Appendix M Technical Specifications

Diavik Diamond Mines Inc., November 28, 2014 2014 Design Report Update - FINAL Project No.: 1207002-600-01

APPENDIX M TECHNICAL SPECIFICATIONS

A21 Dike Design Report_2014-11-28_Final BGC ENGINEERING INC. Technical Specification Revision

LIST OF DEFINITIONS, DRAWINGS AND TECHNICAL No. Date SPECIFICATIONS

14300-41ES-0000 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All June 13/14 June 16/14 June 14/14 Sep 9/14 Sep 9/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 16/14 Nov 16/14 Tender

Technical Specification Revision

LIST OF DEFINITIONS, DRAWINGS AND TECHNICAL No. Date SPECIFICATIONS

14300-41ES-0000 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1

2.0 DEFINITIONS ...... 1

3.0 DRAWINGS ...... 7

4.0 TECHNICAL SPECIFICATIONS ...... 10

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor / Owner shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

2.0 DEFINITIONS The following definitions pertain to the activities related to the A21 Dike and are referenced in the Technical Specifications listed in Section 4.0. 1. ADDITIVES are the ingredients added to the grout mix in small amounts to improve mix flow/setting/strength characteristics. 2. AMENABILITY COEFFICIENT is the ratio of the apparent Lugeon value (during the initial stages of the grouting stage – typically the apparent Lugeon value will decrease during an individual grouting stage) to the Lugeon value as derived from a water pressure test1.

1 The amenability coefficient is a measure of the ratio of apertures accessible to grout that are accessible to water. A low amenability coefficient is an indication that the grout being injected is only penetrating the widest fissure and is not suitable to penetrate the finer apertures that are still accessible to water injection. An amenability coefficient of 0.75 signifies that a residual hydraulic conductivity of at least 25% of the original hydraulic conductivity measured in the grout hole (by means of water pressure testing) can be expected within the grouting radius.

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3. APPARENT LUGEON is a measure of bedrock hydraulic conductivity adjusted on the basis of grout take flow rate and Marsh funnel viscosity. The following equation is used to define the apparent Lugeon value: groutflow ×143×Vmarsh Luapparent = Ls × Pinj × 28

where:

Luapparent = Apparent Lugeon value (Lu units) groutflow = Grout take (litres/minute) Vmarsh = Marsh funnel viscosity, expressed as efflux time for 1 litre of grout (seconds) 143 (psi) = Standard pressure for a Lugeon test Pinj = Grout injection pressure (psi) Ls = Length of the grouting stage (m)

4. BACKFILL AGGREGATE is a specified aggregate material used for back-filling of the pre-drill holes through which the CSM cut-off will be constructed. 5. BENTONITE is a natural clay, of which the principal mineral constituent is sodium montmorillonite. 6. BLEED RATIO is the ratio of bleed2 water after two hours to total grout sample volume at the beginning of the test. 7. CONSTRUCTION PLATFORM is the surface on which the equipment shall operate to construct the Cut-off Wall at elevation (El.) 418 m. 8. CONTRACT is the agreement between Owner and the Contractor that defines the contracted services for which the Contractor’s bid has been accepted or duly modified, as well as the measurement of services and payment. 9. CONTRACTOR is the Contractor named in the Contract Agreement. 10. CONTROL GRADATION TEST is the gradation testing conducted on samples obtained from the crusher or from the stockpiles. 11. CSM is the cutter soil mixing construction technique with which in-situ material is fluidized and mixed in place with injected cement-bentonite slurry to form a portion of the A21 dike Cut-Off Wall.

2 Bleeding of grout refers to the separation of solid particles from the fluid.

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12. CSM CUT-OFF WALL is a low permeable plastic concrete wall constructed in the A21 Dike, and keying into the underlying lakebed overburden soils foundation, by using CSM methodology. 13. DEPTH is the vertical distance from the start to the end of the hole, regardless of the direction of the hole. 14. DOUBLE-FLUID SYSTEM is the injection of cementitious grout slurry at high velocity, sheathed in a cone of air at an equally high velocity, to erode and mix with the soil. 15. EFFECTIVE GROUTING PRESSURE is the pressure of grout, while being pumped, at the midpoint of the stage of the hole being grouted, as calculated from the gauge pressure at the header plus the pressure head due to the weight of grout in the hole and feed lines minus the pressure head due to the water table. 16. EFFLUX TIME is the time required for a measured volume (commonly 1 litre) of grout to flow from a flow cone or funnel. 17. ENVIRONMENT means all natural physical, chemical and biological components as well as all social, cultural and historic components of South Island and any other geographic areas directly associated with the Work. 18. FIVE-STAGE WATER PRESSURE TEST is conducted for a given grout stage using 5 stages of pressure (3 up, 2 down), as described in Technical Specification 14300- 41ES-0015. 19. FLOW CONE is a device for measurement of grout consistency in which a predetermined volume of grout is permitted to escape through a precisely sized orifice, the time efflux (flow factor) being used as the indication of consistency. A flow cone commonly used in grouting is described in ASTM Standard Test Method C939. 20. GAUGE PRESSURE is the pressure measured by pressure gauge at header. 21. GROUT PENETRABILITY is the ratio of grout flow rate to applied injection pressure. 22. GROUT TAKE is a measure of grout injection in the rock or particular stage, in kg of cement. 23. HIGH MOBILITY GROUT is a low viscosity grout capable of extensive penetration into relative fine fractures. Typically water-cement-bentonite mixtures. 24. INFIELD AREA refers to the area between the proposed A21 open pit rim and downstream toe of the A21 Dike toe berm.

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25. JET GROUT COLUMN is the cylindrical column formed by Jet Grouting in weathered bedrock, lakebed till and/or glaciofluvial soils, and a lower portion of the CSM cut-off wall panel. The column will extend into bedrock although it is not expected that the cutting jet will destroy sound bedrock. The jetting action will remove joint infilling and permit replacement by grout. The columns will also be required in Zone 1B fill and/or in lakebed till where the CSM cut-off wall has not been constructed. 26. JET GROUTING is a technique consisting of drilling holes by rotary or roto- percussion method with low pressure water jet until the required depth in rock is reached. Subsequently, a high velocity horizontal jet is used to cut and remove the fine portion of the till and of the infilling joint materials in the bedrock, leaving in place the coarser portion of the soil which is incorporated into the cement bentonite slurry to form a cemented soil column. 27. LENGTH in reference to a curtain grouting hole is the distance from the start to the end of the hole, measured along the axis of the curtain grouting hole. 28. LOW MOBILITY GROUT is a high viscosity grout employed for filling of voids and large open features that cannot be economically and efficiently treated with high mobility grouts. Typically sand is added as a filler to decrease grout mobility. 29. LUGEON is a measure of rock mass hydraulic conductivity3. Equals water take of 1 liter/min/m of hole at an effective test pressure of 10 bar. 30. MANAGER’S REPRESENTATIVE is BGC Engineering Inc. (BGC) duly authorized, as the Engineer, by the Owner to act on its behalf. 31. MARSH FUNNEL is a device used for the field measurement of apparent viscosity of high mobility grouts. Analogous to flow cone used for thick mortars, but much smaller and more sensitive to small differences in apparent viscosity. 32. MUD BALANCE is a simple and rugged field apparatus for determining the density of drilling mud or grout. 33. OWNER is Diavik Diamond Mines (2012) Inc. (DDMI). 34. POOL DEWATERING is the pumping out of the portion of the lake enclosed by the A21 Dike, initially via direct discharge over the dike into Lac de Gras, and subsequently via pumping to Pond 3 and the North Inlet Pond once TSS levels reach levels that prohibit direct discharge to Lac de Gras.

3 One Lugeon approximately equates to a hydraulic conductivity of 1.4 x 10-5 cm/sec.

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35. PRE-DRILLING is the use of large diameter cased boreholes through embankment fill into the lakebed overburden soils foundation. 36. QUALITY ASSURANCE (QA) is a function that will be provided by the Manager’s Representative, and includes observations of QC activities and testing, review of the QC results, inspections, confirmations, and audits to determine and document the quality of the constructed facility. QA involves confirmations, which comprises doing testing to confirm the QC testing, typically at a ratio of one QA test for every ten QC tests, although a greater frequency of QA testing may be required initially for any given construction aspect. 37. QUALITY CONTROL (QC) is a function to be provided by the party executing a specific portion of Work and may be Contractor, supplier or Owner, and comprises testing and measurements to determine compliance with the requirements for materials and workmanship as stated in the Technical Specifications and Drawings. A testing company(s) may be hired to provide this service. 38. RATE OF GROUT TAKE is the rate of injection of cement grout slurry in L/min. in a given stage of a given grout hole. 39. RECORD GRADATION TEST is the gradation testing conducted on samples obtained from the dike embankment. 40. REFUSAL is the point at which grout injection is considered complete in a given stage of a given hole, as defined by Technical Specification 14300-41ES-0014 and as modified by Manager’s Representative. 41. SECTION in relation to curtain grouting is the horizontal length of grout curtain defined by station survey data. 42. SINGLE-STAGE WATER PRESSURE TEST is conducted for a given grout stage using a single applied pressure, generally lasting a maximum of 5 minutes, as described in Technical Specification 14300-41ES-0015. 43. SITE is the Diavik A21 project site and includes, but is not limited to the A21 Dike alignment, access roads, pipelines, water control structures, sediment control structures, disposal areas, stockpile areas and laydown areas. 44. SLURRY is a stable, colloidal, thixotropic suspension of powdered bentonite and cement and slag in water. 45. SPECIFIC GRAVITY is the density of the grout slurry (in kg/m3).

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46. SPLIT SPACING is the procedure of systematic reduction of the grout hole spacing by drilling and grouting additional holes between those holes which have previously been drilled and grouted. 47. SPLIT SPACED GROUT TAKE REDUCTION RATIO is the ratio of the grout take in an intermediate grout hole to the takes in two adjacent, previously drilled and grouted boreholes. A ratio of 0.5 is ideal, with ratios in the range of 0.25 to 0.75 being acceptable. Ratios outside of this range indicate that primary holes (and, consequently, secondary and higher order holes) spacing requires modification. 48. STABLE GROUT is a suspension grout that exhibits little or no settlement, bleed, or shrinkage, defined as a grout mix with a bleed less than 5% in 2 hours. 49. STAGE is specific length of grout hole defined by top and bottom depth, isolated by single/double packer and subjected to water or grout injection. 50. SURFACE WATER is all water that enters the Work area above the ground surface from either natural or artificial sources. 51. SURGING BLOCK is a plunger consisting of one or more stiff rubber or leather discs attached to a heavy shaft. The discs should be about 25 mm smaller in diameter than the well screen inside diameter. 52. TRIPLE-FLUID SYSTEM is the injection of water at high velocity, sheathed in a cone of air at an equally high velocity, to erode the soil while simultaneously tremie- injecting a cementitious grout slurry from beneath the erosion jets. 53. TSS is total suspended solids within the Water Body. 54. TURBIDITY BARRIER: A configuration of curtain (polyester reinforced vinyl fabric), flotation system and anchorage, to control dispersion of suspended solids within the area enclosed by the barrier. 55. UNIT GROUT TAKE is the grout take in kg of cement divided by length of particular stage in a particular grout hole. 56. UNSTABLE GROUT is a cementitious grout that exhibits excessive water bleed, separation, or segregation. 57. VIBRO-DENSIFICATION is a ground improvement technique that densifies granular soils by means of a down-hole vibrator.

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58. WATER BODY shall mean any body of water, whether moving or still, including, but not limited to, rivers, streams, creeks, lakes, ponds, marshes, sloughs, swamps, bogs, ditches with water in them, and shall include the area bounded by these bodies up to and including the high water mark. 59. WATER/CEMENT (W/C) RATIO is the ratio by weight of water to weight of cementitious material. 60. WATER LICENSE is the Diavik Diamond Mines Inc. Water License, which lists permit requirements that DDMI, and any Contractors on site, are required to adhere to. 61. WATER PRESSURE TEST is a test used to assess hydraulic conductivity of bedrock. The test is completed by injecting water into bedrock under a certain pressure and for a certain duration using single or double packers. 62. WORK shall mean, unless otherwise defined, the whole of the construction including equipment, materials, procedures, control, and labour performed by the Owner / Contractor to satisfactorily complete the dike construction as per the Drawings and Technical Specifications.

3.0 DRAWINGS The following Drawings pertain to the activities related to the A21 Dike and are referenced in the Technical Specifications outlined in Section 4.0.

Drawing No. Drawing Title 14300-41D2-1001 Drawing List

14300-41D2-1002 A21 Dike - General Site Layout

14300-41D2-1003.1 Turbidity Barrier Plan

14300-41D2-1003.2 Turbidity Barrier Profile

14300-41D2-1003.3 Turbidity Barrier Typical Plan, Profile and Section

14300-41D2-1004.1 Lakebed Foundation Preparation Plan (Sheet 1 of 2)

14300-41D2-1004.2 Dredging Pipeline Alignments (Sheet 2 of 2)

14300-41D2-1005 Filter Blanket Extent

14300-41D2-1006.1 Embankment Plan (Sheet 1 of 2)

14300-41D2-1006.2 Embankment Plan (Sheet 2 of 2)

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Drawing No. Drawing Title

14300-41D2-1007 Typical Cross-Sections (Sheet 1 of 2)

14300-41D2-1008 Typical Cross-Sections (Sheet 2 of 2)

14300-41D2-1009.1 Plan and Profile - Sta. 0+000 to 0+350 (Sheet 1 of 6)

14300-41D2-1009.2 Plan and Profile - Sta. 0+350 to 0+725 (Sheet 2 of 6)

14300-41D2-1009.3 Plan and Profile - Sta. 0+725 to 1+100 (Sheet 3 of 6)

14300-41D2-1009.4 Plan and Profile - Sta. 1+100 to 1+450 (Sheet 4 of 6)

14300-41D2-1009.5 Plan and Profile - Sta. 1+450 to 1+825 (Sheet 5 of 6)

14300-41D2-1009.6 Plan and Profile - Sta. 1+825 to 2+228 (Sheet 6 of 6) 14300-41D2-1010.1 Site Investigation Plan - Boreholes and Geophysical Surveys (Sheet 1 of 7)

14300-41D2-1010.2 Site Investigation Plan - Sonic Drilling Investigations (Sheet 2 of 7) 14300-41D2-1010.3 Site Investigation Plan - Diamond Drilling Investigations (Sheet 3 of 7) 14300-41D2-1010.4 Site Investigation Plan - Piezocone Investigations (Sheet 4 of 7) 14300-41D2-1010.5 Site Investigation Plan - GPR and Seismic Refraction Lines (Sheet 5 of 7)

14300-41D2-1010.6 Site Investigation Plan - Thermistor Installations (Sheet 6 of 7) 14300-41D2-1010.7 Future Site Investigations Plan (Sheet 7 of 7) 14300-41D2-1011.1 Stratigraphic Profile - Sta. 0+000 to 0+600 (Sheet 1 of 4) 14300-41D2-1011.2 Stratigraphic Profile - Sta. 0+600 to 1+200 (Sheet 2 of 4) 14300-41D2-1011.3 Stratigraphic Profile - Sta. 1+200 to 1+740 (Sheet 3 of 4) 14300-41D2-1011.4 Stratigraphic Profile - Sta. 1+740 to 2+228 (Sheet 4 of 4) 14300-41D2-1012.1 Stratigraphic Section - GPR Sections 5 to 6 (Sheet 1 of 6) 14300-41D2-1012.2 Stratigraphic Section - GPR Sections 7 to 8 (Sheet 2 of 6) 14300-41D2-1012.3 Stratigraphic Section - GPR Sections 9 to 10 (Sheet 3 of 6) 14300-41D2-1012.4 Stratigraphic Section - GPR Sections 11 to 12 (Sheet 4 of 6) 14300-41D2-1012.5 Stratigraphic Section - GPR Sections 13 to 15 (Sheet 5 of 6) 14300-41D2-1012.6 Stratigraphic Section - GPR Sections 18 to 19 (Sheet 6 of 6)

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Drawing No. Drawing Title

14300-41D2-1013 Lakebed Sediment Thickness Plan 14300-41D2-1014 South Island Facilities Layout 14300-41D2-1015 North Abutment Plan and Profile 14300-41D2-1017 South Abutment Plan and Profile 14300-41D2-1018 Thermosyphons Layout - Typical Plans and Sections 14300-41D2-1019 Vibro-Densification - Typical Section and Details 14300-41D2-1020.1 Grout Curtain - Typical Plan and Section Details 14300-41D2-1020.2 CSM Panels and Pre-drilling - Typical Plans and Section Details 14300-41D2-1020.3 Jet Grouting - Typical Plan and Section Details 14300-41D2-1021 Infield - General Plan and Typical Ditch Detail 14300-41D2-1022 Infield - Toe Berm Profile, Plan, Sections and Detail 14300-41D2-1023 Infield - Cross-Sections 14300-41D2-1024 Infield - Dike Pump Station Sections 14300-41D2-1025.1 Construction Staging (Sheet 1 of 2) 14300-41D2-1025.2 Construction Staging (Sheet 2 of 2) 14300-41D2-1026.1 Instrumentation - Plan (Sheet 1 of 3) 14300-41D2-1026.2 Instrumentation - Plan (Sheet 2 of 3) 14300-41D2-1026.3 Instrumentation - Plan (Sheet 3 of 3) 14300-41D2-1027.1 Instrumentation - List of Instruments (Sheet 1 of 2) 14300-41D2-1027.2 Instrumentation - List of Instruments (Sheet 2 of 2) 14300-41D2-1028.1 Instrumentation - Cross-Sections (Sheet 1 of 7) 14300-41D2-1028.2 Instrumentation - Cross-Sections (Sheet 2 of 7) 14300-41D2-1028.3 Instrumentation - Cross-Sections (Sheet 3 of 7) 14300-41D2-1028.4 Instrumentation - Cross-Sections (Sheet 4 of 7) 14300-41D2-1028.5 Instrumentation - Cross-Sections (Sheet 5 of 7) 14300-41D2-1028.6 Instrumentation - Cross-Sections (Sheet 6 of 7)

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Drawing No. Drawing Title

14300-41D2-1028.7 Instrumentation - Cross-Sections (Sheet 7 of 7) 14300-41D2-1029 Relief Well Design 14300-41D2-1030.1 Instrumentation - Details of Installation (Sheet 1 of 3) 14300-41D2-1030.2 Instrumentation - Details of Installation (Sheet 2 of 3) 14300-41D2-1030.3 Instrumentation - Details of Installation (Sheet 3 of 3) 14300-41D2-1031 Data Loggers, Shelters and Buried Cables - Sections and Details 14300-41D2-1032.1 Pool Dewatering Pipeline Alignments (Sheet 1 of 2) 14300-41D2-1032.2 Pool Dewatering Pipeline Alignments (Sheet 2 of 2) 14300-41D2-1033.1 A21 Dike - Layout and Inferred Permafrost - Talik Contact 14300-41D2-1033.2 A21 Dike - South Abutment Section Locations 14300-41D2-1033.3 South Abutment Sections 1+600, 1+700 and 1+800 14300-41D2-1033.4 South Abutment Sections 1+900, 2+000 and 2+100

4.0 TECHNICAL SPECIFICATIONS The following Technical Specifications pertain to the activities related to the A21 Dike.

Technical Technical Specification Title Specification No. 14300-41ES-0000 List of Definitions, Drawings and Technical Specifications

14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0003 Turbidity Barrier 14300-41ES-0004 Dredging and Boulder Removal 14300-41ES-0005 Material Preparation 14300-41ES-0006 Embankment Construction 14300-41ES-0007 Vibro-Densification 14300-41ES-0009 Excavating, Trenching and Backfilling 14300-41ES-0010 Toe Berm and Subsurface Drainage

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Technical Technical Specification Title Specification No.

14300-41ES-0011 Cast-In-Place Concrete 14300-41ES-0012 CSM Cut-Off Wall 14300-41ES-0013 Jet Grouting 14300-41ES-0014 Curtain Grouting 14300-41ES-0015 Water Pressure Testing 14300-41ES-0016 Drilling 14300-46ES-0002 Dike Dewatering 14300-48ES-0001 Piezometers 14300-48ES-0002 Inclinometers 14300-48ES-0003 Survey Markers and Survey Control Monuments 14300-48ES-0004 Thermistor Cables 14300-48ES-0005 Relief Wells 14300-48ES-0006 Automated Data Acquisition System (ADAS) 14300-48ES-0007 Thermosyphons

- END OF TECHNICAL SPECIFICATION

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SITE CONDITIONS No. Date

14300-41ES-0001 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All June 1/14 June 11/14 June 9/14 Sep 9/14 Sep 9/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 16/14 Nov 16/14 Tender

Technical Specification Revision

SITE CONDITIONS No. Date

14300-41ES-0001 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions, Drawings and Technical Specifications ...... 1

2.0 LOCATION ...... 1

3.0 SURFACE CONDITIONS...... 1

4.0 AIR TEMPERATURES ...... 2

5.0 PRECIPITATION ...... 2

6.0 LIGHTNING ...... 2

7.0 WIND ...... 2

8.0 LAKE ICE ...... 3

9.0 SEISMICITY ...... 4

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SITE CONDITIONS No. Date

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1.0 GENERAL A more detailed presentation of site conditions is provided in the following report: BGC Engineering Inc. 2014. A21 Dike - Summary of Site and Foundation Conditions. May 12. The following sections provide a brief summary of site conditions.

1.1. Documents

1.2. Scope of Work

1. This Technical Specification relates to the site conditions for the A21 Dike project site.

1.3. Definitions, Drawings and Technical Specifications

1. A complete list of project Definitions, Drawings and Technical Specifications is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

2.0 LOCATION 1. The A21 Dike project is located at approximately latitude 64°31´ North and longitude 110°20´ West. The project site is situated on South Island, on the eastern side of Lac de Gras, and is about 300 km northeast of Yellowknife in the Northwest Territories, Canada. Refer to Drawing 14300-41D2-1002 for general site layout.

3.0 SURFACE CONDITIONS 1. The mine site is located north of the tree line, in the continuous permafrost zone. 2. The topography on and in the vicinity of the site is gently rolling, with low to moderate relief. The average elevation of the site is 430 meters above mean sea level. The ground surface is rolling, with hills rising to about 40 meters above lake level.

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3. The island is underlain by predominantly granite bedrock of the Canadian Shield. Bedrock is exposed over about 40 percent of the surface area of the island. The balance of the island is covered by ice rich till deposits, with occasional organic deposits and peat in poorly drained depressions.

4.0 AIR TEMPERATURES 1. The mean annual air temperature at the site is approximately -10°C. The mean monthly air temperature varies from about -32°C in January to +10°C in July and exceeds the freezing point only during the period from late May to early September. 2. The air freezing index therefore varies between about 3100°C-days and 5400°C-days, and the air thawing index ranges between 820 °C-days and 1570°C-days.

5.0 PRECIPITATION 1. Average annual precipitation is estimated to be 373 mm, approximately 40% of which (144 mm) occurs as rainfall, and the remainder as snowfall (229 mm snow water equivalent). Snow can fall every month of the year and rain generally falls only between May and October. Net annual average runoff (precipitation minus evapotranspiration and sublimation) is 171 mm.

6.0 LIGHTNING 1. Lightning is common in the Lac de Gras area during the thaw season.

7.0 WIND 1. Winds are moderate to strong and show a slight north-west/south-east tendency, with average wind speeds of 16 to 22 km/h. 2. No significant seasonality was noted during the 1998 to 2013 records from the site, shown in the figure and table following.

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All Data October - May 0 0

315 45 315 45 >0 - 2.5 >2.5 - 5 >5 - 10 >10 - 20 >30

270 90 270 90

0% 2% 4% 6% 0% 2% 4% 6%

225 135 225 135

1997 - 2013 1997 - 2013 based on hourly data based on hourly data 180 n = 112,139 180 n = 71,671 Rose diagrams (winds speed in km/h) for the full year (left) and winter months only (right) based on data reported by Owner between 1997 and 2013. Mean monthly wind speed recorded by DDMI based on 10 year average (2004-2013).

Month Wind speed (km/h) Month Wind speed (km/h) January 17 July 16 February 16 August 19 March 19 September 20 April 20 October 22 May 18 November 18 June 18 December 16

3. The 10 year and 100 year hourly wind speeds are estimated to be about 100 and 128 km/hr from the northwest. Other directions correspond with lower wind speeds.

8.0 LAKE ICE 1. The mean date of the first occurrence of permanent ice on Lac de Gras is October 9. The earliest and latest recorded occurrences are September 28 and October 27, respectively. The mean date for the lake to be clear of ice is June 26. The earliest and latest recorded occurrences are June 9 and July 14, respectively. 2. The mean maximum ice thickness is 1.7 meters. The thickness of the ice can vary significantly over the lake due to currents and other factors.

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SITE CONDITIONS No. Date

14300-41ES-0001 B November/2014

9.0 SEISMICITY 1. The project area is situated in the Canadian Shield, which is considered to be a seismically inactive part of Canada without identifiable active faults and is located at significant distances from other active seismic zones. These may impart a peak ground acceleration at site in the order of 0.023 g for a probability of exceedance of 1% in 100 years (equivalent return period of 10,000 years) according to the current seismic zonation. Note that the values proposed for the 2005 National Building Code for an exceedance of 2% in 50 years (2,500 yr return period) are 0.059 g for Yellowknife and Fort Resolution.

- END OF TECHNICAL SPECIFICATION

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ENVIRONMENTAL PROTECTION No. Date

14300-41ES-0002 A May 2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for comments

Issued for tender

Issued for approval

Issued for tender

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Macdonald G. Macdonald Issued for A All May 2 / 14 May 9 / 14 May 9 / 14 May 12 / 14 May 12 / 14 approval

K. Halisheff B. Powell T. Martin Issued for A May 13 / 14 May 13 / 14 May 13 / 14 tender

Technical Specification Revision

ENVIRONMENTAL PROTECTION No. Date

14300-41ES-0002 A May 2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Specification ...... 1 1.3. Reference Standards ...... 2 1.4. Submittals ...... 2 1.4.1. Initial Submissions ...... 2 1.4.2. Intermittent Submissions ...... 3 1.5. Definitions ...... 3 1.6. Reference Drawings ...... 4

2.0 PRODUCTS ...... 4

3.0 EXECUTION ...... 4 3.1. General ...... 4 3.2. Surface Features ...... 4 3.2.1. Erosion Control ...... 4 3.2.2. Vegetation and Permafrost Protection ...... 5 3.3. Aquatic Resources ...... 5 3.3.1. Watercourse Environmental Protection ...... 5 3.3.2. Water Quality Protection ...... 6 3.4. Air Quality ...... 7 3.4.1. Dust and Air Pollution Measures ...... 7 3.4.2. Burning ...... 7 3.5. Wildlife and Wildlife Habitat ...... 7 3.6. Heritage/Archaeological Resources ...... 8 3.7. Petroleum Products ...... 8 3.8. Sandblasting ...... 9 3.9. Painting ...... 9 3.10. Restoration and Reclamation ...... 10 3.11. Domestic Waste ...... 11

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ENVIRONMENTAL PROTECTION No. Date

14300-41ES-0002 A May 2014

1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Engineer should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Specification

1. The Work refers to the construction site Work at South Island. This specification relates to environmental protection measures associated with the Work. It includes, but is not limited to:

 Protection of surface features (i.e. soils, vegetation, and permafrost)  Protection of aquatic resources (i.e. lakes, streams, and other water courses/water bodies)  Protection of air quality (i.e. with respect to noise, dust, and pollution)  Protection of wildlife and wildlife habitat  Protection of heritage/archaeological resources. 2. The environmental protection measures include provision of suitable waste disposal means, including, but not limited to disposal of:

 Construction wastes  Sanitary wastes  Process wastes  Any other waste materials generated during the conduct of the Work. 3. Environmental protection, as it relates to the Work, requires adherence to all applicable Municipal, Territorial, and Federal Legislation, including Regulations, Orders, Standards, and Guidelines. It requires adherence to all conditions provided in the Owner’s documents referred to in Section 1.3 below. Environmental protection also includes obtaining and complying with provisions of all Permits, Permissions, Allowances and Licenses required by governing bodies for the conduct of the Work.

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ENVIRONMENTAL PROTECTION No. Date

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1.3. Reference Standards

1. The following publications shall be referred to for additional information with respect to legislation and regulations applicable to this Work:

 A21 Specific Environmental Aspects – Foundation Preparation  Operational Phase Contingency Plan  Hazardous Materials Management Plant  Water Management Plan  Canadian Environmental Protection Act  NWT Environmental Protection Act  Fisheries Act  NWT Waters Act  CCME Environmental Code of Good Practice for Aboveground Storage Tank Systems  Containing Petroleum Products  NWT Mine, Health and Safety Act and Regulations  Fire Prevention Act of the NWT  National Fire Code of Canada (NFCC). 2. The first four documents are available electronically for review.

1.4. Submittals

1.4.1. Initial Submissions

1. The Contractor shall submit the following to the Owner for review and acceptance prior to starting the Work or engaging in new aspects of the Work:

 Design Design of all environmental protection measures which are included in the Work and/or incidental thereto.

 Methodology Methodology for all environmental protection measures which are included in the Work and/or incidental thereto.

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ENVIRONMENTAL PROTECTION No. Date

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 Emergency Response Plan Emergency Response Plan for protection of the environment.

 Responsible Parties The names of all responsible parties to the Work and how these persons may be contacted at any time.

1.4.2. Intermittent Submissions

1. The Contractor shall submit evidence of valid Licenses, Permits, Permissions, and Approvals if requested by the Owner, and/or any governing body.

1.5. Definitions

1. CONTRACT is the agreement between the Owner and the Contractor that defines the contracted services for which the Contractor’s bid has been accepted or duly modified, as well as the measurement of services and payment. 2. CONTRACTOR is the Contractor named in the Contract Agreement. 3. ENVIRONMENT means all natural physical, chemical and biological components as well as all social, cultural and historic components of South Island and any other geographic areas directly associated with the Work. 4. MANAGER’S REPRESENTATIVE is BGC Engineering Inc. (BGC) duly authorized, as the Engineer, by the Owner to act on its behalf. 5. OWNER is Diavik Diamond Mines Inc. (DDMI). 6. SITE is the Diavik A21 project site and includes, but is not limited to the A21 Dike alignment, access roads, pipelines, water control structures, sediment control structures, disposal areas, stockpile areas and laydown areas. 7. WATER BODY shall mean any body of water, whether moving or still, including, but not limited to, rivers, streams, creeks, lakes, ponds, marshes, sloughs, swamps, bogs, ditches with water in them, and shall include the area bounded by these bodies up to and including the high water mark. 8. WORK shall mean, unless otherwise defined, the whole of the construction including equipment, materials, procedures, control, and labour performed by the Contractor to satisfactorily complete the Contract as per the Drawings and Technical Specifications.

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ENVIRONMENTAL PROTECTION No. Date

14300-41ES-0002 A May 2014

1.6. Reference Drawings

Drawing No. Drawing Title 14300-41D2-1002 Rev A A21 Dike – General Site Layout

2.0 PRODUCTS NOT APPLICABLE

3.0 EXECUTION

3.1. General

1. The Contractor shall protect the Environment to the satisfaction of the Owner, and all agencies having jurisdiction, and assure the lowest degree of environmental degradation at the Site during and as a result of the Work. 2. Special care shall be taken to prevent any harmful chemicals such as diesel fuel, gasoline, or other products from entering the soil or adjacent Water Bodies, particularly when refueling equipment.

3.2. Surface Features

3.2.1. Erosion Control

1. Exposed, erosion prone soils shall be protected from erosion by one or more of the following methods:

 Covering with a suitable material such as plastic, geotextile or gravel;  Installation of erosion bars, stone check dams, and water diversion structures;

 Application of a soil binding spray. 2. Ditches and waterways shall be protected from erosion by one or more of the following methods:

 Lining with an erosion resistant material  Construction of silt fences using suitable geotextile, or utilizing prefabricated silt fencing

 Diversion of water around the erosive area using flexible pipe, corrugated steel pipe, or other suitable conduit

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ENVIRONMENTAL PROTECTION No. Date

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 Installation of hoarding or other rigid fencing where there is potential for large debris to enter the watercourse. 3. Ditches and culverts shall be properly sized to accommodate anticipated flows as defined by Manager’s Representative. 4. Erosion protection measures shall be undertaken under the direction of the Owner. 5. Re-vegetation, if required, shall be by others. 6. Further information regarding policy on silt fences and erosion control can be found in the Diavik Diamonds Construction Area and Activity Environmental Management Plan.

3.2.2. Vegetation and Permafrost Protection

1. The Contractor shall avoid unnecessary damage to vegetation, and the ground surface in the areas adjacent to the Work. 2. Removal or disturbance of the surface vegetation in permafrost areas has the potential to cause significant permafrost degradation. The Contractor shall not remove the surface vegetation or organic soils unless prior written approval has been obtained from the Owner.

3.3. Aquatic Resources

3.3.1. Watercourse Environmental Protection

1. A Watercourse Environmental Protection Zone shall exist within 75 metres of the high water mark of all Water Bodies, with the exception of onshore and offshore construction related activities, as approved by the Owner. 2. If any of the Work is undertaken within a Watercourse Environmental Protection Zone, the Contractor is advised that conduct of the Work will require particular care to protect the Environment. 3. Activities undertaken within a Watercourse Environmental Protection Zone shall be limited to that absolutely necessary for the performance of the Work. The following activities shall be undertaken only with the specific approval of the Owner:

 Fueling or servicing equipment  Washing of equipment

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ENVIRONMENTAL PROTECTION No. Date

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 Disposal of waste materials, including, but not limited to, waste rock and soils, construction wastes, garbage, or any other materials

 Blasting resulting in deposition of rock or other materials within the wet perimeter of a water body. 4. Work undertaken within a Watercourse Environmental Protection Zone shall be conducted as expeditiously as possible. 5. No fuels, oils, grease, or any other substance, including, but not limited to, paints, solvents, chemicals, cement, grout, or building materials may be stored within a Watercourse Environmental Protection Zone without the specific approval of the Owner. 6. Work within the wet perimeter of a Water Body shall be conducted under the inspection and with the approval of the Owner and the regulatory authority when required. Plans and methods for such Work shall be submitted to the Owner for approval prior to undertaking such Work. 7. Suitable diversions, coffer dams, and other structures shall be established prior to any Work within the wet perimeter of a Water Body where feasible. 8. The Contractor shall ensure that no substances deleterious to fish or fish habitat enter a water body or are placed in such a location that they could enter a water body. 9. Work in and about watercourses shall be avoided during times of fish spawning, aggregation, migrations, and other sensitive periods as defined by the Owner.

3.3.2. Water Quality Protection

1. The Contractor shall detain, or otherwise manage all waters exiting the Site of the Work to ensure that suspended solids, sediments, concrete and/or grout wash water, oil and grease, or any other material is removed, to a level which meets the requirements of the Owner environmental and waste management plans. 2. A sump shall be excavated to contain all excess concrete, grout, laitance, and concrete washwater. The sump shall be located a sufficient distance from watercourses to prevent accidental contamination of the water body. Materials collected in the sump shall be disposed of in a manner consistent with Territorial and local regulations. Further information on disposal of wastes may be found in the Diavik Diamonds Construction Waste Management Plan.

