 -6.3

-7.6 -7.2

-6 -6.1

-5.7 -5.7

-5.5 -5.5

-5.4 -5.4

-5.3 -5.3

-5.1 -5

-4.8 -4.8

-4.6 -4.6

-4.4 -4.4

-4.1 -4

-4 -4

-5.8

-6.9

-6.1

-5.7

-5.4

-5.4

-5.2

-5.1

-4.8

-4.6

-4.4

-4

-3.9

Notes: String Serial No. =

TS1618

Total string length = Estimated stickup: (assume no stickup)

finalized by QJK- check field notes for final stickup

Instrumentation installed August 8, 2004 PVC installed to (m b.g.s.): Drill hole completed to (m b.g.s.):

202.5 m 205 m

SRK-51

Read By

Date

THERMISTOR DATA Bead Bead Bead Bead Bead Bead Bead No. 1 2 3 4 5 6 Bead Location from Top 0.25 1.25 1.50 1.75 2.00 2.50 (m) Bead Depth (m)

Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar) E Ballent (Miramar) Notes:

3.00

3.50

4.00

4.50

5.00

6.00

1.50

2.00

2.50

3.00

3.50

4.00

5.00

-9.5 -10.7 -11.7 -12.9

-12.8

-12.2 -11.3 -10.4

-9.6

-8.6

-21.8 -10.7 -11.2 -11.3 -11.6 -11.9

-11.9

-11.8 -11.4 -10.9 -10.3

-9.3

21.9 27.6 -5.1

-7.8 -6.2 -5.8

-9 -7.5 -7.1

-9.7 -9.4 -9.3

-0.75

2005/04/26 erature (Ce 05/16/2005

Bead Bead Bead Bead Bead Bead 7 8 9 10 11 12

0.3

07/18/2005 09/08/2005 09/26/2005

0.25 0.50 -8.2

3.5 2.1 -0.3

-0.5 1.2 -0.3

0.75

-2.2 -1 -1.2

1.00

-3.7 -2.4 -2.2

-6.1 -4.6 -4.2

String Serial No. = TS2048 Total string length = 6m String stick-up above ground (m) :

1

Drill hole completed to 14.7m, ABS pipe used as casing, placed down to ~.6m below ground surface

-9.7 -8.4 -8

-10 -9 -8.7

-10 -9.3 -9

THERMISTOR DATA

SRK-52

Read By

Date

Bead No. Bead 1 Bead 2 Bead 3 Bead 4 Bead 5 Bead 6 Bead 7 Bead 8 Bead 9 Bead 10 Bead 11 Bead 12 Bead Location from Top 0.25 1.25 1.50 1.75 2.00 2.50 3.00 3.50 4.00 4.50 5.00 6.00 (m) Bead Depth (m)

-0.75

0.25

0.50

0.75

1.00

1.50

2.00

2.50

3.00

3.50

4.00

5.00

6

-7.9

-10.5

-12.7

-14.5

-16

-16.3

-16

-15.3

-14.7

-13.8

-12.9

9.2

-8.8

-10.7

-12.5

-14.2

-15.9

-16.3

-16

-15.4

-14.8

-14

-13.1

-9.8

-9.5

-11.1

-11.9

-12.8

-13.9

-14.5

-14.8

-14.7

-14.4

-13.9

-13.4

21.4

6

0

-2.7

-4.6

-7

-8.8

-10

-10.8

-11.2

-11.3

-11.7

21.2

10.3

2.3

-1.5

-3.1

-5.2

-6.9

-8

-8.8

-9.3

-9.5

-10.1

-1.4

-1.2

-0.9

-1.5

-2.8

-4.8

-6.3

-7.4

-8.2

-8.7

-8.9

-9.6

Dylan MacGregor 04/26/2005 (SRK) D Kary (Miramar) Jay Hallman (Miramar)

05/16/2005 07/18/2005

D Kary (Miramar) 09/08/2005


Dylan MacGregor 2005/04/25 (SRK)

E Ballent 09/26/2005 (Miramar) Notes: String Serial No. = TS2047 Total string length = 6m String stick-up above ground (m) :

1

Drill hole completed to 14.75m, ABS pipe used as casing, placed down to ~.75m below ground surface

THERMISTOR DATA

SRK-53

Read By

Date


Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar)

