gold vat leaching design

Report on

GOLD VAT LEACHING DESIGN

Prepared for

PREMIUM GOLD RECOVERY SERVICES

REPORT NO. 100-020

JUNE 2021

∗ Tailings dam engineering and management

∗ Landform engineering and erosion assessment

∗ Geotechnical engineering

∗ Flood assessment

∗ Dam break assessment

Report on


Prepared for

PREMIUM GOLD RECOVERY SERVICES

Revision Date Description Issuer

A 20 May 21 Internal draft report issued for review FG/SL

B 1 Jun 21 Client Review GMcP

REPORT NO. 106-011/1

JUNE 2021

CONTENTS

1 INTRODUCTION 1

2 TERMS OF REFERENCES 1

3 INFORMATION AND MATERIAL PROVIDED 2

4 SITE VISIT AND SITE INVESTIGATION 2

5 LABORATORY TESTING 6

5.1 Particle size distribution and particle density 7

5.2 Atterberg limit tests 7

5.3 Proctor Standard test 8

5.4 Consolidation test – one dimensional 9

5.5 Triaxial permeability test 9

5.6 Multistage drained direct shear test 9

5.6.1 Geotechnical properties 11

6 GEOMETRIC DESIGN 12

6.1 Formation of the vat leach facilities 12

6.2 Geomembrane liner system 13

6.3 Drainage 13

6.4 Leaking detection 14

6.5 Design drawings 14

7 SLOPE STABILITY ASSESSMENT 15

7.1 Slope stability analyses 15

7.1.1 Acceptance criteria 15

7.1.2 Static stability assessment 15

7.1.3 Summary of factors of safety and probabilities of failure 18

8 SCHEDULE OF QUANTITIES AND TECHNICAL SPECIFICATION 18

8.1 Schedule of quantities 18

8.2 Technical specification 20

9 CONCLUSIONS 20

10 RECOMMENDATIONS 21

LIST OF FIGURES

Figure 4-1: Trench locations .................................................................................................. 3

Figure 4-2: Trench 2 on floor ................................................................................................. 4

Figure 4-3: Trench 3 on slope ................................................................................................ 4

Figure 4-4: Trench 7 on the crest ........................................................................................... 5

Figure 4-5: Geological survey of Zelica Mine ......................................................................... 6

Figure 5-1: Particle size distribution ....................................................................................... 7

Figure 5-2: Moisture density relationship ............................................................................... 8

Figure 5-3: Direct shear test results ...................................................................................... 10

Figure 5-4: Interpretation of the direct shear test .................................................................. 11

Figure 6-1: Proposed dividing wall ........................................................................................ 12

Figure 6-2: Vat leach facility - Section A ............................................................................... 13

Figure 6-3: Vat leach facility - Section B ............................................................................... 13

Figure 7-1: Distribution of materials on the analysis .............................................................. 15

Figure 7-2: Minimum FoS for Case 1 - Static conditions ....................................................... 16




LIST OF TABLES

Table 5-1: Atterberg limit test results ..................................................................................... 8

Table 5-2: Consolidation test results ..................................................................................... 9

Table 5-3: Triaxial permeability test report ............................................................................ 9

Table 5-4: Material Strength Parameters .............................................................................11

Table 6-1: List of drawings ....................................................................................................14

Table 7-1: Minimum FoS .....................................................................................................15

Table 7-2: Summary of minimum FoS .................................................................................18

Table 7-2: Schedule of quantities for Stage 1 and Stage 2 ..................................................19

Table 7-2: Schedule of quantities for Stage 3 ......................................................................19

Report No. 100-020 June, 2021


1 INTRODUCTION

Premium Gold Recovery Services (PGRS) is developing the Zelica gold mine, which is located

in Western Australia, 180 km north-east of Kalgoorlie and near the town of Leonora. PGRS are

undertaking modifications to their current vat leach facility. This project entails the design of

the vat leach facility to extract gold from the leachate of the ore. Water, Waste and Land

Australia Pty Ltd (WWL) have been taken on to propose a design of a gold vat leaching facility

for at least 25,000t from the existing infrastructure constructed several years ago.

A site visit was conducted on the 20P

thP of April to survey the site, inspect the present conditions

of the existing facility and take samples for laboratory testing. The proposed vat leach facility

design considers 3 stages of operation. Stage 1 and 2 consist of cells separated by a dividing

wall with 2m height with 300mm of freeboard and an estimated capacity of 5,700 t and 6,500 t

respectively. Stage 3 considers a raise with 3m extra height and 300mm freeboard and an

estimated capacity of 22,500t. The total estimated capacity for the proposed vat leach facility

is 34,700t.

This report describes the design basis, site conditions, vat leach facility layout and storage

characteristics, drainage design and stability analysis of the proposed design. It is important to

note that the designs presented were produced from the survey provided by the client which is

requested to be reviewed. This survey is sufficient to enable design and engineering to

progress to a practical stage, however prior to construction, it is necessary to obtain a more

accurate survey.

2 TERMS OF REFERENCES

The following Terms of Reference apply to this report:

• Carry out a site visit in conjunction with Mr. Angus Moffat of PRGS to inspect and verify the current condition of the existing structure.

Water, Waste and Land Page 2

WWL Report No. 100-020 Gold vat leaching design June 2021

• Receive and analyse detailed survey.

• Propose a laboratory testing programme for geotechnical assessment.

• Prepare a geometric design for a vat leach facility to operate over three stages, with

considerations to upgrade the existing facility. This includes earthworks, liner and drainage design.

• Develop a slope stability assessment for typical section through the facility.

• Prepare drawings for construction1.

• Prepare schedule of quantities and technical specifications.

• Document the above in a report suitable for submission to the Regulator for approvals.

3 INFORMATION AND MATERIAL PROVIDED

The following information has been provided:

• Survey provided by client (Detailed survey to be available later)

• Process design criteria and mass balance report.

• Emergency procedures.

• Zelica Groundwater and surface water management.

• The original design proposal.

Further to this, the results of laboratory testing as specified by WWL have been provided. This

is discussed in Section 5.

4 SITE VISIT AND SITE INVESTIGATION

A site visit was carried out on the 20P

thP of April to inspect the condition of the current facility.

Seven trenches were excavated using a Komatsu PC 300 excavator in the locations shown in

Figure 4-1.

1 Survey needs to be carried out to update the models prior any construction.



Figure 4-1: Trench locations

Two trenches were carried out in the slope, two in the floor and three trenches were carried

out on the crest.

Figure 4-2 shows the condition of the natural ground, while Figure 4-3 and Figure 4-4 show

the condition of existing embankment.



Figure 4-2: Trench 2 on floor

Figure 4-3: Trench 3 on slope



Figure 4-4: Trench 7 on the crest

There are two types of material present at the site: the floor (or natural ground) and the crest

and slope of the facility.

The floor material is a gravelly silt with sand. The material is classified as dry, red-brown in

colour with veins of grey, hard with strong cementation characteristics and blocky in structure.

The material present with medium to high plasticity and is well compacted.

The material on the slope and crest of the embankment is a gravelly silt with sand. The material

is classified as dry, red/orange-brown in colour, medium to strong stiffness with weak

cementation characteristics and homogenous in structure. The material has low compaction.

The geological survey of the area; which is presented in Figure 4-5; shows the material

originates from porphyritic granitoid rock with colluvium overlaying the base.



Figure 4-5: Geological survey of Zelica Mine

5 LABORATORY TESTING

Laboratory testing has been conducted by E-Precision Laboratory. The following lab tests

were completed:

1. PSD (1microns) and SG

2. Atterberg limits

3. Proctor standard

4. Consolidation test – one dimensional

5. Triaxial permeability test

6. Multistage drained direct shear test

The results for each test are detailed individually below, with the reports from E-Precision

Laboratory included in Appendix A.



5.1 Particle size distribution and particle density

A particle size distribution and a particle density test has been conducted on the borrow

material supplied from the Zelica mine. The specific gravity has been measured to be 2.674.

The particle size distribution is presented in Figure 5-1. From the percentage passing, the soil

gradations (gravel 24.2%, sand 17.2%, fines 58.6%) classify the soil sample as a gravelly silt

with sand.

Sieve Size (mm)

Passing %

Sieve Size (mm)

Passing %

150 100 0.05664 56

75 93.4 0.04748 54.5

53 89.7 0.03382 49.8

37.5 86.8 0.02409 45.1

26.5 84 0.01647 39.6

19 80.2 0.01215 33.8

9.5 77.3 0.00867 28.3

4.75 75.8 0.00619 22.1

2.36 74.7 0.0044 17

1.18 72.5 0.00313 11.9

0.6 69.9 0.00222 9.2

0.425 68.3 0.00158 7.2

0.3 66.2 0.00138 6.4

0.15 63 0.00114 5.7

0.075 58.6 0.00097 5.3

Figure 5-1: Particle size distribution

5.2 Atterberg limit tests

The Atterberg limit tests are summarised in Table 5-1. From the USGS soil classification

criteria, the sample is classified as either ML – inorganic silts, clayey silts of low to medium



plasticity or OL - – organic silts and clays, low to medium plasticity, sandy organic silts and

clays. As no organic material was visible within the sample, the soil may be classified as ML.

Table 5-1: Atterberg limit test results

Test Name Values

Liquid Limit 49.06%

Plastic Limit 35.98%

Plasticity Index 13.08%

Shrinkage Limit 28.74%

Linear Shrinkage 4.76%

Classification ML

5.3 Proctor Standard test

The proctor standard test was conducted to determine the moisture content and 95% maximum

dry density. These are: 1.577 t/m3 and 22.55% respectively. Figure 5-2 shows the moisture

density relationship curve with the maximum dry density being equal to 1.660t/mP

3P with an

optimum moisture content of 15.25%.

Figure 5-2: Moisture density relationship



5.4 Consolidation test – one dimensional

A consolidation test was performed on the foundation material in a sample with bulk density of

1.87 t/mP

3P, a moisture of 15.56%, an initial void ratio of 0.657 and a particle density is 2.674

t/mP

3P. The results are presented in Table 5-2.

Table 5-2: Consolidation test results

Stages

Vertical Disp. (mm)

Cv (mP

2P/year) K

(m/s) Cα (10P

-

3P)

Void ratio (ef)

Vertical strain (%) t50 t90

50 kPa 3.80 36.10 - 7.2E-09 0.80 0.559 3.15

100 kPa 6.55 31.31 - 4.7E-09 1.01 0.523 5.43

150 kPa 9.10 21.79 - 3.1E-09 0.61 0.489 7.54

5.5 Triaxial permeability test

A triaxial permeability test was conducted on a sample material of the foundation. The sample

was remoulded at a 95% of the maximum dry density. The results of this test are presented in

Table 5-3.

Table 5-3: Triaxial permeability test report

Cell pressure

Initial dry density (t/mP

3P)

Moisture content (%)

Initial bulk density (t/mP

3P)

K20

(m/s)

50 kPa 1.612 15.54 1.862 3.91 E-08

100 kPa 1.606 15.29 1.852 2.82 E-08

200 kPa 1.613 15.69 1.866 2.25 E-08

5.6 Multistage drained direct shear test

A drained direct shear test was conducted in a remoulded sample of the foundation material

for a confinement pressure of 50, 100 and 200 kPa. The remoulded sample had an initial bulk

density of 1.87 t/mP

3P, a moisture content of 15.39% and a particle density of 2.674 t/mP

3P. The

interpretation gives the following results:

• Peak resistance: Cohesion (49.2 kPa) and Shear angle (30.11°)

• Residual resistance: Cohesion (43.78 kPa) and Shear angle (25.69°)

Note that the cohesion of both values is high. The normal displacement in Figure 5-3 indicates



that the sample dilated on shearing, which causes the material to desaturate. As a result, it is

11

Water, Waste and Land Page


expected that 50% or more of the calculated cohesion may be a result of pore suction and

apparent cohesion. The real cohesion is unlikely to be greater than 20kPa, however this needs

to be verified.

The graphs of the normal displacement vs. shear displacement and shear stress vs. shear

displacements are presented in Figure 5-3. Figure 5-4 shows the interpretation of the direct

shear test.

Figure 5-3: Direct shear test results

12



Figure 5-4: Interpretation of the direct shear test

5.6.1 Geotechnical properties

In modelling the stability of the proposed design, two materials have been defined. These are

as follows:

• Foundation material: Which corresponds to the natural soil present on the existing trenches.

• Remolded fill: This material corresponds to the compacted foundation material placed on the trenches in order to build the final slopes.