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ENVIRONMENTAL PROTECTION No. Date

14300-41ES-0002 A May 2014

3. All concrete forms used in and around watercourses shall be tight fitting to prevent concrete and laitance from contaminating the watercourse or soils. All water displaced from concrete forms during pouring of the concrete shall be directed into the above mentioned sump. 4. All cast in place concrete shall be totally isolated from flowing waters for a minimum curing period of 48 hours to allow the pH to reach neutral levels. 5. The Contractor shall control all water flowing through the Site of the Work to ensure such water does not become contaminated as a result of the Work. 6. The Contractor shall be responsible to ensure that all water exiting the area of his/her Work meets or exceeds Federal, Territorial or Municipal water quality standards for the activities being undertaken.

3.4. Air Quality

3.4.1. Dust and Air Pollution Measures

1. The Contractor shall control dust emissions from the Work or activities incidental to the Work to the satisfaction of the Owner. 2. All equipment shall be fitted with standard emission control devices appropriate to the equipment and in compliance with Federal and Territorial regulations and standards.

3.4.2. Burning

1. Burning of any material, except fuels in a piece of equipment designed to burn fuels, shall not be permitted except with the express written consent of the Owner. 2. All burning, as permitted above, shall be under the supervision of a responsible party at all times. 3. The Contractor shall have on-site suitable portable firefighting equipment as approved by the Owner. 4. All burning shall be as specified by Federal and Territorial authorities. Valid permits and authorizations shall be obtained from the appropriate authorities and a copy of such shall be submitted to the Owner for any and all burning.

3.5. Wildlife and Wildlife Habitat

1. The Contractor shall avoid disturbance of wildlife and or disruption to wildlife habitat.

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ENVIRONMENTAL PROTECTION No. Date

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2. The Contractor shall use “wildlife-proof” garbage disposal containers for all food scraps, lunchroom scraps, and other wastes which might attract wildlife. 3. Feeding of wildlife, including, but not limited to, bears, birds, and small mammals, shall not be permitted. 4. Site specific wildlife interaction procedures found within the Diavik Diamonds Construction Health/Safety Plan shall be followed.

3.6. Heritage/Archaeological Resources

1. The Contractor shall conduct activities so that social, cultural and historical resources are protected. 2. Archaeological sites or other sites of historic or cultural significance shall be protected. Disturbance of such sites in any manner shall not be permitted except with the express written consent of the Owner and the responsible governing body. 3. The Contractor shall observe all regulations concerning public health and is responsible for providing sanitation facilities if required. Sanitary waste shall be taken to an approved disposal site as outlined in the Diavik Diamonds Construction Waste Management Plan. 4. The Contractor shall ensure that his/her workforce does not adversely impact adjacent communities or individuals.

3.7. Petroleum Products

1. Diesel fuel will be provided by others. The Contractor shall provide his own fuel trucks and obtain supplies at the main Fuel Storage Facility, as required. 2. Storage of other petroleum products by the Contractor, including propane storage and lubricant storage shall be designed to meet or exceed the existing safety regulations of the appropriate Provincial/Territorial Petroleum Association, the National Fire Code, and the Workers’ Compensation Board. 3. All personnel handling fuels shall be trained in contingency measures for spillage and leakage of fuels. 4. Contingency plans to deal with spillage or leakage of fuel shall consist of Contractor supplied absorbent materials as outlined in the Diavik Diamonds Construction Emergency Response Plan. These, and other requirements, shall be approved in writing by the Owner prior to the movement of petroleum products onto the Site of the Work.

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ENVIRONMENTAL PROTECTION No. Date

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5. Any spill of petroleum products by the Contractor greater than 0.5 litres shall be reported immediately to the Owner. Clean-up of such spills shall commence immediately by the Contractor. Reporting of petroleum spills to authorities shall be as set out in the appropriate legislation and regulations. Such reporting is the responsibility of the Contractor. 6. Waste fuel, oil, solvents, and other petroleum products shall be disposed of at an on- site location, which has been approved by the regulatory authorities as outlined in the Diavik Diamonds Construction Waste Management Plan. 7. Waste materials such as oil cans, grease tubes, spent filters, and oily rags shall be collected and properly disposed of on-site as outlined in the Diavik Diamonds Construction Waste Management Plan. 8. Service trucks shall be equipped with suitable spill containment equipment including absorbent pads, containers to hold oil contaminated soils, and oil absorbent materials which can be used to collect spilled oil for disposal.

3.8. Sandblasting

1. All areas to be sandblasted shall be shrouded in such a way that all materials being used in the sandblasting, with the exception of the compressed air, are collected. 2. Collected sand, paint chips, and corroded materials shall be disposed of in accordance with government regulations. 3. Shrouding for sandblasting shall control dust from coming in contact with workers (in accordance with current regulations) or the surrounding area. 4. Removal of shrouding shall be conducted in such a manner, that dust and materials, which have collected in the shrouding are not released to the environment. 5. Shrouding shall be constructed of such materials that the structure and shrouding can withstand normal wind and storm events encountered during the period of Work for the area. Shrouding which becomes torn and/or inoperative due to weather conditions, or construction accidents, shall be repaired prior to resuming Work.

3.9. Painting

1. The following shall apply to the storage and disposal of painting materials:

 Materials used in painting shall be stored in such a manner that accidental release to the environment is prevented.

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ENVIRONMENTAL PROTECTION No. Date

14300-41ES-0002 A May 2014

 Storage facilities shall be set back 75 metres from the high water mark of Water Bodies. The storage facilities shall be diked or otherwise contained so that a release of all stored materials will be contained within the dike.  Storage facilities shall be well away from other buildings, petroleum storage facilities, and other combustibles.  Storage facilities shall be protected with suitable locks and closures against vandalism and wildlife.  Disposal of used brushes, rags, solvents, and other materials shall be to on- site facilities maintained by the Owner consistent with local and territorial regulations and as outlined in the Diavik Diamonds Construction Waste Management Plan.

3.10. Restoration and Reclamation

1. The Contractor shall coordinate with the Owner to ensure that all debris, waste, garbage and other materials not naturally found at the Site are removed at the completion of the Work, and that the Site is left in a neat and tidy condition satisfactory to the Owner. 2. All temporary structures shall be removed at the completion of the Work unless such facilities are required by the owner for future use. 3. Soils and/or other materials contaminated by petroleum products, chemicals or other undesirable materials shall be cleaned up to the satisfaction of the Owner. Materials so fouled shall be excavated and hauled to an approved disposal site as outlined in the Diavik Diamonds Construction Emergency Response Plan and Diavik Diamonds Construction Waste Management Plan, unless otherwise agreed in writing by the Owner. Areas so fouled shall be repaired and restored to the satisfaction of the Owner. 4. Sediments collected in sediment control traps shall be removed at the completion of the Work. Sediment control traps shall be similarly removed unless otherwise directed by the Owner. These materials shall be disposed of in a manner satisfactory to the Owner. 5. All Work areas, staging sites, storage areas and other sites disturbed during the conduct of the Work shall be restored as directed by the Owner.

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ENVIRONMENTAL PROTECTION No. Date

14300-41ES-0002 A May 2014

3.11. Domestic Waste

1. The Contractor shall store domestic solid waste in containers provided for the purpose and dispose of sewage from portable latrines at locations and in a manner approved by the Owner.

- END OF TECHNICAL SPECIFICATION

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TURBIDITY BARRIER No. Date

14300-41ES-0003 A May 2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for comments

Issued for tender

Issued for approval

Issued for tender

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K.Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 7 / 14 May 9 / 14 May 9 / 14 May 13 / 14 May 13 / 14 approval

K.Halisheff B. Powell T. Martin Issued for A May 13 / 14 May 13 / 14 May 13 / 14 tender

Technical Specification Revision

TURBIDITY BARRIER No. Date

14300-41ES-0003 A May 2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Reference Standards ...... 1 1.3. Environmental Protection ...... 2 1.4. Submittals ...... 2 1.5. Definitions ...... 2 1.6. Design ...... 3 1.7. Reference Drawings ...... 3

2.0 PRODUCTS ...... 4 2.1. General ...... 4 2.2. Curtain ...... 4 2.3. Floats ...... 4 2.4. Mooring and Anchorage ...... 5

3.0 EXECUTION ...... 5 3.1. Deployment ...... 5 3.2. Removal ...... 5 3.3. Maintenance ...... 5

4.0 QUALITY CONTROL ...... 6

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TURBIDITY BARRIER No. Date

14300-41ES-0003 A May 2014

1.0 GENERAL

1.1. Documents

1. This Technical Specifications forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Engineer should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Reference Standards

1. American Society for Testing and Materials (ASTM) Standards (most current version): ASTM D3786 Standard Test Method for Bursting Strength of Textile Fabrics: Diaphragm Bursting Strength Tester Method ASTM D3787 Standard Test Method for Bursting Strength of Textiles: Constant-Rate-of Traverse (CRT), Ball Burst Test ASTM D4355 Standard Test Method for Deterioration of Geotextiles by Exposure to Light, Moisture and Heat in a Xenon Arc Type Apparatus ASTM D4491 Standard Test Methods for Water Permeability of Geotextiles by Permittivity ASTM D4533 Standard Test Method for Trapezoid Tearing Strength of Geotextiles ASTM D4595 Standard Test Method for Tensile Properties of Geotextiles by the Wide-Width Strip Method ASTM D4632 Standard Test Method for Grab Breaking Load and Elongation of Geotextiles ASTM D4751 Standard Test Method for Determining Apparent Opening Size of a Geotextile ASTM D4833 Standard Test Method for Index Puncture Resistance of Geomembranes and Related Products

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TURBIDITY BARRIER No. Date

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ASTM D4884 Standard Test Method for Strength of Sewn or Bonded Seams of Geotextiles

1.3. Environmental Protection

1. Comply with the requirements of Specification 14300-41ES-0002 Rev A (Environmental Protection) and of the Owner’s Water License.

1.4. Submittals

1. Submit detailed plan for Turbidity Barrier to the Owner. The Turbidity Barrier shall include:

 General arrangement and description  Details of method of transportation, handling and on site storage prior to deployment  Description and Specification for materials and equipment including boats and lifting equipment  Details of the deployment configuration and procedures  Description and details of floatation, anchorage and mooring  Details of maintenance  Description of removal and storage procedures. 2. Submit detailed design for Turbidity Barrier as shown on Drawings. Design in accordance with criteria specified in this document and industry standards. Design shall include:

 Design criteria  Design calculations  Stamped design and shop drawings.

1.5. Definitions

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3. MANAGER’S REPRESENTATIVE is BGC Engineering Inc. (BGC) duly authorized, as the Engineer, by the Owner to act on its behalf. 4. OWNER is Diavik Diamond Mines Inc. (DDMI). 5. Turbidity Barrier: A configuration of curtain (polyester reinforced vinyl fabric), flotation system and anchorage, to control dispersion of suspended solids within the area enclosed by the barrier. 6. WORK shall mean, unless otherwise defined, the whole of the construction including equipment, materials, procedures, control, and labour performed by the Contractor to satisfactorily complete the Contract as per the Drawings and Technical Specifications.

1.6. Design

1. Design Turbidity Barrier in accordance with the requirements specified herein to extend to a depth corresponding to 1 m above lakebed (except where water depth < 2 m) with a maximum depth of 19 m as shown on the Drawings. 2. Design the Turbidity Barrier to be installed in the lake when there is no ice. 3. Include in the design an anchoring system to hold the curtain in place against wind, wave and current forces while minimizing tearing due to wave action for which the design basis is as per the Manager’s Representative. 4. Include in the design connection details to provide a continuous barrier. Minimum distance between joints should be 30 m. 5. Include in the design a furling or reefing system to lift the curtain for movement in the lake, to adjust depth to suit lakebed bathymetry and for removal to storage.

1.7. Reference Drawings

Drawing No. Drawing Title 14300-41D2-1002 Rev A A21 Dike – General Site Layout 14300-41D2-1003.1 Rev A Turbidity Barrier Plan (Sheet 1 of 3) 14300-41D2-1003.2 Rev A Turbidity Barrier Profile (Sheet 2 of 3) 14300-41D2-1003.3 Rev A Turbidity Barrier Sections and Details (Sheet 3 of 3)

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2.0 PRODUCTS

2.1. General

1. Handle, store and protect all materials from deterioration and contamination. Do not use deteriorated or contaminated materials.

2.2. Curtain

1. Curtain fabric must meet the following minimum requirements:

 Grab tensile strength: 130 lbs (578 N)  Puncture strength: 40 lbs (178 N)  Trapezoidal Tear: 60 lbs (267 N)  Burst Strength: 140 psi (965 kPa)  AOS (US Sieve Size): 70 sieve (210 micron)  Water flow rate minimum: 55 gpm/ft (37 l/s/m). 2. Seams in the fabric shall either be vulcanized, welded, or sewn and shall develop the full strength of the fabric.

2.3. Floats

1. Provide flexible, buoyancy units, contained in a continuous sleeve or collar attached to the curtain such that during high wave condition, the floats may move relative to the suspended portion of the curtain. 2. Provide flotation units sufficient to support the weight of the curtain and load lines and maintain a freeboard of at least 75 mm above the water surface and provide a buoyancy ratio (buoyant force/curtain weight) of at least five. 3. Provide flotation sleeves to meet the following requirements:

 Grab Strength: 170 lbs (756 N)  Low Temp Bend: -88°F (-67°C)  Resistance: 70% after 2000 hrs. 4. Floating portion of barrier to be in bright color (yellow or «international» orange are recommended) and acceptable to the Owner.

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2.4. Mooring and Anchorage

1. Fabricate load lines into the top and bottom of the fabric. 2. Provide the top load line with sufficient break strength to support the load from the wind, waves and handling. 3. Provide bottom load line incorporated into the bottom hem of the curtain with sufficient weight to hold the curtain in vertical position. 4. Provide bottom anchors to hold the curtain in position. 5. Provide end anchorage sufficient to withstand all loads from the barrier.

3.0 EXECUTION

3.1. Deployment

1. Provide barrier folded, for easy extraction at deployment and placed in containers. 2. Select a location to manipulate the curtain ashore free of sharp rocks, debris or other material which may damage the barrier. Alternatively, prepare a working area for same purpose. 3. Install the barrier on the alignment shown on Drawings. 4. Install end anchorages. 5. Position Turbidity Barrier and attach end anchorages and intermediate anchors as required. 6. Unfurl Turbidity Barrier. 7. Limit depth of barrier to 1 m above lakebed or depth as required by Manager’s Representative. Barrier may be grounded in shallow areas (see Drawings).

3.2. Removal

1. Prior to removing the barrier from the water, furl the barrier. 2. Exercise care when the barrier is being brought ashore to protect the skirt and flotation sleeve from damage.

3.3. Maintenance

1. Make periodic inspection of the barrier to ensure effective operation.

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14300-41ES-0003 A May 2014

2. Provide all material and labor necessary to perform repairs to the barrier. 3. Store barrier for re-use by folding the barrier in «accordion style» and cover with opaque plastic sheets.

4.0 QUALITY CONTROL 1. Report.

 Submit coordinates of actual barrier alignment.  Submit post-construction report indicating material types used and corresponding quantities.

- END OF TECHNICAL SPECIFICATION

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DREDGING AND BOULDER No. Date REMOVAL

14300-41ES-0004 A May 2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for comments

Issued for tender

Issued for approval

Issued for tender

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 7 / 14 May 9 / 14 May 9 / 14 May 13 / 14 May 13 / 14 approval

K. Halisheff B. Powell T. Martin Issued for A May 13 / 14 May 13 / 14 May 13 / 14 tender

Technical Specification Revision

DREDGING AND BOULDER No. Date REMOVAL

14300-41ES-0004 A May 2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Submittals ...... 1 1.3. Requirements of Regulatory Agencies ...... 2 1.4. Survey Datum ...... 2 1.5. Floating Plant ...... 2 1.6. Site Information & Reference Documents ...... 3 1.7. Definitions ...... 3 1.8. Reference Drawings ...... 4

2.0 PRODUCTS ...... 4

3.0 EXECUTION ...... 5 3.1. General ...... 5 3.2. Trial Dredging Program ...... 5 3.3. Dredge Requirements ...... 6 3.4. Boulder Removal Requirements ...... 6 3.5. Surveys ...... 7 3.6. Acceptance of Work ...... 8 3.7. Disposal of Dredged Material ...... 8 3.8. Dredge Slurry Pipeline ...... 8 3.9. Disposal of Boulders ...... 9

4.0 QUALITY CONTROL/QUALITY ASSURANCE ...... 9

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DREDGING AND BOULDER No. Date REMOVAL

14300-41ES-0004 A May 2014

1.0 GENERAL

1.1. Documents

1.2. Submittals

1. Submit a detailed dredging plan to Owner. The dredging plan shall include:

 Description, specifications and condition of equipment  Description and specifications of equipment to continuously monitor the slurry density on a real time basis  Description of location control equipment and methodology  Construction methods and procedures including technique and equipment specifications for identifying remaining lake sediment and acceptable foundation  Minimum depth of water for dredging operation  Specific details of dredging equipment and methods to minimize suspended solids in the lake water caused by the dredging operation and to ensure compliance with environmental restrictions  Specific details of equipment to be used for boulder removal  Power supply  Safety plan  Plan for refuelling, servicing, re-crewing dredge during operation  Contingency plan for dealing with fuel and lubricant leaks and spills of dredged material  Plan for dealing with stoppages in cold weather to prevent freezing of pipelines

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 Quality Control (QC) plan. 2. Submit detailed design for pumping from point of dredging to disposal area (Pond 3) and discharge within disposal area. Design in accordance with the following points and industry standards. The design shall incorporate the single 550 mm HDPE line to be installed by DDMI from Station 0+000 to 5+065 (Drawing 60301128-C001 and Drawings 60301128-C100 to C104). The Contractor will review the DR rating shown on the Drawings and advise the Owner if changes in the DR rating would be beneficial. 3. Design for pumping of dredge slurry for discharge into Pond 3 shall include:

 Design calculation for all pipework  Location of booster pumps, if required, in the laid 550 mm pipeline  Inlet pipeline(s) from dredging platform to Station 0+000 Drawing 60301128- C001  Outlet pipeline structure at on land containment facility (Station 5+065 into Pond 3) including air /vacuum valve(s) at Station 5+065  A plan for the disposal of sediment into Pond 3 and dispersal throughout Pond. 4. Submit trial dredging plan.

1.3. Requirements of Regulatory Agencies

1. Comply with Territorial and National Codes and Regulations.

1.4. Survey Datum

1. Reference location control to horizontal and vertical survey datum provided by Manager’s Representative. The Work shall be laid out using the station and offset method from this reference point.

1.5. Floating Plant

1. Dredges or other floating plant to be employed on this Work, to be of Canadian registry, make or manufacture, or, must receive certificate of qualification from Industry, Science and Technology Canada.

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DREDGING AND BOULDER No. Date REMOVAL

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1.6. Site Information & Reference Documents

1. Geotechnical investigations including soundings, drill holes, geophysical surveys and site topographical surveys have been carried out on Site and are available for viewing in Yellowknife, NWT. 2. The following reference documents present geotechnical, geophysical investigation data along the A21 dike alignment, and summarize the dredging experience for the A154 and A418 dikes: Golder Associates Ltd., 2006. A21 Dike and Pit Geotechnical and Hydrogeological Data Interpretation Diavik Diamond Mine. Report to Diavik Diamond Mines Inc., 01 Sept. Golder Associates Ltd., 2007. Winter 2007 A21 Dike and Pit Geotechnical and Hydrogeological Site Investigation Diavik Diamond Mine, Report to Diavik Diamond Mines, 29 June. BGC Engineering Inc., 2014. A21 Dike: Summary of Site and Foundation Conditions, Report to Diavik Diamond Mines, 12 May.

1.7. Definitions

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7. Quality Control (QC) is a planned system by the Contractor to conduct sufficient testing of the Work to demonstrate adherence to the Technical Specifications and Drawings. 8. SITE is the Diavik A21 project site and includes, but is not limited to the A21 Dike alignment, access roads, pipelines, water control structures, sediment control structures, disposal areas, stockpile areas and laydown areas. 9. WORK shall mean, unless otherwise defined, the whole of the construction including equipment, materials, procedures, control, and labour performed by the Contractor to satisfactorily complete the Contract as per the Drawings and Technical Specifications.

1.8. Reference Drawings

BGC Drawings

Drawing No. Drawing Title 14300-41D2-1002 Rev A A21 Dike – General Site Layout 14300-41D2-1004.1 Rev A Lakebed Foundation Preparation Plan (Sheet 1 of 2) 14300-41D2-1004.2 Rev A Dredging Pipeline Alignments (Sheet 2 of 2) 14300-41D2-1013 Rev A Lakebed Sediment Thickness Plan 14300-41D2-1033.1 Rev A A21 Dike – Layout and Inferred Permafrost-Talik Contact

AECOM Pipeline Drawings

Drawing No. Drawing title 60301128-C001 Site Plan A21 to North Inlet 60301128-C100 Plan and Profile Sta. 0+000 to 1+100 60301128-C101 Plan and Profile Sta. 1+100 to 2+250 60301128-C102 Plan and Profile Sta. 2+250 to 3+550 60301128-C103 Plan and Profile Sta. 3+550 to 4+500 60301128-C104 Plan and Profile Sta. 4+500 to END

2.0 PRODUCTS Not used.

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DREDGING AND BOULDER No. Date REMOVAL

14300-41ES-0004 A May 2014

3.0 EXECUTION

3.1. General

1. Mark floating equipment with lights in accordance with Transport Canada Ship Safety and maintain radio watch on board or as directed by Manager’s Representative. 2. Place and maintain buoys, markers and lights required to define Work. 3. Lay out Work from benchmarks and base lines established by Manager’s Representative. Be responsible for accuracy of Work relative to established benchmarks and baseline. Provide and maintain electronic position fixing and distance measuring equipment, laser transits and such other equipment as normally required for accurate dredging control.

3.2. Trial Dredging Program

1. A dredging trial is required in the event that the subcontractor and the cutter suction dredge are other than those used for the A154 and A418 dikes. 2. Select an area for trial dredging on the A21 dike footprint where the water depth is at least 5 m. The area should cover the equivalent of the full sweep width intended for production dredging and two full spud carriage advances. 3. Diver inspection of the area with video camera coverage to be performed prior to dredging. 4. Perform necessary number of passes (according to sediment thickness) to reach till or other acceptable foundation. 5. A diver inspection to establish thickness of residual fluff shall then be carried out and instructions for additional dredging will be transmitted if required. 6. Perform additional passes to remove residual fluff to less than 10 cm average depth. 7. Prepare and submit report describing findings and modifications to dredging procedures which are planned for the production dredging. Include measures deemed necessary to meet total suspended solids (TSS) restrictions.

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DREDGING AND BOULDER No. Date REMOVAL

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3.3. Dredge Requirements

1. The dredging limits shown on the drawings are approximate and may be revised in the field by Manager’s Representative. 2. Remove lake sediment to limits indicated on the Drawings or as modified by the Manager’s Representative based on the trial dredging program, actual site conditions and pre/post dredge echo-sounder bathymetric surveys. 3. The intent of the dredging is to remove the lakebed sediment down to acceptable foundation such as consolidated sediments, dense till or dense granular materials, to the acceptance of Manager’s Representative. Acceptable foundation is defined as a firm base, which can be detected by the dredge master from cutter head response or otherwise indicated by the Contractor’s proposed alternative QC procedures during the dredging trial if different dredging equipment is to be used. Alternative means of lakebed sediments removal that may be proposed are subject to review and approval by the Owner. Lakebed sediments and fine uniform sand will be required to be removed from the dike footprint. Additional dredging along the cut-off alignment or in areas of deep sediments may be required. The use of a clamshell or submersible pump with mechanical and water jet agitation may be required. 4. The technique proposed by the dredge Contractor for identifying the upper boundary of the dense material will be reviewed by the Owner and the Manager’s Representative after the execution of the trial dredging program or after the initial production Work. 5. Residual fluff to a depth of 10 cm will be permitted on the footprint of the Zones 1A/1C filter blankets and 20 cm on the footprint of the upstream Zone 3 shoulder.

3.4. Boulder Removal Requirements

1. The boulder removal limits include the cut-off wall alignment and area within the limits of the Zones 1A/1C filter blanket and Zone 1. 2. Boulders do not require removal below Zone 3, unless deemed otherwise by the Manager’s Representative on a case by case basis.

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DREDGING AND BOULDER No. Date REMOVAL

14300-41ES-0004 A May 2014

3.5. Surveys

1. Geophysical surveys have been carried out over the dike footprint and these form the basis of the pre-dredge bathymetric plots shown on the Drawings. Additional echo- sounding surveys will be undertaken by the Owner in advance of construction and provided to the Contractor. 2. Diver’s pre-dredging inspection shall be carried out along alignments marked by a system of ropes positioned on the lake bed in order to locate the diver’s observations in terms of stations and offsets. The inspections shall proceed in a sweeping manner on both sides of the rope alignments to entirely cover the dike footprint. Boulders are to be identified. 3. Diver’s post-dredging inspection shall be carried out using the same methodology (as pre-dredging inspection) to entirely cover the dredged surface area. 4. The diver shall measure by hand probing the thickness of residual sediment. Tin can samples (minimum 2 Kg) shall be taken on minimum 15 m intervals along the dike axis and at specific locations as required by Manager’s Representative. The Contractor shall provide gradation test results of sampled material as required by Manager’s Representative. 5. A diver’s report summarizing the inspection findings (remaining sediment, boulder nests, etc) shall be submitted to Manager’s Representative. The diver shall be available for debriefing sessions if required. 6. The sediment thickness isopach drawing has been developed from the above bathymetry, the sediment/consolidated deposit boundary reflector, piezocone soundings and drill hole information. 7. Develop a dredging plan (type of equipment/schedule) based on his/her interpretation of the same data sources. 8. Contractor shall monitor for any spills (fuel, lubricants, etc.) into the water. Corrective actions shall be immediately implemented and completed to contain and clean spills. 9. Contractor shall liaise with Owner and Manager’s Representative regarding TSS and turbidity sampling and testing (carried out by Owner). Contractor shall define corrective measures if necessary. 10. Carry out pre-dredging and post dredging geophysical surveys and produce as-built drawings consisting of survey profiles run transversally to the dike axis at intervals of 5 m maximum and a plan locating the profiles.

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DREDGING AND BOULDER No. Date REMOVAL

14300-41ES-0004 A May 2014

11. Complete as-built report including the following items: a. Pre and post dredging bathymetry. b. Pre and post dredging transverse sections, generated at 5 m intervals along the axis of the dike alignment. c. Quantity of dredged material. d. Quantity of boulders removed, and time expended in boulder removal activity. e. Summary of all TSS and turbidity testing results (provided by the Owner). f. Summary of all gradation test results. g. Inclusion of all diving records and reports.

3.6. Acceptance of Work

1. Manager’s Representative will review the survey data, diver reports, in-situ measurements of residual sediment thickness, logs of dredged material and samples taken by divers, records of removed boulders and determine if additional dredging or boulder removal is required. Contractor is to perform the Work to the revised limits within an acceptable time frame.

3.7. Disposal of Dredged Material

1. Dispose of dredged material by depositing in the sediment pond (Pond 3), at the area and in a manner approved by Owner and no closer than 10 m from the containment or filtration dams. Dredge slurry will be transported via pipelines to be installed by others. The Contractor is responsible for all pumping required from dredge to Pond 3. Contractor to inspect and manage deposition in disposal area and ensure uniform disposal without erosion of Pond 3 dam.

3.8. Dredge Slurry Pipeline

1. The dredge slurry pipeline shall be constructed on the right of way constructed for this purpose. The pipeline will be constructed by others, and will be available for use by the Contractor as shown on the Drawings. Contractor to complete routine inspections of all dredge slurry pipelines. 2. The route of the right of way is indicated on the Drawings.

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DREDGING AND BOULDER No. Date REMOVAL

14300-41ES-0004 A May 2014

3.9. Disposal of Boulders

1. Contractor is to remove boulders from areas identified in Section 3.4 and dispose of boulders to either the upstream or downstream of the set limits as identified in Section 3.4.

4.0 QUALITY CONTROL/QUALITY ASSURANCE See QA/QC Plan document (not yet completed).

- END OF TECHNICAL SPECIFICATION

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MATERIAL PREPARATION No. Date

14300-41ES-0005 0 November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 16/14 June 11/14 June 9/14 Sep 9/14 Sep 9/14 review

K. Halisheff B. Powell T. Martin Issued for 0 All Nov 12/14 Nov 16/14 Nov 16/14 Construction

Technical Specification Revision

MATERIAL PREPARATION No. Date

14300-41ES-0005 0 November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Environmental Protection ...... 2 1.7. Rock Supply ...... 2 1.8. Submittals ...... 2

2.0 MATERIALS AND PRODUCTS ...... 3 2.1. Products ...... 3

3.0 EXECUTION ...... 3 3.1. Rock Borrow Operation ...... 3 3.2. Crusher Management Plan ...... 3 3.3. Stockpiling Requirements ...... 4

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 5

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MATERIAL PREPARATION No. Date

14300-41ES-0005 0 November/2014

1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Owner shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the material preparation for construction of the A21 Dike to be completed by the Owner.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Owner is referred to the following Technical Specifications related to the material preparation Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0006 Embankment Construction 14300-41ES-0009 Excavation, Trenching & Backfilling 14300-41ES-0010 Toe Berm and Subsurface Drainage 14300-41ES-1012 CSM Cut-Off Wall

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MATERIAL PREPARATION No. Date

14300-41ES-0005 0 November/2014

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Owner is referred to the following Drawings related to the material preparation Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1007 Typical Cross-Sections (Sheet 1 of 2)

1.6. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and of the Water License.

1.7. Rock Supply

1. No quarry operation is planned. A stockpile of mine rock (North Rock Pile) will be available for the production of all rock products for dike construction. Only Type I waste rock, which is considered by the Owner to be non-reactive and therefore suitable for dike construction, is to be used. The Owner shall confirm that the waste rock used for sourcing dike fill materials is Type I.

1.8. Submittals

1. Submit: a. Equipment and material lists for rock borrow and crusher operations. b. Crusher management plan for construction materials Zones 1, 1A, 1B, 1C, 2, 6, 7 and aggregate for CSM operation. c. Stockpile construction, use and management plans, including plans for minimizing stockpile segregation, and monitoring to confirm the effectiveness of those plans. d. Quality control plan. Plan to adhere to QA/QC document identified in Section 4.0 below as a minimum and include additional Quality Control activities as necessary. The Quality Control plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work.

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MATERIAL PREPARATION No. Date

14300-41ES-0005 0 November/2014

2.0 MATERIALS AND PRODUCTS

2.1. Products

1. The following construction materials are required for the earthworks: Zones 1, 1A, 1B, 1C, 2, 3, 4, 6 and 7 materials, in accordance with Technical Specification 14300-41ES-0006, and aggregate for the CSM operation in accordance with Technical Specification 14300-41ES-0012.

3.0 EXECUTION

3.1. Rock Borrow Operation

1. Preparation a. Dispose of unsuitable materials as directed by the Manager’s Representative. b. Slopes in soil and rock borrow shall be constructed such that they will remain stable during and following excavation. c. The Owner shall provide open ditches and sedimentation ponds, as required, to control runoff and prevent silty water from flowing into streams, ponds or Lac de Gras in accordance with Technical Specification 14300-41ES-0002 - Environmental Protection, and in accordance with the Water License.

3.2. Crusher Management Plan

1. At least six (6) weeks prior to crushing operations for the A21 Dike, the Owner shall prepare a crusher management plan which shall include, but not be limited to, the following information: a. A description of the equipment and manpower which will be used for crushing, screening blending and stockpiling the required dike construction materials Zones 1, 1A, 1B, 1C, 2, 6, 7 and aggregate for the CSM operation. b. A summary of relevant experience for key field personnel who will supervise these operations. c. Stockpile location plan including drainage, collection and control of runoff from the stockpiles. d. The methods for processing and handling crushed materials to prevent contamination, segregation or degradation, and monitoring/testing plans to evaluate the success of these methods.

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e. If required, the blending methods to produce the required materials. f. Expected production rates and contingency plans in the event that production rates are lower than expected. g. A simple bar chart schedule, which demonstrates how the various milestone dates for crushing production will be achieved. h. Material production and projected stockpile depletion curves.

3.3. Stockpiling Requirements

1. The stockpile site shall be prepared such as to ensure that conditions regarding ground levelling, drainage, bearing capacity, as well as preventing contamination at base level and intermixing of adjacent piles are adequate. 2. Stockpiling shall be completed in a method to prevent material segregation. 3. Zone 1 stockpile shall be constructed in such a way as to keep cleaner material (having maximum 5% fines by weight) in a region of the stockpile where it can be selectively used for constructing the deeper, more critical parts of the dike. 4. Coning of piles or end dumping material over the edges of a stockpile will not be permitted because it causes segregation. Dozing of materials across the stockpile surface will not be permitted if segregation is apparent. 5. Re-excavation of stockpiled materials shall be done with equipment and methods which achieve adequate mixing of materials. Remove aggregates from stockpiles in approximately horizontal layers or benches. Provide plank or protected runways for operating trucks on stockpiles where required to prevent contaminants (fine grained material or otherwise) being tracked onto the aggregate. Do not use material taken from the base of stockpiles for construction if the materials have been contaminated by the underlying soil. Reject contaminated or intermixed materials. Remove and dispose of rejected materials as directed by QC personnel or the Manager’s Representative. 6. When it is necessary to use aggregates from one or more sources to produce required gradation, do not blend in stockpiles. 7. If material production and stockpiling takes place during the winter months, incorporation of snow, ice and frozen material into the stockpiles may occur. The Owner shall take all reasonable precautions to minimize incorporation of snow, ice and frozen material.