2005/04/26 erature (Ce 05/16/2005 07/18/2005 09/08/2005


0.60

1.60

2.60

4.60

7.10

9.60

-1.1

-0.8

-0.6

-0.3

-5.8

-5.9

-9.4

-9.7

-9.8

-8.2

-7.3

-6.7

-0.6 0.7

-4.3 -2.7

-6.5 -4.8

-7.8 -6.8

-7.6 -7.1

-7.1 -7

-0.1

-2.5

-4.5

-6.5

-6.9

-6.9

Notes: String Serial No. = TS1625 Total string length = 11m String stick-uppabove ground ,(m) : p p p 1.4 (factory zero markg,1.4m ppabove ground p p surface) wieghted to the bottom of the hole with the inside dry.

THERMISTOR DATA

SRK-54

Read By

Date


Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar) E Ballent (Miramar)

1.0

2.0

3.0

5.0

7.5

10.0

-0.1

0

-0.6

-4.3

-5.7

-6

-14.7

-14.1

-12.9

-9.5

-7.1

-6.8

-12.3

-12.4

-11.9

-9.7

-7.5

-6.9

1.4 1.5

-3.6 -2.1

-6.1 -4.3

-8.3 -6.9

-7.9 -7.6

-7.1 -7.2

0

-1.8

-3.8

-6.4

-7.5

-7.2

2004/09/28 04/21/2005 05/16/2005 07/18/2005

Temperat ure (Celsius)

09/08/2005 09/26/2005

Notes: String Serial No. = TS1626 Total string length = Approximate Stick up above ground (visual estimation from photo) : meter Drill hole completed and pipe installed to

THERMISTOR DATA

SRK-56

Read By

Date


04/21/2005

4/24/2005 05/16/2005 07/18/2005

D Kary (Miramar) 09/08/2005 E Ballent (Miramar)

0.8

3.3

5.8

2004/09/28


Quinn Jordan-Knox (SRK) Dylan MacGregor (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar)

09/26/2005

-2.9

-2.9

-2.6

0

-0.3

-3.6

-12.7

-13.4

-10.7

-11.9

error

error

1.4

1.7

1.6

-11.7

error

error

-12.8

-8.8

-10.4

-10.8

error

error

20.2

18.4

23.7

0.6

error

error

26.3

24

28.6

1.3

error

error

-1.4

-1.5

-1.1

0

error

error

Notes: String Serial No. = TS1621 Total string length = Approximate Stick up above ground (visual estimation from photo Top three beads are above casing (from Quinn's field notes) Drill hole completed and pipe installed to

5.2

THERMISTOR DATA

SRK-57

Read By

Date


D Kary (Miramar) Jay Hallman (Miramar)

0.33

1.33

3.33

5.83

8.33

-6.1

-5.5

-12.9

-12.5

-8.9

-6.6

error

error

error

-12.2

-10.6

-8.8

13.5

error

error

-7.6

-9.1

-9

7.8

error

error

-5.3

-7.3

-8.2

-1.4

error

error

-4.8

-6.8

-7.8

2005/04/26 05/16/2005 07/18/2005

D Kary (Miramar)

09/08/2005

E Ballent (Miramar)

09/26/2005



-0.67

Notes: String Serial No. = TS1623 Total string length = 11m String stick-uppabove ground, (m) : p p p saturated PVC pipe with end cap on bottom.

2.67

(factory zero g, mark g 2.67 m above ground surface)

THERMISTOR DATA

SRK-58

Read By

Date



2005/04/25


04/26/2005

D Kary (Miramar) Jay Hallman (Miramar)

07/18/2005 09/08/2005

E Ballent (Miramar)

09/26/2005

2.07

3.07

5.07

7.57

10.07

-6.5

-6.2

-3.5

-1.5

-0.4

-5.8

-11.3

-10.8

-8.9

-5.1

-2

-6.5

-11.3

-11.2

-10.6

-8.2

-7.3

-6.9

-4.2

-7.6

-9.1

-8.7

-7.7

-7.1

-2.8

-6

-7.9

-8.4

-7.8

-7.2

-2.6

-5.6

-7.5

-8.2

-7.8

-7.3

erature (Ce

05/16/2005

D Kary (Miramar)

1.07

Notes: String Serial No. = TS1622 Total string length = 11m String stick-uppabove ground ,(m) : p p p to the bottom of the hole with the inside dry.