The geotechnical parameters used in the stability assessment as derived from the lab testing

are presented in Table 5-4.

Table 5-4: Material Strength Parameters

Material Bulk unit weight,

(kN/m3)

Dry unit weight,

(kN/m3)

Cohesion,

(kN/m2)

Friction Angle

(°)

Foundation Material 20 18 8 30

Existing wall 18.5 16 5 30

Bench 18.2 15.9 5 30

Process Liquor Solution N/A N/A N/A N/A

13



6 GEOMETRIC DESIGN

The geometrical design details for the vat leach facility, liner and drainage system are detailed

in the sections below.

6.1 Formation of the vat leach facilities

A plan view of the vat leach facility is shown in Figure 6-1 and drawing 100-020-101 in

Appendix B.

It is proposed to modify the existing structure to allow for 3 stages of development within the

existing structures. A dividing wall will be erected to split the current structure into two cells:

Cell 1 and Cell 2. Stage 1 will entail placement of agglomerated ore into Cell 1 to 2m, Stage

2 will fill Cell 2 to 2m and Stage 3 will fill over the dividing wall to reach a total depth of ore of

5m. All stages will include 300mm of freeboard.

Figure 6-1: Proposed dividing wall

The dividing wall will be constructed to an elevation of RL454m with a crest width of 3m, and

a height of 2m with internal and external slopes of 1V:1.5H.

The cross section for section A and B are presented in Figure 6-2 and Figure 6-3 respectively.

Drawings: 100-020-102 and 100-020-103 in Appendix B show these cross-sections in detail.

14



Figure 6-2: Vat leach facility - Section A

Figure 6-3: Vat leach facility - Section B

6.2 Geomembrane liner system

The high density polyethylene (HDPE) liner will cover the whole area inside the vat leaching.

HDPE liner will also be installed on the dividing wall. The HDPE will be 1mm thick.

6.3 Drainage

The drainage system uses slotted concrete sumps to collect the seepage of the solution to be

drained out through a pump. It is proposed that the drainage sumps be place to the following

specifications:

• The slope will be 2% from the centre to the embankment in both directions.

• The sumps will be 1m in diameter, with 12 installed in total.

• The top of the sumps will be RL457m in elevation.

• The lower ring of the sump will be open to ensure only the lower liquor that has had time to dissolve the gold will drain.

• The upper rings will be closed.

• Geonet material place around the slot to prevent ore from penetrating the slots.

15



• To avoid zones of dead storage, the sumps will be countersunk so the slot is level with the base of the floor.

6.4 Leaking detection

A sub-drain system will be placed below liner on the floor as shown in the drawing 100-020-

104. This is a bone fish system to collect any leaking and divert to a sump. A sump receiving

fluid signifies that a leak exists and repair work must be conducted to fix the issue.

The sub-drain from the cross section indicated in Figure 6-4 uses a drain liner of 500x500mm

with slotted pipe of 100mm and a gravel cover.

Figure 6-4: Sub-drainage system cross-section

6.5 Design drawings

Drawings have been prepared for construction.

A list of drawings is shown in the Table 6-1. The drawings are included in Appendix B.

Table 6-1: List of drawings

Drawing Name

100-020-101 Zelica vat leach facility - General Layout

100-020-102 Zelica vat leach facility - Sections

100-020-103 Zelica vat leach facility - Details

100-020-104 Zelica vat leach facility - Leakage detection

system

16



7 SLOPE STABILITY ASSESSMENT

7.1 Slope stability analyses

Limit equilibrium stability analyses have been conducted on the slopes of the cells using the

software SLOPE/W by Geoslope.

7.1.1 Acceptance criteria

Slope stability factors of safety (FoS) are to be in accordance with ANCOLD2. Consolidated

factors of safety are as indicated in Table 7-1.

Table 7-1: Minimum FoS

Condition Minimum FoS

Static long term drained effective stress analysis (ESA) 1.5

Static short term consolidated undrained strength analysis with potential loss of containment (USA) 1.5

7.1.2 Static stability assessment

A typical distribution of the materials is presented in Figure 7-1.

Figure 7-1: Distribution of materials on the analysis

The stability analyses conducted consider 4 cases. These are described as follows:

2 Australian National Committee on Large Dams Incorporated provides comprehensive guidelines on planning, design, construction, operation and closure of tailings dams

17



• Case 1 - Stability of slope for completed initial benches with no process liquor in the cells.

• Case 2 - Stability of slope for completed initial benches with cells full of process liquor.

• Case 3 - Stability of slope for completed final benches with cells partially full of liquor.

• Case 4 - Stability of slope for completed initial benches with cells full of process liquor.

The stability assessment results for each of these are detailed below respectively.

Case 1: First Stage - Initial condition

Figure 7-2 shows the results of the stability analysis for Case 1 under static conditions. The

FoS for this analysis is 2.67.

Figure 7-2: Minimum FoS for Case 1 - Static conditions

Case 2: First Stage - Final condition



18




Case 3: Second Stage - Initial condition


minimum FoS is 1.98.


Case 4: Second Stage - Final condition



19




7.1.3 Summary of factors of safety and probabilities of failure

Values of minimum FoS for static conditions are summarised in Table 7-2.

Table 7-2: Summary of minimum FoS

Condition

Minimum FoS

ANCOLD guidelines Case 1 Case 2 Case 3 Case 4

Static 1.5 2.67 4.83 1.98 4.19

The results in Table 7-2 indicate adequate stability of the slopes for all cases as minimum

factors of safety are above the minimum values specified in ANCOLD guidelines.

8 Schedule of quantities and technical specification

8.1 Schedule of quantities

The schedule of quantities for the proposed stages of design are shown below for the required

earthworks, liner installation and sub-drainage system. Table 8-1 details the quantities for

stages 1 and 2 of the design and Table 8-2 details the quantities for stage 3. Note that cost

and rate have been left blank pending review. These will be updated prior to construction.

20



Table 8-1: Schedule of quantities for Stage 1 and Stage 2

Item

Description

Unit

Quantity

Rate

Cost

1 USite preparation

Strip 200mm topsoil and stockpile at approved stockpile sites within 3km of the facility as specified including doze, stockpile, load, haul and dump to 2m max height and finish as specified or as directed by the Company Representative. Rate to include preparation of disposal sites and all associated stormwater management and erosion control facilities for:

UCutting of interior slope of embankment

Cut inside face of existing facility an average of 1.4m from crest, load, haul and stockpile for construction material as specified or as directed by the Company Representative:

UEarthworks

Fill boundary embankment - moisture conditions and compacted at 95%SMDD at moisture 22 to 25%. In layers of 250mm. Fill divided embankment - moisture conditions and compacted at 95%SMDD at moisture 22 to 25%. In layers of 250mm. Floor - scrape, moisture conditions and compacted at 95%SMDD. Top layer of 200mm. Excavate anchor trench for liner 500x500mm Fill anchor trench - moisture conditions and compacted at 95%SMDD at moisture 22 to 25%.

ULiner installation

Supply and install approved liner including cutting to the required width, joining, installing etc. as specified or as directed by the Company Representative for:

USump installation

Install slotted sumps 1m in diameter, countersunk into the foundation Apply geonet around slot of sump.

ULeakage Detection system

Excavate sub-drain network Install drain liner material, slotted pipe and cover with gravel Install one sump to monitor leakage

Sub-total

1.1

m3

960

2

2.1

m3

3,382

3

3.1

m3

2,787

3.2

m3

438

3.3

m3

3.4 m3 54

3.5 m3 321

4

4.1

m2

7,105

5

5.1 Units 12

5.2 m2

6

6.1 m 280 6.2 m 280 6.3 Units 1

Table 8-2: Schedule of quantities for Stage 3

21



Item

Description

Unit

Quantity

Rate

Cost

1 UEarthworksU t Excavate, load and Transport from borrow material area into 3km from facility Fill boundary embankment - moisture conditions and compacted at 95%SMDD at moisture 22 to 25%. In layers of 250mm. Excavate anchor trench for liner 500x500mm Fill anchor trench - moisture conditions and compacted at 95%SMDD at moisture 22 to 25%.

USupply and install approved liner including cutting to theU Urequired width, joining, installing etc. as specified or asU Udirected by the Company Representative for:

Cell 3

URaise slotted sumps to maximum height of

5mU Raise slotted sumps

Sub-total

1.1

m3

3,023

1.2

m3 3,023 1.3 m3 57 1.4

m3

57

2

2.1

m2

2,648

3

3.1 Units 12

8.2 Technical specification

The technical specifications for the design include:

• Earthworks

• HDPE liner

These are discussed in detail in Appendix C.

9 CONCLUSIONS

In the course of this vat leach facility design, the following have been completed and

documented in this report:

• Design of a vat leach facility to be operated in three stages with Stage 1, 2 and 3 with

respective cell heights of 2m, 2m and 5m and respective capacities of 5,700t, 6,500t

and 22,500t. Each stage will include 300mm of freeboard.

• Incorporation of a geomembrane liner to prevent leakage of process liquor.

• Design of sub-drainage system for leak detection.

22



• Design of a drainage system using 12 concrete slotted slump of 1m diameter for liquor extraction.

• Stability assessments conducted for each stage of development, showing the Factor of Safeties much larger than the required 1.5.

• Quantity schedules for the three stages of development.

• Technical specifications for the earthwork and geomembrane liner.

10 RECOMMENDATIONS

It is recommended that consideration be given to constructing the vats based on the drawings, schedules and specifications provided in this report.

Dr G I McPHAIL MIEAust CPEng RPEQ R M UGAZ MIEAust

For and on behalf of

Water, Waste and Land Australia Pty Ltd

23



APPENDIX A – LABORATORY TESTING

Pass

ing

(%)

PARTICLE SIZE DISTRIBUTION TEST REPORT Test Method: AS 1289 3.6.3 3.5.1

Client: WWL Engineering Pty Ltd Date Tested: 11/05/2021 Project: Premium Gold EP Lab Job Number: WWL Sample No: Soils Sample 1 Depth(m): - Lab_ID: PREMIUM_GOLD_WWL21_PSD Room Temperature at Test: 19°C

Tested by: Kohei 2.36mm Particle Density (t/m³): 3.059 Checked by: Phil

Sieve Size (mm) Passing % PSD Graph 150 100.0

100.0

90.0

80.0

70.0

60.0

50.0

40.0

30.0

20.0

10.0

0.0 0.001 0.01 0.1 1 10 100 1000

Particle Size(mm)

75 93.4 53 89.7

37.5 86.8 26.5 84.0 19 80.2 9.5 77.3

4.75 75.8 2.36 74.7 1.18 72.5 0.6 69.9

0.425 68.3 0.3 66.2

0.15 63.0 0.075 58.6

0.05664 56.0 0.04748 54.5 0.03382 49.8 0.02409 45.1 0.01647 39.6 0.01215 33.8 0.00867 28.3 0.00619 22.1 0.00440 17.0 0.00313 11.9 0.00222 9.2 0.00158 7.2 0.00138 6.4 0.00114 5.7 0.00097 5.3

Notes: Stored and Tested the Sample as received Samples supplied by the Client Authorized Signature:

The results of tests performed apply only to the specific sample at time of test unless otherwise clearly stated. Reference should be made to E- Precision Laboratory's "Standard Terms and Conditions" E-Precision Laboratory ABN 431 559 578 87

Integrity Precision Innovation

Perth Unit 3, 34 Sphinx Way

Bibra Lake WA 6163

Ph: (08) 9418 8742 E-mail: [email protected]

Mob: 0422 814 231

Integrity Precision Innovation Page 1 of 1

Pene

trat

ion

(mm

)

ATTERBERG LIMITS TEST REPORT Test Method: BS1377 AS1289.2.1.1 7.1.1 3.1.1 3.2.1 3.4.1

Client: WWL Engineering Date Tested: 12/05/2021 Project: Premium Gold Lab: EPLAB Sample No: Soil Sample Job Number: WWL Lab ID: PREMIUM_GOLD_WWL21_ATT Depth(m): - Room Temperature at Test: 20°C Tested by: Raymond Sample Description: - Moisture Content (%): - Wet Density (t/m³): -

Dry Density (t/m³): - Liquid Limit (%): 49.06 Plastic Limit (%): 35.98

Plasticity Index (%): 13.08 Liquidity Index (%): -

Shrinkage Limit (%): 28.74 Linear Shrinkage(%): 4.76

Results Chart 100

10

1

1 10 100 Water Content (%)

UNotes:U The sample/s were tested oven dried, dry sieved and in a 125-250mm mould.