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MATERIAL PREPARATION No. Date

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8. Methods shall be used, as required, to avoid the freezing of Zone 1 material and CSM operation aggregate stockpiled during rainy periods. If the pile is frozen, other methods shall be used to thaw the pile and/or eliminate frozen lumps. 9. The stockpile areas are to be left in a tidy, well drained condition, free of standing surface water. Unused materials shall be shaped into compact heaps as directed by the Owner.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

14300-41ES-0005 Material Preparation (Rev 0 Nov 2014) IFC Page 5 Technical Specification Revision

EMBANKMENT CONSTRUCTION No. Date

14300-41ES-0006 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 16/14 June 11/14 June 9/14 Sep 9/14 Sep 9/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 17/14 Nov 17/14 Tender

Technical Specification Revision

EMBANKMENT CONSTRUCTION No. Date

14300-41ES-0006 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Reference Standards ...... 2 1.7. Environmental Protection ...... 3 1.8. Submittals ...... 3

2.0 PRODUCTS ...... 4 2.1. Dike Materials ...... 4

3.0 EXECUTION ...... 7 3.1. Preparation ...... 7 3.2. Embankment Placement in the Wet ...... 8 3.3. Embankment Placement In the Dry ...... 10 3.4. Dike Alignment and Slope Adjustment ...... 11 3.5. Tolerances ...... 12 3.6. Protection of Existing Thermistors ...... 13

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 13

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EMBANKMENT CONSTRUCTION No. Date

14300-41ES-0006 B November/2014

1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor/Owner shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the embankment construction for the A21 Dike to be completed by Owner or Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor/Owner is referred to the following Technical Specifications related to the embankment construction Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0004 Dredging and Boulder Removal 14300-41ES-0005 Material Preparation 14300-41ES-0007 Vibro-Densification

14300-41ES-0006 Embankment Construction (Rev B - Nov 2014) IFT Page 1 Technical Specification Revision

EMBANKMENT CONSTRUCTION No. Date

14300-41ES-0006 B November/2014

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor/Owner is referred to the following Drawings related to the dike construction Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike - General Site Layout 14300-41D2-1005 Filter Blanket Extent 14300-41D2-1006.1 Embankment Plan (Sheet 1 of 2) 14300-41D2-1006.2 Embankment Plan (Sheet 2 of 2) 14300-41D2-1007 Typical Cross-Sections (Sheet 1 of 2) 14300-41D2-1008 Typical Cross-Sections (Sheet 2 of 2) 14300-41D2-1009.1 Plan and Profile - Sta. 0+000 to 0+350 (Sheet 1 of 6) 14300-41D2-1009.2 Plan and Profile - Sta. 0+350 to 0+725 (Sheet 2 of 6) 14300-41D2-1009.3 Plan and Profile - Sta. 0+725 to 1+100 (Sheet 3 of 6) 14300-41D2-1009.4 Plan and Profile - Sta. 1+100 to 1+450 (Sheet 4 of 6) 14300-41D2-1009.5 Plan and Profile - Sta. 1+450 to 1+825 (Sheet 5 of 6) 14300-41D2-1009.6 Plan and Profile - Sta. 1+825 to 2+228 (Sheet 6 of 6) 14300-41D2-1015 North Abutment Plan and Profile 14300-41D2-1017 South Abutment Plan and Profile 14300-41D2-1022 Infield - Toe Berm Profile and Details 14300-41D2-1025.1 Construction Staging (Sheet 1 of 2) 14300-41D2-1025.2 Construction Staging (Sheet 2 of 2)

1.6. Reference Standards

1. American Society for Testing and Materials (ASTM) a. ASTM D422 - Standard Test Method for Particle Size Analysis of Soil. b. ASTM D698 – Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (Standard Proctor Dry Density) c. ASTM D5519 – Standard Test Methods for Particle Size Analysis of Natural and Man-Made Riprap Materials

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1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.8. Submittals

1. Submit dike fill placement plan including: a. Access plan and haul routes. b. Placement sequence. c. Placement methods. d. Survey methods (underwater and on-land works). e. Procedures for monitoring placement of Zones 1, 1A, 1B, 1C, 2 and 3 materials. f. Staffing and execution plan to meet QC requirements as specified in the Quality Assurance/Quality Control Plan document (see Section 4.0). g. List of major equipment with capacities. h. Plans for interfacing with cut-off wall, grouting, and other dike construction activities. i. Preventative measures to avoid fuel/oil spills from barge mounted equipment. j. Safety plan. Plan to comply with the NWT Mines Act/Regulations and Owner safety standards. k. Quality Control plan. Plan to adhere to QA/QC document identified in Section 4.0 below as a minimum and include additional Quality Control activities as necessary. The Quality Control plan is to be reviewed and accepted by Manager’s Representative prior to commencement of Work. 2. Submit survey methodology and techniques for: a. Setting out the dike axis. b. Control and survey of fill placed on lake bottom. c. Survey of underwater dike slopes at the leading edge, for each of Zones 1, 2 and 3. d. On-land surveys.

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2.0 PRODUCTS

2.1. Dike Materials

1. Rock material for dike construction shall be stockpiled by Owner in designated areas. Designated stockpile areas will include the North Rock Pile, South Island or elsewhere designated by Owner. The North Rock Pile will consist of shot rock generally up to a maximum of 2 m in diameter but with some occasional larger sizes. Stockpiles located on South Island (or elsewhere) will consist of crushed material to be used for dike construction, which will be produced, hauled, and stockpiled by the Owner. 2. Select, load, haul products from designated stockpile areas to embankments for construction. 3. Material used for dike shall not to contain organic matter, frozen lumps, ice, weeds, sod, roots or other unsuitable material. 4. Rock containing biotite schist shall be placed only in Zone 3, and at least 2 m below low water level in Lac de Gras. Elsewhere, rockfill shall not contain more than 2% of biotite schist. The Owner is responsible for identifying rock materials that exceed the 2% criterion for planning purposes.

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5. Zone 1A - Only well graded crushed product conforming to the following gradation limits will be acceptable:

Percent Passing Sieve Size by Weight 56 mm 100 50 mm 95 – 100 31.5 mm 78 – 100 25 mm 70 – 100 19 mm 58 – 100 12.5 mm 48 – 83 9.5 mm 41 – 73 6.3 mm 31 – 58 4.75 mm 24 – 49 2.36 mm 12 – 32 1.18 mm 0 – 16 0.6 mm 0 – 11 0.3 mm 0 – 7 0.15 mm 0 – 4 0.075 mm 0 – 2

A fines content (fraction smaller than 0.075 mm) up to 4% by weight is acceptable for individual Zone 1A gradation tests, provided the rolling average of five (5) successive tests for each zone type remains at or below 2%.

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6. Zones 1, 1B and 1C – Only well graded crushed product conforming to the following gradation limits will be acceptable:

Percent Passing by Sieve Size Weight 50 mm 100 31.5 mm 80 – 100 25 mm 70 – 100 19 mm 58 – 100 12.5 mm 48 – 87 9.5 mm 41 – 78 6.3 mm 31 – 66 4.75 mm 24 – 59 2.36 mm 12 – 46 1.18 mm 0 – 34 0.6 mm 0 – 27 0.3 mm 0 – 20 0.15 mm 0 – 15 0.075 mm 0 – 10

A fines content (fraction smaller than 0.075 mm) up to 12% by weight is acceptable for individual Zones 1, 1B and 1C gradation tests, provided the rolling average of five (5) successive tests for each zone type remains at or below 10%. The limitation on the curvature of individual full sample gradation curves shall be

expressed as the coefficient of curvature (Cc) as follows:

2 Cc ≤ 3.0, Cc = D30 / (D60 * D10) where:

D10 = particle size for which 10% of the dry weight of the sample is finer than

D30 = particle size for which 30% of the dry weight of the sample is finer than

D60 = particle size for which 60% of the dry weight of the sample is finer than

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7. Zone 2 - Only well graded crushed product conforming to the following gradation limits will be acceptable:

Percent Passing by Sieve Size Weight 200 mm 100 100 mm 60 – 100 75 mm 45 – 92 50 mm 30 – 77 20 mm 10 – 45 10 mm 0 – 30 5 mm 0 – 18

8. Zone 3 - Only rock fill conforming to the following gradation limits will be acceptable:

Percent Passing by Sieve Size Weight 900 mm 100 300 mm 40 – 100 100 mm 20 – 55 20 mm 0 – 27 10 mm 0 – 20 2.5 mm 0 – 10

9. Road Surfacing – only 50 mm minus crush with a maximum of 10% fines will be acceptable, or as approved by the Manager’s Representative. This material will be crushed and stockpiled by the Owner.

3.0 EXECUTION

3.1. Preparation

1. Place dike materials after removal of lakebed sediment, excavation of boulders as shown on the Drawings or as designated by the Manager’s Representative, and inspection and acceptance of foundation in writing by Manager’s Representative.

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3.2. Embankment Placement in the Wet

1. Place Zones 1, 1A, 1B, 1C, 2 and 3 materials to lines and grades as indicated on the Drawings and as directed by Manager’s Representative. 2. Begin embankment construction in vicinity of the north and south abutments and advance outwards. a. Place Zones 1A and 1C using crane mounted skip or clam shell operated from a barge in deep water conditions or using excavator in shallow water conditions or by other similar technique to meet the requirements of the Work. b. Do not dump Zones 1A and 1C through water or allow Zones 1A and 1C materials to fall through water more than 0.5 m to prevent material segregation. c. Place filter blanket material to minimum distance of 2 m beyond the theoretical downstream toe of embankment placed in the wet, such that upon dewatering no excavation into the embankment is required to expose the filter blanket. d. Place filter blanket material to minimum distance of 2 m upstream of the dike reference line (i.e. centerline of cut-off wall). 3. Use differential global positioning system (DGPS) survey technology (or alternative method approved by Manager’s Representative) to ensure that load by load placement of Zones 1A and 1C fill materials by skip or clamshell in a grid manner permits the construction of a uniform blanket satisfying the requirements shown on the Drawings, and the tolerances specified in Sections 3.4 and 3.5 below. 4. Using ultrasonic echo sounding technique (or alternative method approved by Manager’s Representative), survey the upper surface of the filter blanket along alignments spaced on maximum 5 m intervals and run transversely to dike axis. Compare results with post-dredged surveys to demonstrate filter blanket thickness. Prepare plans and profiles of survey lines showing filter blanket thickness, dike outer envelope, dike axis and offsets marks on 5 m intervals. 5. As and when requested by Manager’s Representative, verify the uniformity of the filter blanket surface by depth soundings (i.e. 300 mm x 300 mm steel plate attached to a rope) coupled with DGPS surveys. Plot results to demonstrate that the required Zone 1A/1C filter blanket thickness is obtained everywhere including between points of skip/clamshell unloading. Adjust load placement method as required to satisfy requirements. 6. Obtain written approval from Manager’s Representative for each surveyed filter blanket profile prior to undertaking placement of overlying materials.

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7. Load, haul, dump, place and spread Zones 1, 1A, 1B, 1C, 2 and 3 materials in such a manner as to minimize segregation and provide homogenous well-graded embankment zones. 8. Underwater placement of Zones 1, 1B, 2 and 3 to be carried out by dumping on the dike working platform (El. 417.0 to El. 418.0 m) close to the leading edge in order to advance Zones 1/1B, 2 and 3 simultaneously. Push the materials forward with a dozer and then, approximately 1 m from the leading edge, in a downward manner to induce a slip displacement and minimize the rolling segregation of the materials. Zones 1 and 1B to generally lead adjacent Zones 2 and 3 to maintain the contact between adjacent zones at the theoretical line or within tolerances. Survey control and careful material placement methods will be required to ensure internal core width of Zone 1 and 1B maintains a width of 10 m at El. 417.0 to 418.0.

Water depth Zone Method of placement Where placed (m) End-dumped core into the 1 lake Lakebed elevation < El. 410 m ≥ 6 Clamshell placement (filter 1A blanket) End-dumped core into the lake Lakebed elevation > El. 410 m < 6 m 1B Fill placed in the dry above Along entire length of dike Not applicable initial dike platform at 417.0 m Clamshell placement (filter 1C 410 m < lakebed El.< 414 m < 6 m blanket)

9. In curved segments, adjust the advance of each zone front at the leading edge so as to maintain the lateral location of the contacts in relation to dike axis as per the Drawings. Perform echo sounding surveys as indicated in the following section to confirm the conformity of the internal zoning or the need to adjust the placement method. 10. Do not place any Zones 1A/1C material within 100 m of un-dredged lakebed sector falling within the specified dredging limits shown on the Drawings, measured along the dike alignment. Where clamshell or dragline removal of sediments is used, or monitoring of total suspended solids (TSS) measurements during marine dredging operations indicate acceptable TSS levels, this restriction may be revised with the approval of Owner and Manager’s Representative.

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11. Do not place any Zone 1, 1B, 2 and 3 materials within 50 m from the advancing Zones 1A/1C placement front. 12. Vibro-Densify Zones 1 and 1B materials from the working platform as shown on Drawings and per Technical Specification 14300-41ES-0007. 13. Push large pieces of Zone 3 material to the outside of Zone 3 section to create a riprap zone at the upstream side of Zone 3. Riprap rock pieces need not be placed individually, but shall be levelled and dressed to ensure the completed face is stable with no tendency to slide, and that there will be no unreasonably large voids. 14. Monitor placement of fill materials to avoid unacceptable conditions, including but not limited to: a. Concentrations of cobbles and boulders except in the riprap zone at the upstream edge of Zone 3. b. Soft foundation material and accumulation of lakebed sediment. c. Deviation from the lines, grades and material thicknesses as shown on the Drawings. d. Evidence of bulging, slumping, sloughing, or material losses during placement. e. Displacement of Zone 1A blanket or Zone 1C blanket by subsequent overlying fill placement. Remove unacceptable materials and replace with material conforming to the Technical Specification requirements and adjust method of placement to prevent further occurrence. 15. In certain areas of the foundation (steep slopes) additional Zone 1A and/or Zone 2 material may be required (as shown on Drawing 14300-41D2-1006.1) to be placed by clamshell, in advance of the main embankment advance, to build a stabilization berm prior to dumping rockfill and avoid embankment slope instability that could result in rupture of Zone 1A/1C blanket.

3.3. Embankment Placement In the Dry

1. Compact Zones 1, 1B, 2 and 3 at working platform after completing Vibro- Densification with four (4) passes of smooth drum vibratory roller specified below, or as directed by the Manager’s Representative. 2. Place fill at Zones 1B, 2, and 3 above the elevation of the working platform and at the downstream toe of the dike after dewatering, in loose lift thickness (before compaction) as identified below, and compact with four (4) passes of the

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“Ingersoll-Rand” SD-180D or approved equivalent smooth drum vibratory roller having the following characteristics: a. Total weight: 18 tonnes. b. Weight at drum: 11 tonnes. c. Frequency: 1300 – 1825 v.p.m. d. Centrifugal force: 360 kN. It may be acceptable to compact the Zone 3 material above the working platform using loaded haul trucks instead of a vibratory roller. The performance of such a method must first be demonstrated by the Contractor to the satisfaction of the Manager’s Representative.

Maximum Permissible Layer Thickness (for placement in the dry) Max. Particle Size Layer Thickness Before Compaction Zones (mm) (mm) 1, 1B 50 500 2 200 500 3 900 1000

3. A pass is considered to have been completed each and every time a compactor passes over a given point with the specified weight and vibratory energy, whether traveling forward or backward. 4. Place 0.15 m road topping (50 mm minus crush) on the completed dike as shown on the Drawings. Compaction to be provided via four (4) passes of the “Ingersoll-Rand” SD-180D or approved equivalent smooth drum vibratory roller.

3.4. Dike Alignment and Slope Adjustment

1. Control embankment alignment using DGPS surveys (or alternative method approved by the Manager’s Representative). 2. The slopes of rockfill dumped underwater have been estimated, on the basis of previous data from the A154 and A418 dikes’ construction, and may vary. The final average outer slope of the Zone 3 upstream shell (above elevation 416.0 m only) and the Zone 2 downstream shell (full height) must be 1.6H:1.0V and 1.7H:1.0V respectively, or angle of repose if flatter. Re-grade to achieve these average slopes. Remove overbuild on the Zone 2 slopes above elevation 416.0 m prior to dewatering. Overbuild on the upstream face may be left in place below elevation 416.0 m. Remove overbuild on the downstream face below El. 416.0 m after dewatering.

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3. The slopes between adjacent dike zones dumped underwater are specified on the Drawings. Survey the underwater embankment slopes at the leading edge using echo sounding devices operated from stable marine equipment. Initially perform surveys daily to develop and adjust methods and sequencing of fill placement that allows the specified contact slopes to be obtained, including in curved segments. Execute surveys along lines spaced on regular intervals parallel and perpendicular to dike axis. Survey spacing along lines parallel and perpendicular to the dike axis shall be 10 m and 20 m, respectively, or more closely spaced when directed by the Manager’s Representative. 4. Prepare contour plans and profiles of the leading edge to determine the underwater slopes in each material zone and locate the trace of the contacts along the plane of the leading edge. The frequency of surveys may subsequently be reduced with the approval of Manager’s Representative after the construction method has been demonstrated to give satisfactory and consistent results. 5. Using the above mentioned underwater survey results or manual depth soundings, verify that no significant bulging occurs at the toe of the leading edge slope, which can be synonymous with rupture of the filter blanket by sliding of the embankment. Adjust construction method as and when required by Manager’s Representative.

3.5. Tolerances

1. The minimum width of the embankment fill zones are shown on the Drawings. 2. The maximum permissible horizontal deviation of the upstream and downstream boundaries of the filter blanket material (Zones 1A & 1C) from the design lines is 500 mm. 3. The maximum permissible deviation in thickness of the filter blanket from the design lines is as follows: a. Zone 1C: minimum 0.8 m thickness at intersection of cones of placed material, and maximum thickness of 1.2 m at apex of placed cones. b. Zone 1A: minimum 0.8 m thickness at intersection of cones of placed material, and maximum thickness of 1.2 m at apex of placed cones. 4. Overbuilding of the upstream Zone 3 shell is typically necessary to achieve design toe as this material typically forms an overall slope steeper than the design 1.6H:1V. Accessible portions of overbuild to be trimmed and the Zone 3 material salvaged. Trimming of overbuild to occur from crest to elevation 417 m, leaving remaining overbuild to assist in wave dissipation.

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5. For embankment fill material placed in the dry (i.e. above El. 417 m) the maximum permissible horizontal deviation of the upstream and downstream Zone 1, 1B, 2 and 3 boundaries from the design lines is 300 mm. 6. The working platform of the core and dike shells for cut-off wall construction (i.e. El. 418.0 m) shall be finished to within ± 100 mm of the design elevation. 7. The final dike crest (i.e. 421.0 m) shall be finished to within 0 to plus 100 mm of the design elevation. 8. The contacts shown on the Drawings between the dike core fill (Zones 1 and 1B) and the upstream shell (Zone 3) and downstream shell (Zone 2) are theoretical. The slip displacement method of placement, and sequencing of advance of the core and shell zones, is to be used to achieve the steepest contact practical and thus minimize Zones 1/1B volume requirements. Survey control and careful material placement methods will be required to ensure internal core width of Zone 1 and 1B maintain a width of 10 m at El. 417.0 to 418.0 m. 9. Tolerances for the road surfacing placed over the completed dike shall be ± 50 mm in elevation, and ± 0.5 m in width.

3.6. Protection of Existing Thermistors

1. Locate, remove and salvage as many existing thermistor cables only as deemed reasonably possible as discussed and agreed to on a case by case basis with the Manager’s Representative. 2. Salvaged thermistor cables shall not be reused in the A21 permanent works unless directed by Manager’s Representative.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

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VIBRO-DENSIFICATION No. Date

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INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 16/14 June 11/14 June 9/14 Sep 15/14 Sep 15/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 17/14 Nov 17/14 Tender

Technical Specification Revision

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TABLE OF CONTENTS

2.0 PRODUCTS ...... 3 2.1. Backfilling of Depressions Created by Densification Process ...... 3

3.0 EXECUTION ...... 3 3.1. Equipment ...... 3 3.2. Layout ...... 3 3.3. Required Densification and Verification ...... 3 3.4. Trial Densification ...... 4 3.5. Densification ...... 4

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 5

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manger’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the Vibro-Densification activities for the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the Vibro-Densification Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0006 Embankment Construction

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

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2. The Contractor is referred to the following Drawings related to the Vibro-Densification Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1007 Typical Cross Sections (Sheet 1 of 2) 14300-41D2-1008 Typical Cross Sections (Sheet 2 of 2) 14300-41D2-1009.1 Plan and Profile – Sta. 0+000 to 0+350 (Sheet 1 of 6) 14300-41D2-1009.2 Plan and Profile – Sta. 0+350 to 0+725 (Sheet 2 of 6) 14300-41D2-1009.3 Plan and Profile – Sta. 0+725 to 1+100 (Sheet 3 of 6) 14300-41D2-1009.4 Plan and Profile – Sta. 1+100 to 1+450 (Sheet 4 of 6) 14300-41D2-1009.5 Plan and Profile – Sta. 1+450 to 1+825 (Sheet 5 of 6) 14300-41D2-1009.6 Plan and Profile – Sta. 1+825 to 2+228 (Sheet 6 of 6) 14300-41D2-1019 Vibro-Densification Typical Plan and Details

1.6. Reference Standards

1. American Society for Testing and Materials (ASTM) a. ASTM D4253 – Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table. b. ASTM D4254 – Standard Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density.

1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and of the Water License.

1.8. Submittals

1. Submit a Vibro-Densification plan that must include, at a minimum: a. Detailed list of equipment, condition and model numbers and number of probes. b. Proposed sequence of work and detailed procedures. c. Densification log form.

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d. Quality Control (QC) plan including detailed methodology(s) to confirm required densification is achieved, for review and approval by the Manager’s Representative. Plan to adhere to Quality Assurance/Quality Control (QA/QC) document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. The QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work.

1.9. Qualifications

1. Vibro-Densification Contractor shall be experienced in the Vibro-Densification process for subsurface conditions similar to those of this project. Submit case histories of densification for similar projects.

2.0 PRODUCTS

2.1. Backfilling of Depressions Created by Densification Process

1. Zone 1B material as specified in Technical Specification 14300-41ES-0006, for the use in backfilling depressions created by the Vibro-Densification process.

3.0 EXECUTION

3.1. Equipment

1. Furnish vibratory units and ancillary equipment of a size and capacity to fully penetrate 25 m of crushed rockfill of which the maximum particle size is 56 mm as shown on the Drawings. The vibratory units shall be electrically powered. 2. High pressure flushing water ejected at the probe tip is a necessity. The use of air alone is not permitted.

3.2. Layout

1. Lay out the penetration pattern using a 2.5 m spacing (see Drawings) and mark the location of each hole with wooden stakes or painted rock fragments.

3.3. Required Densification and Verification

1. A relative density (ASTM D4253 and D4254) of at least 70% is to be achieved throughout the entire Vibro-Densified zone as identified on the Drawings.

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2. The Contractor shall submit a QC plan, for the review and approval by the Manager’s Representative, to outline how they will verify that the specified density is achieved. This plan is to supplement the counting of loads of replacement material added during the Vibro-Densification process, and shall include geotechnical penetration and/or cross-hole geophysical testing, or other suitable means of verification of the achieved relative density.

3.4. Trial Densification

1. Prior to start of densification and if using equipment other than that employed for the Vibro-Densification work for the A154 or A418 dikes, perform trial densification at location designated by Manager’s Representative, to demonstrate performance of the equipment, verify spacing and depths of the penetrations. Trial is also to confirm the suitability of the Contractor’s QC program for confirmation of specified densification. 2. Trial densification section shall be a minimum of 50 m long and may be incorporated in the permanent densification work. Loader bucket counts, of a known volume, of material (Zone 1B) added to compensate for densification-induced depressions shall be kept to evaluate degree of densification achieved. Loader buckets counts, of a known volume, will be tracked for each Vibro-Densified column by the Contractor. Geotechnical penetration and/or cross-hole geophysical testing, or other suitable means shall be undertaken during the densification trial. 3. Survey control will be required to monitor pre-densification and post-densification elevations to determine density increase from densification process. 4. If required density is not achieved, adjust equipment settings, rate/length of withdrawal and penetration spacing and perform further trial densification until penetration resistance is achieved. 5. Submit to the Manager’s Representative a trial Vibro-Densification report outlining the operating parameters and procedures for the production Vibro-Densification work.

3.5. Densification

1. Perform densification in Zone 1 and Zone 1B crushed stone from dike working platform at El. 418.0 m, to the dike foundation and to the limits shown on the Drawings. Add Zone 1B crushed stone as required during the densification process and record the volume of material (number of loader buckets with known volumes to be continuously recorded) added to form each column.

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2. Keep a continuous recording of amperage draw, along with the depth and time parameters, to provide a complete record of each constructed Vibro-Densification column. 3. Hole locations falling on the Zone 1/1B to Zone 3 and Zone 1/1B to Zone 2 interfaces may be relocated 0.5 m away from the interfaces to avoid encountering rock fragments (Zone 2 and Zone 3). 4. While injecting water under pressure at the probe tip, vibrate the probe to the foundation elevation. Perform densification by alternatively withdrawing and allowing the probe to settle in increments of 0.5 m until the maximum amperage of the equipment has been reached and then proceed to the next increment. 5. If the dike fill in the upper part of the working platform is frozen, remove frozen material and replace with new Zone 1B fill. 6. Injection of air in lieu of water during freezing conditions is not an acceptable alternative. 7. If the specified value is not achieved, define area requiring re-densification, and re- densify areas which do not achieve the specified requirement. 8. Do not perform Vibro-Densification within 50 m from the advancing Zones 1, 1B, 2 and three (3) placement fronts.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

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INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 6/14 June 16/14 June 9/14 Sept. 15/2014 Sept. 15/2014 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 17/14 Nov 17/14 Tender

Technical Specification Revision

EXCAVATING, TRENCHING & No. Date BACKFILLING

14300-41ES-0009 B November/2014

TABLE OF CONTENTS

2.0 PRODUCTS ...... 3 2.1. Backfill Materials ...... 3

3.0 EXECUTION ...... 3 3.1. Foundation Preparation On-Land ...... 3 3.2. Cofferdams ...... 3 3.3. Dewatering and Heave Prevention ...... 4 3.4. Excavation ...... 4 3.5. Backfilling ...... 5 3.6. Restoration ...... 5

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 5

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Owner or Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the excavating, trenching and backfilling activities for the A21 project to be completed by the Owner, except where specifically noted otherwise. Activities include: a. Foundation preparation for on-land portion of A21 Dike (above El. 415.8 m). b. Foundation preparation for toe berm following pool dewatering. c. Infield earthworks. d. Trenching required for the toe drain excavation. e. Trenching required for on-land component of cut-off wall at the south abutment.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Owner and Contractor is referred to the following Technical Specifications related to the excavating, trenching and backfilling Work that are be read in conjunction with all other parts of the Contract Documents.

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Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-1006 Embankment Construction 14300-41ES-1010 Toe Berm and Subsurface Drainage 14300-41ES-1012 CSM Cut-Off Wall

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Owner and Contractor is referred to the following Drawings related to the excavating, trenching and backfilling Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1004.1 Lakebed Foundation Preparation Plan (Sheet 1 of 2) 14300-41D2-1006.1 Embankment Plan (Sheet 1 of 2) 14300-41D2-1006.2 Embankment Plan (Sheet 2 of 2) 14300-41D2-1007 Typical Cross-Sections (Sheet 1 of 2) 14300-41D2-1008 Typical Cross-Sections (Sheet 2 of 2) 14300-41D2-1021 Infield – General Plan and Typical Ditch Detail 14300-41D2-1022 Infield – Toe Berm Profile and Details 14300-41D2-1023 Infield – Cross-Sections 14300-41D2-1024 Infield – Dike Pump Station Sections

1.6. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and of the requirements of the Water License.

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1.7. Submittals

1. Submit details of proposed construction dewatering, such as cofferdams, pumping systems, well points, sump and ditches, sheet pile cut-offs or other means to achieve excavation.

2.0 PRODUCTS

2.1. Backfill Materials

1. Zones 1B, 2 and 3 materials as shown on Drawings and in accordance with requirements of Technical Specification 14300-41ES-0006. 2. Zones 4, 6 and 7 materials as shown on Drawings and in accordance with requirements of Technical Specification 14300-41ES-0010. 3. Cut-off wall backfill material at the on-land portion of the south abutment to be determined and will be installed by the Contractor.

3.0 EXECUTION

3.1. Foundation Preparation On-Land

1. Refer to Technical Specification 14300-41ES-0004 for in-lake foundation preparation. The requirements following pertain to on-land foundation preparation Works only at the abutments. 2. Remove obstructions, ice and snow, vegetation, organic soils, frost disturbed, saturated overburden and flow slide material from surfaces within limits indicated on the Drawings to acceptable foundation and as directed by Manager’s Representative. 3. Remove surface exposed boulder nests from areas to be covered with Zones 1, 1A, 1B, 1C and 2 materials. 4. Boulders embedded in a soil matrix that will not be surrounded by significant voids after placement of fill do not require removal if approved by Manager’s Representative.

3.2. Cofferdams

1. Construct temporary cofferdams to heights and locations as required for Work.

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3.3. Dewatering and Heave Prevention

1. Keep excavations free of water while Work is in progress. 2. Do not excavate below groundwater table if a “quick” condition or heave is likely to occur. Prevent piping or bottom heave of excavations by lowering groundwater to at least 1.0 m below bottom of excavation, by sumps, well points, sheet pile cut-offs, and/or other means. 3. Protect open excavations against flooding and damage due to surface run-off. 4. Dispose of water in a manner not detrimental to any portion of the Work completed or under construction or to the environment.

3.4. Excavation

1. Excavate to lines, grades and dimensions as indicated on the Drawings or as directed by Manager’s Representative. 2. For excavation of toe drain trench (Drawing 14300-41D2-1022), prepare a profile along the trench axis indicating the ground level and the proposed toe drain trench invert required to achieve drainage to the pump stations, as indicated on the Drawings. Submit for approval by Manager’s Representative prior to installing toe drain. 3. Excavation of the on-land component of the cut-off wall at the south abutment to be excavated to El. 412.0 m or to bedrock surface. 4. Dispose of surplus and unsuitable excavated material on site as directed by Owner. 5. Do not obstruct flow of surface drainage or Water Bodies which drain to the exterior of the A21 diked enclosure. 6. Base of excavations in overburden soils to be undisturbed soil, level, free from loose, soft or organic matter. Remove unsuitable material from trench bottom to extent and depth as directed by Manager’s Representative. 7. Notify Manager’s Representative when bottom of excavation is reached. 8. Obtain Manager’s Representative’s approval of completed excavation in writing. 9. Possession of written approval will not remove the obligation to carry out additional excavation if the foundation deteriorates between time of excavation and fill placement.

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10. Owner shall take all necessary measures to maintain excavation stability. Owner shall be responsible for the excavation.

3.5. Backfilling

1. Refer to Technical Specification 14300-41ES-0006 for placement and compaction of Zones 1, 1B, 2 and 3 materials for the on-land portions of the dike at the abutments, and Technical Specification 14300-41ES-0010 for placement and compaction of Zones 6 and 1B for toe drain trench backfilling. 2. Earthworks associated with the Infield area shall use Zone 3 material (as defined in Technical Specification 14300-41ES-0006) and Zone 4 material (as defined in Technical Specification 14300-41-ES-0010). Placement and compaction requirements for these materials shall follow these Technical Specifications. 3. Cut-off wall backfill for on-land portion at south abutment to be tremied in place once foundation has been approved. Contractor to remove water from excavated trench prior to tremie backfill operation. 4. Infield backfill grading (Drawings 14300-41D2-1021, 14300-41D2-1023 and 14300- 41D2-1024) to be completed as shown on Drawings. 5. Do not proceed with backfilling operations until Manager’s Representative has inspected and approved excavations and any applicable installations (such as toe drain pipe or on-land portion of cut-off wall at south abutment). 6. Areas to be backfilled to be free from debris, snow, ice and water. 7. Do not use backfill material which is frozen or contains ice, snow or debris. 8. Backfilling with Zone 1B over cut-off wall backfill should not commence within seven (7) days after cut-off wall backfill placement.

3.6. Restoration

1. Upon completion of Work, remove waste materials and debris, trim slopes, and correct defects as directed by Manager’s Representative.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) Plan document.

- END OF TECHNICAL SPECIFICATION

14300-41ES-0009 Excavating Trenching Backfilling (Rev B - Nov 2014) IFT Page 5 Technical Specification Revision

TOE BERM AND SUBSURFACE No. Date DRAINAGE

14300-41ES-0010 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 16/14 June 11/14 June 9/14 Sept. 15/2014 Sept. 15/2014 review

K. Halisheff B. Powell T. Marin Issued for B All Nov 12/14 Nov 17/14 Nov 17/14 Tender

Technical Specification Revision

TOE BERM AND SUBSURFACE No. Date DRAINAGE

14300-41ES-0010 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Reference Standards ...... 2 1.7. Environmental Protection ...... 2 1.8. Submittals ...... 3

2.0 PRODUCTS ...... 3 2.1. Plastic Pipe ...... 3 2.2. Toe Berm Fill Materials ...... 3

3.0 EXECUTION ...... 4 3.1. Unloading and Handling Pipe ...... 4 3.2. Preparation ...... 4 3.3. Trenching for Toe Drain ...... 4 3.4. Pipe Bedding ...... 5 3.5. Installation of Pipe ...... 5 3.6. Toe Berm Construction ...... 6

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 6

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor/Owner shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the toe berm and subsurface drainage for the A21 project to be completed by the Contractor/Owner.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The following Technical Specifications related to the toe berm and subsurface drainage Work are to be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0005 Material Preparation 14300-41ES-0006 Embankment Construction 14300-41ES-0009 Excavating, Trenching & Backfilling

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1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The following Drawings related to the toe berm and subsurface drainage Work are to be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41-D2-1021 Infield – General Plan and Typical Ditch Details 14300-41D2-1022 Infield – Toe Berm Profile, Plan, Sections and Details 14300-41D2-1023 Infield – Cross-Sections 14300-41D2-1024 Infield – Dike Pump Station Sections

1.6. Reference Standards

1. American Society for Testing and Materials (ASTM) a. ASTM D422 - Standard Test Method for Particle Size Analysis of Soil. b. ASTM F405 - Standard Specification for Corrugated Polyethylene (PE) Pipe and Fittings. c. ASTM F667 – Standard Specifications for 3 through 24 in. Corrugated Polyethylene Pipe and fittings d. ASTM D1248 - Standard Specification for Polyethylene Plastics Extrusion Materials for Wire and Cable. 2. Canadian Standards Association (CSA) a. CAN/CSA-B182.14-12/B182.15-12 - Profile steel reinforced polyethylene (SRPE) storm sewer pipe and fittings/Profile steel reinforced polyethylene (SRPE) sewer pipe and fittings.

1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

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1.8. Submittals

1. Submit product data. 2. Submit installation sequence. 3. Submit installation procedure.

2.0 PRODUCTS

2.1. Plastic Pipe

1. 150 mm dia. corrugated polyethylene sewer pipe and fittings: [to CAN/CSA B182.6]. a. Concentric outside ribs to provide rigidity. Pipe to have a complete line of compatible injection molded and fabricated fittings. b. Pipe to be manufactured from high density polyethylene resin meeting the requirements of Type III, Category 5, Grade B33 or P34 Class C ASTM D1248. c. Gasket bell and spigot configuration. d. Manufactured in 4 m minimum lengths which can easily be trimmed to length during assembly at Site. e. 150 mm dia. perforated pipes provide a minimum of 70 cm2 perforated area per meter of pipe. The maximum width of a perforation slot shall be 4 mm. f. Non-perforated pipes of equivalent or greater diameter are required for the connection between drainage trenches and the inlets out the pump station. g. Pipe without perforations to be used for 10 m on either side of the pump station or as directed by Manager’s Representative.