0.93

(factory zero mark 0.93m above g, pp p p ground g surface)

SRK-62

Read By

Date

THERMISTOR DATA Bead Bead Bead Bead Bead Bead Bead Bead Bead Bead No. 1 2 3 4 5 6 Bead 7 Bead 8 9 10 11 Bead Location from Top 0.25 1.25 1.50 1.75 2.00 2.50 3.00 3.50 4.00 4.50 5.00 (m) Bead Depth (m)

Dylan MacGregor (SRK) Dylan MacGregor (SRK) D Kary (Miramar) Jay Hallman (Miramar) D Kary (Miramar) E Ballent (Miramar)

04/25/2005 04/26/2005

-0.75 erature (Ce 7.4 -7.8

05/16/2005 07/18/2005 09/08/2005 09/26/2005

-6.6 13.3 17.6 -1.7

0.25 -4.4 -6.8

6.00

0.50 0.75 1.00 1.50 -7.9 -10.1 -11.3 -12.1 -7.7 -9.5 -10.8 -12

2.00 -12 -12.3

2.50 -11.4 -11.7

3.00 3.50 -10.7 -9.8 -11.1 -10.2

4.00 -9.1 -9.5

5.00 -7.6 -8.1

-10.6 -10.7 -10.9 -10.8 -10.8 2.5 2 1.7 -1.2 -3.2 3.4 2.4 2 -0.4 -1.9 0 -0.1 -0.2 -0.7 -1.6

-10.8 -4.5 -3 -2.7

-10.7 -5.5 -3.9 -3.5

-10.5 -10.2 -6.4 -7.1 -4.8 -5.5 -4.3 -5

-9.9 -7.6 -6.1 -5.7

-8.9 -8 -6.9 -6.5

Notes: String Serial No. = TS2046 Total string length = 6m String stick-up above ground (m) :

Bead 12

1

Drill hole completed to 15.5m, ABS pipe used as casing, placed down 0.6m below ground surface, thermistor placed with no PVC pipe.

Appendix 3 Laboratory Testing

EBA Engineering Consultants Ltd. Unfrozen Water Content by Time Domain Reflectometry Project : Hope Bay Thermal Test Program Project No.: 0701-1780146 Date Tested: June 2, 2005 Calibration Factor Calibration Increment Offset TC Probe 1 Reading (kω) 1 2 3 4 5

1 0 0.135 Temp. (°C)

41.91

-7.23 -5.09 -4.10 -3.10 -2.31

37.67 35.82 34 32.6

Ka^0.5

Ka

3.05

9.27 9.66 10.93 14.17 16.97

3.11 3.31 3.76 4.12

Volumetric Unfrozen Water Content (%) Smith and Topp Tice (1988) et al. (1980) 14.8 15.7 18.8 26.0 31.4

17.8 18.6 21.0 26.6 30.7

Unfrozen Water Content Curve

60 Volumetric Unfrozen Water Content (%)

Specimen No. 62-10L Test Number: TDR-100 Saturation (%):104.2

50 40 30 0.0

Topp et al. (1980) Smith and Tice (1988) Gravimetric

20 10 0 5

4

3

2

1

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

Temperature (°C)

Smith and Tice (1988): θL=-0.1458+0.03868*Ka-0.0008502*Ka^2+0.00000992*Ka^3) Topp et al (1980): θL=-0.0597+0.0318*Ka-0.000738*Ka^2+0.00000814*Ka^3) A. Pre-Test Properties Volume (cm3) 3764

Mass (g) 6901.4

Mass (dry) (g) 4796

Mass Density Water Content (g/cm3) (% solids) 1.83 43.90

Volumetric Water Content (% solids)* (% total) 120.7 55.9

B. Post-Test Properties Volumetric Mass Water Content Volume Mass Mass (dry) Density Water Content Saturation (cm3) (g) (g) (g/cm3) (% solids) (% solids)* (% total) (%) n/a n/a n/a n/a n/a n/a n/a 104.2 Remarks: Average volumetric water content= 55.9 2.75 *estimated using a specific gravity=

Appendix F SRK Technical Memorandum Re: Wave Run-up Calculations


Tel: 604.681.4196 Fax: 604.687.5532


Brian Labadie

Date:

September 6, 2005

cc:

Project File

From:

Lowell Wade, Maritz Rykaart

Subject:

Wave Run-up Calculation to Determine Hydraulic Freeboard for Doris North Project Tailings Dam

Project #:

1CM014.006

1

Introduction This technical memorandum documents the wave run-up calculations that were used to determine the appropriate wave run-up portion of the hydraulic freeboard design height for the North Dam of the Doris North Project.