Stored and Tested the Sample as received Samples supplied by the Client Authorised Signature:


mailto:[email protected]


Dry

Dens

ity (t

/m³)

MOISTURE DENSITY RELATIONSHIP REPORT Test Method: AS1289.5.1.1

Client: WWL Engineering Date Tested: 11/05/2021 Project: Premium Gold Lab: EPLAB Sample No: Soil sample Job Number: WWL Lab ID: PREMIUM_GOLD_WWL21_SMDD Depth(m): - Room Temperature at Test: 20ᵒC Checked by: Phil Sample Description: Tested in Mould B Moisture Content (%): - Wet Density (t/m³): -

Dry Density (t/m³): -

Results

Maximum Size (mm): 37.50 Maximum Dry Density (t/m³): 1.700 Oversize dry (%): 13.20 Optimum Moisture Content (%): 15.00

2.8 0 Air Voids Line

2.6

2.4

2.2

2

1.8

1.6

1.4

1.2

1 0 5 10 15 20 25 30 35 40

Moisture Content (%)

UNotes:U * Particle density 2.674 t/m³ Stored and Tested the Sample as received Samples supplied by the Client Authorised Signature:



CONSOLIDATION - ONE DIMENSION Method: AS1289 6.6.1 / Inhouse Method

Client: WWL Engineering Date Tested: 14/05/2021 Project: Premium Gold Sample ID: Soil Sample EP Lab Job Number: WWL Lab ID: PREMIUM_GOLD_WWL21_OED Lab: EPLab Depth (m): - Room Temperature at Test: ~ 19°C

Tested by: Phil Initial Moisture (%): 15.56 Test Condition: Saturated Height (mm): 120.64 Final Moisture Content (%): 26.44 Sample Condition: Insitu Diameter (mm): 61.80 Bulk Density (t/m³): 1.87 Particle Density (t/m³): 2.674 Direction: Vertical Dry Density (t/m³): 1.61 Initial Void Ratio (eRiR): 0.657

Void Ratio (eRfR) Vs Log of Vertical Pressure (kPa)

0.80

0.75

0.70

0.65

0.60

0.55

0.50

0.45

0.40

0.35

0.30 1 10 100 1000

Log Vertical Pressure (kPa)

Void

Rat

io (e

f)



Client: WWL Engineering Date Tested: 14/05/2021 Project: Premium Gold Location: Soil Sample EP Lab Job Number: WWL Lab ID: PREMIUM_GOLD_WWL21_OED Lab: EPLab Depth (m): - Room Temperature at Test: ~ 19°C

Vertical Strain (%) Vs Log of Vertical Pressure (kPa) 1 10 100 1000

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

Log Vertical Pressure (kPa)

Vert

ical

Str

ain

(%)



Client: Project: Sample ID: Lab ID: Depth (m):

WWL Engineering Premium Gold Soil Sample PREMIUM_GOLD_WWL21_OED -

Date Tested: EP Lab Job Number: Lab: Room Temperature at Test:

14/05/2021

WWL EPLab

~ 19°C *

UTest Results

Stages Vert Disp

(mm) Cv (m²/yr) Compressibility

Mv (m²/kN) K (m/s) Cα (10P

-3P)

Void Ratio (eRfR)

Vertical Strain (%) t50 t90

Stage 1 @ 50kPa 3.80 36.104 - 6.30E-04 7.2E-09 0.80 0.559 3.15 Stage 2 @ 100kPa 6.55 31.308 - 4.71E-04 4.7E-09 1.01 0.523 5.43 Stage 3 @ 150kPa 9.10 21.787 - 4.47E-04 3.1E-09 0.61 0.489 7.54

* Values interpreted via lab only

Comments: Sample remolded to 95% SMDD @ OMC Cv values to be interpreted via Engineer

S



Cv (m

²/yr

) M

v (m

²/kN

)


Client: WWL Engineering Date Tested: 14/05/2021 Project: Premium Gold Sample ID: Soil Sample EP Lab Job Number: WWL Lab ID: PREMIUM_GOLD_WWL21_OED Lab: EPLab Depth (m): - Room Temperature at Test: ~ 19°C

Cv (m²/yr) Vs Log of Vertical Pressure (kPa)

1 10 100 1000 0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

Log Vertical Pressure (kPa) * Plot based on Log (time) data

Mv (m²/kN) Vs Log of Vertical Pressure (kPa) 1 10 100 1000

0.0E+00

1.0E-04

2.0E-04

3.0E-04

4.0E-04

5.0E-04

6.0E-04

7.0E-04 Log Vertical Pressure (kPa)



Client: Project:

WWL Engineering Premium Gold

Date Tested: 14/05/2021

Sample ID: Soil Sample EP Lab Job Number: WWL Lab ID: PREMIUM_GOLD_WWL21_OED Lab: EPLab Depth (m): - Room Temperature at Test: ~ 19°C

UStage 1 @ 50kPa

Square Root Time (min)

120.00

119.50

119.00

Log Time

Square Root Time

118.50

118.00

117.50

117.00

116.50 0.001 0.01 0.1 1 10 100 1000 10000

Log Time (min)

Vert

ical

Rea

ding

(m

m)



Client: Project:




UStage 2 @ 100kPa Square Root Time (min)

117.00

116.50

116.00

Log Time

Square Root Time

115.50

115.00

114.50

114.00

113.50 0.001 0.01 0.1 1 10 100 1000 10000

Log Time (min)

Vert

ical

Rea

ding

(mm

)



Client: Project:




UStage 3 @ 150kPa

Square Root Time (min)

113.20

113.00

112.80 Log Time

Square Root Time

112.60

112.40

112.20

112.00

111.80

111.60

111.40 0.001 0.01 0.1 1 10 100 1000 10000

Log Time (min)

Vert

ical

Rea

ding

(m

m)

of 3 Integrity Precision Innovation

TRIAXIAL PERMEABILITY TEST REPORT Test Method: AS1289 6.7.3 / KH. Head

Client: WWL Engineering Date Tested: 14/05/2021 Project: Premium Gold Date Reported: 21/05/2020 Lab: EPLAB EP Lab Job Number: WWL Tested by: Phil Checked by: Phil

Lab ID: PGOLD_01_TP PGOLD_02A_TP PGOLD_03B_TP

Client ID: Soil Sample Soil Sample Soil Sample

Sample Depth (m): - - -

Sample Conditions: Remolded @ 95% MMDD

Remolded @ 95% MMDD

Remolded @ 95% MMDD

Diameter / Height (mm): 61.80 / 122.54 61.80 / 124.39 61.80 / 120.07

Effective Cell Pressure (kPa):

50

100

200

Inlet Pressure / Outlet Pressure (kPa):

50 / 25

50 / 25

50 / 25

Initial Bulk Density(t/m³):

1.862

1.852

1.866

Moisture Content (%): 15.54 15.29 15.69

Initial Dry Density(t/m³): 1.612 1.606 1.613

Saturation (Skempton's B):

1.00

1.00

1.00

KR20R (m/s): 3.909 EP

-8 2.819 EP

-8 2.253 EP

-8

UNotes: Stored and Tested the Sample as receSamples supplied by the Client NATA: 19078

The results of tests performed apply only to the specific sample at time of test unless otherwise clearly stated. Reference should be made to E-Precision Laboratory's "Standard Terms and Conditions" E-Precision Laboratory ABN 431 559 578 87



Client: WWL Engineering Date Tested: 14/05/2021 Project: Premium Gold Date Reported: 21/05/2020 Lab: EPLAB EP Lab Job Number: WWL

8.0E-08

7.0E-08

PGOLD_01_TP

PGOLD_02A_TP

PGOLD_03_TP

6.0E-08

5.0E-08

4.0E-08

3.0E-08

2.0E-08

1.0E-08

0.0E+00 1 10 100 1000 10000

Log Time (min)

Notes: Stored and Tested the Sample as received Samples supplied by the Client

Authorised Signatory (Geotechnical Eng


Perm

eabi

lity

K (m

/s)



Client: WWL Engineering Date Tested: 14/05/2021 Project: Premium Gold Date Reported: 21/05/2020 Lab: EPLAB EP Lab Job Number: WWL

Sample Photo

UNotes: Stored and Tested the Sample as received Samples supplied by the Client

Authorised Signatory (Geotechnical Engin



Nor

mal

Dis

plac

emen

t (m

m)

Shea

r Str

ess

(kPa

)

MULTISTAGE DRAINED DIRECT SHEAR TEST REPORT Method: AS1289.6.2.2 / In-house Method

Client: WWL Engineering Date Tested: 14/05/2021 Project: Premium Gold EP Lab Job Number: WWL Sample No: Soil Sample Lab: EPLab Sample ID: PREMIUM_GOLD_WWL21_DDST3 Depth (m): - Room Temperature at Test: 20°

Type of Test: Intact Multistage Drained Sample Description: Remolded Dimensions (mm): 100 x 100 UParticle Density (t/m³):U 2.674

Rate of Strain (mm/min): 0.055 Initial Bulk Density (t/m³): 1.87

Failure Criteria: Horizontal Shear Moisture Content (%): 15.39 UNormal Displacement Vs Shear Displacement Plot

0.5

0.4

0.3 Stage 1

0.2

Stage 2

0.1 Stage 3

0

0 2 4 6 8 10 12 14 16

-0.1

Shear Displacement (mm)

UShear Stress Vs Shear Displacement Plot

180

160

140

120

100 Stage 1

80 Stage 2

60 Stage 3

40

20

0 0 2 4 6 8 10 12 14 16

Shear Displacement (mm)


Shea

r Str

ess (

kPa)



U(Peak / Ultimate) Normal Stress Vs Shear Stress 180

Peak Stress

160

Ultimate / Residual Stress y = 0.4806x + 43.783 140

Stage 1 R² = 0.9949

120 Stage 2

Stage 3 100

y = 0.579x + 49.188 R² = 0.997

80

60

40

20

0 0 50 100 150 200 250

Normal Stress (kPa)

UDefect SurfaceU N/A UDip Angle (°):U 2.674

Peak Shear Angle (ᵒ) 30.11 Normal Stress (kPa) Shear Stress (kPa) Cohesion (kPa) 49.19

R² 0.9970 Stage 1 51 Stage 1 77 Stage 2 103 Stage 2 111 Stage 3 204 Stage 3 166

Ultimate / Residual

Shear Angle (ᵒ) 25.69 Cohesion (kPa) 43.78

Normal Stress (kPa) Shear Stress (kPa) Stage 1 57 Stage 1 69 Stage 2 113 Stage 2 102 Stage 3 226 Stage 3 151

R² 0.9949




UPhoto of Sample Post Testing ( bottom shear box)

UNotes:U Sample remoulded as requested by client to 95% MDD @ OMC Stored and Tested the Sample as received Samples supplied by the Client

Authorised Signature (Geotechnical Engineer):

The results of tests performed apply only to the specific sample at time of test unless otherwise clearly stated. Reference should be made to E-Precision Laboratory's "Standard Terms and Conditions" E-Precision Laboratory ABN 431 559 578 87




UConsolidation Graph (Axial Deformation Vs Log Time)

0.001

0.01 0.1

0

0.5

1

1.5

2

2.5

3

3.5

4

1 10 100

Log Time (min)

Axia

l Def

orm

atio

n (m

m)

23


APPENDIX B – DRAWINGS


N

2m HIGH BENCH

U A 102

EXISTING EMBANKMENT CREST

6,767,700 mN

CELL 2

SUMP 1m Ø (TYPICAL)

CELL 1

U B 102

DIVIDER WALL

6,767,600 mN

0 10m 20m 40m 60m

SCALE 1:1,000 ISSUED FOR INFORMATION ONLY

PREMIUM GOLF RECOVERY SERVICES

ZELICA VAT LEACH FACILITY GENERAL LAYOUT

DWG. NUMBER

TITLE

COORDINATE SYSTEM PROJECTION: UTM ZONE 51J

DATUM: MGA94

SCALE

1:1,000

SHEET SIZE

A3

NAME

DATE

DRAWN

12-05-2021

CHECKED

12-05-2021

APPROVED DRAWING NO. 100-020-101

REV.