2.2. Toe Berm Fill Materials

1. Zones 1B, and 2, and road topping materials for the toe berm shall meet the required gradation limits as specified in Technical Specification 14300-41ES-0006. 2. Zone 4 – Only well graded till as approved by the Manager’s Representative, with minimum fines content (fraction smaller than 0.08 mm) of 15%, will be acceptable.

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3. Zone 6 – Only well graded crushed product conforming to the following gradation limits will be acceptable:

Percent Passing by Sieve Size Weight 28 mm 100 20 mm 90 – 100 10 mm 25 – 60 5 mm 0 – 10 2.5 mm 0 – 5

4. Zone 7 – Coarse Processed Kimberlite (CPK), 1 mm to 6 mm in size.

3.0 EXECUTION

3.1. Unloading and Handling Pipe

1. Unload by hand or by lifting apparatus with fabric slings, do not use cables or chains. 2. Once removed, lay pipes flat on smooth surface or on sleepers to provide broad bearing surface. 3. Lift, do not drag pipe when moving.

3.2. Preparation

1. Soft lakebed sediments within the toe berm alignment will be removed via dredging coincident with dredging of the main embankment footprint. 2. Following dewatering of the A21 pool additional removal of sediments and excavation of boulders nests within the toe berm footprint may be required to achieve acceptable foundation conditions as directed by the Manager’s Representative. 3. Isolated re-grading of the till surface following sediment and boulder removal may be required in order to achieve the design grades for the toe drain piping.

3.3. Trenching for Toe Drain

1. Perform trenching work in accordance with Technical Specification 14300-41ES- 0009.

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2. Trench alignment to be established on site to minimize excavation depth and provide continuous sloping profile. Commencement of trenching to be approved by Manager’s Representative. 3. All excavations in unfrozen till shall have side slopes of 2H:1V unless otherwise approved by the Manager’s Representative. 4. Toe drain trench to be excavated a minimum of 1 m into unfrozen till unless bedrock is encountered at shallower depth. 5. Use drainage/dewatering measures as per requirements of Technical Specification 14300-41ES-0009. 6. Place filter material after approval of excavation by Manager’s Representative.

3.4. Pipe Bedding

1. Place two 150 mm thick layers of Zone 1B material on approved subgrade over the full width of adequately dewatered trench and compact each layer with a minimum of four (4) passes of a vibrating plate compactor (500 lbs). 2. Place 150 mm layer, 1 m wide of Zone 6 over top of compacted Zone 1B material in the center of adequately dewatered trench and compact with a minimum of four (4) passes of a vibrating plate compactor (500 lbs). 3. Contaminated bedding material to be removed and replaced.

3.5. Installation of Pipe

1. Lay pipe on prepared bed, true to lines and grades with invert smooth and free of sags or high points. Ensure barrel of each pipe is in contact with bed throughout full length. 2. Lay perforated pipes with perforations at 120° and 240° positions from crown of the pipe. 3. Lay bell and spigot pipe with bell ends facing upstream. 4. Fill excavation below bottom of specified bedding adjacent to pumping station with compacted Zone 1B fill. Any contaminated material is to be removed. 5. Surround and cover drain with Zone 6 material in uniform 150 mm loose lift thickness to an elevation at least 150 mm above top of drain and compact each lift with a

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minimum of four (4) passes of a vibrating plate compactor (size to be determined upon completion of final pipe design) over each layer. 6. Backfill remainder of trench to requirements of Technical Specification 14300-41ES- 0009. 7. Do not place frozen material in bedding, surround, and backfill. Prevent freezing before completion of trench backfill. 8. Handle, lay, and join pipe in accordance with manufacturer’s recommendations. In general, place pipe from high to low points in trench profile. 9. Use adequate measures to prevent water and foreign material from entering pipes during construction. 10. Whenever work is suspended, install removable watertight bulkhead or pipe cap at upstream end of last pipe laid to prevent entry of foreign materials. 11. Place non-perforated pipe adjacent to pumping station. 12. Make water tight connections to pumping station.

3.6. Toe Berm Construction

1. Upon completion of toe drain trench backfilling, construct toe berm as shown on the Drawings. 2. Zone 2 material and road topping material placement and compaction for toe berm to requirements per Technical Specification 14300-41E2-0006 (Section 3.3) for “in the dry” placement. 3. Zone 7 (coarse processed kimberlite) will be stockpiled by the Owner. Where placed over the crest of the toe berm, Zone 7 will be placed to a 0.15 m thickness, per the Drawings. Compaction will be via four (4) passes of the smooth drum vibratory roller as described in Specification 14300-41ES-0006 or as necessary. Where placed over the 2H:1V slope of the toe berm, no compaction is required.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) Plan document.

- END OF TECHNICAL SPECIFICATION

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CAST-IN-PLACE CONCRETE No. Date

14300-41ES-0011 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All Jun 9/14 June 11/14 June 9/14 Sept. 15/2014 Sept. 15/2014 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 17/14 Nov 17/14 Tender

Technical Specification Revision

CAST-IN-PLACE CONCRETE No. Date

14300-41ES-0011 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Reference Standards ...... 2 1.7. Environmental Protection ...... 3 1.8. Submittals ...... 3

2.0 PRODUCTS ...... 3 2.1. Concrete Materials ...... 3 2.2. Concrete Accessories ...... 4 2.3. Reinforcing Steel and Accessories ...... 4 2.4. Formwork Materials ...... 4 2.5. Design Mix ...... 4

3.0 EXECUTION ...... 5 3.1. Fabrication and Placing of Reinforcing Steel ...... 5 3.2. Placing Concrete ...... 5 3.3. Finishing Formed Surfaces ...... 6 3.4. Finishing Unformed Surfaces ...... 6 3.5. Curing ...... 6 3.6. Grout ...... 6 3.7. Concrete Mix Schedule ...... 7

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 7

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manger’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the materials and workmanship, equipment and methods to be used for the supply, placing, curing and finishing of cast-in-place concrete including supply and installation of form work and reinforcing steel.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the cast- in-place concrete Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-48ES-0003 Survey Markers and Survey Control Monuments

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1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Drawings related to the cast-in-place concrete Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1030.3 Instrumentation Details of Installation (Sheet 3 of 3)

1.6. Reference Standards

1. Canadian Standards Association (CSA) a. CAN3-A23.3 – Design of Concrete Structures. b. CAN/CSA-A23.1 – Concrete Materials and Methods of Concrete Construction. c. CAN/CSA-A23.2 – Methods of Test and Standard Practices for Concrete. d. CAN/CSA-A5 – Portland Cement. e. CAN/CSA-A23.5 – Supplementary Cementing Materials. f. CAN/CSA-G30.5 – Welded Steel Wire Fabric for Concrete Reinforcement. g. CAN/CSA-G30.18 – Carbon Steel Bars for Concrete Reinforcement. h. CSA W186 – Welding of Reinforcing Bars in Reinforced Concrete Construction. i. CAN/CSA-S269.3 – Concrete Formwork. 2. American Society for Testing and Materials (ASTM) a. ASTM C494 – Standard Specification for Chemical Admixtures for Concrete. b. ASTM C260 – Standard Specification for Air Entertaining Admixtures for Concrete. 3. American Concrete Institute (ACI) Detailing Manual – SP-66 4. Concrete Reinforcing Steel Institute – (CRSI) 5. Reinforcing Steel Institute of Ontario (RSIO), Manual of Standard Practice Metric Supplement

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1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.8. Submittals

1. Submit the following: a. The mill from which the cement is to be supplied and mill test reports covering physical and chemical testing by the manufacturer. b. Manufacturer’s technical specifications of proposed admixtures. c. All characteristics required by CSA-A23.1 for fine and coarse aggregates. Test results shall not be older than 90 days and shall include those specified in Appendix B of CSA-A23.1 for aggregate reactivity. d. Determine proportions of concrete materials so as to obtain the required physical characteristics as outlined in the concrete mix schedule, and submit details of trial mixes for review. e. Detailed descriptions of the proposed placing equipment and methods. f. Copies of mill test reports and certificates of reinforcing steel. g. Concrete delivery ticket at the time the concrete is delivered. h. Quality Control (QC) plan for concrete placement and testing. Plan to adhere to Quality Assurance/Quality Control (QA/QC) document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. The QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work. i. Bar bending schedules including placing drawings for reinforcing steel and welded steel wire fabric as well as support and placing details.

2.0 PRODUCTS

2.1. Concrete Materials

1. The concrete materials to conform to the following standards: a. Portland Cement: to CAN/CSA-A5. Type 10 unless specified otherwise.

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b. Aggregates: to CAN/CSA-A23.1. Unless authorized in writing by the Manager’s Representative, do not use aggregates deemed reactive when tested for Alkali- Aggregate Reactivity in accordance with CAN/CSA A23.1. c. Water: to CAN/CSA-A23.1. d. Supplementary Cementing Materials: to CAN/CSA-A23.5. Obtain the written authorization of the Manager’s Representative prior to use of admixtures. Use the same admixture throughout the work. Do not use any admixtures containing calcium chlorides.

2.2. Concrete Accessories

1. Liquid Membrane Forming Curing Compound: CAN/CSA-A23.1. 2. Grout: non-shrink pre-mixed type with a minimum of 20 MPa compressive strength at 24 hours and 40 MPa at 28 days.

2.3. Reinforcing Steel and Accessories

1. Reinforcing Steel Bars: to CAN/CSA-G30.18, grade 400 deformed billet steel bars. 2. Steel Wire Fabric: to CSA-G30.3, Cold-drawn Steel Wire for Concrete Reinforcement, and CSA-G30.5, Welded Steel Wire Fabric for Concrete Reinforcement. 3. Chairs, Bolsters, Bar Supports, Spacers: adequate for strength and support of reinforcing. Non-corrosive and non-staining where specified.

2.4. Formwork Materials

1. Formwork: to CAN/CSA-A23.1. 2. Form Ties: non-corrosive and non-staining at surfaces where concrete will be exposed. 3. Form Oil: non-staining and non-volatile type.

2.5. Design Mix

1. Supply concrete mix proportioned to produce concrete specified in concrete mix schedule. 2. Requirements not specified in the concrete mix schedule shall conform to CAN/CSA- A23.1.

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3. Use of admixtures, other than air-entraining admixtures, are not permitted without prior approval of Manager’s Representative.

3.0 EXECUTION

3.1. Fabrication and Placing of Reinforcing Steel

1. Fabricate hooks, bends, laps and similar details to ACI Detailing Manual SP-66, and Metric Supplement of the Reinforcing Steel Institute of Ontario (R.S.I.O.) Manual of Standard Practice. 2. Identify each bar with the same code used in the bar bending schedule and placing drawings. 3. Place reinforcing steel in accordance with the tolerances requirements of CAN/CSA- A23.1 except as shown on the shop drawings. 4. Provide minimum concrete cover to reinforcing steel in accordance with CAN/CSA- A23.1 except where indicated otherwise on shop drawings. 5. Provide non-corrosive and non-staining reinforcing steel supports. 6. Reinforcing steel shall not be re-bent or straightened after initial fabrication unless so indicated on shop drawings and approved by the Manager’s Representative. 7. Do not weld reinforcing steel unless authorized by the Manager’s Representative.

3.2. Placing Concrete

1. Ensure source, methods of mixing, delivery and placing of concrete are in accordance with CAN/CSA-A23.1 2. Prepare existing concrete surfaces on which fresh concrete shall be placed in accordance with CSA-A23.1 clause 19.5. Mix and brush on bonding agent in accordance with manufacturer’s instructions. 3. Correct improperly positioned reinforcing prior to placing concrete. 4. Obtain Manager’s Representative written approval before placement of concrete commences to ensure that all aspects of cast-in-place concrete are verified including subgrade approval. 5. Use winter concreting methods to control and protect concrete in accordance with CAN/CSA-A23.1 when the mean daily temperature falls below 5°C and obtain Manager’s Representative written approval before execution.

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6. Do not disturb formwork. Compact concrete thoroughly using appropriate vibrators designed for use on each particular application. Avoid contact of vibrators with formwork and reinforcing steel. 7. Perform additional sampling and testing of concrete if, in the opinion of the Manager’s Representative, test results or other field observations indicate changes in the quality of the concrete being supplied.

3.3. Finishing Formed Surfaces

1. Rough Finish Concrete Surfaces Not Exposed to View: place concrete against forms reasonably true and plane. Cut off form ties a minimum of 10 mm below concrete surface. Patch tie holes and defects. Remove fins exceeding 5 mm. 2. Smooth Finish Surfaces Exposed to View: place concrete against plywood, steel or tempered hardboard. Patch tie holes and defects. Remove fins.

3.4. Finishing Unformed Surfaces

1. Scratch Finish Surfaces: consolidate and strike off concrete to true plane not exceeding 5 mm in 5 meters and roughen with broom before initial set.

3.5. Curing

1. Keep concrete surfaces continuously damp for a period of seven (7) days during which time the surfaces of the concrete shall be protected from direct sun rays, winds and freezing temperatures. 2. Protect freshly placed and consolidated concrete against damage and from adverse weather conditions. 3. Acceptable Curing Methods: a. Ponding or continuous sprinkling. b. Absorptive mat or fabric kept continuously wet. c. Damp sand, earth, or similar moist material. d. Continuous steam vapor mist bath not exceeding 66°C. 4. Curing compounds can be used if approved specifically by Manager’s Representative.

3.6. Grout

1. Mix to flowable consistency and place in accordance with manufacturer’s instructions.

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3.7. Concrete Mix Schedule

Min. Comp. Max Max Slump Strength @ Nominal Air Content Cement Components Water/Cement Range 28 days Agg. Size Range (%) Types Ratio (mm) (MPa) (mm) Concrete 30 0.45-0.50 20 20-100* 5-8 10

Final slump will depend on type and thickness of element to be poured.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) Plan document.

- END OF TECHNICAL SPECIFICATION

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INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 22/14 June 18/14 June 11/14 Sept. 15/2014 Sept. 15/2014 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov. 17/14 Nov 17/14 Tender

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TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 1 1.6. Reference Standards ...... 2 1.7. Environmental Protection ...... 3 1.8. Submittals ...... 3 1.9. CSM Laboratory Trial Mix Program ...... 4 1.10. CSM Acceptance Criteria ...... 5 1.11. Qualifications ...... 7

2.0 PRODUCTS ...... 7 2.1. Materials ...... 7 2.2. Storage ...... 9 2.3. Testing Equipment ...... 9

3.0 EXECUTION ...... 10 3.1. Pre-Drilling Equipment ...... 10 3.2. CSM Equipment ...... 10 3.3. Field Trials ...... 11 3.4. Guide Trench/Wall ...... 12 3.5. Pre-Drilling ...... 13 3.6. CSM ...... 14 3.7. CSM Cut-Off Wall Geometry ...... 15 3.8. CSM Panel Depth ...... 15 3.9. CSM Panel Verticality ...... 15 3.10. CSM Mix Volume Measurements ...... 16

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 16

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1.0 GENERAL

1.1. Documents

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the CSM activities for the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the CSM Work that are to be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0016 Drilling

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

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2. The Contractor is referred to the following Drawings related to the CSM Work that are to be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike - General Site Plan 14300-41D2-1007 Typical Cross-Sections (Sheet 1 of 2) 14300-41D2-1008 Typical Cross-Sections (Sheet 2 of 2) 14300-41D2-1009.1 Plan and Profile - Sta. 0+000 to 0+350 (Sheet 1 of 6) 14300-41D2-1009.2 Plan and Profile - Sta. 0+350 to 0+725 (Sheet 2 of 6) 14300-41D2-1009.3 Plan and Profile - Sta. 0+725 to 1+100 (Sheet 3 of 6) 14300-41D2-1009.4 Plan and Profile - Sta. 1+100 to 1+450 (Sheet 4 of 6) 14300-41D2-1009.5 Plan and Profile - Sta. 1+450 to 1+825 (Sheet 5 of 6) 14300-41D2-1009.6 Plan and Profile - Sta. 1+825 to 2+208 (Sheet 6 of 6) 14300-41D2-1011.1 Stratigraphic Profile - Sta. 0+000 to 0+600 (Sheet 1 of 4) 14300-41D2-1011.2 Stratigraphic Profile - Sta. 0+600 to 1+200 (Sheet 2 of 4) 14300-41D2-1011.3 Stratigraphic Profile - Sta. 1+200 to 1+725 (Sheet 3 of 4) 14300-41D2-1011.4 Stratigraphic Profile - Sta. 1+725 to 2+228 (Sheet 4 of 4) 14300-41D2-1012.1 Stratigraphic Section - GPR Sections 5 to 6 (Sheet 1 of 6) 14300-41D2-1012.2 Stratigraphic Section - GPR Sections 7 to 8 (Sheet 2 of 6) 14300-41D2-1012.3 Stratigraphic Section - GPR Sections 9 to 10 (Sheet 3 of 6) 14300-41D2-1012.4 Stratigraphic Section - GPR Sections 11 to 12 (Sheet 4 of 6) 14300-41D2-1012.5 Stratigraphic Section - GPR Sections 13 to 15 (Sheet 5 of 6) 14300-41D2-1012.6 Stratigraphic Section - GPR Sections 18 to 19 (Sheet 6 of 6) 14300-41D2-1014 South Island Facilities Layout 14300-41D2-1015 North Abutment Plan and Profile 14300-41D2-1017 South Abutment Plan and Profile 14300-41D2-1020.2 CSM Panels and Pre-Drilling - Typical Plans and Sections 14300-41D2-1025.1 Construction Staging (Sheet 1 of 2) 14300-41D2-1025.2 Construction Staging (Sheet 2 of 2)

1.6. Reference Standards

1. American Petroleum Institute (API) a. API Specification 13A, Specification for Drilling-Fluid Materials

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b. API Recommended Practice 13B-1, Recommended Practice for Field Testing Water-Based Drilling Fluids, 4rd Edition , 2009. 2. American Society for Testing and Materials (ASTM) a. ASTM C143 Revision A, Standard Test Method for Slump of Hydraulic Cement Concrete b. ASTM D2166, Standard Test Method for Unconfined Compressive Strength of Cohesive Soil c. ASTM D2850, Test Method for Unconsolidated, Undrained Strength of Cohesive Soils in Triaxial Compression d. ASTM D4647, Standard Test Method for Identification and Classification of Dispersive Clay Soils by the Pinhole Test e. ASTM D4832, Standard Test Method for Preparation and Testing of Controlled Low Strength Material (CLSM) Test Cylinders f. ASTM D5084, Standard Test Method for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter g. ASTM D6391, Standard Test Method for Field Measurement of Hydraulic Conductivity Using Borehole Infiltration 3. Canadian Standards Association (CSA) a. CAN/CSA-A23.1, Concrete Materials and Methods of Concrete Construction b. CAN/CSA-A23.2, Test Methods and Standard practices for Concrete

1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License. 2. Grade working surfaces towards waste trench to prevent spills and contaminated run off flowing into the Water Body. 3. Promptly remove pre-drilled materials and waste CSM slurry from the Construction Platform. Stockpiling of pre-drilled materials on the platform is not permitted and shall be stockpiled on South Island for subsequent re-handle.

1.8. Submittals

1. The Contractor must submit at least eight (8) weeks prior to the start of mobilization, a detailed CSM Cut-Off Wall construction and testing plan including the following:

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a. Proposed construction methodology including: i. Methods of pre-drilling. ii. Details of CSM panel installation method, construction sequence and construction methodology. iii. Methods of measuring and maintaining panel vertical and horizontal alignment. b. List of all equipment to be used for pre-drilling, slurry preparation and panel installation. Include the number of units, model, year, type of the equipment. c. Detailed procedures for identifying and correcting panel deficiencies. d. Quality Control (QC) plan, including procedures and equipment for wet sampling from CSM panels, and for coring of cured panels. Plan to adhere to Quality Assurance/Quality Control (QA/QC) document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. The QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work. 2. Prior to the commencement of Work the Contractor must submit: a. Shop drawings of the guide wall design. b. Shop drawings of the Contractor’s panel layout and numbering system. c. Details of CSM mix including mix proportions and additives. d. Confirmation that equipment is in conformance with North American electrical standards and NWT Mines Act. e. Owner compliant heavy vehicle risk assessment that identifies equipment hazards and the measures that are in place to control (via eliminating or minimizing) these hazards. The risk assessment shall be completed prior to mobilization of equipment to site for evaluation by the Owner so that potential deficiencies identified by the Owner can be corrected by the Contractor prior to mobilization. 3. Qualifications of personnel (see Section 1.11).

1.9. CSM Laboratory Trial Mix Program

As part of the feasibility study for the use of CSM in the cut off wall, Tetra Tech EBA performed laboratory testing to evaluate potential mix designs for the CSM Cut-Off Wall. Further laboratory work is required to determine the final mix design and as such, this Technical Specification will be updated once that laboratory testing is complete and the final

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mix is established. Once established, the mix design may require adjustment on the basis of field trials.

1.10. CSM Acceptance Criteria

1. Further laboratory testing is required to determine the Cut-Off Wall acceptance criteria for compressive strength and stiffness and as such, this Technical Specification will be updated once that laboratory testing is complete and the final criteria is established. Correlations between UU tests, which govern design, and UCS tests, will be established as UCS testing will form the bulk of the QA/QC testing. 2. Unconsolidated Undrained Triaxial Compression Test ASTM D2850 (150 kPa confining pressure, samples cured at 2 °C) – compressive strength and initial tangent modulus shall fall within the bounds illustrated in the figure below based on samples cured for 100 days, and listed as follows: a. Maximum UU strength 3 MPa. b. Minimum UU strength 1.0 MPa. c. Maximum initial tangent modulus 300 MPa. d. Minimum initial tangent modulus 100 MPa.

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3. Unconsolidated Undrained Triaxial Compression Test ASTM D2850 (150 kPa confining pressure, samples cured at 2 °C). a. Minimum strength at 28 days 0.7 MPa. b. Maximum strength at 28 days 1.2 MPa. c. Initial Tangent Modulus (E) 25 MPa < E < 100 MPa. 4. Unconfined Compression Strength Test ASTM D2166 (samples cured at 23 °C). a. Maximum strength at 28 days 3 MPa. b. Minimum strength at 28 days 1 MPa. 5. Hydraulic Conductivity Test ASTM D5084 a. Hydraulic conductivity < 1 x 10-8 m/sec (hydraulic gradient of 10) for samples cured for 28 days at 23°C. 6. Slump Test ASTM C143 To be determined. 7. Cracked Specimen Erosion Test ASTM D4647 Non-dispersive (ND).

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1.11. Qualifications

1. Field personnel: Provide an experienced (10 years minimum) full time, on-site Project Manager and Superintendent, CSM Specialists, QC Engineer and support personnel specifically experienced with CSM seepage cutoffs. Provide one full time Supervisor per pre-drilling rig per shift, and one full time CSM Specialist per shift for the CSM operation, as well as one full time field QC Engineer for pre-drilling and CSM operations. Submit resumes of the proposed personnel. 2. Design personnel: Identify design engineering support personnel to be assigned to confirm any modifications of the design of the cut-offs and prepare submittals. Submit resumes of design personnel highlighting relevant experience with deep (approximately 30 m) CSM Cut-Offs. 3. Manager’s Representative review of qualifications: Manager’s Representative will review the qualifications of the proposed personnel for approval or rejection. This review may include interviews with the personnel by Manager’s Representative.

2.0 PRODUCTS

2.1. Materials

1. Bentonite a. Wyo-Ben Big Horn 200 bentonite for the CSM mix. This material is supplied by the Owner. Bentonite shall conform to API Specification 13A, Specification for Drilling-Fluid Materials. 2. Water a. Potable, clean and free from deleterious amounts of soil, salts, oil and organic matter such that the resulting slurry has the necessary properties for the CSM mix. b. Identify source of water and if other than directly from Lac de Gras, submit water quality test results to the Manager’s Representative for approval. c. Specified values are shown below:

Test Specified Values pH About 7.0 Hardness 70 ppm or less Organic Content 50 ppm or less Total dissolved solids 500 ppm or less

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3. Slag/Cement a. GranCem ground granulated blast furnace slag produced by Holcim (Mississauga, Ontario). b. GU cement (Portland Cement) produced by Holcim (Mississauga, Ontario). Where faster setting time is required for portions of the CSM constructed shortly before pool dewatering, high early strength (Type 30) Portland cement may be required as directed by Manager’s Representative. Additives such as dispersants, plugging agents, viscosity enhancers and/or softeners may be added to obtain proper workability of the CSM mix. Submit details of additives to the Manager’s Representative for approval. c. All cementing materials (slag and cement) to be obtained from the same manufacturing source. d. Cementing materials are supplied by the Owner. 4. Backfill Aggregate a. Backfill Aggregate shall be provided by the Owner and approved by the Manager’s Representative. b. Backfill Aggregate shall be free of roots, organic material, trash, debris, frozen material or any other deleterious material. c. Well graded crushed product with a maximum particle size of 12.5 mm and conforming to the following gradation.

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Sieve Size Total Passing Sieve, (mm) Percentage by Dry Mass 12.5 100 9.5 84 – 100 6.3 72 - 85 4.75 63 - 75 2.36 44 - 59 1.18 34 - 44 0.6 24 - 34 0.3 14 - 24 0.15 7 - 16 0.075 4 - 12

2.2. Storage

1. Store bagged cement, slag and bentonite in original unopened containers protected at all times from moisture. Ensure laydown area is well graded with positive drainage. 2. If bulk storage is used, provide protection at all times from moisture. 3. Provide heat to ensure that water is at a minimum of 5°C at time of mixing, but not warmer than 20°C.

2.3. Testing Equipment

1. As a minimum, provide and maintain at site the following equipment: a. Marsh Funnel set. 2. Direct Indicating Viscometer (hand crank or electric). 3. Mud Balance (direct reading of density and specific gravity). 4. Sampler for sampling CSM wet mix at depths up to 30 m. Provide details of the sampling equipment and methodology. 5. Graduated probes, weighted tapes and other devices to measure depths of pre- drilling, backfill and to characterize the material at the bottom of the pre-drilled hole.

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6. Provide requisite number of sets of equipment listed above to suit quantity of equipment working including adequate supply of extras as necessary. 7. Calibration records shall be provided for all gauges, meters, etc. used for measuring activities prior to and during the CSM operation.

3.0 EXECUTION

3.1. Pre-Drilling Equipment

1. Use appropriate drilling equipment to execute the required pre-drilling through dike rock fill and to bedrock or 3 m into the foundation till (whichever has a higher elevation) as shown on the Drawings. In areas where glaciofluvial foundation material is encountered, drilling depths may extend deeper than 3 m into the foundation material, as directed by the Manager’s Representative. Provide a detailed description of drilling equipment, productivity, and methodology. 2. Pre-drill equipment shall be capable of casing the entire length of borehole, to allow for effective backfilling with Backfill Aggregate and to prevent hole collapse. 3. Predrill equipment to incorporate remote operator activated casing locks on the casing driver. 4. Contractor shall provide various drill bit types capable of penetrating and removing embankment fill (Zone 1) and lakebed till without causing delays in schedule. 5. Contractor shall provide funnel or hopper to direct Backfill Aggregate (12.5 mm crush) into the pre-drilled borehole, in stages as the casing is being withdrawn.

3.2. CSM Equipment

1. Employ state of the art equipment to perform CSM with precise orientation through dike core Backfill Aggregate material as shown on the Drawings. 2. The Contractor shall maintain a sufficient array of equipment to permit CSM operations to proceed efficiently without causing delays in schedule. 3. CSM equipment shall include cutter head with an appropriate set of CSM cutting and mixing wheels and teeth. 4. The equipment shall be capable of mixing the minimum required panel dimensions in a single pass of the CSM cutter head as shown on the Drawings.

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5. CSM equipment shall incorporate the capability to directly obtain the wet bulk samples from the freshly placed CSM panel at depths as directed by the Manager’s Representative. 6. CSM equipment shall have sufficient instrumentation to continuously record the following during operation: a. Depth and penetration/extraction rate of the CSM head. b. Slurry flow rate and total volume of slurry injected into the panel. c. Slurry injection pressure. d. Slurry-soil pressure in the CSM panel. e. Pumped slurry volume with time and with depth. f. Inclination of ‘X’ and ‘Y’ direction with an accuracy of 0.1% of depth (‘Z’ direction). g. Rotation speed and torque of mixing wheels. 7. The positioning of the pre-drilling and CSM equipment shall be done with the aid of a GPS system (or alternative as approved by the Manager’s Representative) capable of providing a level of accuracy to 10 mm in the ‘X’ and ‘Y’ directions. 8. The Contractor shall have available at all times sufficient equipment spare parts, in particular those subject to significant wear. 9. Use of CSM cutter equipped with suitable cutter teeth to construct joints between panels satisfying the specified requirements. 10. Depending on whether the one-phase or two-phase method is applied for the CSM method, a scratching belt, pump and de-sander will also be required (two-phase system). 11. Contractor to provide sufficient number of slurry mixing plants suitable for equipment quantity and schedule. Mixing plants shall be suitable for producing both bentonite slurry and cement/slag/bentonite slurry required for CSM operation.

3.3. Field Trials

1. Construct test sections at location defined by Manager’s Representative before proceeding with production. 2. Execute trials consisting of 10 panels to evaluate: a. Equipment performance and verticality.

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b. Characteristics of fresh and cured CSM product. c. Confirmation of acceptance criteria. d. Confirmation of QA and QC procedures and requirements. 3. Obtain bulk samples from freshly placed CSM mixed product and complete testing as required in the field sampling and testing program outlined in the QA/QC Plan (refer to Section 4.0). 4. Obtain core samples from cured panels at least seven days after completion of the placement of CSM test panels and complete testing as required in the field sampling and testing program outlined in the QA/QC Plan. One-hundred percent core recovery is required. 5. Perform in-situ hydraulic conductivity testing by a falling or rising head test as directed by the Manager’s Representative. 6. Cooperate with Manager’s Representative in carrying out down-hole televiewer camera surveys (or similar) of the boreholes as required.

3.4. Guide Trench/Wall

1. A guide trench approximately 0.5 m deep shall be constructed from the Construction Platform at El. 418.0 m along the CSM Cut-Off Wall alignment. 2. The guide trench alignment shall be verified using a GPS system, or other survey methods approved by the Manager’s Representative. 3. A cast-in place guide wall shall be constructed along one side of the guide trench to assist with alignment and to support tracking of panel completion. 4. The size of guide wall shall be established by the Contractor. 5. Guide wall shall be removed at locations of thermosyphon groups after panel installation, sampling and testing have been completed. 6. Back flow material from the CSM operation shall be removed from the guide trench and hauled to disposal areas designated for such purpose by the Owner. 7. After proper curing of the plastic concrete panels, the guide trench will be cleaned and covered with Zone 1B material to Construction Platform elevation (418.0 m).

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3.5. Pre-Drilling

1. Provide appropriate drilling equipment as outlined in Section 3.1, with adequate spare parts and qualified supervision to execute the pre-drilling. 2. Survey borehole locations along the alignment of the cut-off wall prior to the drilling operation. 3. Drill along the cut-off wall axis as shown on the Drawings. 4. Drilled boreholes shall have a diameter of 1180 mm drilled at a center to center spacing of 870 mm. The use of a template or drilling guide is required to ensure proper drill hole spacing is retained. 5. The holes will be extended from the Construction Platform at elevation 418.0 m to the bedrock surface or 3 m in the lakebed till (whichever has a higher elevation). In areas where glaciofluvial foundation material is encountered, drilling depths may extend deeper than 3 m into the foundation material if so directed by the Manager’s Representative. 6. Casing shall be installed through the Zone 1 dike core and the lakebed till or glaciofluvial material as each hole is advanced to prevent sloughing from occurring. 7. Zone 1 and lakebed till or glaciofluvial material within the borehole shall be removed by drilling equipment. The Contractor shall monitor for, and implement measures to prevent, heave at the bottom of the borehole. 8. Measure and record the progress and depth of each pre-drill excavation. 9. Monitor and record the type and volume of material evacuated from the borehole. 10. Using data from exploratory and/or grout holes and observations during pre-drilling to characterize foundation soil profile and conditions for each hole. 11. Prior to completion of pre-drilling for each hole, review the foundation soil profiles with Manager’s Representative and reach agreement regarding final depth of drilling. 12. Do not pre-drill panels within 50 m of the advancing Vibro-Densification limits. 13. Sound bottom of borehole to verify cleaning prior to backfilling using a heavily weighted tape. 14. Horizontal tolerance of pre-drilled holes at the collar: +/-25 mm. Hole location shall be recorded. 15. Pre-drill holes shall maintain verticality within 0.5 % of full depth of the hole. Verticality shall be recorded by the Contractor.

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16. Pre-drilled holes with a horizontal or vertical deviation that exceeds specified tolerances shall be re-drilled unless directed otherwise by the Manager’s Representative. 17. Do not start backfilling until Manager’s Representative has accepted borehole cleaning in writing (sign-off form). 18. The hole should be continuously backfilled with 12.5 mm crush Backfill Aggregate to a higher level than the bottom of the casing as the casing is extracted. 19. Monitor and record the volume of Backfill Aggregate placed into the borehole. 20. Maintain daily records for all borehole drilling and backfilling.

3.6. CSM

1. CSM panel installation shall use a GPS system (or other survey method approved by the Manger’s Representative) that continuously monitors and records the location of the equipment, CSM cutter head and panel location. 2. Survey CSM panel locations along the alignment of the cut-off wall prior to the CSM operation. 3. Injected slurry shall be pumped to meet requisite acceptance criteria. 4. Waste slurry within the guide trench will be disposed of in the location designated by the Owner. 5. The penetration and extraction rates as well as slurry pumping rate shall be established and controlled by the Contractor to allow the specified slurry content in the CSM mixture to be achieved, and to yield a uniform cut-off wall. 6. The rates noted above will need to be determined during initial panel installation and monitored throughout the project duration, and updated as required on the basis of monitoring and QA/QC testing. 7. Parameters to be continuously electronically monitored and recorded by the CSM equipment include: a. Depth and penetration/extraction rate of the CSM head. b. Slurry flow rate and total volume of slurry injected into the panel. c. Slurry injection pressure. d. Slurry-soil pressure in the CSM panel. e. Pumped slurry volume with time and with depth.

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f. Inclination of the CSM head. g. Rotation speed and torque of mixing wheels. 8. Freezing of CSM slurry and/or panels is prohibited. Mixing and installation of the CSM Cut-Off Wall and construction during colder months of the year shall be avoided unless measures are taken to prevent freezing. 9. Primary panels are first installed followed by overlapping secondary panels at least 24 hours later.

3.7. CSM Cut-Off Wall Geometry

1. Depth: From El. 417.5 m to 3 m into till, or to refusal on bedrock if till is less than 3 m in thickness as shown on the Drawings. 2. Thickness: 0.80 m minimum. 3. Primary and secondary panel length: maximum 2.8 m. 4. Overlap between primary and secondary panels: Minimum 200 mm over entire length of panel as shown on the Drawings. Transverse overlap shall be a minimum of 600 mm over entire length of panel as shown on the Drawings. 5. Alignment: As shown on the Drawings.