2

Previous Wave Run-up Calculation A preliminary calculation of the wave run-up was documented in SRK (2005), and used empirical tables correlating wind speed, fetch and wave height (USDI 1987). Based on an arbitrary maximum wind speed of 160 km/hr, with a maximum fetch distance of 3,200 m (equal to the maximum distance between the North and South Dams); the resultant wave height would be 1.13 m, requiring a 1.7 m vertical freeboard height. Since this value is obviously too conservative, a more rigorous assessment of the wave run-up height was carried out as described in the following sections.

3

Wind Speed Determination A long term database of site specific wind data is not available for the Doris North Project site. The data that is available includes two years of data from a weather station at Doris Lake, as well as approximately 5 years of data at the Boston site 60 km south of the Project (Golder 2005a, b; AMEC 2003). Golder (2005b) carried out a correlation between wind data at Roberts bay (4 km north of the site) with wind data from Cambridge Bay (160 km north of the site); however, this involved only a few days of data. Neither of these data sets is sufficient to estimate wind speeds required for wave run-up calculations. SRK contracted Mr. Pat Bryan, P.Eng., an associate hydrologist to determine design wind speeds for any given recurrence interval that could be used at the Doris North site. The estimation of extreme winds entailed a three step process. The first step was to extract an annual series of annual maximum hourly wind speed from the climate record of the Cambridge Bay Airport (see Table 1). This station has been measuring wind speed since 1953 and its record now spans 52 years. The largest event on record occurred on October 3, 1974 and attained an hourly average wind speed of 101 km/h.

EMR

1CM014.006_Wave Runup calculation_emr_20051006.doc, Oct. 11, 05, 3:09 PM

SRK Consulting

Page 2 of 4

The second step involved fitting the annual series of maximum wind speeds to three different frequency distributions to estimate extreme wind speeds for a variety of return periods. The results of the analysis are presented in Table 2. All three distributions provided reasonably similar estimates for all return periods from 2 to 500 years. The largest estimate of the 500-year event was generated by the Log-Pearson Type III distribution and is only 11% greater than the smallest estimate, which was generated by the Generalized Extreme Value distribution. Table 1: Observed Annual Maximum Hourly Wind Speeds at Cambridge Bay. Calendar Year 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Minimum Average Maximum

Annual Maximum Hourly Wind Speed (km/h) 71 80 68 71 76 80 89 69 76 71 89 69 72 68 69 72 85 84 80 89 82 101 87 97 80 93 83 89 65 67 70 69 80 80 70 69 74 83 74 74 67 70 82 76 74 83 65 74 80 65 70 65 65 76.7 101


SRK Consulting

Page 3 of 4

Table 2: Estimated Annual Maximum Hourly Wind Speeds (km/h) at Cambridge Bay for Various Return Periods. Frequency Distribution Used to Predict Extreme Hourly Wind Speeds:

Return Period (years)

Generalized Extreme Value

3-Parameter Lognormal

Log-Pearson Type III

75 84 89 95 102 107 112 118

75 83 89 95 104 111 118 128

74 83 89 96 105 112 120 131

2 5 10 20 50 100 200 500

The third step entailed determining how representative the Cambridge Bay wind data are of the mine site. This was done by comparing annual extremes at the two mine site weather stations with the corresponding annual extremes at Cambridge Bay. Table 3 tabulates the annual maximum wind speeds at the three stations over the period 2000 to 2004. The annual peak hourly wind speeds at the Boston station tended to be about 17% smaller than the annual peaks measured at Cambridge Bay. The peaks at Doris North, on the other hand, were nearly identical to the peaks observed at Cambridge Bay. Accordingly, these data suggest the Cambridge Bay data are reasonably representative of the mine site conditions. The Boston site provided four annual peaks for the comparison while the Doris Site provided two. Table 3: Comparison of Maximum Wind Speeds at Cambridge Bay and Mine site Meteorological Stations. Cambridge Bay Airport