B FRANCISCO GARCIA TRAVIS DEGOIS

421,000 mE

420,500 mE

420,000 mE

419,500 mE

REF

EREN

CES

REV

ISIO

NS

B 27.05.21 INTERNAL REVIEW T.D F.G

A 12.05.21 INTERNAL REVIEW T.D F.G

No. DATE DESCRIPTION BY CHKD

475m

470m

465m

460m

455m

450m

CUT EXISTING EMBANKMENT (3382m³)

200mm TOPSOIL STRIP (960m³)

475m

470m

465m

460m

455m

450m



445m

440m

DETAIL

1

103

445m

440m

10m 20m 30m 40m 50m 60m 70m 80m 90m 100m 110m 120m 130m 140m 150m 160m 170m 180m 190m 200m 210m 10m 20m 30m 40m 50m 60m 70m 80m

475m

470m

465m

460m

455m

2m HIGH BENCH (2787m³)

LINER

DIVIDER WALL (438m³)

SLOTTED SUMP 1m Ø (TYPICAL)

475m

470m

465m

460m

455m

2m HIGH BENCH (2787m³)

LINER

450m

445m

440m

DETAIL

2 103

DETAIL

3 103

450m

445m

440m

2% 2%


475m

470m

465m

460m

455m

300mm FREEBOARD

CELL 1 (5,707t)

LINER

300mm FREEBOARD

CELL 2 (6,512t)

300mm FREEBOARD

475m

470m

465m

460m

455m

300mm FREEBOARD

CELL 1 (5,707t)

LINER

450m

445m

440m

DETAIL

4 103

DETAIL

5 103

450m

445m

440m

2% 2%


475m

470m

465m

460m

455m

450m

445m

440m

FINAL BENCH (3,023m³)

300mm FREEBOARD

DETAIL

6 103

CELL 3 (22,456t) LINER

DETAIL

7 103

300mm FREEBOARD

475m

470m

465m

460m

455m

450m

445m

440m


300mm FREEBOARD

CELL 3 (22,456t)

2% 2%

LINER


SECTION SCALE 1:1,000

A

101

SECTION THROUGH VAT LEACH BULK EARTHWORKS

SECTION SCALE 1:1,000

B

101

SECTION THROUGH VAT LEACH BULK EARTHWORKS

ISSUED FOR INFORMATION ONLY

ELEV

ATIO

N (R

L)

ELEV

ATIO

N (R

L)

ELEV

ATIO

N (R

L)

ELEV

ATIO

N (R

L)

ELEV

ATIO

N (R

L)

ELEV

ATIO

N (R

L)

ELEV

ATIO

N (R

L)

ELEV

ATIO

N (R

L)

PREMIUM GOLF RECOVERY SERVICES ZELICA VAT LEACH FACILITY

SECTIONS


DATUM: MGA94

SCALE

1:1,000

SHEET SIZE

A3

NAME

DATE

DRAWN

12-05-2021

CHECKED

12-05-2021


REV.


REV

ISIO

NS

REF

EREN

CES

100-020-103 ZELICA VAT LEACH FACILITY - DETAILS

100-020-101 ZELICA VAT LEACH FACILITY - GENERAL LAYOUT

DWG. NUMBER TITLE

EXISTING EMBANKMENT 1.4m


LINER TIE-IN TRENCH

0.5m

LINER


0.5m

DETAIL SCALE 1:200

1

102

DETAIL OF OUTER EMBANKMENT CUT

DETAIL SCALE 1:50

8 DETAIL OF LINER TIE-IN TRENCH -

3.0m 2m HIGH BENCH (2787m³) DIVIDER WALL (438m³)

SLOTTED SUMP 1m Ø

SLOTTED SUMP 1m Ø


(TYPICAL) (TYPICAL)

DETAIL 8 -

LINER LINER

DETAIL SCALE 1:200

2 102

DETAIL OF OUTER EMBANKMENT BENCH AND SUMP DETAIL SCALE 1:200

3 102

DETAIL OF DIVIDER WALL AND SUMPS

LINER

300mm FREEBOARD

CELL 1 (5,707t)

CELL 1 (5,707t)

LINER

300mm FREEBOARD 300mm FREEBOARD

CELL 2 (6,512t)

DETAIL SCALE 1:200

4 102

DETAIL OF OUTER EMBANKMENT CELL 1 FILL



DETAIL SCALE 1:200

5 102

DETAIL OF DIVIDER WALL CELL 1 & 2 FILL

3.0m

300mm FREEBOARD LINER

CELL 3 (22,456t)


CELL 3 (22,456t) SLOTTED SUMP 1m Ø (TYPICAL)

DETAIL SCALE 1:200

6 102

DETAIL OF OUTER BENCH RAISE AND CELL 3 FILL DETAIL SCALE 1:200

7 102

DETAIL OF DIVIDER WALL CELL 3 FILL LINER

0.5m


PREMIUM GOLF RECOVERY SERVICES ZELICA VAT LEACH FACILITY

DETAILS


DATUM: MGA94

SCALE

1:1,000

SHEET SIZE

A3

NAME

DATE

DRAWN

12-05-2021

CHECKED

12-05-2021


REV.


REV

ISIO

NS

REF

EREN

CES

100-020-102 ZELICA VAT LEACH FACILITY - SECTIONS

DWG. NUMBER TITLE




N

LEAKAGE DETECTION SUMP

LEAKAGE DETECTION PIPE

6,767,700 mN

EXISTING EMBANKMENT CREST U C

-

GRAVEL

100mm Ø HDPE PIPE

50mm SAND BEDDING

SECTION SCALE 1:20

0.50

C SECTION THROUGH LEAKAGE DETECTION PIPE -

6,767,600 mN

0 10m 20m 40m 60m

SCALE 1:1,000


PREMIUM GOLF RECOVERY SERVICES ZELICA VAT LEACH FACILITY LEAKAGE DETECTION SYSTEM


SCALE

1:1,000

SHEET SIZE

A3

NAME DATE

DRAWN

420,500 mE

420,000 mE

419,500 mE

REF

EREN

CES

REV

ISIO

NS

0.50

100-020-102 ZELICA VAT LEACH FACILITY - SECTIONS

DWG. NUMBER TITLE




12-05-2021

CHECKED

12-05-2021

APPROVED

DRAWING NO.

100-020-104

REV.

B

FRANCISCO GARCIA TRAVIS DEGOIS

24


APPENDIX C – TECHNICAL SPECIFICATIONS


WWL Project No. 100-020 Zelica Mine Vat Leaching Facility Construction Technical Specification

May 2021

TECHNICAL SPECIFICATION FOR

EXCAVATION, EARTHWORKS, DRAINAGE AND LINER INSTALLATION

FOR CONSTRUCTION OF PREMIUM GOLD RECOVERY SERVICES ZELICA MINE GOLD VAT LEACHING FACILITY

REV DATE DESCRIPTION AUTHOR A 27 May 2021 Draft for Internal review SL

Page i

WWL Report No. 100-020 Zelica Mine Vat Leaching Facility Construction Technical Specification

May 2021

1 INTRODUCTION 1 3

2 TERMS OF REFERENCES 1 3

3 INFORMATION AND MATERIAL PROVIDED 2 3

4 SITE VISIT AND SITE INVESTIGATION 2 3

5 LABORATORY TESTING 6 3

6 GEOMETRIC DESIGN 12 3

7 SLOPE STABILITY ASSESSMENT 15 3

8 SCHEDULE OF QUANTITIES AND TECHNICAL SPECIFICATION 18 4

9 CONCLUSIONS 20 4

10 RECOMMENDATIONS 21 4

1. GENERAL 1

2. DEFINITIONS 1

3. PRECEDENT OF CONTRACT DOCUMENTS 2

4. CODES AND STANDARDS 3

5. ABBREVIATIONS 5

6. DRAWINGS 5

7. SITE INSPECTION 5

8. WORKPLACE HEALTH, SAFETY AND ENVIRONMENT 6

9. SITE ESTABLISHMENT AND DISESTABLISHMENT 6

10. EQUIPMENT AND LABOUR 7

11. CONSTRUCTION PROGRAMME 7

12. LEGAL RELATIONSHIPS AND RESPONSIBILITY TO THE PUBLIC 7

13. CONTRACTOR SUBMITTALS 8

PART A: EARTHWORKS AND DRAINAGE 9

14. GENERAL SETTING OUT 9

15. EXISTING SERVICES AND CLIENT PERMITS 11

16. CONSTRUCTION CONTROL POINTS (HOLD POINTS) 12

17. ENVIRONMENTAL CONTROLS 12

18. DE-WATERING 13

19. STRIPPING AND STOCKPILING OF VEGETATION AND TOPSOIL 14

20. SPOIL DISPOSAL 14

21. MEASUREMENT AND CLASSIFICATION OF EXCAVATION MATERIALS 15

22. “OVERBREAK” 15

23. OVER-EXCAVATION 16

24. SAFETY PRECAUTIONS IN EXCAVATIONS 16

25. CONTRACTOR’S LIABILITY IN EXCAVATION 17

26. FALL IN OF GROUND 17

27. UNAUTHORISED EXCAVATIONS 17

28. EXCAVATIONS TO BE PASSED 17

Page ii


May 2021

29. EXCAVATION OF THE EARTHFILL EMBANKMENT KEY TRENCH 18

30. EXCAVATION OF UNSUITABLE FOUNDATION MATERIAL 18

31. EXCAVATION OF STORMWATER DRAINAGE TRENCHES 19

32. BORROW AREAS 19

33. HAULAGE 21

34. BACKFILLING 21

35. PREPARATION OF FOUNDATIONS 22

36. CONSTRUCTION OF EARTHFILL EMBANKMENTS 22

37. COMPACTION OF EMBANKMENTS TO A SPECIFIED DENSITY 23

38. COMPACTION TO A PERFORMANCE SPECIFICATION 27

39. FINISH OF EARTHWORKS AND TOLERANCES 28

40. MEASUREMENT AND PAYMENT 28

PART B: PE LINER INSTALLATION 31

41. PE LINER MATERIALS 31

42. QUALITY CONTROL 31

43. LINER WARRANTY 37

44. LINER PANEL LAYOUT DRAWING 37

45. AREAS TO BE LINED 38

46. LINER INSTALLATION 38

47. JOINING OF LINERS 39

48. INSPECTIONS, TESTING AND REPAIR 41

49. CLEANING UP 46

50. ACCEPTANCE CRITERIA 46

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May 2021

1. GENERAL

This Specification defines the minimum technical requirements earthworks and liner systems for the gold vat leach facility at Premium Gold Recovery Services’ (PGRS) Zelica Mine Project.

2. DEFINITIONS

For the purpose of this project, the following terms are applied.

Table 2-1: Definitions include in the Specification

TERM DEFINITION

Approval Approval from the Company in writing.

Approved Approved by the Company in writing.

As directed As directed by the Company in writing.

Company Zelica Mine Project.

Company Representative

The Company Representative is the person(s) nominated by the Company as the project’s Project Manager or their nominated Construction Supervisor. The Company Representative reports to the Principals Project Superintendent or nominated Manager.

Construction Supervisor

The Construction Supervisor is the Principals appointed Representative, approved by the Project Superintendent, to ensure the Works are carried out according to the design as set out on the IFC Drawings and in this Construction Specification.

Contractor The Party awarded the Contract to complete the Works.

CQA Inspector Construction Quality Assurance (CQA) Inspector(s), is the Design Consultants Representative, approved by the Principal and is responsible for construction quality inspections to ensure the works are being completed to the requirement of this Specification.

Drawings Drawings and sketch drawings, supplied by the Company and included in the Contract, and as revised and reissued as revisions as necessary through the duration of the Works.

Engineer Company’s design engineer. Nominally the Engineering Manager or Consulting Engineer under the Engineering Managers delegated authority.

Hold Point An identified point in the Construction process/sequence where the Contractor(s) must halt work to provide required information to the Company Representative. The Contractor(s) must not resume work until the Hold

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May 2021

TERM DEFINITION

Point is released, in writing, by the Company Representative.

Includes Includes, but is not necessarily limited to.

Including Including, but is not necessarily limited to.

Inspection Point

An identified point in the construction process/sequence where the Contractor(s) is required to provide written notification in advance of commencing work on identified items to allow the Company Representative the opportunity to inspect the work. Notification must be provided when indicated, and in no case less than 24 hours prior to commencement of the works.

May Stated action is allowable.

Principal Client, Company or Owner of the mine – Zelica Mine Project.

Project Superintendent

The Principals appointed Representative responsible for overseeing the Contract between the Principal and the Contractor.

Shall Stated action is mandatory.

Should Stated action is recommended, but not mandatory.