3.8. CSM Panel Depth

1. Pre-drill to requisite depth as shown on the Drawings, or as otherwise directed by the Manager’s Representative. Penetration depth shall be measured by welded marks on the drill casing. Depths shall be recorded. 2. The CSM panel depth shall be measured by welded marks placed on the CSM rig. Depths shall be recorded. 3. The panel depth shall be further verified by full-depth coring as directed by the Manager’s Representative.

3.9. CSM Panel Verticality

1. Maintain panel verticality within 0.5% of full depth of the panel within tolerances as indicated on the Drawings. Verticality shall be recorded. 2. Calibrate inclinometers in CSM equipment at start of work and verify regularly (minimum every two weeks). Provide records of such verification to the Manager’s Representative.

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3. Measure panel deviation using inclinometers in equipment or other approved methods. The preferred convention for deviations is positive towards both pit side and increasing dike reference line stationing. 4. The operator shall monitor and record inclination in the “X” and “Y” directions with a minimum accuracy of 10 mm. 5. CSM panels with a horizontal or inclination deviation that exceed specified tolerances shall be corrected at the Contractor’s expense.

3.10. CSM Mix Volume Measurements

1. Monitor slurry quantity introduced during CSM cutter head down-stroke and upstroke. 2. Compare actual and theoretical volumes of slurry pumped into the panel after placement of each panel. 3. An increase from theoretical volume indicates possible CSM mix/slurry is being lost. 4. Abnormal slurry volumes, > 10% deviation of actual vs theoretical, recorded during down-stroke or up-stroke of the CSM cutter head may be indicative of improper pre- drilling or deviation from wall alignment and shall be flagged immediately to the attention of the Manager’s Representative for assessment.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

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INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 17/14 June 18/14 June 14/14 Sep 17/14 Sep 17/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

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TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Reference Standards ...... 3 1.7. Environmental Protection ...... 3 1.8. Submittals ...... 4 1.9. Qualifications ...... 6 1.10. Safety ...... 6

2.0 Jet Grouting Design Requirements ...... 6 2.1. Mix Ratios ...... 7 2.2. Unconfined Compression Strength (UCS) ...... 7 2.3. Hydraulic Conductivity ...... 7 2.4. Cracked Specimen Erosion ...... 7

3.0 EQUIPMENT ...... 8 3.1. Drilling ...... 8 3.2. Jet Grouting ...... 9 3.3. Mixing and Delivery ...... 9 3.4. Testing Equipment ...... 10

4.0 PRODUCTS ...... 10 4.1. Materials ...... 10 4.2. Dye ...... 11 4.3. Storage ...... 11

5.0 EXECUTION ...... 11 5.1. General ...... 11 5.2. Jet Grouting Cut-off Requirements ...... 11 5.3. Test Sections ...... 12 5.4. Jet Grouting Depth ...... 13 5.5. Directional Control ...... 14

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5.6. Joints ...... 14 5.7. Horizontal Alignment ...... 15 5.8. Grout Mixing ...... 15 5.9. Delivery ...... 15 5.10. Jet Grout Placement ...... 15

6.0 FIELD RECORDS ...... 17

7.0 VERIFICATION CORE DRILLING ...... 19

8.0 DEFICIENCIES ...... 19

9.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 20

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1.0 GENERAL

1.1. Documents

This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

This Technical Specification covers the Work specific to the Jet Grouting activities for the A21 project to be completed by the Contractor.

1.3. Definitions

A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). The Contractor is referred to the following Technical Specifications related to the Jet Grouting Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0002 Environmental Protection 14300-41ES-0016 Drilling 14300-41ES-0012 CSM Cut-Off Wall 14300-41ES-0014 Curtain Grouting

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1.5. Reference Drawings

A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). The Contractor is referred to the following Drawings related to the Jet Grouting Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1007 Typical Cross-Sections (Sheet 1 of 2) 14300-41D2-1008 Typical Cross-Sections (Sheet 2 of 2) 14300-41D2-1009.1 Plan and Profile - Sta. 0+000 to 0+350 (Sheet 1 of 6) 14300-41D2-1009.2 Plan and Profile - Sta. 0+350 to 0+725 (Sheet 2 of 6) 14300-41D2-1009.3 Plan and Profile - Sta. 0+725 to 1+100 (Sheet 3 of 6) 14300-41D2-1009.4 Plan and Profile - Sta. 1+100 to 1+450 (Sheet 4 of 6) 14300-41D2-1009.5 Plan and Profile - Sta. 1+450 to 1+825 (Sheet 5 of 6) 14300-41D2-1009.6 Plan and Profile - Sta. 1+825 to 2+228 (Sheet 6 of 6) 14300-41D2-1011.1 Stratigraphic Profile - Sta. 0+000 to 0+600 (Sheet 1 of 4) 14300-41D2-1011.2 Stratigraphic Profile - Sta. 0+600 to 1+200 (Sheet 2 of 4) 14300-41D2-1011.3 Stratigraphic Profile - Sta. 1+200 to 1+740 (Sheet 3 of 4) 14300-41D2-1011.4 Stratigraphic Profile - Sta. 1+740 to 2+228 (Sheet 4 of 4) 14300-41D2-1012.1 Stratigraphic Section - GPR Sections 5 to 6 (Sheet 1 of 6) 14300-41D2-1012.2 Stratigraphic Section - GPR Sections 7 to 8 (Sheet 2 of 6) 14300-41D2-1012.3 Stratigraphic Section - GPR Sections 9 to 10 (Sheet 3 of 6) 14300-41D2-1012.4 Stratigraphic Section - GPR Sections 11 to 12 (Sheet 4 of 6) 14300-41D2-1012.5 Stratigraphic Section - GPR Sections 13 to 15 (Sheet 5 of 6) 14300-41D2-1012.6 Stratigraphic Section - GPR Sections 18 to 19 (Sheet 6 of 6) 14300-41D2-1014 South Island Facilities Layout 14300-41D2-1015 North Abutment Plan and Profile 14300-41D2-1017 South Abutment Plan and Profile 14300-41D2-1020.3 Jet Grout Typical Plan and Detail 14300-41D2-1025.1 Construction Staging (Sheet 1 of 2) 14300-41D2-1025.2 Construction Staging (Sheet 2 of 2)

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1.6. Reference Standards

American Petroleum Institute (API) a. API Specification 13A, Specification for Drilling-Fluid Materials. b. API Recommended Practice 13B-1, Recommended Practice for Field Testing Water-Based Drilling Fluids, 4rd Edition , 2009. American Society for Testing and Materials (ASTM) a. ASTM C31, Standard Practice for Making and Curing Concrete Test Specimens in the Field. b. ASTM C150, Standard Specification for Portland Cement. c. ASTM C494, Standard Specification for Chemical Admixtures for Concrete. d. ASTM C1017, Standard Specification for Chemical Admixtures for Use in Producing Flowing Concrete. e. ASTM D1633, Standard Test Methods for Compressive Strength of Molded Soil- Cement Cylinders. f. ASTM D2166, Standard Test Method for Unconfined Compressive Strength of Cohesive Soil. g. ASTM D2850, Standard Test Method for Unconsolidated-Undrained Triaxial Compression Test on Cohesive Soils. h. ASTM D4647, Standard Test Method for Identification and Classification of Dispersive Clay Soils by the Pinhole Test. i. ASTM D5084, Standard Test Method for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter. Canadian Standards Association (CSA) a. CAN/CSA-A23.1, Concrete Materials and Methods of Concrete Construction. b. CAN/CSA-A23.2, Test Methods and Standard Practices for Concrete.

1.7. Environmental Protection

Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License. Use equipment and construction methods to avoid loss of grout into the Water Bodies. Promptly remove return fluid and waste grout from the dike. Stockpiling of

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waste materials on the dike is not permitted, except in engineered containment facilities approved by the Manager’s Representative.

1.8. Submittals

Submit at least 30 days prior to start-up of the Work, a jet grouting construction plan including the following: a. Owner compliant heavy vehicle risk assessment that identified equipment hazards and the measures that are in place to control (eliminate or minimize) these hazards. The risk assessment shall be completed prior to mobilization of equipment to site for evaluation by the Owner so that potential deficiencies identified by the Owner can be corrected by the Contractor prior to mobilization. b. Proposed construction methodology: i. Provide plans showing the proposed grouting plant and equipment and their layout. ii. Description of basic Jet Grouting system proposed (triple fluid system is required) and method of drilling. iii. Description of methodology should jet grouting be required to seal large bedrock joints (single fluid system was used where this contingency was invoked on the A418 dike). iv. Details of maintaining and measuring borehole orientation. Provide references of previous work where proposed directional survey equipment has been used successfully. v. Details of air, water, and grout pressure and flow rate, withdrawal rate and rotation speed of the drill rods. vi. Description of a test program to fine tune the above Jet Grouting parameters. c. List of equipment to be used. Provide information of the: i. Drill rods and drill bits – drill steels shall be capable to perform the Work, and Contractor shall provide documentation to support this. ii. Grout injection monitors with nozzles. iii. Grout pumps. iv. Air compressor system.

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v. Details of batching plant, grout holding tanks and transfer system. vi. Details of automatic injection control system and data recording equipment. vii. Calibration records for gauges to be used during Jet Grouting process. d. Details of disposal of waste material resulting from all Jet Grouting operations. e. Detailed procedures for correcting hole alignment deficiencies. f. Outline steps to be followed if, due to ground conditions, no grout return to surface is obtained. g. Details of the Quality Control (QC) plan. Plan to adhere to Quality Assurance/Quality Control (QA/QC) document identified in Section 9.0 below as a minimum and include additional QC activities as necessary. The QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work. Submit example packages for shift reports, including drilling and Jet Grouting data, and describe electronic QC data that will be provided to the QA team. h. Proposed trial mix design and testing program for Jet Grouting including: i. Material sources (including water). ii. Material testing. iii. Description of proposed trial mixes and trial field testing program, including verification drilling, sampling, and testing for the trial program. Submit resumes of the proposed superintendent, specialists, field QC engineer, and other site personnel. Identify engineering support personnel to be assigned to propose any modifications of the design of the Jet Grouted Cut-Off and prepare submittals and indicate corporate and assigned site personnel experience with deep Jet Grouted Cut-Offs used for seepage control. During the course of construction submit the following: a. Copies of QC test results. b. Details of air, water, and grout pressure and flow rate, withdrawal rate and rotation speed of the drill rods. c. Complete records of drilling, orientation measurements and grouting.

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d. Samples of materials in sufficient amount for independent quality assurance testing. Assume 3 litres of grout sampled in the column for every fifth Jet Grout Column. e. As built drawings.

1.9. Qualifications

Field personnel: Provide an experienced (10 years minimum) full time, on-site project manager. Provide a superintendent, Jet Grouting specialists, QC staff and support personnel specifically experienced with Jet Grouted cut-offs. Provide one full time supervisor per rig per shift and one full time specialist per shift for the batch plant, and a field QC engineer. Manager’s Representative review of qualifications: Manager’s Representative will review the qualifications of the proposed personnel for approval or rejection. This review may include interviews with the personnel by Manager’s Representative.

1.10. Safety

Comply with the NWT Mines Act/Regulations, CSA and Owner safety standards pertaining to all compressed air related equipment and Work on-site. Comply with all site safety standards during preparation and execution of drilling and grouting activities.

2.0 Jet Grouting Design Requirements This section establishes the parameters which provide a continuous low permeable Jet Grouting cut-off while minimizing the consumption of cement. The objectives are to obtain the specified hydraulic conductivity, the continuity of the overlapping jet grout columns, and the specified strengths. Verification coring of the Jet Grout Columns (along with the CSM plastic concrete above and the bedrock grout curtain below) will be required. The required core recovery is 100%, and assigned personnel, equipment, and drilling/coring methodology shall be compatible with this requirement. By means of the trials and the laboratory testing results obtained from the production columns, collaborate with the Manager’s Representative to confirm as soon as possible the water/cement ratio which will attain the objectives.

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2.1. Mix Ratios

Maximum Water to Cement Ratio (W:C) a. 1.25 for triple fluid system. b. Minimum Bentonite/Water Ratio of 0.03. i. Such as to ensure a stable mix (bleed less than 5 % of clear water above settled solids) and so as to ensure the compliance with Sections 2.2. to 2.4 of this Technical Specification.

2.2. Unconfined Compression Strength (UCS)

UCS test as per ASTM D2166 (23°C) for samples representing in-situ mix at 28 days (Note: mix subject to confirmation or revision after trials). a. Minimum UCS 2 MPa b. Maximum UCS 6 MPa UCS test as per ASTM D2166 (23°C) for samples representing in-situ mix (at seven (7) days (Note: mix subject to confirmation or revision after trials). a. Minimum UCS 1 MPa Tolerances - 2/10 samples may be less than 2 MPa at 28 days but not less than 1.5 MPa and 1/10 samples may be less than 2 MPa but not less than 1 MPa. Establish correlations between characteristics of cylinders prepared from fresh slurry and cylinders prepared from slurry sampled in the completed column prior to setting. Carry out routine control testing of the fresh slurry based on these correlations.

2.3. Hydraulic Conductivity

Test as per ASTM D5084 on samples obtained from columns and cured at 2°C. a. Hydraulic conductivity at 28 days shall be less than 1x10-6 cm/sec under a gradient of 30. (Note mix subject to confirmation or revision after trials). Tolerances - 1/10 samples may exceed 1x 10 -6 cm/sec but not to exceed 1x10 -5 cm/sec.

2.4. Cracked Specimen Erosion

Test ASTM D4647 ND (Non-dispersive), for wet samples cured at 23 °C for 28 days, and cored samples cured in situ for at least 28 days.

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3.0 EQUIPMENT

3.1. Drilling

Employ state of the art equipment to produce minimum 75 mm diameter holes with precise orientation through plastic concrete, crushed stone, medium dense to very dense till, including boulders, and bedrock. Drilling equipment may be part of grout system or separate. Drilling rods and bits need to be robust to conserve the drilling equipment, minimize break-downs, and avoid delays in the construction schedule. Use rotary or roto-percussion drilling technique with water flush. Use drilling tools and methods to prevent damage to the CSM Cut-Off Wall. Casing needs to be used in the CSM Cut-Off Wall to prevent damage to the wall. The borehole shall be stable and have sufficient annular space between the Jet Grout drill rods and the sidewalls of the drill hole to be able to maintain a constant flush of cuttings to the surface. Use drilling technique able to achieve a maximum drilling deviation of 1% or less. The presence of boulders in till will necessitate drilling equipment capable of drilling through these materials. Use equipment capable of drilling and Jet Grouting to depths up to 35 meters. Equip the Jet Grout drill with an integrated real-time data acquisition system which during drilling will continuously monitor the following: a. Clock Time. b. Depth below ground surface (m). c. Drilling Speed (m/min). d. Down thrust on Drill Rods (kN). e. Torque (kN-m). f. Drill rod RPM’s (rev/min). g. Drilling fluid pressure (MPa). Drills are to be supplied with downhole sampling tools to recover samples from the jetted columns prior to column setting.

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3.2. Jet Grouting

Use triple fluid Jet Grout system. The water cutting jet is sheathed in an envelope of compressed air. For triple jet systems, a lower cement-bentonite grout jet is positioned in relation to water jet, and the fresh mix is chosen such that the resulting in-situ grout acquires the specified characteristics despite effects of dilution caused by in-situ mixing with water. Establish rod rotation speed and lift speed according to Contractor’s experience, trial columns (evaluated by wet sampling, and drilling/coring/testing of cured columns), and real-time monitoring data. Equip the jetting system with real-time data acquisition units and appropriate instrumentation to continuously acquire the following jet grouting parameters: a. Clock Time. b. Depth below ground surface (m). c. Water Pressure and Flow Rate (MPa and m 3/min). d. Air Pressure (MPa). e. Grout Pressure, Flow Rate, Density, and depth below ground surface. f. Rate of extraction of the rods during grouting (m/min). g. Drill Rod RPMs (rev/min).

3.3. Mixing and Delivery

Provide automatic batch plants on site for production of grout for the cutoff wall, with a capacity to permit continuous operation of the jet grouting. Provide compressors and pumps to deliver air, water and grout to the jet grout sites at the required rates and pressures. It is anticipated that the pressures at the nozzles will be at least the following: Air 7 bars (0.7 MPa) Water 400 bars (40 MPa) Grout 100 bars (10 MPa) Provide mixing and pumping equipment capable of delivering grout at a rate of 110 to 250 L/min.

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3.4. Testing Equipment

As a minimum, provide and maintain at site the following equipment: a. One (1) Marsh Funnel Set per jet grout plant. b. One (1) Mud Balance (direct reading of density and specific gravity) per jet grout plant. c. Down hole directional survey equipment for measuring inclination of boreholes equipped with surface read out facilities. The equipment shall be capable of making inclination observations on two orthogonal axes parallel and perpendicular to the cut-off alignment. The probe shall fit into the triple fluid rods and descend the entire length of the holes to the top of the injection monitor. The Contractor shall have a sufficient number of sampling tools to obtain samples of grout from the columns before setting.

4.0 PRODUCTS

4.1. Materials

Bentonite a. Wyo-Ben Big Horn 200 (sodium montmorillonite bentonite) or approved equivalent. This product will be supplied by the Owner. Water a. Potable, clean and free from deleterious amounts of soil, salts, and organic matter meeting the following requirements. Identify source of water and if other than directly from Lac de Gras, submit water quality test results for approval.

Test Specified Values pH About 7.0 Hardness 70 ppm or less Organic Content 50 ppm or less Total dissolved solids 500 ppm or less

b. Water shall be free from oil. c. Provide heat to ensure that water is at a minimum of 5°C at time of mixing. Cement a. Cement to be type 10 or type 30 Portland Cement, in accordance with CAN/CSA-A5.

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b. Obtain all cement from the same manufacturing source. c. Cement will be provided by the Owner. Admixtures a. Admixtures can be added to the grout mix immediately before or during mixing to alter its chemical or physical properties. Admixtures shall conform to ASTM D494, and flowing concrete admixtures shall conform to ASTM C1017.

4.2. Dye

Upon request from Manager’s Representative, supply environmentally acceptable dye for use in jet grout mix in columns where verification borehole camera survey is required and planned in advance. Manager’s Representative will specify type of dye.

4.3. Storage

Store bagged cement and bentonite in original unopened containers protected at all times from moisture. If bulk storage is used, provide protection at all times from moisture.

5.0 EXECUTION

5.1. General

Construct Jet Grouted cut-off penetrating a minimum of 1.5 m deep into the bedrock and rising to cut at least 1.0 m into the base of the CSM panels, the base being defined as the lowest penetration point of the cutter head wheels, to complete the continuous seepage barrier of the A21 dike. Continuously record all the drilling parameters listed in clause 3.2.5 of this Technical Specification and provide a plot of parameters versus clock time for each drill hole.

5.2. Jet Grouting Cut-off Requirements

Jet Grouting scope: Drilling a single row of holes and produce columns of an adequate diameter such that the minimum transverse overlap is 800 mm. Continuity of the Jet Grout Columns with the CSM Cut-Off Wall and the curtain grouting is essential. Depth: Minimum of 1.5 m into bedrock.

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Transverse width: 0.80 m minimum (at column points of contact). Holes to be vertical. Inclination: Holes to be vertical. Length: As shown on the Drawings and as modified by Manager’s Representative based on foundation conditions. Alignment: As shown on the Drawings. Spacing between columns: 0.75 m or as approved by Manager’s Representative. Minimum spacing requirements may need to be revised in frozen till at abutment areas depending on the results of the test program and monitored Jet Grouting parameters during column construction in frozen ground.

5.3. Test Sections

Construct test sections at location defined by Manager’s Representative before proceeding with production. The test columns shall be installed to the same depth and diameter of the production Jet Grout Columns required for the Work. Certain test holes will be allowed in parallel with production. Execute trials consisting of 3 or 4 groups of three columns in a triangular configuration to be used to demonstrate column diameter. Set inter-axis spacing of each group at 0.866 times the anticipated diameter or propose alternative method to confirm the achieved diameter. Use grout with W:C ratio of 0.85:1 for these columns to permit early coring. Locate groups such that two columns of each group form part of the permanent cut-off. Identify groupings as A1, A2 etc. Monitor the following: a. Equipment performance. b. Deviation of the columns. c. Characteristics of fresh grout, return grout and grout sampled from completed columns. Perform test drilling in the columns and column groups at least seven days after completion of the Jet Grout Columns with W:C ratio of 0.85:1. Drill minimum S size coreholes or approved equivalent at the centroid of column groups A in compliance with Technical Specification 14300-41ES-016 (Drilling). The center of the column and the edge shall be cored no earlier than 36 hours after installation. Core recovery shall be a minimum of 100%. Measure hole deviation.

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Column diameter will be inferred from the presence or absence of grout in the drill cores. Place core samples in core boxes, label depths of core run, protect from freezing and turn over to the Manager’s Representative for laboratory inspection and testing. Boxes shall be labeled with hole number, date, run x/y, box x/y and project name. Core shall be consistently and sequentially placed in boxes with upper portion of drill run at top left area of box, and bottom of drill run at bottom right of box. Perform pump-out tests in the boreholes to verify water tightness. Measure rate of rise of water level in the borehole to calculate hydraulic conductivity by calculation procedure to be agreed upon with Manager’s Representative. Cooperate with Manager’s Representative in carrying out borehole camera survey of the holes, if required. Based on the results of the test program, the Manager’s Representative may require modifications to the Jet Grout Column procedures to achieve satisfactory results, and subsequent test sections to prove any new modifications.

5.4. Jet Grouting Depth

Penetrate 1.5 m depth into bedrock and treat by Jet Grout process. Adjust drilling depth to ensure that grout jet reaches 1.5 m depth into bedrock. Ensure that Jet Grouting overlaps a minimum of 1.5 m with curtain grouting so as to avoid the occurrence of any window. Carry out single fluid Jet Grouting in bedrock using grout pressure of at least 100 bars and grout flow of at least 150 litres/min (water and air almost shut off) and maintaining the same withdrawal rate until the water/air nozzle reaches the elevation of the bedrock surface. Extend Jet Grout column to at least 1.0 m but not more than 1.5 m above the lowest position of bottom of each CSM panel based on the deepest penetration of the cutter head wheels, and according to information derived from CSM and drilling parameters. Avoid carrying out the water jetting any higher than 1.0 m into the base of the CSM Cut-Off Wall. Turn off water and air and complete grout injection in lower portion of panel until neat grout appears at collar of holes. Sample grout in column below base of CSM Cut-Off Wall in first ten columns and thereafter in every fifth column, as directed by Manager’s Representative.

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5.5. Directional Control

Maintain drill hole orientation within 1.0 % of the full depth of the hole. Deviations will be tolerated only if joint overlap (see sections 5.2 and 5.6 in this Technical Specification) is maintained. Check orientation using an inclinometer or other approved methods. Check orientation for each borehole. Correct deviations from specified tolerance by re-drilling hole or replacement with additional columns as required. Any costs for deviation correction including material costs will be borne by the Contractor.

5.6. Joints

Construct columns to provide a minimum transverse width of 800 mm over their entire height at column overlap. In the event of a conflict between the orientation tolerance and the 800 mm minimum width over the entire height of the column, the 800 mm width requirement governs. Redo columns not meeting these requirements or construct additional columns. Any cost to redo columns based on not meeting the minimum requirements in 5.6.1 and 5.6.2 including material costs will be borne by the Contractor. Additional columns may be required when the Manager’s Representative determines from the drilling parameter records that the boulder content is significant. The additional columns will be located on an alignment parallel to and on the upstream side of the dike axis. Maintain Jet Grout parameters (grout pressure and flow, air pressure, water pressure and flow, withdrawal rate, rotation speed, etc) within 10% of values set as a result of the trials unless any deviation from the established Jet Grout parameters is otherwise accepted by Managers’ Representative. In the event of deviations outside these limits, or in the event of temporary failure of automatic recording system, provide adequate information to demonstrate that the column has been correctly constructed. Add additional columns, at no cost to Owner, if the said demonstration cannot be made.

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5.7. Horizontal Alignment

Carry out Jet Grouting on the centerline alignment of the CSM Cut-Off Wall as actually built with a tolerance of plus or minus 25 mm at the collar as measured between adjacent columns. Prior to commencing Jet Grouting operations, survey column centers and place adequate markers (e.g. pins and paint) on concrete guide walls to identify column position and I.D. number.

5.8. Grout Mixing

Jet Grout mix shall be adjusted based on QA/QC and test sections. Mix bentonite and water and check for adequate hydration as follows. Plot viscosity versus time of mixing in order to determine time of mixing to attain a constant or near constant viscosity. Mix the cement and the hydrated bentonite. Mix in high shear colloidal mixer and continuously agitate in holding tanks. Provide grout at time of injection at a minimum temperature of 5°C at the jet grout rig. In permafrost areas temperature is not to exceed 20°C. Provide cold temperature protection for batch unit and delivery lines if required.

5.9. Delivery

Insulate and heat delivery lines for cold weather operation as required. All line connections shall be provided with whip checks. Provide communication system and controls to permit rapid pump shut off and line closure to prevent grout spill in case of line breakage or damage.

5.10. Jet Grout Placement

Prior to commencing Jet Grouting operations, prepare a table indicating for each column: station, column number, assumed bedrock level (from exploration data), bedrock level as established from curtain grouting, bedrock elevation interpreted from Jet Grout drilling records, actual column depth required, etc. Do not drill holes for Jet Grouting until the plastic concrete cut-off wall has aged for a minimum of seven (7) days.

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Should the work schedule require that Jet Grouting be carried out in a CSM plastic concrete primary panel whose adjacent secondary panel has not been built yet, jetting shall not be carried out at a distance of less than five column diameters from the panel ends. Inject grout with rod rotation speed and withdrawal rates as determined from trials and as acceptable to the Manager’s Representative. Maintain the grout delivery and monitor return of grout at hole collar at all times to ensure that after grouting an effective Jet Grouting cut-off with no voids or unconnected zones is constructed. Use a split spacing construction sequence. Adjust sequence of borehole drilling and grouting so as to maintain a distance of at least one column diameter between the freshly installed columns and panels and any new injection. A minimum time of approximately 24 hours is to elapse before Jet Grouting next to an existing column. Place mixing plant in a secure location and operate to prevent spillage of material into the Water Body. Promptly remove debris and water from storage, mixing, transport, placement and clean-up of equipment from the Construction Platform. Ensure that drilling facilities include recovery system for mud or additives to prevent such materials from being discharged into the Water Body. Top up drill holes with grout after completion of grouting as necessary to compensate for decantation or leakage. Record instances of above average grout requirement. The triple fluid technique uses a water jet which causes grout dilution and bleeding. When drilling in the cut-off wall is carried out adjacent to columns whose grout has not set, install a riser pipe at the collar of such locations to prevent ingress of drill cuttings and fluid and thus ensure that each hole drilled across the cut-off wall has been filled entirely with grout only. Verify the grout level regularly in the freshly grouted columns and top up as necessary. Ensure a signoff form is prepared for each column and approved by the Work supervisor, the QC personnel and the Manager’s Representative to testify that each column has been constructed with the required standards of quality.

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6.0 FIELD RECORDS Prepare and submit daily activity report with Work completed, with a sketch identifying the columns completed, delays, and problems encountered, breakdowns, etc. Such reports are due within 48 hours. Contractor shall provide Manager’s Representative and Owner with daily records in electronic format and hard copy of completion for each and every column. For each rig, prepare a table indicating bedrock elevation from all available sources (including curtain grout hole drilling) and the required column depths to be jetted and submit daily (hard copy and Excel format). Keep records of the following for each column and submit daily: a. Geometry for each completed Jet Grout Column (location, length, and size). b. Time of beginning and completion of each column. c. I.D. Number, depth and date of hole drilling and injection. d. Drill rod and bit size. e. Type and depth of materials encountered in drilling. f. Drilling and jetting parameter recordings over full depth. g. Drilling deviation survey for each borehole. h. Other observations (communication between grout columns, lost return at the ground surface, heave or subsidence, etc.). i. Grout mix proportions. j. Density of mix. k. Viscosity of mix. l. Total air, water, and grout volumes used to construct each grout column, with the variations of grout volume versus depth. Compare the originally anticipated (calculated) total air, water, and grout volumes for each column. m. Injecting grout pressure. n. Rate of rod withdrawal. o. Rotation speed of drill rods. p. Jet Grout consumption and loss, description of return.

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q. Details of corrective measures. r. Signoff form for each column jetted. Digitized data to be submitted along with a hard copy output. The hard copy of drilling and jetting recordings is to be provided with color coded graphs. The exact format of the digitized data to be coordinated with the Manager’s Representative. Note: A digital ASCII file of drilling and grouting parameters, suitable for conversion to input into Microsoft Excel Spreadsheet will be acceptable. The files should contain the following data scanned continuously: a. During drilling: clock time, depth, drilling rate, rotary speed, thrust on tool, rotary torque, drilling fluid pressure. b. During Jet Grouting: clock time, depth, water pressure and flow rate, air pressure, grout density/pressure/flow rate, and revolutions per minute (rpm). Batching and Mixing Records. a. Document the following: i. Mix proportion ii. Time of mixing iii. Sample identification numbers. b. Provide 3 copies of above records for each day, distributed as follows: i. Copy 1: Contractor ii. Copy 2: Manager’s Representative’s Monitor iii. Copy 3: Manager’s Representative’s central file. Prepare and submit daily a spreadsheet in Excel format indicating all related data pertinent to columns jetted, including column number, panel number and bottom elevation, station, date of jetting, shift, type of column (primary, secondary, closure, repair, additional), column top and bottom elevation, deviation measurements, mix used, volume of grout jetted, elevation of bedrock, and laboratory test results (hydraulic conductivity, compressive strength and triaxial test results at 7, 14 and 28 days). Prepare and submit daily as-built plans and profiles to indicate the location of columns as determined from inclinometer measurements made in every hole prior to jetting.

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Prepare and submit daily a table of effective column diameter, inter-axis spacing at surface and at depth (z at 3 meters intervals) for each Jet Grout Column interval and wall thickness at the overlap, at depth intervals of 3 m in order to document the calculated column overlaps.

7.0 VERIFICATION CORE DRILLING Perform vertical or inclined verification boreholes with minimum S size triple tube core barrel equipment in compliance with Technical Specification 14300-41ES-0016 to obtain samples of CSM plastic concrete, grout and rock to a depth of 2 m minimum into rock. One hundred percent core recovery is required. One hole per 50 m of cut- off length is required unless otherwise instructed by the Manager’s Representative. Place cores in core boxes, protect from freezing and deliver to Manager’s Representative. Laboratory testing on selected core samples (strength testing, density, etc.) as directed by Manager’s Representative. Core boxes shall be clearly labeled as identified in clause 5.3.6. Provide detailed description (using standardized terminology as agreed with Manager’s Representative) and colour photographs of cores. Document that all soil-cement retrieved from core runs in Jet Grout treated area is well mixed cemented soil without any detrimental cavities or untreated soil inclusions. Document presence of curtain grout in rock joints. Cooperate with Manager’s Representative in carrying out borehole camera survey of the holes if required. Perform pump out tests and rising head measurements to determine hydraulic conductivity as specified by Manager’s Representative. Ninety percent (90%) of tests to comply with requirement of 1 x 10 -6 cm/s, no test result to exceed 1 x 10 -5 cm/s. Should the hydraulic conductivity in any test exceed 1 x 10 -5 cm/s, the Contractor shall make necessary repairs at the cost of the Contractor. Hydraulic conductivity testing shall be performed by the Contractor.

8.0 DEFICIENCIES Contractor to correct deficiencies in columns such as inadequate top or bottom elevations, occurrences of windows in cut-off due to Jet Grouting parameters not conforming with approved requirements, lack of grouting records, inadequate column spacing, etc. at no cost to Owner.

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Proposed correctives measures to Manager’s Representative for approval. Correct deficiencies within 15 days of notification of Manager’s Representative.

9.0 QUALITY ASSURANCE/QUALITY CONTROL Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

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INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 19/14 June 18/14 June 13/14 Sep 17/14 Sep 17/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 11/14 Nov 20/14 Nov 20/14 Tender

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TABLE OF CONTENTS

1.0 GENERAL ...... 2 1.1. Documents ...... 2 1.2. Scope of Work ...... 2 1.3. Definitions ...... 2 1.4. Related Technical Specifications ...... 2 1.5. Reference Drawings ...... 3 1.6. Reference Standards ...... 4 1.7. Environmental Protection ...... 4 1.8. Submittals ...... 4 1.9. Qualifications ...... 6

2.0 PRODUCTS ...... 6 2.1. General ...... 6 2.2. Grout ...... 6 2.3. Water ...... 6 2.4. Cement ...... 6 2.5. Sand ...... 7 2.6. Bentonite ...... 7 2.7. Additives ...... 7 2.8. Storage and Supply ...... 7

3.0 EXECUTION ...... 8 3.1. Drilling ...... 8 3.2. Grouting Equipment ...... 9 3.3. Schedule ...... 11 3.4. Direction by Manager’s Representative ...... 12 3.5. Records ...... 12 3.6. Mixing ...... 13 3.7. Grouting Procedures ...... 13 3.8. Grout Mix Selection ...... 15 3.9. Significant Fractures/Voids Encountered During Grouting ...... 16 3.10. Pressure ...... 17 3.11. Refusal ...... 17 3.12. Tertiary and Additional Grout Holes ...... 18

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3.13. Hole Communications ...... 18 3.14. Back Filling ...... 18 3.15. Clean-up ...... 19

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 19 1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the grout curtain activities for the A21 project to be completed by the Contractor. Technical aspects of the curtain grouting operation will be directed by the Quality Assurance (QA) representative as outlined in Section 3.4.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the grout curtain Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0002 Environmental Protection

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14300-41ES-0015 Water Pressure Testing 14300-41ES-0016 Drilling

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Drawings related to the grout curtain Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1007 Typical Cross-Sections (Sheet 1 of 2) 14300-41D2-1008 Typical Cross-Sections (Sheet 2 of 2) 14300-41D2-1009.1 Plan and Profile - Sta. 0+000 to 0+350 (Sheet 1 of 6) 14300-41D2-1009.2 Plan and Profile - Sta. 0+350 to 0+725 (Sheet 2 of 6) 14300-41D2-1009.3 Plan and Profile - Sta. 0+725 to 1+100 (Sheet 3 of 6) 14300-41D2-1009.4 Plan and Profile - Sta. 1+100 to 1+450 (Sheet 4 of 6) 14300-41D2-1009.5 Plan and Profile - Sta. 1+450 to 1+825 (Sheet 5 of 6) 14300-41D2-1009.6 Plan and Profile - Sta. 1+825 to 2+228 (Sheet 6 of 6) 14300-41D2-1011.1 Stratigraphic Profile – Sta. 0+000 to 0+600 (Sheet 1 of 4) 14300-41D2-1011.2 Stratigraphic Profile – Sta. 0+600 to 1+200 (Sheet 2 of 4) 14300-41D2-1011.3 Stratigraphic Profile – Sta. 1+200 to 1+725 (Sheet 3 of 4) 14300-41D2-1011.4 Stratigraphic Profile – Sta. 1+725 to 2+228 (Sheet 4 of 4) 14300-41D2-1012.1 Stratigraphic Section - GPR Sections 5 to 6 (Sheet 1 of 6) 14300-41D2-1012.2 Stratigraphic Section - GPR Sections 7 to 8 (Sheet 2 of 6) 14300-41D2-1012.3 Stratigraphic Section - GPR Sections 9 to 10 (Sheet 3 of 6) 14300-41D2-1012.4 Stratigraphic Section - GPR Sections 11 to 12 (Sheet 4 of 6) 14300-41D2-1012.5 Stratigraphic Section - GPR Sections 13 to 15 (Sheet 5 of 6) 14300-41D2-1012.6 Stratigraphic Section - GPR Sections 18 to 19 (Sheet 6 of 6) 14300-41D2-1014 South Island Facilities Layout 14300-41D2-1015 North Abutment Plan and Profile 14300-41D2-1017 South Abutment Plan and Profile 14300-41D2-1020.1 Grout Curtain - Typical Plan and Section Details

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Drawing No. Drawing Title 14300-41D2-1020.2 CSM Panels and Pre-Drilling - Typical Plans and Section Details 14300-41D2-1020.3 Jet Grouting - Typical Plan and Section Detail 14300-41D2-1025.1 Construction Staging (Sheet 1 of 2) 14300-41D2-1025.2 Construction Staging (Sheet 2 of 2)

1.6. Reference Standards

1. Canadian Standards Association (CSA) a. CAN/CSA-A5 - Portland Cement. b. CAN/CSA-A23.1 - Concrete Materials and Methods of Concrete Construction. c. CAN/CSA-A23.2 - Test Methods and Standard Practices for Concrete. 2. American Petroleum Institute (API) a. API Specification 13A, Specification for Drilling Fluid Materials. b. API Recommended Practice 13B-1, Recommended Practice for Field Testing Water-Based Drilling Fluids, 4th edition. 2009. 3. American Society for Testing and Materials (ASTM) a. ASTM C109: Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2 in or 50 mm Cube Specimens). b. ASTM C807: Standard Test Method for Time of Setting of Hydraulic Cement Mortar by Modified Vicat Needle c. ASTM C939: Standard Test Method for Flow of Grout for Preplaced-Aggregate Concrete (Flow Cone Method) d. ASTM C940: Standard Test Method for Expansion and Bleeding of Freshly Mixed Grouts for Preplaced-Aggregate Concrete in the Laboratory.