4

Meteorological Station Boston

Year

Completeness of Annual Record

Annual Maximum Hourly Wind Speed

(%)

(km/h)

(%)

(km/h)

2000 2001 2002 2003 2004

99.8 99.9 100 100 100

74 80 65 70 65

99.7 81.5 99.2 70.0

57 65 57 60 n/a

Doris North





(%)

(km/h)

49.3 90.1

n/a n/a n/a 71 64

Fetch Length The maximum fetch length for any waves that may connect with the North Dam, for any wind direction, when the full supply level of 33.5 m has been reached in Tail Lake, is 1,326 m (northwest direction). Similarly, the maximum fetch length impacting the South Dam is 3,012 m (northnorthwest direction).


SRK Consulting

5

Page 4 of 4

Wave Run-up Calculations For the wave run-up calculations the extreme wind speeds calculated according to the Log Pearson Type III method (Table 2) was used. Calculations were carried out for a 1:100 year and 1:500 year recurrence interval, at fetch lengths of 1,326 and 3,102 m. Table 4 list the results of the wave run-up calculations according to the method described in Sorenson (1997, Section 2.9). Table 4: Summary of Wave Run-up Calculation Results. Parameter Fetch Recurrence Interval Wind Speed (km/hr) Wind Speed (m/sec) Significant Wave Height (m) Peak Spectral Period (sec) Wavelength (m) Wave Run-up, Smooth Surface (m) Wave Run-up, Rip-rap Surface (m)

6

North Dam 1,326 m 1:100 1:500 112 131 31.1 36.4 0.58 0.68 2.2 2.3 7.2 8.1 0.33 0.38 0.16 0.19

South Dam 3,012 m 1:100 1:500 112 131 31.1 36.4 0.87 1.02 2.8 3.0 12.5 13.9 0.50 0.59 0.25 0.29

Conclusion Based on the wave run-up calculations documented in this technical memorandum, the maximum hydraulic freeboard required to prevent overtopping of the dams due to wave run-up is 0.29 m.

7

References AMEC Earth & Environmental Ltd. 2003. Meteorology and Hydrology Baseline, Doris North Project. November. Golder Associates Ltd. 2005a. Doris North Project Air Quality Assessment Methods. Report No. 051373-008, May. Golder Associates Ltd. 2005b. Potential Impacts on Shorelines Due to Construction of a Jetty at Roberts Bay, Miramar Doris North Project. Report No. 04-1373-009.4100, May. Sorenson, R.M., 1997. Basic Coastal Engineering. Chapman & Hall. ISBN: 041212341X. pp. 288. SRK Consulting (Canada) Inc. 2005. Revised Dam Design, Preliminary Engineering, Hope Bay Doris North Project, Nunavut, Canada. Project No. 1CM014.04. May. United States Department of the Interior, Bureau of Reclamation. 1987. Design of Small Dams. A Water Resources Technical Publication, Third Edition, 66. 860.


Appendix G Larger Scale Drawings of Thermal Modelling Results


Tel: 604.681.4196 Fax: 604.687.5532


Brian Labadie

Date:

July 25, 2005

cc:

Project File

From:

Maritz Rykaart/Michel Noel

Subject:

Larger Scale Drawings of Thermal Simulations

Project #:

1CM014.006

Figures 1 through 3 below provides the cyclic temperature as modeled along the centerline of the dam at an elevation of 33.5, which is the FSL of the dam. The simulation results presented in the main body of the report, Figures 17 through 20 reflects the warm peaks presented in these figures for the simulation periods of 5, 15, 25 and 40 years respectively. These peaks happen to occur in the month of September every year. Therefore the depth of maximum summer thaw is clearly indicated by the isotherms on the drawings. This is deemed the best way to present the data since a table of depths can only be presented for a specific location on the dam, whereas the isotherms clearly show the temperature at any point along the dam. Furthermore the summer thaw depths associated with any freezing temperature as compared to the design criteria can be evaluated with this data. Figures 4 though 15 below are larger scale drawings of the upper zone of the dam, and each Figure coincides with the simulations presented in Figures 17 through 20 of the main report. The readers attention is drawn to the fact that these Figures (including those in the main report) have been produced using a vector based format and therefore the zoom tool in any PDF reader can be used to enlarge these drawings to any scale without loss of resolution. Predictions for upset conditions for the case without thermosyphons were not presented in the report, since the analysis indicated that in order to ensure the design objectives of the dam core temperature thermosyphons would be required.