Works All construction works required to complete the Project as detailed in the Project Scope of Works, IFC Drawings, this Construction Specification and the Contract.

3. PRECEDENT OF CONTRACT DOCUMENTS

Should any discrepancy (from a technical perspective) exist between the Contracts, Construction Drawings (provided by the Principal), this Specification, the Principal’s Standards, Australian Standards, and any other regulations or codes, the following order of precedence shall apply, from highest precedence to lowest:

a) Construction Drawings (IFC Drawings).

b) Technical Specification (this document).

c) Statutory Regulations and Codes.

d) Australian Standards.

e) Principal’s Standards.

f) Schedule of Quantities.

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May 2021

4. CODES AND STANDARDS

4.1. General

All work shall comply with the Codes, Standards, and Regulations applicable in Western Australia.

All work performed and all materials furnished under this Specification shall comply with the applicable statutory requirements of the Australian – Federal, State and Local Authorities (Western Australian), the requirements of this Specification, the Principal’s (PGRS Zelica mine) Technical Specifications, standard specifications, Drawings, and the latest revision of Codes, Standards, and Regulations referenced herein.

4.2. Statutory Regulations and Codes The statutory authorities having jurisdiction over the design and construction of the embankments are the Department of Mines, Industry Regulation and Safety (DMIRS) Western Australia and the Department of Water and Environmental Regulation (DWER) Western Australia.

The design and manufacture of all equipment shall comply with all relevant government acts, by-laws and regulations, both state and federal. Where an applicable national standard is not available, an appropriate internationally recognised standard may be utilised upon prior approval of the Company. These include:

a) Occupational Safety and Health Act, 1984:

b) Occupational Safety and Health Regulations, 1988;

c) Mines Safety and Inspections Act, 1994; and

d) Mines Safety and Inspection Regulations, 1995.

4.3. Standards

Table 4-1: Standards Applied in this Technical Specification STANDARD DESCRIPTION

AS 1141 Series

Methods for Sampling and Testing Aggregates

AS 1181-1982 Method of Measure of Civil Engineering Works and Associated Building Works

AS 1289 Series

Methods of testing soils for engineering purposes

AS 1470-1986 Health and Safety at Work, Principles and Practices

AS 3705 Geotextiles - Identification, marking and general data

AS 3706 Geotextiles - Methods of testing

AS/NZS 3905.2-1997

Quality Guidelines for Construction

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May 2021

AS/NZS 4130- 2003

Polyethylene Pipes for Pressure Purposes

AS/NZ 3905.2- 1997

Quality Systems Guidelines

AS/NZS ISO 9002 1994

Quality Systems – Model for quality assurance in production, installation and servicing

ASTM D1004 Standard Test Method for Tear Resistance (Graves Tear) of Plastic Film and Sheeting

ASTM D1238 Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer

ASTM D4437 Standard Practice for Non-Destructive Testing (NDT) for Determining the Integrity of Seams Used in Joining Flexible Polymeric Sheet Geomembranes.

ASTM D5199 Standard Test Method for Measuring Nominal Thickness of Geosynthetics

ASTM D5820 Standard Practice for Pressurized Air Channel Evaluation of Dual Seamed Geomembranes

ASTM D6392 Standard Test Methods for Determining the Integrity of Non-Reinforced Geomembrane Seams Produced Using Thermo Fusion Methods

ASTM D6497 Standard Practice for Geomembrane Seam Evaluation by Vacuum Chamber

ASTM D6365 Standard Practice for the Non-destructive Testing of Geomembrane Seams using the Spark Test.

ASTM D6392 Standard Test Method for Determining the Integrity of Nonreinforced Geomembrane Seams Produced Using Thermo Fusion Methods.

ASTM D6747 Standard Guide for Selection of Technologies for Electrical Detection of Potential Leak Paths in Geomembranes

GRI Standard GM6

Pressurized Air Channel Test for Dual Seam Geomembranes

GRI Standard GM10

Specification for Stress Crack Resistance of HDPE

GRI Standard GM13

Test Properties, Testing Frequency and Recommended Warranty for High Density Polyethylene (HDPE) Smooth and Textured Geomembranes

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May 2021

5. ABBREVIATIONS

The abbreviations in Table 5-1 have the following meaning in the Specification:

Table 5-1: Abbreviations Relevant to this Technical Specification ABBREVIATION DESCRIPTION

AS Australian Standard

ASTM American Society for Testing and Materials

HDPE High Density Polyethylene

ITP Inspection and Testing Plan

LDPE Low-Density Polyethylene

LLDPE Linear Low-Density Polyethylene

MMDD Modified maximum dry density

NATA National Association of Testing Authorities

OGL Original Ground Level

OMC Optimum Moisture Content

PE Polyethylene, including HDPE, LDPE, LLDPE, etc.

PSD Particle size distribution (material grading)

SMDD Standard maximum dry density

SoQ Schedule of Quantities

SoW Scope of Work

SWI Safe Work Instruction

6. DRAWINGS

This construction technical specification shall be read in conjunction with IFC Drawings where supplied, other relevant project specific drawings and other associated tender/contract documentation as referenced in the ‘Scope of Work’.

7. SITE INSPECTION

The Contractor shall be deemed to have examined the site and surroundings and to have informed themselves fully as to the physical conditions on and below the surface, and as to any measures required to obtain access.

Where a site investigation report is provided, the Contractor may use factual information, such as strata descriptions and levels, as a basis for planning and construction of the works, but the opinions and interpretations in the report shall be utilised at the Contractor's risk. Should the Contractor wish to conduct further investigations, these investigations will be subject to approval by the Company and at the Contractor’s expense.

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May 2021

8. WORKPLACE HEALTH, SAFETY AND ENVIRONMENT

Prior to commencing work on site, the Contractor shall prepare a Health, Safety, and Environmental Management Plan for Approval by the Principal (Hold Point). The Contractor shall take all necessary actions to ensure the safety of personnel throughout all activities related to the Works of the Buttresses. In particular, the Contractor should note the following requirements.

a) The Contractor shall provide all necessary signage, exclusion zone notifications and traffic management plans for the duration of the Works.

b) The Contractor shall be responsible for the adequate training and induction of all their personnel and persons within the area of Works.

c) The Contractor shall be responsible for obtaining all works and access clearance permits and certificates from the Principal prior to execution of any work.

d) The Contractor shall obtain dig clearance permits and certificates from the Principal prior to execution of any excavations.

e) The Contractor shall take all necessary actions to ensure the safety of personnel throughout all activities related to the supply construction of the works. The Contractor will prepare Safe Work Instructions for each activity detailing the specific tasks, requirements, precautions and battery limits for each activity.

9. SITE ESTABLISHMENT AND DISESTABLISHMENT

9.1. General

The following section covers all work and costs associated with the establishment of the Contractor’s site management systems, and plant on the site, and removal thereof and reinstatement of the area after completion of the Works to the satisfaction of the Company Representative.

9.2. Office Accommodation, Messing and Laydown

9.2.1. The Contractor shall provide and establish its site office and messing facilities as required for the Contractor’s personnel at a location designated by the Company Representative. The Contractor shall provide suitable amenities for personnel including a crib room (which shall include furnishings) and a power generator. A potable water connection point for ablutions will be provided by the Principal.

9.2.2. The Contractor shall establish its construction facilities at a site designated by the Company Representative. The facilities should include all material laydown areas, workshops, maintenance areas, stores, hydrocarbon storage areas, material laydown areas and appropriate protection facilities, vehicle parking area, vehicle washing areas, communication control facilities, and the support equipment for the Works.

9.2.3. The Contractor shall mobilise all necessary plant and personnel to site prior to commencing the Works and shall demobilise the same from the site after completion of the Works, leaving the site clean, tidy, and free from obstructions and contamination, to the satisfaction of the Company Representative.

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10. EQUIPMENT AND LABOUR

10.1. Equipment

The Contractor shall provide and maintain all plant and equipment necessary to complete the works safely, efficiently and in accordance with the schedule. Equipment shall be maintained and operated to ensure safe, efficient working at all times. Equipment shall be maintained to ensure a minimum production availability of 90%. If satisfactory availability cannot be demonstrated the Contractor shall remove the defective item(s) of equipment from site after obtaining approval from the Company and replace with acceptable equipment within a time period agreed to by the Company.

All associated costs will be at the Contractor’s expense.

10.2. Labour

10.2.1. Plant operators shall be experienced and where appropriate qualified in the operation of the equipment being used. Work practices shall comply with the requirements of the relevant National legislation and regulations governing construction safety.

10.2.2. The Contractor shall provide as part of the Tender a histogram detailing the weekly manpower requirements for the duration of the Works.

11. CONSTRUCTION PROGRAMME

11.1. At the Tender stage, the Contractor shall prepare a construction programme that

identifies the work to be carried out, sequencing of work, and any hold points as nominated in the Technical Specifications and Drawings. The construction programme shall identify and clearly state all key milestone dates, hold points, critical paths, and dates by which information or approvals are required from the Company Representative or the Principal for the execution of the Contract.

11.2. The construction programme shall be prepared in Microsoft Project 2019 or a similar compatible program and shall be updated to a detailed construction program, approved by the Principal prior to site establishment (HOLD POINT). This shall be the baseline program for the duration of the project.

11.3. The detailed construction program shall be updated on a weekly basis showing the works achieved and forecasting remaining work to be done relative to the baseline program. Failure to update the Construction Programme accurately and timeously may result in the works being stopped until such time as the Company Representative is satisfied with the accuracy of the Construction Programme.

11.4. The programme and any modifications agreed prior to signing of the Contract shall form part of the Contract.

12. LEGAL RELATIONSHIPS AND RESPONSIBILITY TO THE PUBLIC

The Contractor shall take such steps as are necessary to comply with the terms of PGRS’s Zelica Mine Project General Conditions of Contract, particularly with respect to the insurances and indemnities required, and shall comply with all regulations of Statutory Authorities.

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13. CONTRACTOR SUBMITTALS

13.1. The following summarises the Contractor’s minimum submittals to the Company

Representative prior to as well as during the Works:

13.1.1. The Contractor shall prepare and submit detailed Inspection and Test Plans (ITPs) including test equipment, materials, construction earthworks, liner installation, and filter drainage installation, to the Company Representative before commencing the Works.

13.1.2. The Contractor shall prepare and submit detailed Construction Method Statements before commencing each task(s):

13.1.3. The Contractor shall submit periodic surveys as the work is completed to support measurements for monthly payment claims.

13.1.4. As outlined in the Scope of Work document issued by the Company and this Specification, the Contractor shall also submit the following:

• a Health, Safety and Environmental Management Plan

• a Dig Plan

• a Traffic Management Plan(s) for each activity or change in activity

• a Quality Control Procedures Manual

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PART A: EARTHWORKS AND DRAINAGE

14. GENERAL SETTING OUT

14.1. All survey shall be carried out in Map Grid Australia Datum 94 (MGA94) (51J) system.

14.2. The Company Representative will provide four benchmarks near the Works for survey control. The Contractor shall, using a qualified surveyor, check, verify, and accept these benchmarks for use and shall submit results to the Company Representative for verification before adopting each benchmark as a true benchmark for construction purposes (HOLD POINT). The Contractor will be responsible for replacement of the benchmarks should they be damaged during the Works.

14.3. As the number of permanent benchmarks is limited, the Contractor may establish additional benchmarks to adequately and efficiently set out and monitor the Works. The establishment of additional benchmarks shall be completed to a standard consistent with the rest of the site and surveying best practice. During, or at completion of the Works, the Company Representative may request the additional benchmark information from the Contractor. At the end of the Works, the temporary benchmarks are to be removed, excluding those required by the Company Representative to remain.

14.4. Immediately following the issue of the order to commence, and prior to the start of construction of the works, the Contractor shall, at his own expense, carry out and record a detailed check survey of the area of the works to verify the elevations levels shown on the construction drawings.

Any discrepancies of the levels shown on the construction drawings causing non- acceptance by the Contractor are to be pointed out to the Company Representative within two weeks of the above order being given (HOLD POINT). The elevations in dispute (and the associated design survey data) will be checked, revised as necessary and approved by the Design Consultant. Failing this, the original levels as shown on the construction drawings will be deemed correct and acceptable.

14.5. The Contractor shall use a qualified surveyor, approved by the Company Representative, to carry out the detailed set-out of the works. The detailed set-out shall include establishment of all lines, levels and grades necessary for construction of the works. On completion of the detailed set-out of each portion of the works the Contractor shall notify the Company Representative, in writing, and shall obtain approval to proceed with construction (HOLD POINT).