1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.8. Submittals

1. Submit at least 60 days prior to start-up of the Work, a grouting plan including the following at a minimum:

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a. Equipment list including grout mixers, grout pump, hoses, holding tanks, packers and rods or tubing. b. Spare parts list. c. Layouts of expected grouting arrangements, including protection for work in cold weather. d. Sequence of work and schedule of activities related to the dike construction, Zone 1 and Zone 1B densification and CSM cut-off wall construction. e. Methods of recording quantities of materials used and grout fluid injected. f. Grouting approach and methodology including planned hole size in cut-off wall or Zones 1 and 1B fills, overburden till and rock, packer size and type, and grout tubing size and type. g. Supplier and specification for materials used in grout mixes (ex. admixtures). h. Results of laboratory testing on the proposed grout mixes, including for each grout mix: water-cement-admixture ratios, density, viscosity, bleeding, temperature, initial and final setting time, unconfined compressive strength at 3, 7, 14 and 28 days. i. Calibration certificates for all measuring devices. j. Equipment to be available, contingency procedures to be employed, and alternative grout mix designs and admixtures, in the event of substantial grout takes and inability to achieve closure of the grout curtain. k. Owner compliant heavy vehicle risk assessment that identifies equipment hazards and the measures that are in place to control (eliminate or minimize) these hazards. The risk assessment shall be submitted at least 60 days prior to mobilization of equipment to site for evaluation by the Owner so that potential deficiencies identified by the Owner can be corrected by the Contractor prior to mobilization. l. Details of the Quality Control (QC) plan. Plan to adhere to QA/QC document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of Work. 2. Resumes for all proposed project personnel.

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1.9. Qualifications

1. Field personnel: Provide an experienced (10 years minimum) full time, on-site project manager. Provide a superintendent, curtain grouting specialists, QC staff and support personnel specifically experienced with curtain grouting. Provide one full time supervisor per rig per shift and one full time specialist per shift for the grout plant, and a field QC engineer. 2. Manager’s Representative review of qualifications: Manager’s Representative will review the qualifications of the proposed personnel for approval or rejection. This review may include interviews with the personnel by Manager’s Representative.

2.0 PRODUCTS

2.1. General

1. Handle, store and protect all materials from deterioration and contamination. Do not use deteriorated or contaminated materials.

2.2. Grout

1. A mixture of Portland cement, water and super-plasticizer designed to suit particular conditions. Sand and/or bentonite and other additives may be added to the grout, if required and acceptable to Manager’s Representative. The grout must be stable, i.e. it must have a bleeding ratio of less than 5 % after 2 hours (ASTM C940).

2.3. Water

1. Water for grouting shall be obtained from Lac de Gras. At the time of mixing, the temperature of water used in grout mixes shall be less than 25°C and greater than 5°C. 2. Provide adequate water storage facilities to ensure a continuous supply of water for the grouting operations, and to ensure that grouting operations are not hindered by a temporary breakdown in the main supply line.

2.4. Cement

1. Type 30 Portland Cement, in accordance with CAN/CSA-A5. This is an Owner supplied product.

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2. Do not use cement containing lumps or foreign matter which Manager’s Representative considers detrimental to the results of the grouting program. 3. Store each shipment of cement so that it is protected from the weather and is readily distinguished from other shipments. Use oldest batches first, but otherwise use in most efficient manner. Cement shall be double bagged.

2.5. Sand

1. Clean, durable stone particles from natural sand or crushed stone, free from lumps of clay and foreign matter, at a moisture content of less than 3 percent of the dry weight conforming to CAN/CSA-A23.1 with the following modified gradation requirements or equivalent approved by Manager’s Representative:

Sieve Size Total passing sieve, (mm) percentage by mass 2.5 100 1.25 95-100 0.630 65-85 0.315 30-50 0.160 10-30 0.075 0-5

2.6. Bentonite

1. Bentonite: Wyo-Ben Big Horn 200 (sodium montmorillonite bentonite). This is an Owner supplied product. Bentonite shall be double bagged.

2.7. Additives

1. Use retarding, expanding and high-range water reducing (super-plasticizer) admixtures for cement and sand-cement grouts obtained from the same manufacturer to ensure that they are compatible with each other. 2. Mix, handle, store and apply admixtures in accordance with manufacturer’s recommendations.

2.8. Storage and Supply

1. A sufficient quantity of all materials shall be on hand at the A21 Dike construction site to ensure that grouting operations will not be interrupted or delayed. The Contractor

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shall provide adequate storage facilities to protect cement, water, bentonite, sand and admixtures from adverse weather and temperature conditions, in such a manner that the quality of the materials is maintained. 2. A sheet or required/pertinent Material Safety Data Sheets (MSDS) shall be available.

3.0 EXECUTION

3.1. Drilling

1. Drill cased grout holes through the cut-off or Zones 1 and 1B fills, lakebed overburden soils, and into rock in accordance with Technical Specification 14300-41ES-0016 using casing as necessary to support the grout hole. Drilling and grout curtain activities to take place at locations shown on the Drawings. 2. The Contractor shall perform a thorough inspection of equipment conditions prior to mobilizing any drilling equipment, in order to ensure that no delay is caused by mobilizing improper equipment to the site. 3. The Contractor shall ensure that sufficient quantities of suitable casings, drill bits, and spare parts in general shall be available on site at all times. 4. In-filled joints and seams that are encountered during grout hole drilling shall be thoroughly flushed with water or drilling mud to remove the in-filled silt and sand, as evidenced by visual observation of clear return water. 5. No grout hole drilling shall take place within a nominal distance of 6 meters from other holes in the process of being grouted or which have been grouted in the previous 24 hours. The Manager’s Representative may, on the basis of exploratory core holes drilled in advance of the curtain grouting, stipulate exceptions to this restriction and reduce the 6 m limit, or reduce the 24 hour limit based on Vicat Needle test results (ASTM C807) and/or grout takes on a hole by hole basis. 6. Measure grout hole deviation in accordance with Technical Specification 14300- 41ES-0016. 7. All grout holes shall be drilled within 0.15 m of their specified location at the top of the grout hole (collar location). The grout hole collar shall be advanced slowly for the first 2 m to maintain the target borehole orientation. 8. The grout holes shall have an inclination of 75 degrees measured from the horizontal except at abutments where, if required, hole inclination in the plane of the cut-off may be changed to better match the grout hole pattern with the permafrost boundary. The Manager’s Representative may further designate different orientations along portions

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of the dike alignment to optimize interception of prevailing geologic structure, and to ensure a continuous grout curtain in areas of bends in the A21 Dike alignment. 9. All grout holes shall be drilled within 1 degree of the specified azimuth and inclination. Higher deviations will be accepted provided that the deviation of the grout hole at the top of bedrock does not exceed 0.5 m, measured from the centerline of the target grout hole orientation. 10. Deviation of the grout hole’s orientation within the bedrock shall not exceed 1 degree relative to the hole’s orientation at the surface of the bedrock. However, deviations of up to 2 degrees may be accepted, on a case by case basis, at the discretion of the Manager’s Representative, based on the deviation component parallel to the axis of the dike versus the deviation component transverse to the axis of the dike. 11. In the event of complete loss of flush return, drilling shall immediately cease and the grout hole shall be grouted in the bottom 3 meters. Following the initial set, drilling shall resume to complete the grout hole to design depth. 12. The Manager’s Representative may, at its absolute discretion, reject any grout hole that is outside these tolerances and direct that the Contractor drill a replacement grout hole at the Contractor’s cost. 13. Final grout hole logs shall be submitted within 48 hours of completion of the grout hole to the Manager’s Representative.

3.2. Grouting Equipment

1. Provide grouting equipment including mixers, grout pumps, packers, pipes, grout lines, fittings, valves, nipples, drills, pressure gauges, gauge savers, electronic grout flow meters, telephones or radios, lighting circuits, supplies, tools and spare parts necessary to inject a continuous supply of grout into the rock foundation under accurate pressure control and to closely monitor the operation. 2. The grouting equipment shall be capable of mixing and pumping relatively thick grouts having water-cement ratios by weight as low as 0.5 to 1. 3. Provide equipment that is new or completely overhauled to an “as-new” condition. Up to date calibration records to be provided for gauges, meters, etc. associated with grouting equipment. 4. Cement Handling Equipment – Since cement in bulk form will be used, it shall be stored in weather tight bins or silos that are arranged to discharge directly into a weighing hopper, and as a result into the grout mixer, without spillage or intermediate handling. Handling will be in such a way as to eliminate dust exposure to all workers.

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5. Mixers - High speed colloidal mixer (operating speed 1400 to 2000 rpm), capable of thoroughly mixing water, cement, and bulk fillers (such as sand) to produce a grout of uniform texture and consistency. Provide facilities at the mixer for the accurate measurement of grout materials so that mix proportions can be controlled. Mixers shall match the capacity of the pumping plant. 6. Maintain grout materials in suspension in a mechanically agitated sump or holding tank, equipped with paddles rotating at adjustable speeds of 40-200 rpm to prevent segregation of the grout. The outflow shall pass through a #4 wire mesh (4.75 mm size opening) or finer to remove hardened grout or foreign matter. Graduate the sump or tank in liters. No mix shall be kept for greater than two ( )2 hours. 7. Pumps - Progressive cavity (Moyno) type capable of pumping at least 110 litres/minute of grout at a maximum discharge pressure of 2 MPa. Locate pumps at a distance not greater than 100 m from the hole being grouted. 8. Hoses, Connections and Headers: a. Headers will be adaptable to accommodate alternating jets of pressurized air and water for the purpose of infill removal from joints and fractures in the bedrock. b. Provide a circulating system of hoses, of minimum 25 mm internal diameter, from the pump to the header and back to the holding tank. c. Provide grouting headers for feeding grout into the hoses located at the top of the grout hole. The grout headers include a supply connection, a connection with a valve to the hole, a return line with a valve, and two pressure gauges for the appropriate pressure range. One pressure gauge located at the grout pump to indicate the pressure of the supply of grout to the hole. The other to measure the pressure of grout going into the hole. d. Provision of headers and connections suitable for simultaneously injecting up to three (3) grout holes shall be made. e. Provide hoses, valves, joints and couplings capable of withstanding pressures double those required for grouting. f. All connections shall be provided with chain whip checks. 9. Water Meters - Single-disc type calibrated to measure liters and 1/10 of liter equipped with an accumulative totalizer and a reset knob (or equivalent) shall be used with each mixer. The Contractor shall test and calibrate the flow meters each week.

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10. Pressure Gauges - Bourdon tube type of heavy duty quality 150 mm minimum dial gauge diameter. The gradation of the pump discharge pressure gauge shall be the same as the header gauge and both gauges shall be changed, to suit the range of grouting pressures required by Manager’s Representative. Gauges shall be provided for the following three pressure ranges: 0 to 345 kPa, 0 to 690 kPa and 0 to 1380 kPa. Pressure gauges accuracy shall be no less than 1% of the full-scale range. Pressure gauges shall be of the non-clogging type or shall be prevented from clogging by using membrane-type straightway gauge savers filled with glycerin, or equal non-freezing fluid or grease. An accurately calibrated high-precision master gauge shall be provided, against which all other gauges shall be checked on a weekly basis for accuracy and satisfactory operation. Spare gauges shall be available at the plant at all times. 11. Communications - Provide telephone or radio communications between mixing station, pumping station and grout hole location. 12. Compressed Air Supply - Supply sufficient compressed air to operate compressed air equipment at full capacity. 13. The Contractor shall protect the drilling water supply, water pressure testing equipment, grout plant, monitoring equipment, and header unit from freezing by providing heated enclosures and insulations. 14. The Contractor shall provide an adequate backup supply of key plant and equipment parts to minimize disruptions and stoppages in the Work.

3.3. Schedule

1. Complete laboratory tests on trial mixes at least 30 calendar days before starting the work. Provide all test results to the Manager’s Representative at least 25 calendar days before starting the Work. 2. In general, curtain grouting will precede CSM Cut-off Wall construction. 3. Drill grout holes from Construction Platform at El. 418 m. 4. Do not drill grout holes within 6 m of another grout hole which is being drilled, water pressure tested or grouted. Exceptions are as discussed in Section 3.1, Item 5 of this Technical Specification.

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3.4. Direction by Manager’s Representative

1. Manager’s Representative will provide monitoring staff that will provide technical input and direction related to the grouting operations. Technical input and direction will be limited to: a. Grout pressures. b. Mix proportions, and timing for changes of mix proportions as grouting of each hole proceeds. c. Duration and rate of injection. d. Orientation of drill holes. e. Sequence and layout of grout holes. f. Requirement for additional holes. g. Type and number of water pressure tests. h. Depth of packer settings. i. Refusal criteria. 2. Contractor will provide all other direction and supervision necessary to perform the Work in accordance with the Drawings and this Technical Specification and will cooperate with the Manager’s Representative to complete the Work. 3. Perform grouting in presence of Manager’s Representative.

3.5. Records

1. Prepare and submit to Manager’s Representative completed and signed copies of grouting records for all grouting at the end of each shift. 2. Grouting records submitted by the Contractor shall include: project name; Contractor’s Site Supervisor; name and signature of individual supervising the grouting and record keeping; date(s) and time(s) of all grouting: location and I.D. number of hole; hole diameter; type, number and depth of packers for each grouting increment or stage; water/cement ratio and changes and time of change of water/cement ratio; volume of grout injected for each stage, number of bags of cement injected for each stage, grout wasted; pressure, changes in pressure and time of change; volume of sand or bentonite added, liters of water added to mix; and in general any changes in procedures, pressure, grout takes, mix or equipment that has direct effect on grouting operations.

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3. Real time graphical display of pressure versus grout flow rate, and penetrability (ratio of grout flow rate to pressure plotted against time), provided continuously during grout injection. This data will be used to evaluate the grouting and to adjust the grouting procedures. Electronic data for all monitored parameters shall be provided by the Contractor to the Manager’s Representative on a daily basis. 4. Assign each hole a grout hole number defined by the station number as determined by site surveys. Provide a marker at each hole with the grout hole number clearly and permanently identified. 5. Record losses of drill bits, rods and/or casings in hole and provide description and depth of lost items.

3.6. Mixing

1. Mix grout in a mechanically operated, high-speed colloidal mixer. Start by mixing hydrated bentonite and water for a minimum of 30 seconds, then add cementitious materials and additives and mix for an additional two (2) minutes before injection into the grout holes. Provide facilities at the mixer for the accurate measurement of grout materials so that mix proportions can be carefully controlled. 2. Hydrate bentonite for a minimum of 24 hours or as directed by the Manager’s Representative prior to incorporating in a grout mix. 3. Inject grout when the temperature of the grout mix is between 5° and 25°C. No material incorporated in a grout mix shall be a temperature less than 2°C. 4. When grouting is performed in freezing conditions protect materials from freezing throughout the mixing, agitation and pumping period right up to the time of injection. Cover and heat the grout plant and Work area around the grout hole. 5. Grout that is not injected within two hours of mixing shall be disposed of in a disposal area as designated by the Owner. 6. Mix grout in batches of a volume suitable to permit water-cement ratios and composition of grouts to be changed to ensure continuous flow and minimum waste. 7. All mix proportions are specified by weight.

3.7. Grouting Procedures

1. Water pressure test grout holes before grouting as required by Manager’s Representative in accordance with Technical Specification 14300-41ES-0015.

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2. Thoroughly wash all grout holes immediately before water pressure testing or grouting the hole to remove fines, sludge or foreign materials which will interfere with the grout take of the hole. Wash by injection of water and air at the bottom of the hole for five minutes or until return water is clear. Water (and air) pressures will be adjusted to provide the maximum cleaning condition for the grout holes. The water pump shall be capable of producing about 1 m3 per minute at a minimum pressure of 500 kPa. 3. Grout holes grouted within 8 hours of completion of water pressure test need not be rewashed. If grout is moved into a grout hole by grouting nearby holes after the grout hole has been washed, the mud will be removed by rewashing the grout hole. Return wash water to be collected and disposed of in such a manner as to meet environmental requirements. 4. Grout holes shall be grouted in 5 meter stages from the bottom of the hole upwards using a single packer. 5. Ensure packer is tightly sealed against grout hole walls and, with regard to upper stage, as close to bedrock surface as possible. If grout or water leak is observed, reset packer properly and re-grout the stage. If bypasses cannot be overcome, the packer may be raised or lowered 0.5 m to avoid the connecting feature. 6. Inject grout in a continuous operation until specified refusal criteria are achieved in all stages of the grout hole. If equipment breaks down, flush the hole with water until the return water is clear and re-grout the hole. 7. Grouting, particularly in zones near the surface, shall be executed with extreme caution to prevent uplift of the rock or excessive leakage at the surface. 8. During grouting of a hole, adjacent un-grouted holes shall be left uncapped to facilitate the passage of air and water. If grout begins to flow in adjacent holes, the Contractor shall be prepared to make multiple connections to the affected grout holes and grout them simultaneously with the active grout hole. The use of water pressure tests in advance of grouting will facilitate identification of such conditions in advance. 9. The grout curtain will be achieved using the split spacing technique. Commence grouting with the primary grout holes on 6 meter centers followed by split spaced secondary grout holes. Tertiary and higher order grout holes will be drilled as required by the Manager’s Representative. Secondary grout holes will be located mid-way between primary holes, and tertiary holes mid-way between primary and secondary holes. The Manager’s Representative may adjust primary spacing on the basis of the exploratory core hole drilling conducted in advance of the curtain grouting operations.

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10. The 6 m primary grout hole spacing is a general guideline. The intent is to, on the basis of grouting results and the exploratory core holes, optimize primary grout hole spacing to achieve maximum cut-off effectiveness at the lowest possible grout takes. The spacing will be optimized on the basis of split spaced grout take reduction ratios, meaning that a grout hole drilled between two previously drilled and grouted holes will have a take between 0.25 and 0.75 (ideally 0.5). Primary grout hole spacing will be adjusted as directed by the Manager’s Representative to stay within this range. 11. Additional grout holes may be required according to the results. After grouting primary and secondary holes in a given section, the Manager’s Representative will determine the need for additional grouting. 12. In situations where hydraulic fracturing is suspected, the Contractor shall immediately reduce grouting pressures. In cases where back pressure is indicated at the completion of a stage or a hole, the Contractor shall maintain the grouting pressure (using a closed valve at the collar or the header) until zero back pressure is observed.

3.8. Grout Mix Selection

1. Grout each stage starting with a stable mix (water/cement ratio between 0.4 and 0.8 by weight with suitable proportions of superplasticizer). As directed by the Manager’s Representative, maintain or thicken mix depending on injection rate and duration as directed by Manager’s Representative. The use of bentonite if required to stabilize the cement in suspension should be carried out in accordance with directives from the Manager’s Representative. When used, bentonite must be fully hydrated prior to cement addition. As injection proceeds, the characteristics of the rate of decrease of grout penetrability (flow rate divided by applied pressure), which shall be continuously monitored, shall be evaluated and used by the Manager’s Representative to assess when to increase the viscosity of the grout mix (i.e. decrease the w/c ratio). Each stage shall be grouted to refusal as defined in Section 3.11 below. 2. Each mix shall achieve a stable grout, measurable via a bleed ratio of less than 5% in 2 hours. The requisite bentonite content shall be determined during testing of the trial mixes (and ongoing testing as the grouting program proceeds 3. Inject initial grout mix with grout pump operating at constant speed. If the rate of injection drops steadily, continue with the starting mix until refusal criterion is achieved. If the rate of injection is high and does not permit achieving refusal after injection of 1,000 litres, then decrease the content of superplasticizer and inject successively thicker mixes. Inject each mix for a 10 minute period until the grout injection stabilizes or refusal criterion is reached.

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4. Add sand to the grout mix in areas of high grout takes as directed by the Manager’s Representative. 5. For the information of the Contractor, the table below summarizes the grout mixes utilized for the curtain grouting operation for the A418 dike (source: Nishi-Khon SNC Lavalin report entitled “A418 Water Retention Dike: As-Built Report”, dated March 2007).

3.9. Significant Fractures/Voids Encountered During Grouting

1. In the event that significant and extensive fractures and/or voids are encountered: a. High-range water reducing admixtures will be used to decrease the flowability of the grout and enhance penetration in the rock joints. The amount of water reducing admixture will depend on the properties of the grout used. b. In situations where the grout absorption rate drops suddenly, the mix shall be immediately thinned to prevent the hole from becoming plugged. At the discretion of the Manager’s Representative, this may require bleeding the lines and flushing of the hole with water to remove grout sitting in the grout hole below the packer. c. If a grout hole continues to accept grout after a specified amount of the thickest workable grout mixture has been injected (1,500 L), the Manager’s Representative may specify a reduced pumping speed and/or the use of

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accelerators, or may direct that pumping be halted temporarily to permit the grout to set. d. Grouting shall be discontinued in grout holes that do not respond to the above procedures and the holes shall be re-drilled and re-grouted later, or the area of high grout absorption shall be grouted from adjacent grout holes until the design objective has been achieved, at the direction of the Manager’s Representative. e. In areas of high grout takes, or when grout holes do not respond to the above measures, The Manager’s Representative may direct that sand be added to the grout mix. Contractor’s proposed equipment and procedures for dealing with areas of anomalously high grout takes shall be provided under submittals, see Section 1.7 of this Technical Specification. f. The Contractor shall perform a mud balance specific gravity test and a Marsh Funnel viscosity test on each grout mix specified by the Manager’s Representative. On a daily basis, the Contractor shall also conduct a bleed test on each grout mix used.

3.10. Pressure

1. The required grouting pressure at the mid point of a stage is calculated at plus 20 kPa per meter measured vertically from the top of the grouting platform to the top of bedrock, plus 25 kPa per meter, measured vertically below the bedrock surface. The minimum pressure required at mid-stage is 75 kPa above the hydrostatic head from water level and the maximum is 1,500 kPa.

3.11. Refusal

1. Refusal criteria per grouting stage is defined as a grout absorption rate of less than 0.2 litres/min over a 10 minute interval at the maximum required grouting pressure as defined above in Section 3.10 of this Technical Specification. The refusal criteria may be adjusted by the Manager’s Representative over the course of the Work on the basis of monitored grouting results. 2. If the grout take is such that it is impossible to reach the specified pressure after pumping a volume of grout corresponding to 2,000 litres or as directed by Manager’s Representative, reduce the rate of pumping or stop pumping temporarily and allow sufficient time for the grout to stiffen. Repeat this procedure until refusal is reached. If this procedure is not successful discontinue grouting, allow grout to set and perform additional grouting in the grout hole or adjacent grout holes as directed by Manager’s Representative.

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3.12. Tertiary and Additional Grout Holes

1. Tertiary grout holes are required when any adjacent hole has a stage that absorbs more than 20 kg/m or when the hydraulic conductivity is greater than 3 Lugeons. The length of any additional grout hole shall be such as to exceed by at least 5 m the bottom elevation of the stage in which an absorption greater than 20 kg/m has been recorded.

3.13. Hole Communications

1. If during the grouting of any hole, grout is found to communicate with an adjacent ungrouted hole, place a packer in the latter grout hole and grout both holes together starting from the bottom until the depth where the communication has been observed or, alternatively, after completing the grouting of the former hole, wash the ungrouted hole with water until the return water is clear and perform grouting after allowing the initial setting of the grout in the first hole.

3.14. Back Filling

1. On completion of grouting, back fill each grout hole with 0.5:1 grout mix (water/cement by weight) by tremie grouting through a pipe extending to the bottom of the hole. 2. Where grouting has been carried out before CSM Cut-Off Wall construction, backfill a volume of grout sufficient to fill the hole to a minimum height of 5 m above bedrock level. Over the following four (4) hours, or as necessary, regularly check the grout level in the grout hole and pour additional volume of grout as necessary to ensure complete filling of hole. Report any unusual drop in grout level. 3. Where grouting has been carried out after CSM Cut-Off Wall construction, backfill the grout hole to 417.5 m elevation. Over the following four (4) hours, or as necessary, regularly check the grout level in the hole and pour additional volume of grout as necessary to ensure complete filling of the grout hole. Report any unusual drop in grout level. 4. Backfill all grout holes during the same shift as they were grouted. If a series of grout holes are backfilled at the same time, place a temporary cone at the collar of the same to prevent blockage by falling debris.

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3.15. Clean-up

1. Keep grouting areas free of water, excess grout, sludge oil or deleterious material. 2. After grouting is completed, the Contractor shall remove the grouting plant and all related parts, equipment and supplies from the site, including unused material and waste.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

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INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 20/14 June 16/14 June 10/14 Sep 22/14 Sep 22/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

Technical Specification Revision

WATER PRESSURE TESTING No. Date

14300-41ES-0015 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Environmental Protection ...... 2 1.6. Submittals ...... 2

2.0 PRODUCTS ...... 2

3.0 EXECUTION ...... 2 3.1. Equipment for Water Pressure Testing ...... 2 3.2. Water Pressure Testing ...... 3 3.3. Type and Frequency of Testing ...... 5

4.0 QUALITY ASSURANCE AND QUALITY CONTROL ...... 5

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the Water Pressure Testing activities for the A21 project to be completed by the Contractor. Testing is specific to exploratory holes and curtain grout holes, or as required by the Manager’s Representative.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the Water Pressure Testing Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0014 Curtain Grouting 14300-41ES-0016 Drilling

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1.5. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.6. Submittals

1. Submit Water Pressure Test plan including a list of proposed equipment, a Water Pressure Testing schematic and proposed test record sheets. The schematic is to be a simple line sketch showing pumps, gauges, valves, hoses, hookups, and all other associated equipment to be used in Water Pressure Testing. An equipment check list is attached at the end of this section (ref. Attachment A). 2. Submit calibration certificates for pressure gauges and flow-meters.

2.0 PRODUCTS Not Used.

3.0 EXECUTION

3.1. Equipment for Water Pressure Testing

1. Furnish Water Pressure Testing equipment of a type and capacity and in mechanical condition suitable for performing the work satisfactorily. Equipment size shall comply with Technical Specification 14300-41ES-0016 (Drilling). 2. Equipment shall include pumps, piping, pressure gauges, valves, fittings, seal assemblies (packers), and all other accessories necessary to complete the Work. Provide pumps of gear, centrifugal, or other approved type, with an output of not less than 250 liters per minute, and shall be capable of maintaining constant pressures up to 1.5 MPa. 3. Supply water storage tanks having sufficient capacity for the pumps in addition to two (2) sets of flow-meters and Bourdon gauges for calibration and checking purposes. 4. The packers or seals to be of the multiple leather cup, mechanically expanded rubber ring, or pneumatically expanded rubber sleeve type capable of sealing holes at any specified level to a maximum depth of 50 m without leakage. Provide packers capable of being used either singly or in pairs, separated by up to 3 m of perforated pipe. The diameter of the pipes used for separating the packers and for placing the packers in holes shall be the maximum practical for the size of the hole. The packers

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shall be capable of withstanding the maximum gauge plus existing water column pressure without leakage for a period of 10 minutes.

3.2. Water Pressure Testing

1. Manager’s Representative to witness Water Pressure Testing for grouting. 2. Thoroughly wash each hole under pressure immediately before pressure testing to remove any accumulation of fines, sludge, or foreign materials. Wash holes by injection of water at the bottom of the hole for five minutes or until the return water is clear. Water shall comply with Technical Specification 14300-41ES-0016 (Drilling). 3. Water Pressure Testing in sections shall be carried out as required by Manager’s Representative. Each section shall be isolated by means of two packers spaced a maximum distance of 3 meters apart. Closer spacing of packers may be required by Manager’s Representative to isolate leakage zones near the top of rock. For each section, back pressure shall be measured at the collar of the hole with the hole full of water. Water pressure shall then be applied to the section for a minimum period of five (5) minutes and the volume of water inflow shall be measured to the nearest liter and recorded. The water pressure variation during the five (5) minute duration is not to exceed 5% of test pressure. 4. Manager’s Representative will determine water pressure to be applied to test section. Generally the maximum effective water pressure at the mid-point of a stage is calculated at 25 kPa per meter of depth measured vertically from the bedrock surface. The minimum pressure is 75 kPa (or hydrostatic head created by the water column in the test apparatus) and the maximum is 1500 kPa. 5. The packers shall be inflated to pressures adequate to achieve and maintain a proper

seal. Inflation pressures (Pi) shall be calculated relative to the working pressure (Pw) as per the following:

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6. The Manager’s Representative shall determine, for each test section, whether a) a 5- stage multiple pressure test, or b) Single-stage Water Pressure Test, is to be conducted. a. For 5-stage multiple pressure tests1, perform tests in five pressure increments 1/3, 2/3, 1, 2/3, 1/3 times maximum pressure. Hold each pressure increment for five (5) minutes. Measure flow for each five (5) minute period. b. For Single-stage Water Pressure Tests2, the pressure will be applied at the pressure designated by the Manager’s Representative, generally 80% of the maximum grouting pressure. The pressure shall be held for a minimum of two (2) minutes of stable conditions, meaning less than 5% variation in flow rate or pressure. In general Single-stage Water Pressure Tests will last, upon application of the requisite pressure, a maximum of five (5) minutes. Measure continuously flowrate and pressure versus time. 7. For both types of Water Pressure Tests, the effective hydraulic conductivity shall be expressed in terms of Lugeon units. The Manager’s Representative shall use the Lugeon values so derived to set grout mixes and to determine when closure criteria is achieved. 8. Check for flow out of the hole at the collar or for rise in water level in the hole during the test as this indicates leakage around the packers. If leakage is confirmed, stop the test, reset the packers and re-test. 9. Contractor to plot/tabulate test results and provide immediately to Manager’s Representative.

1 The 5-stage tests shall be required by the Manager’s Representative to ascertain, by identifying “washout” conditions, if potentially erodible infillings are present in the fractures that might then dictate pressure- washing procedures to use prior to grouting, and closer than initially planned hole spacing to maximize intersections with fractures containing such infillings. The 5-stage tests shall also be required where the Manager’s Representative requires investigation into whether the flow into the fractures is laminar or turbulent, and whether the water take is due to a few wide fractures or a large number of narrow fractures.

2 The Single-stage Water pressure Tests shall be carried out for all grout stages in secondary, tertiary, and higher-order grout holes. These tests shall be used by the Manager’s Representative to: • help decide whether further grouting is necessary or feasible, • provide a basis for the selection of the appropriate starting grout mix formulation, • assist in identification of anomalously low grout takes in stages with relatively high hydraulic conductivity so that corrective action may be taken, • identification of communication between grout holes • identification of potential surface leakage in abutment areas, • to assess the effects of the split spacing closure sequence, or • to verify that the desired closure criterion has been achieved.

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3.3. Type and Frequency of Testing

1. Perform Water Pressure Testing as directed by the Manager’s Representative. 2. In general, the frequency and type of Water Pressure Testing shall be as follows: a. Exploratory core holes: five stage Water Pressure Tests, generally three (3) per hole, for 50% of the holes, and Single-stage Water Pressure Tests, three (3) to four (4) per hole, for the other 50%. b. Primary grout holes: five stage Water Pressure Tests for approximately 20% of the grout stages, and Single-stage Water Pressure Tests for approximately 20%. Those primary grout hole stages requiring Water Pressure Testing shall be as designated by the Manager’s Representative. c. Secondary and higher order grout holes: Single-stage Water Pressure Tests for all grout stages, unless: 1) the Manager’s Representative instructs a 5-stage pressure test be conducted, or 2) the hole in question has been previously observed to be in indirect hydraulic communication with adjacent hole(s).

4.0 QUALITY ASSURANCE AND QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

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ATTACHMENT A WATER PRESSURE TESTING EQUIPMENT CHECKLIST

Guages: Number of Number of Range 0 to: kPa Range 0 to: kPa Type: Type: Manufacturer: Manufacturer: Diameter: mm Diameter: mm

Water Meter: Type:

Reading Accuracy: liters

Packers: Type:

Size:

If gas filled, max. inflation pressure: kPa

Water Pump: Type:

Capacity: litres/min. kPa

Model:

Manufacturer:

- END OF TECHNICAL SPECIFICATION

14300-41ES-0015 Water Pressure Testing (Rev B - Nov 2014) IFT Page 6 Technical Specification Revision

DRILLING No. Date

14300-41ES-0016 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for comments

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 20/14 June 18/14 June 14/14 Sep 22/14 Sep 22/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

Technical Specification Revision

DRILLING No. Date

14300-41ES-0016 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Reference Standards ...... 2 1.7. Environmental Protection ...... 2 1.8. Submittals ...... 2

2.0 PRODUCTS ...... 3

3.0 EXECUTION ...... 3 3.1. Drilling Equipment ...... 3 3.2. Drilling ...... 3 3.3. Tolerance on Drill Holes ...... 4 3.4. Casing...... 4 3.5. Water for Drilling and Washing ...... 5 3.6. Washing of Holes ...... 5 3.7. Hole Deviation ...... 5

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 6

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the drilling activities for the A21 project to be completed by the Contractor. Drilling activities are specific to exploratory, Jet Grout, CSM verification coring, Jet Grout columns verification coring, grout curtain hole drilling, and instrumentation and survey monument installation.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the drilling Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0015 Water Pressure Testing

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1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Drawings related to the drilling Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout

1.6. Reference Standards

1. American Society for Testing and Materials ASTM C109 - Test for Compression Strength of Hydraulic Cement Mortars (Using 2 in or 50 mm Cube Specimens). 2. Canadian Standards Association CAN/C SA-A23.1 - Concrete Materials and Methods of Concrete Construction.