EMR

App G - Larger Scale Thermal Simulations.doc, 3:24 PM, Oct. 11, 05

SRK Consulting

Page 2 of 16

HOPE BAY DORIS NORTH - North Dam ⏐ 26 Jul 2005 ⏐

0

Ground temperature (°C)

-2

-4

-6

-8 -10

-12 Average climate - Top of core elev. 33.5 m

-14 0

5

10

15

20

25

30

35

40

Time (years) Figure 1: Cyclic temperature along the North Dam core center line at an elevation of 33.5 m (FSL), under average climatic conditions without any thermosyphons present.

EMR


SRK Consulting

Page 3 of 16


0


-2

-4

-6

-8 -10

-12 Average climate with thermosyphons - Top of core elev. 33.5 m

-14 0

5

10

15

20

25

30

35

40

Time (years) Figure 2: Cyclic temperature along the North Dam core center line at an elevation of 33.5 m (FSL), under average climatic conditions with thermosyphons present.

EMR


SRK Consulting

Page 4 of 16


0


-2

-4

-6

-8 -10

-12 Warm climate with thermosyphons - Top of core elev. 33.5 m

-14 0

5

10

15

20

25

30

35

40

Time (years) Figure 3: Cyclic temperature along the North Dam core center line at an elevation of 33.5 m (FSL), under warm climatic conditions with thermosyphons present.

EMR


SRK Consulting

Page 5 of 16

North Dam Avg climate Year 5 ⏐ 26 Jul 2005 ⏐ T

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-1-142-13

-6

-11 -10

-9 -8

-6

-4

-4

1

2

-3

3

-14 -12-13

-5

-7

-2

-5

-10 -7

-11

0

-9

-8

-2

-3

-2

-3

-3

Elevation (m)

-4

30

-5

-5

-4

-5 -6

-2 -4

-5

-4

-3

-6

-5

-7 -7

-7

20

60


Figure 4: Temperature prediction for the North Dam core after 5 years, under average climatic conditions without any thermosyphons present (equivalent to Figure 17 in SD A1).

EMR


SRK Consulting

Page 6 of 16


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-14 -12 -8 -6

-7

-9

11

-13 -10 -4 -5 -3

-11 -6 -4

-9 -5

0

-12 -7 -8

Elevation (m)

-1 -10 3

-11

-9

-2

-3

-3

-1

-4

-3 -4

-5

-5

3

-3 -4-5 -2 -1

-2

30

2

- 14

-6

-1

-3

1

-6

-6

20

60



EMR


-2

SRK Consulting

Page 7 of 16


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-14

-10

-13-12 -5

-11 -8-9 -4

-7

-13-12 -6

-10

2

3

-7

-1

-14

-2 -1

-1

1

-1 -8-9 1

-6

-1

-2

0

-131

-3

2

-6 -5

-2

-2

-4

-1

Elevation (m)

-3

-3

30

-2

-4

-3

-5

-5

-6 -6

20

60



EMR


SRK Consulting

Page 8 of 16


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-11 0 -9 -1 -6 -5 -4 -3 -1

-13

-8

-14-12

-13

-9 -10 -6

-7

0

1

-11 -5 -8 -7

0

2

3

-14 -1

2

- 13 -3

-6

-9 -4

-2

-2

Elevation (m)

-3

30 -3

-4

-3

-4

-5

-5

-5

20

60



EMR


SRK Consulting

Page 9 of 16

North Dam Avg climate Thermosyphons Year 5 ⏐ 26 Jul 2005 ⏐ T

Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-8 -5

-6

-1 -3

-7

-3

-2

1

2

3

-6

-4

0

-4

0

-8 -5

-1

0

-7

-2

-1

-3

0

-1 -3

-2

-4

-2

Elevation (m)

-4 -3

-5

-4

-6

-5

-4

-3

30 -7

-6

-7

-8 -7 -8

-9

-9

-10

-8

-8

20 60


Figure 8: Temperature prediction for the North Dam core after 5 years, under average climatic conditions with thermosyphons present (equivalent to Figure 18 in SD A1).