The Company Representative may elect to check the Contractor's set-out, but approval to proceed, whether the Company Representative has checked the set-out, shall not diminish the Contractor's responsibility for the accuracy of the work.

14.6. Full records of all field work shall be kept in accordance with good surveying practice. Field books shall be available for inspection by the Company at any time. All set-out data shall be issued to the Company Representative electronically in either .dwg (AutoCAD)

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or .dxf format as soon as completed (HOLD POINT) for review and verification of accuracy of the works and for use in determining the final contract quantities for payment.

14.7. The detailed check survey is to be issued to the Company Representative in electronic format prior to the start of construction for review and approval and will be used as the basis for measurement of final quantities and payment for the works (HOLD POINT). Should the detailed check survey not be issued to the Company Representative for approval prior to the start of Construction of the Works, the design survey will be used for final measurement of quantities and payment.

14.8. The Contractor shall be responsible for maintaining accurately ascertained site datum levels at his own expense. The Contractor shall further ensure that all level control and setting out of the works is executed in accordance with the survey data given on the construction drawings.

In addition to the above, the following survey tasks shall be undertaken by the Contractor for agreement with the Company Representative.

14.8.1. Ground levels shall be recorded on a 10 m of smaller grid along and on both sides of the centre line and along upstream and downstream toe positions of all embankments and fills after site clearance (HOLD POINT), again after removal of unsuitable material (HOLD POINT) and after compaction of the foundation (HOLD POINT). In the case of large embankments or fills the Company Representative may specify that the intensity of recorded levels be increased to that of a 5 m grid.

14.8.2. Ground levels shall be recorded at 2.5m and 5m intervals along all changes in geometry including, but not limited to the upstream crest, upstream trench invert, trench centreline, downstream trench invert and downstream crest for the entire length of all trenches, canals and drains prior to excavation (HOLD POINT) and again on completion of the excavation to the required depths and grades (HOLD POINT).

14.8.3. Ground levels shall be recorded on a 10 m or smaller grid over all bulk earthworks areas and borrow areas. After removal of unsuitable material and/or topsoil and/or fill material as required, the Contractor shall re-survey the ground and record levels as described above (HOLD POINT). The grids and lines before and after soil removal shall be coincident in plan.

14.9. The Contractor shall allow for undertaking of the baseline survey and all additional survey required to complete construction of the works to the design geometry in the Preliminary and General Section of the Schedule of Quantities. No separate payment will be made for these surveying operations. The agreed survey data shall be the basis of all earthworks measurement.

14.10. All survey submitted by the Contractor is to be checked and approved in writing by the Company Representative before being considered valid as a basis of measurement.

14.11. The Contractor is to inform the Company Representative in writing upon the completion of any stripping of topsoil, excavation of unsuitable material, trenches, etc. and construction any fills or embankments. Thereafter, a check may be carried out by

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the Company Representative to verify these elevations and cross-sections. (HOLD POINT)

14.12. It shall be the Contractor’s responsibility to carry out all necessary survey and calculations to clearly demonstrate construction quantities indicated in both the monthly progress claims and final claim. These will be submitted to the Company Representative to review prior to approval and payment. The Company Representative may, at its own expense, take levels and calculate cut and fill quantities if they should wish to check the Contractor’s quantities and confirm their accuracy.

14.13. The cost of the check survey will be paid for by the Principal only if the results of the survey show that the design levels and cross-sections have been achieved. The Contractor shall pay for the costs of check surveys where the results show that the design levels and cross-sections have not been achieved.

14.14. Any further costs involved to check if the required design levels and cross-sections have been obtained after the corrective measures have been applied shall be borne by the Contractor.

15. EXISTING SERVICES AND CLIENT PERMITS

15.1. The Contractor shall be responsible for obtaining the necessary digging permits, HV

vicinity permits, or any other permits (other than works approvals and clearing permits), that the Company requires as stated in its Standards or required safety procedures current at the time of the works (HOLD POINT).

15.2. The Contractor shall be responsible for any necessary diversions of existing services, including above ground or buried cables, pipework, trenches, drains, etc. indicated on the drawings and for the cost thereof.

15.3. Where existing services are crossed, due care shall be taken to avoid damage to them (HOLD POINT. The Contractor must ascertain the true position (alignment and depth or height) thereof. The Contractor will be responsible for any damage to existing services

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and shall, at his own expense, take all measures necessary to support and protect these services while exposed in excavations and trenches.

15.4. Any damage to existing services during the contract shall be made good by the Contractor at his own expense.

16. CONSTRUCTION CONTROL POINTS (HOLD POINTS)

16.1. The Company Representative shall indicate construction control points (HOLD POINTS)

on the project plan.

16.2. The construction control points shall indicate when a formal inspection and approval of the works immediately prior to the control point shall be undertaken by the Company Representative before subsequent works may commence.

16.3. The Contractor will prepare detailed Inspection and Test Plans (ITP’s) for each aspect of the works and issue these to the Company Representative for review and approval prior to the start of the works (HOLD POINT).

16.4. Should the Company Representative deem the works immediately prior to the control point as not meeting the Design and/or Project Technical Specifications, the Contractor shall be liable for the cost of any necessary works to rectify the works.

16.5. The Contractor shall make provision for a survey pickup of the works immediately prior to the control point. The Contractor shall provide to the Company Representative the required survey data as both a ‘hard copy’ and electronically, in AutoCAD or DXF format.

17. ENVIRONMENTAL CONTROLS

17.1. DUST SUPPRESSION

17.1.1. Where site conditions require it, the Company Representative may direct the Contractor to provide adequate dust suppression systems to minimise any hazards or nuisance from dust generated in carrying out the works on the site including the site access roads, stockpiles, haul roads, borrow pits and the works area.

17.1.2. The Contractor shall be responsible for and shall bear the cost of dust suppression on the works to the approval of the Company Representative.

17.1.3. Dust suppression water shall be sourced from water points to be provided by the Company.

17.1.4. Dust suppression is to be carried out to the Company Representatives satisfaction in the vicinity of any drain construction works to ensure no contamination of the filter drains.

17.2. Site Erosion and Sediment Control

17.2.1. The Contractor shall take all necessary measures to control, minimise and monitor the degradation of the site resulting from construction activities and to prevent discharge off the site of water runoff contaminated by transported sediment. The

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Contractor’s operations shall comply with the Contractor’s approved Erosion and Sedimentation Control Plan and other environmental management documentation.

17.2.2. Erosion and sediment control measures may include:

a) the installation of silt fences, filter drains, sediment traps and the like downslope of areas disturbed by construction;

b) construction of diversion drains and the like to divert storm-water flow from entering the areas disturbed by construction; and

c) scheduling the work to minimise the bare earth area vulnerable to erosion at all times.

17.2.3. All erosion control devices shall be regularly inspected and maintained, especially after rainfall events.

17.2.4. Any gullies or erosion channels greater than 50 mm deep, which are formed during the construction or maintenance period, shall be backfilled and compacted and the surfaces returned to their original condition. This shall apply to outside embankment faces, embankment crests, inside slopes, berms and canals.

17.2.5. The Contractor will receive no payment for repairing erosion damage.

18. DE-WATERING

18.1. The Contractor shall provide, operate and maintain all pumps, pumping equipment, well points and all other water devices necessary to properly de-water and maintain free from water all excavations, including those at the borrow pits, until completion of the works, at his own expense.

18.2. No work shall be carried out or material excavated in water without the written permission of the Company Representative (HOLD POINT).

18.3. The Contractor shall be entirely responsible for keeping the whole of the works thoroughly drained and clear of water for as long as may be required, and if considered necessary by the Company Representative, continuously day and night.

18.4. The Contractor is responsible, at no extra cost over and above the rates for excavation in the priced Schedule of Rates, for preventing the ingress of groundwater or stormwater flow into any excavations.

18.5. The contractor is to be responsible for construction of proper drainage channels, sumps, supply and running of pumps and everything necessary for the exclusion of water from excavations, whether such water arises through storm flow, groundwater, springs or seepage. The Contractor is responsible for the protection and de-watering of all

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excavations until all construction is complete to the satisfaction of the Company Representative. Rates for excavations include for all such de-watering.

18.6. Channels or sumps excavated outside the works for de-watering purposes, must be refilled and made good to a standard equivalent to the original conditions, (and as directed by the Company Representative) when they are no longer required.

18.7. Where the Company Representative may order permanent works to be constructed to deal with springs or seepage liable to endanger the work after completion of the Contract, such will be paid for as extra work and paid for at scheduled rates.

18.8. The rates in the priced Schedule of Quantities will be held to cover the cost of any rectification or work, whether specified under this Contract or not, which the Company Representative may order or decide to be necessary as a result of the Contractor’s de- watering or storm water flow arrangements being negligent, inadequate or improper. The cost of all such rectification work will be at the Contractor’s expense.

19. STRIPPING AND STOCKPILING OF VEGETATION AND TOPSOIL

19.1. The Contractor shall not damage any trees and flora adjacent to the area of the Works

or as nominated by the Company Representative.

19.2. All topsoil including vegetation is to be stripped from areas within the footprint of the proposed infrastructure, as well as within impoundment areas, excavations, haul roads, borrow pits, etc. to a depth of 200 mm or to such depths and extent as indicated on the drawings or as directed by the Company Representative and shall be stockpiled for later re-use in rehabilitating the embankment side slopes. The topsoil material removed shall be transported to and stockpiled at an approved site as indicated on the drawings or as directed by the Company Representative. The disposal area shall be within 3,000m of the site from which it was removed. (Distance is one way)

19.3. The unit of measurement for topsoil shall be the cubic metre of in-situ material removed. The rates tendered must allow for the operation as described and haulage to within 3,000 m of the site. The disposal area is to be left as described in Section 17.

20. SPOIL DISPOSAL

20.1. Spoil disposal areas (which may include used borrow pits) shall be allocated for the

disposal of all surplus material from site clearing operations, excavations and removal of unsuitable material etc. These areas shall be maintained in a neat condition and when completed, levelled off by grading to within 150 mm from level or a given surface as directed. The rates tendered must allow for all such levelling, trimming and final shaping. These areas are indicated on the drawings or shall be specified by the Company

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Representative. Such areas shall be within 3,000m of the sites of excavation. (Distance is one way.)

20.2. Topsoil must be stripped and stockpiled separately for re-use as detailed in Section 19.

21. MEASUREMENT AND CLASSIFICATION OF EXCAVATION MATERIALS

21.1. All excavation quantities throughout in all classes of material will be measured Nett. Excavations shall be measured per cubic metre divided into the following classes:

21.1.1. Material Class “A”

21.1.1.1. This classification shall include all kinds of ground encountered except those defined in Class “B” hereinafter and shall include made-up ground, paving, rubbish, gravel, sand, silt and calcareous material, clay, soft rock, ground interspersed with small boulders of rock not exceeding 0.5 mP

3P (one half of a cubic metre), dumped

waste rock, material in compacted embankments and all other materials which can, in the opinion of the Company Representative, be excavated by hand or by machine without drilling and blasting.

21.1.2. Material Class “B”

21.1.2.1. In the case of trench and small excavation, this classification shall mean granite, quartz, dolomite etc, or rock of similar hardness which in the opinion of the Company Representative, can only be removed by drilling and blasting (HOLD POINT).

21.1.2.2. Solid boulders greater than 0.5 mP

3P (one half of a cubic metre) will be classified in

this category. This classification shall apply whether blasting is authorised.

21.1.2.3. In the case of bulk excavation this classification shall mean granite quartz, dolomite etc. or rock of similar hardness found in its original position which cannot be loosened by a bulldozer having a minimum fly wheel power of 170 kW and operating weight of 23,000 kg (e.g. a Caterpillar D7, Komatsu D85 or equivalent in good condition, fitted with an approved single tine ripper and driven by a competent operator). This classification shall apply whether blasting is authorised.

21.1.2.4. If the Contractor considers that any material to be excavated is classified as Class “B” above, he shall submit a written request to the Company Representative for his ruling (HOLD POINT). Failing such a request, the excavations shall be deemed to be in Class “A”. The decision of the Company Representative as to the classification of the material shall be final and binding.