1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 and with the requirements of the Water License.

1.8. Submittals

1. Submit at least 60 days prior to mobilizing to site, a drilling plan to include at a minimum: a. Methods of drilling in rock, overburden, rockfill and cut-off wall for curtain grouting, instrumentation and geotechnical exploration work if required. b. Equipment and methods for verification coring in CSM Cut-Off Wall and Jet Grouted cut-off. c. Equipment lists of drills, compressors and other specialty equipment, including type, condition, model and number on site. d. Drill steel and casing quantity and types, including manufacturer specifications and recommended replacement frequency. Include plan for minimizing and removing lost drilling steel and casings. e. Layout and sequence of work. f. Method for measuring inclination/orientation of boreholes.

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2. Submit drill log templates to Manager’s Representative for approval prior to commencement of the Work.

2.0 PRODUCTS Not used.

3.0 EXECUTION

3.1. Drilling Equipment

1. Provide all drilling equipment of adequate type, size, number and capacity and in mechanical condition suitable for performing work satisfactorily. All reasonable efforts shall be made by the Contractor to provide state-of-the-art drilling equipment that minimizes labour and equipment interactions, such as automatic rod and casing handling tools. 2. Use drilling techniques that can drive casing and drill bit simultaneously and/or where required, rotary core drilling with continuous core recovery in cut-off wall and in bedrock. 3. Equipment must be capable of achieving the hole size, inclination, depth, recovery and drilling tolerance specified. 4. Except for core drilling, provide drills with instruments that continuously monitor drilling speed, thrust on drill rods, water/air pressure or other useful parameters during drilling with a view to accurately locating the bedrock surface. 5. Provide all necessary equipment to measure the inclination and orientation of the boreholes. 6. Weather protection for drilling shall be provided, as necessary, such that drilling is not affected by cold temperatures.

3.2. Drilling

1. Manager’s Representative will witness drilling. 2. Locate and drill holes in the sequence, orientation, and to the depths as shown on the Drawings, or as required by Manager’s Representative. 3. Do not use rod dope, drilling mud, excessive grease or other lubricants as an aid to drilling grout holes and instrumentation holes. Wipe excess grease from outside of rod or casing joints.

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4. Protect each hole from clogging or obstruction by means of a temporary cap or other suitable means at the collar. Clean out any hole that becomes clogged or otherwise obstructed before completion in a manner acceptable to Manager’s Representative or drill another hole at no additional cost to Owner. 5. Do not drill grout holes within 12 m of another hole that is being grouted or that has been grouted within the previous 24 hours. 6. Do not perform re-drilling of a hole until the grout last pumped in the hole has achieved initial setting. 7. Do not perform drilling in any part of the cut-off wall until at least seven (7) days after completion of that part of the cut-off wall. 8. Grout holes shall have a minimum 50 mm diameter. 9. Verification core holes in CSM Cut-Off wall and Jet Grout columns shall be drilled using triple tube core barrels recovering minimum S size core diameter, with 100% core recovery required. 10. Place core samples in core boxes, label depths of core run, protect from freezing and turn over to the Manager’s Representative for laboratory inspection and testing. Boxes shall be labeled with hole number, date, run x/y, box x/y and project name. Core shall be consistently and sequentially placed in boxes with upper portion of drill run at top left area of box, and bottom of drill run at bottom right of box. 11. In core holes, use suitable drilling fluid and/or additives to maximize core quality and recovery.

3.3. Tolerance on Drill Holes

1. The maximum allowable offset measured at the collar of all drill holes in any direction is 50 mm. 2. The drill hole deviation, at any point along the drill hole and in any direction, with respect to the orientations specified on drawings, shall be less than 1.0% of the hole length at that point.

3.4. Casing

1. Except for rotary drilling for core sampling of the completed CSM and Jet Grout components of the completed cut-off wall, install steel casing over the whole length of all holes drilled in the dike fill and overburden and anchor steel casing a minimum of 0.5 m into bedrock.

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2. For rotary core drilling in CSM Cut-Off Wall, install a starter casing tightly sealed/grouted at hole collar to avoid erosion and other damage to the top of the CSM Cut-Off Wall. Ensure return water does not accumulate and pond at hole collar. 3. Casing size to be compatible with drilling methods, required hole size and drilling tolerances. 4. Provide flush jointed casing complete with cutting bits and shoes necessary for installation. 5. While drilling in overburden, boulders and rockfill, maintain casing cutting edge in close proximity to the drill bit at all times to ensure hole stability. 6. When drilling through any part of the cut-off wall, limit water/air pressure to safe levels to avoid damage to the cut-off wall. Use drill bits which permit evacuation of the maximum aggregate size without damage to the wall or oversize of the hole. 7. Progressively withdraw casing as hole is backfilled. 8. Keep bottom of casing below surface of backfill as the casing is withdrawn.

3.5. Water for Drilling and Washing

1. Fresh water, clean and free of oil, silt, organic matter, alkali, acids, salts and other impurities and conforming to the requirements of CAN/CSA-A23.1 2. Provide adequate water storage facilities to ensure a continuous supply of water for washing drill holes.

3.6. Washing of Holes

1. Thoroughly wash all holes immediately before grouting the hole or installing instrumentation to remove fines, sludge or foreign materials. Wash by injection of water at the bottom of the hole for five minutes or until return water is clear. 2. Return wash water to be collected and disposed of in such a manner as to meet environmental requirements.

3.7. Hole Deviation

1. Use down hole directional survey equipment for measuring hole deviation capable of making inclination measurements in two orthogonal axes parallel and perpendicular to the cut-off alignment. The probe shall fit tightly into the casing and descend the entire length of the holes.

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2. Check calibration of the survey equipment at start of work in presence of Manager’s Representative and verify bi-weekly thereafter in a reference hole maintained for the duration of the work.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

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DIKE DEWATERING No. Date

14300-46ES-0002 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 21/14 June 11/14 June 9/14 Sep 22/14 Sep 22/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

Technical Specification Revision

DIKE DEWATERING No. Date

14300-46ES-0002 B November/2014

TABLE OF CONTENTS

2.0 PRODUCTS ...... 4

3.0 EXECUTION ...... 4 3.1. General ...... 4 3.2. Water Quality ...... 5 3.3. Water Level Monitoring ...... 5 3.4. Additional Pumping ...... 5 3.5. Access ...... 5 3.6. Acceptance ...... 6

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 6

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Owner/Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the dike dewatering activities for the A21 project to be completed by the Contractor/Owner.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the dike dewatering Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

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2. The Contractor is referred to the following Drawings related to the dike dewatering Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1032.1 Pool Dewatering Pipeline Alignments (Sheet 1 of 2) 14300-41D2-1032.2 Pool Dewatering Pipeline Alignments (Sheet 2 of 2)

1.6. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.7. Climatic Conditions

1. Refer to Technical Specification 14300-41ES-0001.

1.8. Submittals

1. Submit a dewatering plan, and include: a. Description of pumping arrangements. b. Specifications for pumps. c. Details of floating equipment platforms. d. Details of power supply arrangement and power requirement. e. Description of methods to move pumps within the dike area. f. Description of methods of access to move and remove pumps and pipelines within the dewatered areas. g. Description of equipment and methods for pool dewatering during periods of lake ice cover. 2. Submit: a. Design criteria for dewatering including schedule and design temperature for pump and pipeline design. b. Design and shop drawings of pumping arrangement. c. Design and shop drawings of pipelines. d. Design and shop drawings of barges and anchoring system.

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e. Design and shop drawings of diffuser for discharge to Lac de Gras. f. Procedure for water quality monitoring, including water sampling equipment and methods for total suspended solids (TSS) testing.

1.9. Design

1. Design system to dewater area enclosed by the A21 Dike in accordance with the water quality requirements and schedule referenced below. 2. Estimated volume of water to be removed from inside the A21 Dike enclosure: a. 6.7 x 106 m3 Volume of water to be pumped shown above was estimated based on the following: a. Lake surface elevation of 415.8 m b. Bathymetric survey of lakebed c. Allowance for precipitation, entrapped water and seepage. 3. Design system to minimize disturbance of lakebed sediments and thus manage water quality in the area enclosed by the A21 Dike, and maximize the period during which low TSS allow for direct discharge to Lac de Gras. 4. Design pump system to be capable of discharging water directly to Lac de Gras, Pond 3 and the North Inlet pond with a suitable valve system to direct water from one discharge point to the other. Pipelines will be in place (by the Owner) for Contractor use from South Island to Pond 3 and to the North Inlet Pond. 5. Design barge systems to provide floating working platforms for pumps and generating units as required. Platforms to be capable of movement up to 100 m range (horizontal) to reach optimum locations for discharge water quality and topographic low points for complete dewatering. Design anchor system to resist ice, wind and hydraulic and mechanical forces. 6. Design a temporary road system in the lakebed to move and remove barges, pumps, pipelines and ancillary equipment when dewatering is complete. 7. Design temporary diffuser for discharge of clean water directly to Lac de Gras. Approximate location is shown on Drawings. Adjust as necessary and consider presence of lake ice in design. Diffuser shall permit discharge up to maximum pump capacity without disturbance of sediments. Design anchor system to resist ice, wind and hydraulic and mechanical forces.

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1.10. Power Supply

1. Construction power, 600 V/3 PH/60 Hz for site offices and ancillary usages shall be provided by Owner at location as designated by the Owner. Contractor to provide all control, protection, and distribution from this location to his/her equipment. All power requirements for the dike dewatering shall be supplied by the Contractor.

2.0 PRODUCTS Not applicable.

3.0 EXECUTION

3.1. General

1. Commence dewatering after cut-off wall and Jet Grouting have been completed, after plastic concrete in cut-off wall has achieved 14 day strength requirements and after the installation of piezometers, inclinometers and relief wells have been completed on dike crest. 2. Delay start of pumping if high winds are predicted. 3. Pump at a rate such that the water level surface is lowered by maximum average of 400 mm per day. Plan for four days of pumping at a drawdown rate of 500 mm per day followed by a 24 hr period of zero pump discharge. Manager’s Representative may require the rate of dewatering to be reduced or may permit it to be increased based on instrumentation monitoring of dikes, pipeline constraints, containment availability and visual observation of the dikes and shorelines. 4. Move pumps or install secondary portable pumps to low points within dike retention area to provide complete dewatering of all areas. 5. Provide spare pumps and parts to ensure that pumping can be performed continuously at a rate sufficient to meet the dewatering schedule requirements. 6. Protect dewatering equipment from freezing and maintain fully operational in freezing conditions down to the design minimum temperature. 7. On completion, remove from site all materials and equipment.

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3.2. Water Quality

1. Discharge water from within the A21 Dike into Lac de Gras at location shown in Drawings and as per the limits specified by the Water License. Water not meeting this requirement shall be pumped to Pond 3 or the North Inlet as directed by Manager’s Representative. 2. Monitor TSS as per the approved sampling plan. 3. Move intake (up to 100 m range) as necessary maximize volume of water (meeting the required water quality standards) which can be discharged directly to Lac de Gras. 4. Adjust depth of submergence of pump intakes to maximize the volume of pumped water meeting the required water quality standards.

3.3. Water Level Monitoring

1. Install water level monitoring gauge and record water level every 24 hours while dewatering. Move gauge as necessary to measure water level as shoreline recedes. 2. Keep monitoring gauge free of ice.

3.4. Additional Pumping

1. Provide additional submersible pumps to pump water from isolated pond areas to main pumping locations. 2. Provide temporary construction dewatering in the dike retention area until the long term water handling system is installed and in operation and permanent works are completed.

3.5. Access

1. Provide access for operating and maintaining all pumps, platforms, pipelines, and ancillary equipment during dewatering and until system is decommissioned. 2. Provide access roads within dike retention areas for access to pumps, pipelines and power cables. 3. Provide boat access (or otherwise) to floating equipment platforms at all times during dewatering.

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3.6. Acceptance

1. Initial dewatering shall be considered complete when the pool is drawn down to El. 380 m. Subsequent dewatering for removal of runoff and seepage will be classified as temporary construction dewatering.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

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PIEZOMETERS No. Date

14300-48ES-0001 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Reviewed Remarks Approved By Revised By By By By G. K. Halisheff B. Powell T. Martin D. Guigon A Stephenson All Issued for review May 21/14 June 18/14 June 16/14 Sep 25/14 Sep 25/14

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

Technical Specification Revision

PIEZOMETERS No. Date

14300-48ES-0001 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Reference Standards ...... 2 1.7. Environmental Protection ...... 3 1.8. Submittals ...... 3 1.9. Sequencing ...... 3

2.0 PRODUCTS ...... 4 2.1. Materials for Vibrating Wire Piezometers ...... 4 2.2. Storage ...... 5

3.0 EXECUTION ...... 5 3.1. Drilling ...... 5 3.2. Installation ...... 5

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 6

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers Work specific to the piezometer activities for the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the piezometer Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0009 Excavating, Trenching and Backfilling 14300-41ES-0016 Drilling 14300-48ES-0006 Automated Data Acquisition System

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1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Drawings related to the piezometer Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1026.1 Instrumentation - Plan (Sheet 1 of 3) 14300-41D2-1026.2 Instrumentation - Plan (Sheet 2 of 3) 14300-41D2-1026.3 Instrumentation - Plan (Sheet 3 of 3) 14300-41D2-1027.1 Instrumentation - List of Instruments (Sheet 1 of 2) 14300-41D2-1027.2 Instrumentation - List of Instruments (Sheet 2 of 2) 14300-41D2-1028.1 Instrumentation - Cross-Sections (Sheet 1 of 7) 14300-41D2-1028.2 Instrumentation - Cross-Sections (Sheet 2 of 7) 14300-41D2-1028.3 Instrumentation - Cross-Sections (Sheet 3 of 7) 14300-41D2-1028.4 Instrumentation - Cross-Sections (Sheet 4 of 7) 14300-41D2-1028.5 Instrumentation - Cross-Sections (Sheet 5 of 7) 14300-41D2-1028.6 Instrumentation - Cross-Sections (Sheet 6 of 7) 14300-41D2-1028.7 Instrumentation - Cross-Sections (Sheet 7 of 7) 14300-41D2-1030.1 Instrumentation Details of Installation (Sheet 1 of 3)

1.6. Reference Standards

1. American Society for Testing and Materials (ASTM) a. ASTM A53/A53M – Specification for Pipe, Steel, Black and Hot-Dipped, Zinc- Coated Welded and Seamless. b. ASTM D2467 – Standard Specification for Poly Vinyl Chloride (PVC) Plastic Pipe Fittings, Schedule 80. 2. Canadian Standard Association (CSA) a. CAN/CSA-A23.1 - Concrete Materials and Methods of Concrete Construction.

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1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.8. Submittals

1. Submit piezometer installation plan prior to commencement of the Work. Include as a minimum: a. Material lists. b. Equipment lists. c. Manufacturer’s installation procedures. d. Installation sequence. e. Spares list. f. Installation details and drilling method. g. Quality Control (QC) plan. Plan to adhere to Quality Assurance/Quality Control (QA/QC) document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. The QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work.

1.9. Sequencing

1. Coordinate work so that instruments will not be damaged by construction equipment or personnel. Repair, replacement and associated costs for damaged equipment will be borne by the person(s) responsible for the damage. 2. Install all piezometers, other than installations at the dike toe, prior to commencing dewatering. Piezometers located at the downstream toe of the dike will be installed after initial pool dewatering. 3. Verify proper operation of all piezometers prior to installation and post installation.

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2.0 PRODUCTS

2.1. Materials for Vibrating Wire Piezometers

1. Piezometer Unit (obtain from RST Instruments). Stainless steel 19 mm diameter housing with low air entry filter and integrated thermistor, range from 0 to 700 kPa, 0 to 350 kPa and 0 to 170 kPa with maximum overload of twice the measuring range, built in surge/lightning protection, resolution of 0.025% of full scale, accuracy of ±0.1% of full scale, serial number and range to be etched on housing, complete with calibration chart. Integrated thermistor to have a range of -30° to +60 °C with an accuracy of 0.5 °C. 2. Cables (obtain from RST Instruments) Shielded cables with two 92) pairs of 22 AWG conductors with ground wire and polyethylene jacket. Cables for individual piezometers to be supplied without joints to lengths required for connection to junction boxes to be located near the upper extremity of each drill hole. Individual cable lengths shall correspond to the distance between the piezometer tip and the fill surface, increased by an extra 5 m length to allow for the availability of a lead above fill surface and for variations in the elevation of the anticipated stratigraphic contacts. 3. Bentonite pellets, high density, in watertight containers. 4. Concrete sand conforming to standard ASTM C-33. 5. One portable readout unit compatible with vibrating wire piezometers and thermistors, with data logging capacity (min. 2000 data sets), transfer capability to PC, -20°C to 50°C minimum operating temperature limits, interface cable and adapter to connect to PC, jumper cable and computer software. 6. Junction Boxes a. Weatherproof boxes, type NEMA 4X, to house surge arrestor protection boxes permitting connections between piezometer cables and multi-conductor cables as indicated on the Drawings. 7. All installation and readout accessories as recommended by the manufacturer. 8. Grounding of piezometer system to be via copper wire extending from junction box to bottom of the piezometer borehole.

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2.2. Storage

1. Store all materials and equipment in heated, weatherproof storage area, away from direct sunlight. 2. Store PVC pipes as recommended by manufacturer in factory shipping crates stored flat to keep straight.

3.0 EXECUTION

3.1. Drilling

1. As specified in Technical Specification 14300-41ES-0016, drill holes for piezometers into dike fill and foundation, with minimum diameters as shown on the Drawings and as approved by Manager’s Representative. 2. Case the holes with drill casing as required for piezometer installation. Casing to be progressively withdrawn in lengths, to prevent sloughing of sidewalls, as the piezometer hole is backfilled.

3.2. Installation

1. Install piezometers in accordance with manufacturer’s recommendations. 2. Install piezometers as indicated on Drawings or as otherwise directed by Manager’s Representative. 3. Concrete sand to be used to fill the hole around the piezometer as shown on the Drawings. 4. Bentonite pellets to be used to fill the hole between two successive piezometers as shown on the Drawings. 5. Piezometer cables to be extended and/or grouped in junction boxes for connection to multiconductor cables that are routed to data acquisition system as per the requirements of Technical Specification 14300-48ES-0006. 6. Cables to be buried as shown on Drawings and as per the requirements of Technical Specification 14300-41ES-0009. 7. Hand over equipment, readout unit and spares, and ancillary equipment in full working order to Manager’s Representative at completion of installation.

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4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

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INCLINOMETERS No. Date

14300-48ES-0002 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Reviewed Remarks Approved By Revised By By By By

K. Halisheff B. Powell T. Martin D. Guigon G. Stephenson Issued for A All May 21/14 June 18/14 June 16/14 Sep 25/14 Sep 25/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

Technical Specification Revision

INCLINOMETERS No. Date

14300-48ES-0002 B November/2014

TABLE OF CONTENTS

2.0 PRODUCTS ...... 3 2.1. Materials for Inclinometers ...... 3 2.2. Storage ...... 4

3.0 EXECUTION ...... 4 3.1. Drilling ...... 4 3.2. Installation ...... 4

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 5

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the inclinometer activities at the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the inclinometer Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0016 Drilling

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

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2. The Contractor is referred to the following Drawings related to the Inclinometer Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike - General Site Layout 14300-41D2-1026.1 Instrumentation - Plan (Sheet 1 of 3) 14300-41D2-1026.2 Instrumentation - Plan (Sheet 2 of 3) 14300-41D2-1026.3 Instrumentation - Plan (Sheet 3 of 3) 14300-41D2-1027.1 Instrumentation - List of Instruments (Sheet 1 of 2) 14300-41D2-1027.2 Instrumentation - List of Instruments (Sheet 2 of 2) 14300-41D2-1028.1 Instrumentation - Cross Sections (Sheet 1 of 7) 14300-41D2-1028.2 Instrumentation - Cross Sections (Sheet 2 of 7) 14300-41D2-1028.3 Instrumentation - Cross Sections (Sheet 3 of 7) 14300-41D2-1028.4 Instrumentation - Cross Sections (Sheet 4 of 7) 14300-41D2-1028.5 Instrumentation - Cross Sections (Sheet 5 of 7) 14300-41D2-1028.6 Instrumentation - Cross Sections (Sheet 6 of 7) 14300-41D2-1028.7 Instrumentation – Cross-Sections (Sheet 7 of 7) 14300-41D2-1030.1 Instrumentation - Details of Installation (Sheet 1 of 3)

1.6. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.7. Submittals

1. Submit an inclinometer installation plan prior to the commencement of the Work. Include as a minimum: a. Material lists. b. Equipment lists. c. Manufacturer’s installation procedure. d. Installation sequence. e. Spares list. f. Installation details and drilling method.

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INCLINOMETERS No. Date

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g. Non-shrink cement grout mix. h. Quality Control (QC) procedures. Plan to adhere to Quality Assurance / (Quality Control (QA/QC) document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work.

1.8. Sequencing

2.0 PRODUCTS

2.1. Materials for Inclinometers

1. Mobile Inclinometer Probe. a. RST Digital MEMS Inclinometer system, or equivalent approved by the Owner and Manager’s Representative. System to include one stainless steel inclinometer probe with two force balanced servo-accelerometers, 0.5 m long wheel base, resolution of 0.005 mm per 500 mm, -40° to +70°C minimum operating temperature limits, complete with 50 m long polyurethane covered control cable with steel core and vulcanized depth marks on 0.5 m intervals, one slip-ring reel and one pulley assembly with cable clamp. Inclinometer probe shall include a compatible readout unit capable of storing and validating data in the field and downloading it to a PC. 2. Software. a. RST Inclinalysis software package required to transfer, process and graph inclinometer data. 3. Inclinometer Casing. a. Standard ABS plastic or fiberglass self-aligning casing, 85 mm OD in 3m sections complete with standard couplings in bedrock and telescopic couplings in cut-off wall capable of accommodating 75 mm in compression or extension.

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4. Accessories. a. All accessories including inclinometer probe calibration chart, as provided by manufacturer. 5. Non-shrink cement grout. a. Grout consists of non-shrink cement and bentonite, such that the hydraulic conductivity of the mix is comparable with that of the plastic concrete cut-off wall, with a maximum of 1 x 10-8 m/sec. 6. Concrete head box and steel casing as shown on the Drawings. 7. Glycol – to avoid water freezing within the inclinometer casings.

2.2. Storage

1. Store all materials and equipment, in heated, weatherproof storage area. 2. Store inclinometer casing as recommended by manufacturer in factory shipping crates, stored flat and evenly supported to keep casing straight and to prevent spiraling. Store away from direct sunlight.

3.0 EXECUTION

3.1. Drilling

1. Drill inclinometer holes (located on the crest of the dike) into cut-off or in Zone 1B fill after completion of Jet Grouting and pressure grouting, after approval by Manager’s Representative and in accordance with Technical Specification 14300-41ES-0016. Minimum hole diameter as shown on the Drawings. 2. Allow minimum 24 hours from completion of pressure grouting and seven (7) days from completion of CSM Cut-Off Wall and Jet Grouting before commencing drilling for inclinometer in cut-off wall. 3. For inclinometer casing installations within the cut-off wall, at any given depth during drilling the deviation from the vertical shall be less than 0.5% of the hole length at that depth within the plastic concrete, and less than 1% at that depth within the Jet Grout portion of the cut-off wall.

3.2. Installation

1. Install inclinometer casing and telescopic couplings at locations and depths indicated on the Drawings and in accordance with manufacturer’s recommended procedure.

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2. Orient casing in borehole with one pair of grooves in a plane perpendicular to the dike axis. Do not disturb the inclinometer casing until grout has set. 3. Attach a grout pipe to exterior of inclinometer casing extending to bottom of borehole. Grout the annulus around the inclinometer casing with non-shrink cement grout, through the grout pipe and inject grout until the annular space around the inclinometer casing is completely filled with grout. Fill inclinometer with water prior to grouting to counter buoyancy and to prevent the ingress of grout or deleterious materials into the casing. 4. Install concrete head box and steel casing as shown on the Drawings. 5. Circulate clean water to flush out any grout or debris from the casing and fill the casing with glycol after cleaning with water. 6. Verify proper operation with mobile inclinometer probe immediately after casing installation. 7. Hand over inclinometer probe, readout unit and spares in full working order to Manager’s Representative at completion of installation.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

14300-48ES-0002 Inclinometers (Rev B - Nov 2014) IFT Page 5 Technical Specification Revision

SURVEY MARKERS AND No. Date SURVEY CONTROL MONUMENTS

14300-48ES-0003 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin G. Stephenson G. Stephenson Issued for A All May 21/14 June 18/14 June 16/14 Sep 22/14 Sep 22/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

Technical Specification Revision

SURVEY MARKERS AND No. Date SURVEY CONTROL MONUMENTS

14300-48ES-0003 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Reference Standards ...... 2 1.7. Environmental Protection ...... 3 1.8. Submittals ...... 3 1.9. Sequencing ...... 3

2.0 PRODUCTS ...... 3 2.1. Materials ...... 3

3.0 EXECUTION ...... 4 3.1. Drilling ...... 4 3.2. Installation ...... 4

4.0 QUALITY ASSURANCE / QUALITY CONTROL ...... 4

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the survey markers and control monuments for the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the survey markers and control monuments Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0016 Drilling 14300-41ES-0011 Cast-In-Place Concrete

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1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Drawings related to the survey marker and control monuments Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike - General Site Layout 14300-41D2-1026.1 Instrumentation - Plan (Sheet 1 of 3) 14300-41D2-1026.2 Instrumentation - Plan (Sheet 2 of 3) 14300-41D2-1026.3 Instrumentation - Plan (Sheet 3 of 3) 14300-41D2-1027.1 Instrumentation - List of Instruments (Sheet 1 of 2) 14300-41D2-1027.2 Instrumentation - List of Instruments (Sheet 2 of 2) 14300-41D2-1028.1 Instrumentation - Cross-Sections (Sheet 1 of 7) 14300-41D2-1028.2 Instrumentation - Cross-Sections (Sheet 2 of 7) 14300-41D2-1028.3 Instrumentation - Cross-Sections (Sheet 3 of 7) 14300-41D2-1028.4 Instrumentation - Cross-Sections (Sheet 4 of 7) 14300-41D2-1028.5 Instrumentation - Cross-Sections (Sheet 5 of 7) 14300-41D2-1028.6 Instrumentation - Cross-Sections (Sheet 6 of 7) 14300-41D2-1028.7 Instrumentation - Cross-Sections (Sheet 7 of 7) 14300-41D2-1030.3 Instrumentation - Details of Installation (Sheet 3 of 3)

1.6. Reference Standards

1. American Society for Testing and Materials (ASTM) a. ASTM A53/A53M – Specification for Pipe, Steel, Black and Hot-Dipped, Zinc- Coated Welded and Seamless. 2. Canadian Standard Association (CSA) a. CAN/CSA-G30.18 – Carbon Steel Bars for Concrete Reinforcement. b. CAN/CSA-A23.1 – Concrete Materials and Methods of Concrete Construction.

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1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and of the Water License.

1.8. Submittals

1. Submit an installation plan for survey markers and survey control monuments prior to commencement of the Work. Include as a minimum: a. Material lists. b. Equipment lists. c. Spares list. d. Installation procedures. e. Installation sequence. f. Installation details. g. Quality Control (QC) plan. Plan to adhere to Quality Assurance / Quality Control (QA/QC) document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. The QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work.

1.9. Sequencing

1. Coordinate Work so that instruments will not be damaged by construction equipment or personnel. Repair, replacement and associated costs for damaged equipment will be borne by the person(s) responsible for the damage. 2. Survey control monuments, the locations of which are to be confirmed by the Owner, will be installed first. 3. Install all survey markers, other than installations at downstream toe of the dike, prior to initial pool dewatering.

2.0 PRODUCTS

2.1. Materials

1. Reinforcing steel 25 mm diameter CAN/CSA-G30.18. 2. Brass survey cap.

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3. Concrete in accordance with Technical Specification 14300-41ES-0011. 4. Schedule 40 steel pipe ASTM A53/A53M with cap and steel casing as shown on the Drawings. 5. Non-shrink cement grout. 6. Concrete sand conforming to standard ASTM C33. 7. Bentonite pellets, high density, in watertight containers.

3.0 EXECUTION

3.1. Drilling

1. As specified in Technical Specification 14300-41ES-0016, drill hole in dike fill, CSM Cut-Off Wall, overburden and rock at locations indicated on the Drawings.

3.2. Installation

1. Install survey markers into upper surface of embankment fill or CSM Cut-Off Wall and locate by survey (horizontal precision 10 mm, vertical 5 mm). Survey markers to be located as shown on the Drawings. 2. Install survey control monuments at locations as identified by Owner prior to A21 Dike construction activities.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

14300-48ES-0003 Survey Markers and Control Monuments (Rev B - Nov 2014) IFT Page 4 Technical Specification Revision

THERMISTOR CABLES No. Date

14300-48ES-0004 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Reviewed Remarks Approved By Revised By By By By

K. Halisheff B. Powell T. Martin D. Guigon G. Stephenson Issued for A All May 22/14 June 19/14 June 16/14 Sep 25/14 Sep 25/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

Technical Specification Revision

THERMISTOR CABLES No. Date

14300-48ES-0004 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 2 1.6. Reference Standards ...... 2 1.7. Environmental Protection ...... 3 1.8. Submittals ...... 3 1.9. Delivery, Storage and Handling ...... 3 1.10. Sequencing ...... 3

2.0 PRODUCTS ...... 4 2.1. Materials ...... 4 2.2. Cable Fabrication ...... 5 2.3. Thermistor Calibration ...... 7

3.0 EXECUTION ...... 7 3.1. Installation of New Cables ...... 7 3.2. Extension of Existing Cables ...... 8

4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 8

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the thermistor (ground temperature) cables for the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the thermistor cable Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection 14300-41ES-0016 Drilling 14300-41ES-0009 Excavating, Trenching and Backfilling

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1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Drawings related to the thermistor cable Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike - General Site Layout 14300-41D2-1026.1 Instrumentation - Plan (Sheet 1 of 3) 14300-41D2-1026.2 Instrumentation - Plan (Sheet 2 of 3) 14300-41D2-1026.3 Instrumentation - Plan (Sheet 3 of 3) 14300-41D2-1027.1 Instrumentation - List of Instruments (1 of 2) 14300-41D2-1027.2 Instrumentation – List of Instruments (2 of 2) 14300-41D2-1028.1 Instrumentation Cross Sections (Sheet 1 of 7) 14300-41D2-1028.2 Instrumentation Cross Sections (Sheet 2 of 7) 14300-41D2-1028.3 Instrumentation Cross Sections (Sheet 3 of 7) 14300-41D2-1028.4 Instrumentation Cross Sections (Sheet 4 of 7) 14300-41D2-1028.5 Instrumentation Cross Sections (Sheet 5 of 7) 14300-41D2-1028.6 Instrumentation Cross Sections (Sheet 6 of 7) 14300-41D2-1028.7 Instrumentation – Cross-Sections (Sheet 7 of 7) 14300-41D2-1030.1 Instrumentation - Details of Installation (Sheet 1 of 3) 14300-41D2-1030.2 Instrumentation - Details of Installation (Sheet 2 of 3)

1.6. Reference Standards

1. American Society for Testing and Materials (ASTM) a. ASTM A53/A53M - Specification for Pipe, Steel, Black and Hot-Dipped, Zinc- Coated Welded and Seamless. b. ASTM D1784 - Specification for Rigid Poly Vinyl Chloride (PVC) Compounds and Chlorinated Poly Vinyl Chloride (CPVC) Compounds. c. ASTM D2466 - Specification for Poly Vinyl Chloride (PVC) Plastic Pipe Fittings, Schedule 40.

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1.7. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.8. Submittals

1. Submit thermistor installation plan prior to commencement of the Work. Include as a minimum: a. Material lists. b. Equipment lists. c. Manufacturer’s installation procedures. d. Installation sequence. e. Spares list. f. Granular backfill. g. Installation details and drilling method. h. Verification of proper operation. i. Quality Control (QC) plan. Plan to adhere to Quality Assurance/Quality Control (QA/QC) document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. The QC plan to be reviewed and accepted by Manager’s Representative prior to commencement of the Work.

1.9. Delivery, Storage and Handling

1. Carefully store materials to protect against deterioration and physical damage.

1.10. Sequencing

1. Coordinate work so that ground temperature cable will not be damaged by construction equipment or personnel. Repair, replacement and associated costs for damaged equipment will be borne by the person(s) responsible for the damage. 2. Install all cables in the vicinity of thermosyphons prior to thermosyphon commissioning, and the remainder of cables prior to dewatering.

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2.0 PRODUCTS

2.1. Materials

1. Thermistor Beads a. YSI Model 44033 or an approved alternate bead with a 0.1°C accuracy and a nominal resistance of 2.252 ohms at 25°C. 2. Cable a. Cable of stranded copper conductors, water block, 16 pairs of insulated conductors, 24 gauge with a Kevlar jacket, or approved equivalent. 3. Connectors a. Supply cable with an Amphenol connector comprising the following components; a shell end (97-3057-1012-1), male insert (97-20-29P), male shell (97-MS3106A- 20), and screw cap (97-60-20P) with chain attachment to shell end. 4. Thermistor Molding a. Vulcanized rubber molding, or an approved equivalent, to seal the thermistor beads. The outside diameter of the molding should be compatible with installation in a 25 mm I.D. PVC pipe. The cable shall remain watertight under a water head of 100 m. 5. Identification Tag a. An identification tag, permanently installed, with the project name and ground temperature cable serial number. 6. Containment Casing a. Schedule 80, 25 mm I.D. PVC pipe, conforming to ASTM D1784 and ASTM D2466 with watertight flush threaded joints and end caps. 7. Non-shrink cement grout a. Grout consists of non-shrink cement and bentonite, such that the hydraulic conductivity of the mix is comparable with that of the plastic concrete cut-off wall, and no higher than 1 x 10-8 m/sec. 8. Concrete sand conforming to standard ASTM C33. 9. Steel Casing and Head Box a. Schedule 40, ASTM A53/A53M steel pipe with head box, as shown on the Drawings.