EMR


SRK Consulting

Page 10 of 16


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-7

-5 --21

-6 -3

-6 -3

-4 0

-5 -2 -1

00

2

3

-7

-1

-2

1

-4

0

0 -1

0

-6 -3

0 -1

-2

-21

0

-5

-3 -4

Elevation (m)

-3

-3

-5

-4

-3

-6

-2

30 -5

-4

-7

-7

-6 -8

-6

-8

-9

-8

20 60



EMR


SRK Consulting

Page 11 of 16


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-3 -6 -4 -1

-7

-5

0

0

Elevation (m)

1

3

-2

0

0

-3

-5

-7 -1

-1 -2

-1

-4

-6

0

-3

-2

-4

-3

-5

-5

30

2

-6

0

-1 -1

-4

-1

-2

0

-2 -3

-6 -5 -7

-7 -8

-8

-7

20 60



EMR


SRK Consulting

Page 12 of 16


Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-5

-6

-2

-3

-4

-5

-2

0

2

3

-4 -1

0

0

1

-6

-3

-1

0

0 0

0

-2

-1

-3

-2

Elevation (m)

-3

-3

-4 -2

-5

-4

30

-4

-5 -6

-5

-6

-7

-7

-7

-6

-7

20

60



EMR


SRK Consulting

Page 13 of 16

North Dam Warm climate Thermosyphon Year 5 ⏐ 26 Jul 2005 ⏐ T

40 Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-3 -4

-6

-3

-4

-5 -1

-2

-6

-2

0

0

1

2

3

-5 -1 0

0

-3

0

-4

-2

0

Elevation (m)

-6

-1

-2

-2

-3 -4

-3 -5

-4

30

-1

-6

-7

-6

-5

-6

-8

-8

-7

-7

-8

20 60


Figure 12: Temperature prediction for the North Dam core after 5 years, under warm climatic conditions with thermosyphons present (equivalent to Figure 19 in SD A1).

EMR


SRK Consulting

Page 14 of 16


40 Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-6

-4 -1-2

-5 -3

0

-4 -2 -1

0

-6

0

2

3

-3 -5

0

0

-1

-1

Elevation (m)

1

--4 2

0

-1 -2

-3

-4

-1 -5

30

-5

-6

-5 -4 -6

-7

-6 -7

-8

-8

-7

-8

20 60



EMR


SRK Consulting

Page 15 of 16


40 Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-5 -4

-1 -2

-5-4 -3 0

0

1

2

3

-3

-1

-2 -1

0

0

-2

-1

-3

-2

-4

-3

30

-2

0

-1

0

Elevation (m)

0

-4

-4 -5

-5

-4

-6 -6

-6

-6

20

-7

-7

-5

-7

60



EMR


SRK Consulting

Page 16 of 16


40 Te: -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1

-1

-5 -3-4

2

3

-1

-2 0

0

0 0

0

Elevation (m)

1

5 -3--4

-2

0

0

0

-2

-2

30

-4

-4

-3

-1

-2

-3

-3

-5

-6 -5

-4

20 60



EMR


Appendix H Detailed Slope Stability Results

Miramar Hope Bay Ltd. - Doris North Project North Tailings Dam Stability Analysis March 2005

Miramar Hope Bay Ltd. - Doris North Project North Tails Dam - Block Failure along liner File Name: N Dam-US-Block2.slp Last Saved Date: 29/03/2005 A nalysis Method: Morgenstern-Price P.W.P. Option: Piezometric Lines / Ru Seismic Coef ficient: (none)

Material Properties

Geometry Dam Height UpstreamSlope Downstream Slope

Unit Weight (kN.cu.m.) 20 21 21 18 18.5

60

11.0 m 9.5 deg. (6H:1V) 14.0 deg. (4H:1V)

Results Title Upstream Block Failure Upstream Block Failure Upstream Circular Failure Upstream Circular Failure Downstream Block Failure Downstream Block Failure Downstream Circular Failure Downstream Circular Failure

50

40

FOS 2.7 1.7 3.2 2 3 2.4 2.3 1.8

g 0 .06g 0 .06g 0 .06g 0 .06g

2.673 Rock Shell

1 Water Soil Model: No Strength Unit Wei ght: 9.807 Piezometric Line #: 1 Pore-Air Press ure: 0

Soil Model: Mohr-Coulomb Unit Weight: 20 Piezometric Line #: 1 Pore-Air Pressure: 0