22. “OVERBREAK”

22.1. All excavation quantities throughout, in all classes of material will be measured Nett.

22.2. Excavation in Class “B”

22.2.1. Items measured in square metres, of extra for overbreak in Class “B” excavation material, including filling with selected earth filling and compacting in 250mm layers once compacted will be measured to the area of vertical earthfill embankment abutting against Class “B” excavation material for the fill material. These items will be

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measured and paid for in the final account to all vertical faces of the earthfill embankment abutting against Class “B” excavation material faces, and the tender rate will apply irrespective of any discrepancy between the system (as above described) tendered on and the system used in construction.

22.2.2. Similarly, items measured in square metres of extra for overbreak in Class “B” excavation material including filling with suitable earthfill embankment construction material have been measured to the area of horizontal or sloping earthfill embankment abutting against Class “B” excavation material.

22.2.3. These items will be measured and paid for over and above the earthfill embankment requirements of the drawings and no extra soil in filling will be measured, no matter what extra depth may have been excavated and back filled. However, should the Company Representative instruct that the excavation be carried out to depths greater than that required on the drawings, then the above described square metre item will not be measured, but such excavation and backfilling shall be measured and paid for.

22.3. Excavations in Class “A” material

22.3.1. Where no Class “B” material as described is encountered in any one excavation, the excavation quantities will be measured Nett.

22.4. Where Class “A” and “B” material as described are encountered in any one excavation, the excavation in Class “A” material will be measured only as stated in Section 22.3.1, irrespective of any over-excavation for any reason whatsoever, and the excavation in Class “B” material will be measured only as stated in Section 22.2, irrespective of any over-excavation for any reason whatsoever.

23. OVER-EXCAVATION

23.1. Backfilling to over-excavation below the required levels or depths necessary to achieve

the required depth or to obtain a suitable bottom is to be carried out to the instructions and satisfaction of the Company Representative and entirely at the Contractor’s expense (HOLD POINT).

24. SAFETY PRECAUTIONS IN EXCAVATIONS

24.1. Excavation will be measured and paid for only to the Nett sizes required for designed

structures or as indicated on the drawings.

24.2. The Contractor shall assume full responsibility for the safety of all excavations, and shall at his own expense adopt all measures necessary to secure this end, either by planking and strutting or by side sloping of the ground provided that, the Company Representative may instruct the contractor to plank and strut banks and sides of excavations, etc. and/or side slope such banks and sides of excavations etc without cost to the Employer over

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any surface where he may consider the excavations dangerous, and/or to conform with any safety precaution in terms of the relevant regulations. (HOLD POINT)

24.3. Such instructions shall be considered final and legally binding.

24.4. The Contractor shall be held fully responsible for ensuring that all planking and strutting is sufficient strength to ensure the safety of all persons in the excavations and is suitably arranged to permit the construction of whatever is necessary.

24.5. No payment will be made for side sloping and timbering and shoring work, and these shall be deemed to be included in the rates for excavation.

25. CONTRACTOR’S LIABILITY IN EXCAVATION

25.1. The Contractor shall be responsible for making good, or having made good, at his own

expense any slips, falls, caving-in of ground, damage to walls, structures or works caused due to his acts or works, or by causes within his control and shall indemnify the Company and the Company Representative against any claims made in respect of loss of life, or injury or damage to persons, animals or things, caused by reasons or his works or through causes in his control. The Contractor’s rates will be held to cover all such liabilities and the Company Representative shall have the right, if they shall have suffered loss due to the above, to deduct the value of such loss from any monies due or that may become due to the Contractor.

26. FALL IN OF GROUND

26.1. Should any ground or any excavations collapse, collapsed material must be dug out, and

excavations made good as outlined in Clause 24. (HOLD POINT)

26.2. These remedial measures will be carried out to the written approval of the Company Representative at the Contractor’s expense.

27. UNAUTHORISED EXCAVATIONS

27.1. The Contractor is prohibited from making excavations other than those approved by the

Company or the Company Representative as necessary for completion of the works.

28. EXCAVATIONS TO BE PASSED

28.1. Excavation Works shall not commence in any zone prior to inspection and approval of the Contractor’s survey markers in that zone by the Company Representative (HOLD POINT).

28.2. Before any fill is placed in any excavation all excavation and foundation surfaces must be clean and generally prepared to receive it to the Design and Construction

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Specification and to the satisfaction of the Company Representative (HOLD POINT). The cost of this work must be included in the tendered rate for concrete work.

28.3. In no case must fill material be placed until the excavation has been surveyed and the express written consent of the Company Representative has been obtained (HOLD POINT).

28.4. The Contractor shall ensure the safety of any excavations and preparedness of any such excavation prior to placement of fill to the excavation. The Contractor shall bear all liability in the case of damage to or loss of life, equipment, or things that occur during the filling of an excavation.

29. EXCAVATION OF THE EARTHFILL EMBANKMENT KEY TRENCH

29.1. Excavation Works shall not commence in any zone prior to inspection and approval of

the Contractor’s survey markers in that zone by the Company Representative. (HOLD POINT)

29.2. The Contractor shall excavate whatever materials are encountered to the depths, cross- sections and grades shown on the drawings.

29.3. Excavated material not required or unsuitable for embankment construction shall be transported to and disposed of at a designated site away from the site of works as directed by the Company Representative. The disposal area shall be within 3,000m of the area from which it was excavated.

29.4. The unit of measurement for all excavation shall be the cubic metre of in-situ material excavated (measured Nett).

29.5. Where trenches are excavated, the payment for these excavations is limited to that of the maximum vertical design dimension of the trench. Similarly, the measurable width shall be the design width of each cross-section. All costs associated with excavation greater than these dimensions (i.e. including construction of the earthfill embankment) shall not be considered for payment.

29.6. The rates tendered must allow for the operation as described and haulage to within 3,000m of the site. The disposal area is to be left as described in Section 20.

30. EXCAVATION OF UNSUITABLE FOUNDATION MATERIAL

30.1. Unsuitable natural soil below the earthfill embankments and compacted walls shall be

removed to such depths widths and lengths as the Company Representative may determine after the completion of the site clearance and topsoil stripping (HOLD POINT). The material so removed shall be inspected by the Company Representative and designated either as topsoil/ growth medium, to be stockpiled for later use, or as spoil material. Topsoil/growth medium material shall be transported to designated stockpile areas where it will be spread loosely to a maximum depth of 2m. Spoil material shall be

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transported to designated spoil areas and disposed of as directed by the Company Representative.

30.2. The disposal area shall be within 3,000m of the area from which it was excavated.

30.3. The unit of measurement for unsuitable material removal shall be the cubic metre of in- situ material removed (measured Nett). The rates tendered must allow for the stockpiling or spoil dumping as described and haulage to within 3,000m of the site.

31. EXCAVATION OF STORMWATER DRAINAGE TRENCHES

31.1. The contractor shall clear the land of vegetation and strip topsoil to 200mm wherever

and only where the drawings indicate the extent of the drainage trenches. Payment for clearance of vegetation and topsoil stripping shall only be considered for the design width of the drains at ground surface.

31.2. Topsoil from the stripping of the land along the extent of the drainage trenches shall be disposed of as directed by the Company Representative and within 3,000 m haul distance of the trench, for stockpiling and future use, and as detailed in Section 20. The rates tendered must include a provision for such removal.

31.3. The Contractor shall excavate whatever materials are encountered to the extents, depths, cross-sections and grades shown on the drawings.

31.4. Excavated material from the drainage trenches shall be transported to and disposed of at a designated spoil site away from the site of works as directed by the Company Representative. The disposal area shall be within 3,000 m of the area from which it was excavated and shall be as detailed in Section 20.

31.5. The unit of measurement for all excavation shall be the cubic metre of in-situ material excavated (measured Nett).

31.6. The payment for these excavations is limited to that of the maximum vertical design dimension of the drainage trench. Similarly, the measurable width shall be the design width of each cross-section. All costs associated with excavation greater than these dimensions (i.e. including construction of the earthfill embankments) shall not be considered for payment.

32. BORROW AREAS

32.1. The designated Borrow Area is the current vat leaching facility that is to be stripped as

part of the construction works.

32.2. The Contractor shall be responsible for ensuring that materials obtained from borrow areas conform to the material requirements specified in the Design and this Technical Specification and approved by the Company Representative from time to time. These criteria include the material particle size distribution (i.e. grading envelope), Atterberg

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Limits, permeability, density and moisture content requirements as detailed in Section 36.

32.3. To this end the Contractor will be required to excavate a reasonable number of trial pits at his own cost to prove the suitability of each borrow area location.

32.4. The contractor shall prepare and submit to the Company Representative a development (dig) plan detailing their proposed method for development of the borrow area, including flitch depth, borrow pit floor elevation control and maintenance, surface water management, dust control, access and egress routes, traffic management, etc. and, where required, rehabilitation of the borrow area. (Hold Point)

32.5. The Contractor, unless otherwise directed, shall obtain the required material by borrowing in these cuttings to such widths, lengths and depths as the Company Representative may direct. No payment for removal of borrow material to fill will be made (Payment will be for the formation of embankments, only - refer Section 36 below). The Contractor is to allow in his rates for embankment formation for any staging and spoiling of borrow materials that may be required.

32.6. Payment for the opening of borrow areas not allocated by the Company Representative, will not be considered.

32.7. Borrow from borrow areas will normally be limited to material which can be loosened using mechanical rippers having a minimum fly wheel power of 170 kW and operating weight of 23,000 kg (e.g. a Caterpillar D7, Komatsu D85) in good condition and driven by a competent operator.

32.8. All borrow areas are to be left in a safe and neat state as directed by the Company Representative at no extra cost. Perimeter bunds will be constructed on the upstream crest of the borrow pit. Outer side slopes of the borrow pit will be cut to slopes and benches as directed by the Company Representative.

32.9. Should stripping of unsuitable material overlying a borrow area be required it shall be to such widths, lengths and depths as determined by the Company Representative. This unsuitable material shall be disposed of at a suitable spoil material stockpile away from the site works as directed by the Company Representative. The spoil disposal area shall be within 3,000m of the area from which it was removed.

32.10. When the Contractor estimates that sufficient material to complete the entire works has been hauled to the works stockpile, before ceasing haulage operations from the borrow area, the Contractor shall seek written approval from the Company Representative to cease haulage.

32.11. Before closure of any borrow area outside of the open pit is commenced by the Contractor, the Contractor shall seek written approval from the Company Representative to continue with closure.

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33. HAULAGE

33.1. The Contractor shall at his own cost construct and maintain temporary haul roads as

required along the route designated by the Company Representative and approved by the Company.

33.2. The costs of maintenance of designated haul roads between the site of the works and the designated borrow area shall be included in the rates and shall include the use of grading equipment, watering equipment, or any other equipment and/or labour that the Company Representative deems appropriate and necessary to maintain the haul roads in a condition approved in writing by the Company Representative.

33.3. Traffic management along the haul route between the designated borrow area and the works, by reasonable and sufficient means, shall be the Contractor’s expense.

33.4. The Contractor shall be restricted to the routes designated by the Company Representative.

33.5. The Company Representative may change the designated routes between the designated borrow area and the site of the works. Payment for haulage shall be at the rates tendered for the original haul route.

33.6. Free haulage of material excavated from a borrow pit, excavation, etc. shall be limited to the distance specified for each item measured from the centroid of the borrow facility, along the designated route, to the centroid of the facility being constructed.

33.7. All distances indicated in this specification are based on the shortest distance by road and indicate the haul distance in single direction.

33.8. Overhaul is that portion of the total haulage beyond the free haul limit and is measured separately.

33.9. The unit of measurement of overhaul in the case of compacted fill or placed material shall be the cubic metre - kilometre being the product of distance measured in kilometres to the nearest tenth of a kilometre and the cubic metres (mP

3P) of compacted or placed

(whichever is applicable) material transported. However, in the case of cut to spoil, or stockpile the unit of measurement for overhaul shall be the cubic metre-kilometre (mP

3P

km) being the product of the distance measured in kilometres to the nearest tenth of a kilometre (km) and the cubic metre (mP

3P) of undisturbed in-situ material transported.

34. BACKFILLING

34.1. Where Compaction is not required:

34.1.1. The unit of measurement for all backfill shall be the net design cubic metre (mP

3P) of

consolidated material placed.

34.2. Where Compaction is required:

34.2.1. Backfilling to trench extensions shall be paid for under the items provided in the Schedule of Quantities and shall be carried out by replacing selected fill material in loose layers not exceeding 250 mm once compacted before the succeeding layer is placed as indicated on the drawings or such other ways as may be directed by the

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Company Representative. In areas where specified compaction densities are required for backfill, the identical testing and approval procedures as outlined in Section 37 will applied. Only sand replacement testing may be done near concrete foundations.