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10. Terminal Boxes a. Weatherproof type NEMA 4X boxes to house cable ends with 17 pin Amphenol female connectors mounted on a panel. 11. Multimeter a. FLUKE model 87 V true RMS digital multimeter with two decimal place display at 30 kilo ohms, and with an accuracy of ±0.5% and resolution of 0.01 kilo ohms, or approved equivalent. 12. Switch Box a. A switch box (Lakewood Systems Ltd. TSSB16, or approved equivalent) with 17 pin Amphenol female threaded metal connector and dual banana plug to test thermistors in-situ.

2.2. Cable Fabrication

1. Provide cables with a total of 16 beads except where indicated otherwise on the Drawings. Cable fabrication details are as follows: a. Beads are to be spaced within 10 mm of the required location on the cable. b. Bead are to be installed at depths and intervals as indicated on the Drawings. c. Provide sufficient lead cable above the first bead to extend the cables to the head boxes, terminal boxes or data loggers as applicable. d. Wire cables preferably using the wiring code as shown on Table 1 in this Technical Specification to enable compatibility with cables currently existing on site.

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Table 1. Thermistor Cable Wiring Details Thermistor Bead Wire Colour Terminal Letter on Number (Note 1) Connector 1 RED A 2 BROWN B COMMON GREY M 3 BLACK C 4 WHITE D 5 BLUE E 6 PURPLE F COMMON BROWN M 7 ORANGE G 8 GREEN H 9 YELLOW J 10 BLUE K COMMON GREY M 11 RED L 12 BLACK N 13 WHITE P 14 PURPLE R COMMON GREY M 15 GREEN S 16 BLUE T COMMON ORANGE M COMMON YELLOW M Note 1: Wire color not mandatory, but preferable e. Mark the identification and serial number of each cable permanently onto the body of the connector. f. Prepare the cable harness by removing 25 to 35 mm length of cable jacket (jacket cutouts) at each bead location and extract the appropriate wire for the bead location and the common wire for the cable. g. Ensure that stripped wires are clean and free of “water stop” residue. Solder beads to both wires with some slack incorporated into the wiring and placed on

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the outside of the cable bundle. During soldering, protect the beads to keep their temperature below manufacturer’s recommended limit. h. Cover the beads with a layer of heat reflectant tape with the adhesive side not in contact with the bead. Place a second layer of heat reflectant tape with the adhesive side down to 15 mm on either side of the jacket cutout. i. Cover each bead with injection molding extending a minimum of 40 mm above and below the bead location.

2.3. Thermistor Calibration

1. Verify that each ground temperature cable is functioning properly prior to and post installation and calibrate the thermistor beads. Use the following calibration procedure: a. Prepare bath of ice and water cooled to at least 0.03°C and monitor the temperature with a thermometer accurate to 0.01°C. b. Immerse each section of the cable with a thermistor bead into the ice bath and after it reaches thermal equilibrium, record the resistance reading using a digital multimeter as specified above. c. Repeat the process a minimum of three times and determine average 0°C correction for each bead.

3.0 EXECUTION

3.1. Installation of New Cables

1. Install cables after obtaining approval by Manager’s Representative. 2. As specified in Technical Specification 14300-41ES-0016, drill hole for cables into dike fill and foundation with minimum diameters as shown on the Drawings. 3. Case the holes with drill casing as required. 4. Install the containment PVC pipe to the bottom of the hole. Verify that the pipe is clean and dry. 5. Casing to be withdrawn as the annulus between the casing and the containment PVC pipe is being filled with non-shrink cement grout. 6. Install cable in PVC pipe and locate first bead as indicated on the Drawings.

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7. On dike crest, cables are to be buried in fine grained protective fill in trenches excavated in the dike fill, as shown on Drawings and as per the requirements of Technical Specification 14300-41ES-0009. Thermistor cables installed adjacent to thermosyphons are to be grouped and extended to individual terminal boxes as indicated on the Drawings. 8. Thermistor cables installed on the dike crest where the head box is directly above the drill hole shall be installed so that the cables can be removed from the 25 mm PVC pipe in the event of a cable malfunction after installation. 9. Cables in trenches are to be laid with a minimum slack of 1 m per 10 m length and a minimum spacing of 50 mm between cables. 10. Hand over equipment, readout unit, spares in full working order to Manager’s Representative at completion of installation.

3.2. Extension of Existing Cables

1. Remove existing cable connector and attach suitable length of extension lead of same type cable. Ensure that stripped wires are cleaned with solvent to remove all “water stop” residue, prior to connecting extension wires by soldering. Protect soldered connection on individual wires with heat shrink tubing and further protect entire wire bundle with a single piece of heat shrink tubing of a diameter equivalent to the cable insulation. 2. Extend protective steel casing vertically, route cable in trench and extend to head boxes as indicated on the Drawings. 3. Protect and/or salvage, where deemed practical by the Contractor and the Manager’s Representative, existing thermistor cable installations during dike construction.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

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RELIEF WELLS No. Date

14300-48ES-0005 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Reviewed Remarks Approved By Revised By By By By

K. Halisheff B. Powell T. Martin D. Guigon G. Stephenson Issued for A All May 22/14 June 16/14 June 10/14 Sep 25/14 Sep 25/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 12/14 Nov 19/14 Nov 19/14 Tender

Technical Specification Revision

RELIEF WELLS No. Date

14300-48ES-0005 B November/2014

TABLE OF CONTENTS

2.0 MATERIALS ...... 3 2.1. Materials for Relief Wells ...... 3

3.0 EXECUTION ...... 4 3.1. Location ...... 4 3.2. Drilling ...... 4 3.3. Installation ...... 5 3.4. Well Development ...... 6

4.0 QUALITY ASSURANCE AND QUALITY CONTROL ...... 6

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the relief wells at the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the relief well Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

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2. The Contractor is referred to the following Drawings related to the relief well Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike – General Site Layout 14300-41D2-1026.1 Instrumentation - Plan (Sheet 1 of 3) 14300-41D2-1026.2 Instrumentation - Plan (Sheet 2 of 3) 14300-41D2-1026.3 Instrumentation - Plan (Sheet 3 of 3) 14300-41D2-1027.1 Instrumentation - List of Instruments (Sheet 1 of 2) 14300-41D2-1027.2 Instrumentation – List of Instruments (Sheet 2 of 2) 14300-41D2-1028.1 Instrumentation – Cross-Sections (Sheet 1 of 7) 14300-41D2-1028.2 Instrumentation – Cross-Sections (Sheet 2 of 7) 14300-41D2-1028.3 Instrumentation – Cross-Sections (Sheet 3 of 7) 14300-41D2-1028.4 Instrumentation – Cross-Sections (Sheet 4 of 7) 14300-41D2-1028.5 Instrumentation – Cross-Sections (Sheet 5 of 7) 14300-41D2-1028.6 Instrumentation – Cross-Sections (Sheet 6 of 7) 14300-41D2-1028.7 Instrumentation – Cross-Sections (Sheet 7 of 7) 14300-41D2-1029 Relief Well Design

1.6. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.7. Submittals

1. Submit a relief well installation plan. Include: a. Material list. b. Spare parts list. c. Installation procedure. d. Installation sequence. e. Installation details and drilling method. f. Well development method. g. Pump specifications.

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h. Quality Control (QC) plan. Plan to adhere to Quality Assurance/Quality Control (QA/QC) document identified in Section 4.0 below, as a minimum, and include additional QC activities as necessary. QC plan to be reviewed and accepted by Manager’s Representative prior to commencement of the Work.

1.8. Sequencing

1. Coordinate work so that relief wells will not be damaged by construction equipment or personnel. Repair, replacement and associated costs for damaged equipment will be borne by the person(s) responsible for the damage. 2. Install all relief wells prior to commencing dewatering. 3. Verify proper operation of all relief wells post installation.

1.9. Delivery, Storage and Handling

1. Carefully handle and store materials to protect against deterioration and physical damage.

2.0 MATERIALS

2.1. Materials for Relief Wells

1. Riser. a. Grade B, schedule 20, 150 mm nominal internal diameter steel pipe. 2. Screen. a. Wire-wound continuous V-slot fabricated of cold drawn triangular wire wound around an internal array of longitudinal support bars, AISI type 304 stainless steel; 150 mm nominal diameter with wall thickness capable of supporting the overlying riser pipe without deformation. i. Screen opening size for lower screen (installation in bedrock): 20 mesh (0.03 inch opening), heavy duty. ii. Screen opening size for upper screen (installation in filter blanket): 7 mesh (0.10 inch opening), heavy duty. 3. Joints and Caps. a. Bottom cap to consist of welded stainless steel plate. Top cap to consist of standard well cap. Joints to consist of stainless steel welding rings.

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4. Backfill Materials. a. Backfill materials to be placed as indicated on the Drawings. Two backfill materials are required: i. Concrete sand (ASTM C-33). ii. Coarse concrete aggregate, with gradation as follows:

5. Centering Guides. a. Centering guides to consist of four 12 gauge steel blades and clamps as shown on the Drawings. 6. Protective Surface Casing. a. 250 mm nominal diameter steel tubing, as shown on Drawings. 7. Pumps. a. Submersible pumps with a capacity of 25 L/min under a dynamic head of 30 m.

3.0 EXECUTION

3.1. Location

1. The actual location of each relief well will be selected by Manager’s Representative based on the subsurface conditions established during the various phases of dike construction. Relief wells are anticipated to be between stations 1+025 and 1+350, as shown on the Drawings.

3.2. Drilling

1. Drill holes 5 m into bedrock at locations approved by Manager’s Representative after the dike has been built to its final elevation. 2. Drill using a temporary casing of minimum 300 mm diameter to support the drill hole walls and prevent the formation of cavities around the casing.

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3. Use of bentonitic drilling fluid is forbidden. Biodegradable drilling fluid may be employed provided DDMI Environmental requirements are met.

3.3. Installation

1. Assemble sections of riser and screen as shown on the Drawings taking into account the stratigraphic conditions established during the Cut-Off Wall construction, Jet Grouting and pressure grouting phases. 2. Install centering guides on minimum 6 m centers on the riser only, ensuring that the blades are adequately aligned and that the annulus around the riser and screen is uniform. 3. During installation in the hole, ensure the assembled sections of screens and risers are lowered with great care to prevent damage to the screens. Wells in which a submersible pump cannot be lowered to the base of the lower screen due to buckling or tearing of the screen sections shall be replaced at cost to the Contractor. 4. After approval by Manager’s Representative, place filter material at the bottom of the hole, as shown on the Drawings. 5. Lower the assembled riser/screen/centering guides into the hole and carefully place the coarse concrete aggregate material using a tremie to avoid material segregation and bridging within the tremie pipe. 6. Initially, the tremie pipe shall be lowered to the bottom of the hole, filled with coarse concrete aggregate material and gradually lifted. Coarse concrete aggregate to be raised a minimum of 0.6 m above the top of the No. 20 mesh steel screen, installed in bedrock, as shown on the Drawings. 7. Gradually lift the temporary casing while ensuring that its lower end is always buried at least 1 m into the coarse concrete aggregate material. 8. Around the lower part of the riser, place concrete sand material up to about 0.3 m above the overburden - Zone 1A interface as indicated on the Drawings. From that point to 1.5 m below the dike crest, backfill around the well casing is to comprise coarse concrete aggregate. For the top 1.5 m to the crest of the dike, backfill with concrete sand. 9. Develop the well using the surging method as outlined in Section 3.4 below, or any other method as approved by the Manager’s Representative, to remove fine particles present in the screen or in the surrounding filter material. Add filter material in the well annulus if required to maintain its upper level at the specified level.

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10. Development is considered complete when water is clear and free of visible suspended sediments. 11. Install the protective surface casing as shown on the Drawings. 12. Install a submersible pump and associated discharge pipe in wells selected by Owner.

3.4. Well Development

1. Relief well development shall be undertaken via mechanical surging, using a plunger or Surging Block. Surging consists of moving water in and out of the screen using the up and down motion of the surge block through short sections of the well screen. 2. Pump or bail the well to ensure a relatively free inflow of water prior to surging. 3. The plunger or surging block shall be moved up and down at a speed of approximately 0.5 - 0.75 meter per second for a minimum period of one hour. Surging shall begin with a slow and gentle motion above the well screen and continue with more vigor from the top of screen downward. 4. Sand accumulation at the bottom of the well shall be monitored frequently during development and removed by air lifting if so instructed by the Manager’s Representative. Surging shall continue until the accumulation pulled through the well screen in fifteen up-and-down motions of the surging block is less than 6 cm.

4.0 QUALITY ASSURANCE AND QUALITY CONTROL 1. Refer to the Quality Assurance and Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

14300-48ES-0005 Relief Wells (Rev B - Nov 2014) IFT Page 6 Technical Specification Revision

AUTOMATED DATA No. Date ACQUISITION SYSTEM (ADAS)

14300-48ES-0006 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin D. Guigon Issued for A All May 23/14 June 19/14 June 16/14 Nov/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 21/14 Nov 22/14 Nov 22/14 Tender

Technical Specification Revision

AUTOMATED DATA No. Date ACQUISITION SYSTEM (ADAS)

14300-48ES-0006 B November/2014

TABLE OF CONTENTS

2.0 PRODUCTS ...... 3 2.1. Materials for Data Acquisition System ...... 3 2.2. Storage ...... 4

3.0 EXECUTION ...... 5 3.1. Installation ...... 5

4.0 QUALITY ASSURANCE / QUALITY CONTROL ...... 5

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AUTOMATED DATA No. Date ACQUISITION SYSTEM (ADAS)

14300-48ES-0006 B November/2014

1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Works specific to the automated data acquisition system (ADAS) for the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the ADAS that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES-0001 Site Conditions 14300-41ES-0002 Environmental Protection

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

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2. The Contractor is referred to the following Drawings related to the ADAS Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike - General Site Layout Data Loggers, Shelters and Buried Cables - Sections 14300-41D2-1031 and Details

1.6. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.7. Submittals

1. Submit a plan for the ADAS prior to the commencement of the Work. Include as a minimum: a. Material list. b. Equipment lists and specifications. c. Installation procedure. d. Installation sequence. e. Interfaces with Owner’s local area network. f. Cable layouts. g. Wiring diagrams. h. Spares list. i. Data processing software and user’s manual. j. Quality Control (QC) plan. Plan to adhere to Quality Assurance/Quality Control (QA/QC) document identified in Section 4.0 below as a minimum and include additional QC activities as necessary. The QC plan is to be reviewed and accepted by Manager’s Representative prior to commencement of the Work. k. Commissioning and handover plan.

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1.8. Sequencing

1. Coordinate work so that instruments will not be damaged by construction equipment or personnel. Repair, replacement and associated costs for damaged equipment will be borne by the person(s) responsible for the damage. 2. Install all ADAS prior to commencing dewatering. The piezometers located at the downstream toe of the dike to be installed and connected to the data loggers following dewatering. 3. Verify that all instrumentation (vibrating wire piezometers) identified by the Manager’s Representative are tied into the ADAS and verified as functional, and that all ADAS components including, but not limited to, the data logging network, radio communications, and data viewing software package are fully functional and tested.

2.0 PRODUCTS

2.1. Materials for ADAS

1. Data Loggers. l. Data logger model Flex DAQ, or approved equivalent, by RST Instruments Ltd. Datalogger installations shall incorporate the following components suitable for reliable measurement, data storage and communication to host PC: i. NEMA 4X weatherproof enclosure. ii. Campbell Scientific model CR800 or CR1000, or approved equivalent, measurement and control unit. iii. RST Instruments model Flexi-Mux multiplexers, or approved equivalent. iv. Comprehensive transient protection. v. Sensor signal conditioners (AVW200 Vibrating Wire Interface, or approved equivalent). vi. Battery charger and rechargeable battery with self-sufficiency for one week during power outage. vii. Unlicensed frequency hopping spread spectrum radio (900 MHz frequency), coaxial cable, coaxial transient arrestor, antenna and all devices to acquire and transmit data from instruments identified on the Drawings to the LAN interface to be located as directed by the Owner.

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viii. Data loggers to allow manual measurements on multiplexers or transient protection modules using portable readouts. ix. One pressure sensor within the data logging network to record barometric pressure reported in meters of head of water. x. AC power provided by others. 2. Software and Programming. a. Most recent Windows compatible version of all necessary software and programming to acquire, transmit and retrieve data, to perform real-time graphic display and alarm management as well as to produce and access graphs. 3. Multiconductor Cables. a. All shielded heavy duty multiconductor cables rated for direct burial and related accessories required to group and connect instruments to individual data loggers. 4. Cable Protection Pipe. a. Single wall corrugated HDPE “Big O” with 100 mm inside diameter. 5. Data Logger Shelters. a. Approximately 1.5 m x 1.5 m x 2.4 m high shelters made of gauge 14 steel, with 2 lifting hooks on roof, one anchor plate at each corner, a neoprene gasket and silicone seal on the perimeter of the bottom frame, R-20 insulated walls and roof, approximately 81 cm x 203 cm insulated steel door and internal/external epoxydic paint protection. Concrete floor slabs to be provided by the Owner. 6. PVC Pipe. a. Schedule 80 150 mm inside diameter PVC pipe.

2.2. Storage

1. Store all equipment in heated, weather proof storage area. 2. Store all electrical and electronic accessories as recommended by the manufacturer.

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3.0 EXECUTION

3.1. Installation

1. Cables. a. Cables to be buried within fine grained protective fill in trenches excavated in the A21 Dike crest and downstream toe berm as shown on the Drawings and as per the requirements of Technical Specification 14300-41-ES-0009. Cables to be installed with a minimum uniform slack of 1 m per 10 m length and with a minimum spacing of 50 mm between each cable. Actual trench locations and alignments shall be approved by Manager’s Representative prior to execution. Cables installed on the downstream slope of the dike shall be contained in a corrugated polyethylene pipe protected by backfill as indicated on the Drawings. 2. Data loggers. a. Data loggers to be installed in shelters on the dike crest. Locations of data loggers may be adjusted (field fit), with Manager’s Representative approval, to optimize the number of loggers and the lengths of cables and trenching required. 3. Software and Programming. a. Software to be installed at central workstation and programming performed to enable the instrumentation system to be operated as per the Owner’s requirements regarding reading frequencies, data display and alarm management. Owner’s requirements to be specified on site. Software and central workstation provided by the Owner. 4. Hand over equipment, readout unit and spares and ancillary equipment in full working order to Manager’s Representative at completion of installation.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

14300-48ES-0006 Automatic Data Acquisition System (Rev B - Nov 2014) IFT Page 5 Technical Specification Revision

THERMOSYPHONS No. Date

14300-48ES-0007 B November/2014

INSTRUCTION TO DOCUMENT CONTROL

Entire specification revised. Reissue all pages.

Reissue revised pages only

STAMP THE SPECIFICATION AS FOLLOWS:

Issued for review

Issued for tender

Issued for approval

Issued for purchase

Issued for construction

SPECIFICATION REVISION INDEX

(BGC) (BGC) (BGC) (External) (External) Pages No. Prepared Reviewed Approved Remarks Reviewed By Approved By Revised By By By

K. Halisheff B. Powell T. Martin D. Guigon Issued for A All May 22/14 June 19/14 June 16/14 Nov/14 review

K. Halisheff B. Powell T. Martin Issued for B All Nov 21/14 Nov 22/14 Nov 22/14 Tender

Technical Specification Revision

THERMOSYPHONS No. Date

14300-48ES-0007 B November/2014

TABLE OF CONTENTS

1.0 GENERAL ...... 1 1.1. Documents ...... 1 1.2. Scope of Work ...... 1 1.3. Definitions ...... 1 1.4. Related Technical Specifications ...... 1 1.5. Reference Drawings ...... 1 1.6. Environmental Protection ...... 2 1.7. Climatic Conditions ...... 2 1.8. Design Criteria ...... 2 1.9. Reference Standards ...... 2 1.10. Submittals ...... 3 1.11. Sequencing ...... 3 2.0 PRODUCTS ...... 3 2.1. Materials ...... 3 3.0 EXECUTION ...... 5 3.1. General ...... 5 3.2. Location ...... 5 3.3. Thermosyphon Installation ...... 5 3.4. Welding ...... 6 3.5. Flange Assembly ...... 7 3.6. Threaded Joints ...... 7 3.7. Dielectric Joints ...... 7 3.8. Branch Connections ...... 7 3.9. Connections to Equipment ...... 8 3.10. Valves ...... 8 3.11. Reducers ...... 8 3.12. Fittings ...... 8 3.13. Slopes ...... 8 3.14. Supports, Anchors and Guides ...... 9 3.15. Additional Requirements for the Mechanical Refrigeration ...... 9 3.16. Cleaning ...... 10 4.0 QUALITY ASSURANCE/QUALITY CONTROL ...... 10

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THERMOSYPHONS No. Date

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1.0 GENERAL

1.1. Documents

1. This Technical Specification forms part of the Contract Documents and is to be read, interpreted, and coordinated with all other parts. 2. The Contractor shall immediately notify the Manager’s Representative should uncertainties arise with the Drawings and/or Technical Specifications. 3. Should a conflict between the Drawings and Scope of Work and Technical Specifications exist, the Drawings shall govern.

1.2. Scope of Work

1. This Technical Specification covers the Work specific to the thermosyphons at the A21 project to be completed by the Contractor.

1.3. Definitions

1. A complete list of project Definitions is listed in Technical Specification 14300-41ES- 0000 (List of Definitions, Drawings and Technical Specifications).

1.4. Related Technical Specifications

1. A complete list of Technical Specifications is listed in Technical Specification 14300- 41ES-0000 (List of Definitions, Drawings and Technical Specifications). 2. The Contractor is referred to the following Technical Specifications related to the thermosyphon Work that are be read in conjunction with all other parts of the Contract Documents.

Technical Specification Technical Specification Title 14300-41ES- 0001 Site Conditions 14300-41ES- 0002 Environmental Protection

1.5. Reference Drawings

1. A complete list of Drawings is listed in Technical Specification 14300-41ES-0000 (List of Definitions, Drawings and Technical Specifications).

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2. The Contractor is referred to the following Drawings related to the thermosyphon Work that are be read in conjunction with all other parts of the Contract Documents.

Drawing No. Drawing Title 14300-41D2-1002 A21 Dike - General Site Layout 14300-41D2-1015 North Abutment Plan and Profile 14300-41D2-1017 South Abutment Plan and Profile 14300-41D2-1018 Thermosyphons Layout - Typical Plan and Sections 14300-41D2-1026.1 Instrumentation - Plan (Sheet 1 of 3) 14300-41D2-1026.3 Instrumentation - Plan (Sheet 3 of 3)

1.6. Environmental Protection

1. Comply with the requirements of Technical Specification 14300-41ES-0002 (Environmental Protection) and the requirements of the Water License.

1.7. Climatic Conditions

1. Refer to the Site Conditions Technical Specification 14300-41ES-0001 for information.

1.8. Design Criteria

1. The hybrid thermosyphons shall have sufficient heat transfer capacity and be adequately spaced to maintain the abutment interface frozen at all times during operation of the dike based on the following design criteria: a. Climatic information as collected by the Owner on site and published by the Atmospheric Environmental Service of Environment Canada. b. Granular material thermal properties to be based on a density of 2000 kg per cubic meter at 7% moisture content.

1.9. Reference Standards

1. American Society for Testing and Materials (ASTM) a. ASTM A53/A53M - Specification for Pipe, Steel, Black and Hot-Dipped, Zinc- Coated Welded and Seamless. b. ASTM B88M - Specification for Seamless Copper Water Tube (Metric)

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c. ASTM B280 - Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service 2. Steel Structures Painting Council a. SSPC-SP10 - Near-White Blast Cleaning. 3. American Society of Mechanical Engineers a. Boiler and Pressure Vessel Codes. 4. Northwest Territories Codes and Regulations.

1.10. Submittals

1. Submit shop drawings of thermosyphons and condensing units, piping and connection details, including supports, insulation and accessories. 2. Submit manufacturer’s recommended installation and operation procedures, including procedures for cleaning pipes, welding, on site painting, vacuuming, charging, pressure testing and leak detection. 3. Submit design analysis and calculations to demonstrate adequacy of the system and compliance with the required design criteria.

1.11. Sequencing

1. Coordinate work so that thermosyphons will not be damaged by construction equipment or personnel. Repair, replacement and associated costs for damaged equipment will be borne by the person(s) responsible for the damage. 2. Verify proper operation of all thermosyphons and condensing units post installation. 3. Install, test and verify functionality of all thermosyphons and condensing units prior to commencing dewatering.

2.0 PRODUCTS

2.1. Materials

1. Thermosyphons a. Two phase liquid-vapor type thermosyphons charged with carbon dioxide as manufactured by Arctic Foundations of Canada Inc., Winnipeg, Manitoba or approved equivalent.

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b. Construct the evaporator section of the thermosyphons from black steel pipe (not galvanized) in accordance with ASTM A53/A53M, 2 inch NPS, Sch. 40 Grade B. c. All welds to meet ASME boiler and pressure vessel code requirements. d. Sandblast the thermosyphon radiator, the above ground pipe and the upper 2.2 m of the evaporator below ground to near white condition in accordance with SSPC- SP10, aluminize and paint with white epoxy paint. e. Construct radiators from ASTM A53/A53M, 3 inch NPS, Sch. 40 Grade B black steel pipe with segmented carbon steel fins, 1.2 mm thick, 13 rows of fins per 100 mm of pipe and a total radiator area 19.5 m2. f. Typical dimensions of the evaporator and radiator are as shown on the Drawings. g. Each thermosyphon shall have a minimum thermal conductance value of 178 W/°C for a wind velocity of 8 km/hr. h. Include a heat exchanger encased in an insulated ASTM A53/A53M, 6 inch NPS, Sch. 40 Grade B black steel pipe. The active heat exchanger shall comprise a 9.5 mm seamless Sch. 80 steel cooling coil through which a refrigerant (R404A) can be circulated from a condensing unit. i. Include the insulated part of ASTM A53, 2 inch NPS, Sch. 40 Grade B black steel pipe, and 6 inch, Sch. 40 Grade B black steel pipe as shown on the Drawings. 2. Condensing Unit a. 30 hp, 600 volt, 3-phase, 60 Hz, air cooled condensing unit, rated at a capacity of 65 kW (225,600 BTU/hr), at an operating temperature of -18°C for thermosyphons as shown on the Drawings. Apart from standard equipment (semi-hermetic compressors, aluminum condenser fans/guards, discharge and suction line vibration isolators, condensing coils, flooding head pressure control valve, fan cycling, etc.), each condensing unit shall include a suction accumulator with replaceable filter, heated and insulated liquid receiver, head cooling fans, CO2 thermostat/thermowell, replaceable liquid line kit with solenoid valve and fused disconnect switch. The same refrigeration capacity which was used for the A418 Dike shall be used for the A21 Dike. b. Refrigerant R404A or approved alternate. c. Refrigerant shall be circulated through a type ”L” ACR copper tubing header with connections to each individual thermosyphon. The refrigerant piping shall be sized by the Contractor/manufacturer but in no case shall be less than 25 mm for the supply liquid line and 50 mm for the suction vapor return. If the characteristics

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of the condensing unit change, the piping network shall be modified accordingly. All brazed joints to be done with Stay-Brite Tin-antimony (96-4) alloy. d. Concrete base for the condensing units to be provided by the Owner.

3.0 EXECUTION

3.1. General

1. Carry out piping (also implies thermosyphons) installation in a neat permanent workmanlike manner, workmanship being equal, in every respect to the best practice known to the trade. 2. Piping dimensions, fabrication, assembly, welding and installation shall conform to all applicable sections of the ASME/ANSI B31.1 code, chapters IV and V. 3. Piping and fittings shall be clear and free from cutting or threading burrs, scales and defects. Ream the ends of all piping. 4. Arrange and install piping as indicated, straight, plumb, as direct as possible. On parallel piping runs, leave a minimum free space of 150mm to allow for expansion. 5. Install the electrical equipment from a 600 V, 5 phase, 60 Hz source provided by others.

3.2. Location

1. The final layout of each thermosyphon group will be selected by Manager’s Representative after determination of the location of the permafrost boundary during the construction of the dike. 2. Excavation and backfill shall be done according to Technical Specification 14300- 41ES-0009.

3.3. Thermosyphon Installation

1. Supply a skilled crew specialized in fabrication, assembly, charging and testing the thermosyphon system. 2. Install thermosyphon evaporators in cased drill holes with a minimum 100 mm inner diameter. 3. The radiators shall be erected plumb and shall be braced to each other in a manner that will allow them to be free standing. Install the thermosyphons within the following tolerances:

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a. Horizontal location at dike surface: 100 mm b. Maximum Inclination: 2° c. Elevation: 100 mm 4. Place the evaporator in the drill hole in sections. Welding to be carried out by thermosyphon manufacturer. Provide a crane to lift and install the evaporator sections in the drill hole. Owner to advise Contractor as to crane supplier. 5. Remove the casing following installation of the evaporator. Alternatively, with the Manager’s Representative approval, the casing may be left in the drill hole. If the casing is left in the drill hole, the annulus between the casing and the evaporator must be filled with sand slurry or an equivalent approved by Manager’s Representative. Record accurate measurements of the volume of sand slurry used in the annulus to verify that the annulus is completely filled. 6. Welding of the radiator, the heat exchanger and the insulated part to the evaporator to be carried out by the thermosyphon manufacturer. Provide a crane to lift and support the radiator section during welding.

7. Pressure testing and charging of the thermosyphons with CO2 to be done by the thermosyphon manufacturer.

3.4. Welding

1. All pipe welding shall be done by certified welders. 2. Fabricate piping according to the Pipe Fabrication Institute Standard ES-3 (Fabricating Tolerances). 3. Welding procedures and welders shall conform to the ASME code (Boiler and Pressure Vessel), section XI, (Welding and Brazing Qualifications). 4. Submit welding procedures and welders qualification certificates to the Manager’s Representative. No welding to commence without his/her approval. Include the procedure(s) for storing, handling, control and distribution of electrodes and wires. Wet electrodes shall be discarded. Each procedure shall be certified and registered by the Boiler and Pressure Vessel Branch of the Local Jurisdiction. The procedures shall be qualified on the same grades of pipe materials as those to be welded during fabrication. 5. Ends and adjacent surfaces shall be free of all traces of paint, oils, lubricants and rust, prior to commencement of welding.

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6. All butt welding shall be full thickness penetration. The bottom of a "stub-in" shall be flush with the pipe. Care shall be taken to ensure a minimum of weld metal deposit on inside of piping. 7. Pipe welding shall conform with the following codes: CSA-W47.1 Certification of companies for fusion welding of structural steel. CSA-W48-14 Filler metals and allied materials for metal arc welding CSA-W117.2 Code for safety in welding, cutting and allied processes. CSA-W178 Qualification code for welding inspection organization.

3.5. Flange Assembly

1. Flange facings shall be true, parallel and perpendicular to the axis of piping. Bolt connections properly. Pull bolts evenly tight to ensure leak proof and stress-free connections. Bolt holes shall straddle centrelines. Steel flanges are normally raised face, but flanges that are to be bolted to cast iron, bronze or plastic full face flanges shall be furnished with a flat face and fitted with full face gaskets.

3.6. Threaded Joints

1. Make piping threaded joints tight with an approved pipe joint compound or tape.

3.7. Dielectric Joints

1. Install dielectric unions or insulated couplings between copper or brass piping material and steel material. Use approved union or insulated couplings for pipe sizes 2" and smaller, and approved dielectrically gasketed flanges for pipes 2½" and larger.

3.8. Branch Connections

1. For welded pipes, use straight tees or reducing tees if commercially available. Otherwise, use (Weldolets) or (Sockolets). Cut-in welding connections shall not be used. 2. Outlets for small valves, air vents, drains, etc. not exceeding ¾" size may be made by extra strong half-couplings welded to the main.

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3.9. Connections to Equipment

1. Make connections to equipment, such as using braided hose connections, so that lines do not impart any stress on equipment due to misalignment, deflection, expansion and vibration. The mating flange of the piping shall be the same type as on equipment. 2. Riser pipes shall have additional unistrut bracing part way up the risers to prevent differential movement of the risers in high winds. This additional bracing is currently not shown on the Drawings.

3.10. Valves

1. Install all the necessary valves required to adequately control piping services and equipment and as shown on the Drawings. Install a valve at each pipe connection to equipment and one at each branch connection to a main. 2. Install warning marker to include “CONTENTS UNDER PRESSURE” on the thermosyphon charging connection or install applicable bleed valve.

3.11. Reducers

1. Where piping is graded to a low point, avoid the formation of pockets that will trap the liquid in the pipe. Unless otherwise specified, use eccentric reducers. In general, avoid large reduction in one single fitting. Use two or more eccentric reducers in series. Fabricated reducers are not acceptable.

3.12. Fittings

1. Unless otherwise indicated, elbows shall be of the long radius type. 2. Simplify layout so as to keep fittings to a minimum.

3.13. Slopes

1. Refrigerant piping shall be pitched with a slope of not less than 1:240, unless otherwise indicated on the Drawings.

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3.14. Supports, Anchors and Guides

1. General a. Support piping by hangers or other supports as shown on the Drawings or as required at maximum spacing specified below. b. Install necessary anchors and guides in proper relation to expansion swings or bends to control, limit and direct the thrust of expansion in piping. Locate them where shown on the Drawings and elsewhere as required. c. Support independently every pipe that is connected to a fixture or a piece of equipment. d. Copper piping shall not be in contact with steel, iron or ferrous materials. 2. Spacing a. The maximum horizontal spacing of the copper piping supports shall be as follows:

Piping Size Maximum Spacing (inch) (meter) ½ 1.5 ¾ 1.5 1 1.8 1½ 1.8 1 2.4 2 2.4 2 ½ 2.4 3 2.4 4 2.4 6 2.4

3.15. Additional Requirements for the Mechanical Refrigeration

1. Refrigeration work to be done according to CSA B52-M, ASME/ANSI B31.5 code and to ARI and ASHRAE standards using certified frigorists. 2. Welding test in accordance with ASME B31.1.

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3. Use only ACR seamless copper tubing that has been cleaned and sealed at the factory, meeting ASTM B88M and B280 standards. Piping shall remain sealed until it is assembled and connected to the equipment. 4. Fittings to be forged copper or forged brass, conforming to ASTM B16/B16M standards. For connections that need to be dismantled, use flare joints. 5. Circulate dry nitrogen when welding capillary effect. Use an alloy with a maximum melting point of 600oC. Weld pipes and fittings using a Tin/Antimony 96-4 Alloy, such as ”Harris”, ”Stay-Brite”. Prepare joints using a ”Stay-Clean” flux. 6. Supply and install service connections compatible with the use of ”Glo-Stick” leak detection capsules. 7. Install piping for proper oil return to compressors. 8. Suction side branch connections to be done from the main suction pipe crown (top).

3.16. Cleaning

1. Before connecting to equipment, or closing of piping, flush out or otherwise clean piping thoroughly of any foreign matter. 2. Clean refrigerant piping with refrigerant R-11 or R-113. Do not purge refrigerant to atmosphere. Recover the whole refrigerant content using approved refrigerant recovery equipment.

4.0 QUALITY ASSURANCE/QUALITY CONTROL 1. Refer to the Quality Assurance/Quality Control (QA/QC) plan document.

- END OF TECHNICAL SPECIFICATION

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