-25

Return Period 0 2475 0 2475 0 2475 0 2475

0

25

50

Fs= Infinite Slope Fs=

75

Distance (m)

6 Foundation Silt Soil Model: Mohr-Coulomb Unit Weight: 18.5 Piezometric Line #: 1 Pore-Air Pressure: 0

100

125

150

5 Core Soil Model: Mohr-Coulomb Unit Wei ght: 21 Piezometric Line #: 1 Pore-Air Press ure: 0

Miramar Hope Bay Ltd. - Doris North Project North Tails Dam - Dow nstream Block Failure File Name: N Dam-DS-Block2.slp Last Saved Date: 29/03/2005 A nalysis Method: Morgenstern-Price P.W.P. Option: Piezometric Lines / Ru Seismic Coef f icient: (none)

Manual Infinite Slope Case Analysis Slope angle = Waste rock phi =

3 T ransition Soil Model: Mohr-Coulomb Unit Weight: 21 Piezometric Line #: 1 Pore-Air Press ure: 0

30

20 -50

14 35 deg Tan(35)/Tan(14)

60

2.81 Elevation (m)

# 1 3 2 4 5 7 6 8

4 GCL Liner Soil Model: Mohr-Coulomb Unit Weight: 18 Piezometric Line #: 1 Pore-Air Pressure: 0

2

Elevation (m)

Material Rock Shell Core Transition GCL Foundation Silt

Angle of Internal Friction Cohesion (degrees) (kPa) 40 0 32 0 35 0 15 0 30 0

50

40

2 Rock Shell Soil Model: Mohr-Coulomb Unit Wei ght: 20 Piezometric Line #: 1 Pore-Air Press ure: 0


4 GCL Liner Soil Model: Mohr-Coulomb Unit Weight: 18 Piezometric Line #: 1 Pore-Air Press ure: 0

3.023

3 T ransi tion Soil Model: Mohr-Coulomb Unit Weight: 21 Piezometric Line #: 1 Pore-Air Pressure: 0

30

20 -50

-25

0


25

50

Distance (m)

75

100

125

5 Core Soil Model: Mohr-Coulomb Unit Weight: 21 Piezometric Line #: 1 Pore-Air Pressure: 0

150

3.231

Miramar Hope Bay Ltd. - Doris North Project North Tails Dam - Upstream Circular Failure File Name: N Dam-US-Circ-2.slp Last Saved Date: 29/03/2005 A nalysis Method: Morgenstern-Price P.W.P. Option: Piezometric Lines / Ru Seismic Coef ficient: (none)

Miramar Hope Bay Ltd. - Doris North Project North Tails Dam - Dow nstream Circular Failure File Name: N Dam-DS-Circ2.slp Last Saved Date: 29/03/2005 Analysis Method: Morgenstern-Price P.W.P. Option: Piezometric Lines / Ru Seismic Coef ficient: (none) 2.314

60

50

40

2 Rock Shell Soil Model: Mohr-Coulomb Unit Weight: 20 Piezometric Line #: 1 Pore-Air Pressure: 0


4 GCL Liner Soil Model: Mohr-Coulomb Unit Wei ght: 18 Piezometric Line #: 1 Pore-Air Press ure: 0

3 T ransition Soil Model: Mohr-Coulomb Unit Wei ght: 21 Piezometric Line #: 1 Pore-Air Press ure: 0

30

20 -50

-25

0


25

50

Distance (m)

75

100

125

5 Core Soil Model: Mohr-Coulomb Unit Weight: 21 Piezometric Line #: 1 Pore-Air Pressure: 0

150

Elevation (m)

Elevation (m)

60

50

40

2 Roc k Shell Soil Model: Mohr-Coulomb Unit Wei ght: 20 Piezometric Line #: 1 Pore-Air Press ure: 0


4 GCL Liner Soil Model: Mohr-Coulomb Unit Weight: 18 Piezometric Line #: 1 Pore-Air Pressure: 0

3 T ransition Soil Model: Mohr-Coulomb Unit Wei ght: 21 Piezometric Line #: 1 Pore-Air Press ure: 0

30

20 -50

-25

0


25

50

Distance (m)

75

100

125

5 Core Soil Model: Mohr-Coulomb Unit Wei ght: 21 Piezometric Line #: 1 Pore-Air Press ure: 0

150

Revised Dam Design

Recommend Documents