34.2.2. Backfilling to embankment foundations shall be paid for under the items provided in the Schedule of Quantities and shall be carried out by placing specified fill material in loose layers not exceeding the design layer thickness after compaction, each layer being thoroughly compacted, before the succeeding layer is placed or such other ways as may be directed by the Company Representative. In areas where specified compaction densities are required for backfill then the identical testing and approval procedures as outlined in Section 37 will be applied.

34.2.3. Any defects caused due to subsidence of the backfilling, because of improper workmanship, shall be made good at the Contractor’s expense. If required or before expiry of the maintenance period or at such other times as the Company Representative may direct, all refilled excavations shall be examined and dressed and, where depressions have occurred, these shall be made good by refilling and ramming with suitable material at the Contractor’s expense.

35. PREPARATION OF FOUNDATIONS

35.1. Prior to the commencement of construction of compacted earthfill embankments, the

Company Representative shall approve the foundation material beneath the base areas, after stripping of topsoil. If the Company Representative approves the natural soil, the material shall be broken up by ripping or other means to a depth of 200mm and compacted a density of 95% of SMDD compaction.

35.2. The onus is placed on the Contractor to compact this layer to such a degree to ensure that the indicated densities, or such lesser densities as may be specified by the Company Representative, can be achieved on subsequent layers. The unit of measurement for ripping and compaction of the approved founding layer is the design square metre (mP

2P).

36. CONSTRUCTION OF EARTHFILL EMBANKMENTS

36.1. Embankment Zones and Material Specifications

36.1.1. The following embankment zones are included in the designs:

36.1.1.1. Borrow Material: Borrow material from foundation comprising of a gravelly silt with sand soil (UCS Classification ML).

36.1.2. Material Specifications by Zone

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Table 36-1: Embankment Material Specifications

Test Australian Standard Borrow Material

Maximum Particle Size (mm) AS 1289.3.6.3

Minimum percentage passing 75µ AS 1289.3.6.3

Minimum clay content AS 1289.3.6.3

Minimum plasticity Index (PI) AS 1289.3.1.1 & AS 1289.3.2.1

Emerson Class range (Dispersivity) AS 1289.3.8.1

36.2. Embankments shall be constructed by obtaining selected soil from excavations,

approved borrow pits and stockpiles as indicated on the drawings or otherwise, and forming it to the dimensions and elevations given on the drawings.

36.3. Material forming the embankment shall be compacted in layers as detailed on the drawings and to the Technical Specifications in Section 37 to form durable embankments of good, regular appearance with all cross-sections having the minimum sizes detailed on drawings and having side slopes not steeper than specified.

36.4. The sides of the embankments must be compacted to hard durable faces. Any spoil resulting from this operation is to be removed and placed on the following lift, if it meets the material construction specification or disposed of at an approved spoil site within 3,000 m at no extra cost.

36.5. The unit of measurement for embankment construction shall be the design cubic metre (mP

3P) of placed material after compaction, trimming and forming to the specified

dimensions.

36.6. The Contractor shall not be paid for embankments constructed in excess of the design dimensions. The Company Representative shall decide on acceptance or rejection of embankments which are oversized. The Contractor shall bear the cost of trimming of embankments in the event of the Company Representative judging the overfill to be unacceptable.

36.7. The Contractor is to allow in his rate for forming and compacting an oversized embankment and cutting back and compacting the sides of the embankment to the correct geometry approved by the Company Representative.

37. COMPACTION OF EMBANKMENTS TO A SPECIFIED DENSITY

37.1. General

37.1.1. The standards of compaction required are shown on the drawings and the Contractor shall be entirely responsible for obtaining a density not less than the minimum specified Standard Maximum Dry Density (SMDD) in accordance with the general

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requirements of the latest edition of AS 1289 (hereafter referred to as specified density).

37.1.2. All fill material used to form infrastructure is to be placed to the following specification:

37.1.2.1. Borrow Material: Borrow material is to be moisture conditioned, placed and spread in 300mm loose layers.

37.1.3. All construction material shall be loaded, handled and placed in such a manner as to avoid segregation.

37.1.4. Material Compaction Specifications by Zone

Table 37-1: Embankment Material Compaction Specifications

Parameter Australian Standard Borrow material

Minimum Standard Compaction Density Ratio (SMDD) AS 1289.5.1.1 95%

Minimum Moisture Content AS 1289.2.1.1 22%

Maximum Moisture Content AS 1289.2.1.1 25%

37.1.5. Earthfill embankments:

37.1.5.1. Loose horizontal layers of fill material shall not exceed depths indicated in Section 37.1.2 prior to compaction to the specified densities indicated on the drawings or in Section 37.1.4.

37.1.5.2. A uniform moisture content with a range as specified in Section 37.1.4 is to be achieved throughout the layer prior to compaction.

37.1.6. 1-Bases of tailings dam impoundments

37.1.6.1. Foundation materials shall be ripped and moisture conditioned to a depth of 200mm and compacted to a density not less than 95% SMDD, the minimum specified density.

37.1.6.2. A uniform moisture content as specified on the drawing and in Section 37.1.4 is to be achieved throughout the layer prior to compaction.

37.1.7. All compaction shall be carried out parallel to the longitudinal centre line of the earthworks, working on a predetermined pattern which shall ensure that the whole area of the layer receives uniform compaction.

37.1.8. Compacted layers with moisture contents outside the specified range shall be deemed to have failed regardless of the densities achieved.

37.1.9. Should the moisture content of a layer fall outside the project specification the Contractor shall advise the Company Representative within 6 hours of completion of

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testing. Corrective measures deemed appropriate by the Company Representative shall be entirely the expense of the Contractor.

37.2. Compaction Control

37.2.1. The Contractor shall provide, at its own expense, an adequate site laboratory, equipment, facilities and suitably qualified and experienced personnel for carrying out the required compaction tests. Should the Company Representative at any time consider any of the above to be inadequate for this purpose, he shall instruct the Contractor to cease further work on compaction until the Contractor has remedied the deficiency.

37.2.2. The onus shall be on the Contractor to ensure the following:

37.2.2.1. The state of the material when placed is such that the compaction as specified in Section 37.1.4 is obtained;

37.2.2.2. Material selected for use in compacted embankments shall be approved by the Company Representative on the basis of the SMDD being equal to or greater than a minimum density specified in Section 37.1.4 and based on the particle size distribution and permeability of the material falling within a specified envelope.

37.2.3. Hence, with the object of controlling the selection of all materials used in the various layers of fill, the Contractor shall perform grading analyses, SMDD, Atterberg Limit and permeability tests, whichever is applicable on each type of material which he proposes to use, including mixed or blended materials.

37.2.4. In addition to the tests required for his own control the contractor shall allow for density checks as detailed in Table 37-2.

Table 37-2: Minimum Test Requirements for Construction Materials Parameter Borrow

Material

Minimum requirement for Density Tests. 500mP

3P or 2

test per day

37.2.5. The recognised method of determining the density is the sand replacement test.

However, the Radio Isotope or other approved method may be used for soil materials (if approved by the Company Representative) for density and moisture checks, provided suitable agreement is obtained between this method and the sand replacement method and provided the necessary calibration and specified tests to these instruments are undertaken at intervals to be specified by the Company Representative.

37.2.6. If a nuclear density measuring devices is used, it shall be calibrated and certified by the relevant NATA authority.

37.2.7. Nuclear density measurement device readings shall be compared to sand replacement test results based on one (1) sand replacement test for every ten (10)

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nuclear density measurements made. The contractor shall provide these testing certificates to the Company Representative.

37.2.8. If an alternative method of density determination is accepted, the sand replacement method shall be used to check every tenth density determination, and the moisture content of the sample shall be determined using tests specified in Section 37.1.4.

37.2.9. To account for material variability, approved density tests will be accepted based on the following, for the Earthfill embankment Zones:

37.2.9.1. Borrow material: Embankments compacted to 95% Standard Maximum Dry Density:

a) If any one of the two density tests per 400mP

2P block is below 93%, then the entire

block will be re-ripped, re-watered and re-compacted.

b) If one or both of the two density tests per 400mP

2P block is between 93% and 95%

then two more density tests will be undertaken in the 400 mP

2P block. If the average

of the four density tests is greater than or equal to 95% then the block will be passed. If the average is less than 95% then the entire block will be re- ripped, re-watered and re-compacted.

c) If both of the two density tests for the 400mP

2P block lie between 95% and 100%

then the block will be passed (i.e. a range of –3% and +2% from SMDD). Tests achieving densities more than 100% will not be accepted. In this case the block will have to be re-ripped, re-watered and re-compacted.

37.2.10. Compaction control tests shall be carried out as specified in AS 1289.

37.2.11. Moisture determination tests shall be carried out by oven drying as per the latest relevant section of AS 1289.2.1.1. Moisture samples shall be taken from mid-layer of the layer being tested and shall be taken from every location where a density measurement is made.

37.2.12. The Contractor shall allow for additional testing in the same fashion outlined in the abovementioned Sections, of the layer immediately preceding the latest tested layer, when directed to do so by the Company Representative. The Company Representative may request such testing on one out of every three placed layers. The costs of these tests will be paid for by the Company only if the results of the tests show that the specified density has been obtained.

37.2.13. Field density and moisture content tests are to be carried out within two hours of completion of each section of the layer. If such tests are not carried out by the Contractor within this period then the Company Representative may fail a layer or section of the layer regardless of any test results which may then or subsequently be provided, and this decision shall be final.

37.2.14. When the compaction of any section of any layer, for which a density and moisture content is specified is completed, the Contractor shall supply to the Company Representative copies of tests results, both as hard copies and electronically, whether successful or otherwise, within 6 hours of determination.

37.2.15. Should the Contractor place subsequent layers onto a prior layer that has not met the project specification, corrective measures required to construct the prior layer to the

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project specification, which include but is not limited to removal of the subsequent layers, re-ripping, re-moisture conditioning, and re-compaction of the prior failed layer or any other measures deemed necessary by the Company Representative, shall be entirely at the Contractor’s own expense.

37.2.16. The Contractor shall maintain updated, accurate records of all compaction control tests, i.e. test data, test locations and layer elevation as hard copies (paper copy, filed), electronically (.pdf or .jpg format) and in tabular format (MS Excel Spreadsheet).

37.2.17. These records shall always be available on site for inspection by the Company Representative.

37.2.18. Where tests reveal that the density or moisture content of any layer, at any depth, is not to specification, the Contractor shall re-rip, re-water and re-compact as necessary such material, and shall entirely bear any costs associated with this action. If the specified density cannot be obtained by further compaction of the material, such material shall be removed and replaced by material capable of yielding the specified density.

37.2.19. Tests to check the density, moisture content and particle size distribution of the compacted material and/or to check the testing procedures of the Contractor as described above, may be carried out by the Company Representative. The costs of these tests will be paid for by the Company only if the results of the tests show that the specified density has been obtained.

37.2.20. The Contractor shall pay for all such tests where the results show that the specified density has not been obtained; also, he shall pay for any further tests to check if the required density, moisture content and particle size distribution has been obtained after the specified corrective measures have been carried out.

38. COMPACTION TO A PERFORMANCE SPECIFICATION

38.1. Should the Company Representative deem it to be an appropriate and sufficient

compaction control mechanism, certain specified embankments and fill may be constructed by applying a performance specification to each placed layer (hereinafter referred to as nominal or performance compaction).

38.2. These embankments and fill shall be formed by compacting selected moisture conditioned material in loose horizontal layers to the specified layer thickness prior to

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compaction and by applying a minimum number of passes to be specified by the Company Representative of an approved vibratory roller or loaded haul truck.

38.3. The minimum number of passes will be determined on site jointly by the Contractor and the Company Representative and will be based on the number of passes required to obtain the material specific compaction specification per Section 37.1.4.

38.4. The Company Representative reserves the right to re-execute these tests and to re- specify the minimum number of passes from time to time dependent on material variability, compactor type, moisture content etc.

38.5. If necessary, during and/or prior to compaction, water shall be provided to bring the soil to the correct moisture contents as directed by the Company Representative.

38.6. The Company Representative reserves the right to stop and condemn all “nominal/ performance” compaction work if in his opinion the Contractor is seen not to be executing the works as described above. All such remedial works shall be for the Contractor’s account. Compaction control shall thenceforth purely be subject to Section 37.

39. FINISH OF EARTHWORKS AND TOLERANCES

39.1. All embankments and excavations shall be neatly trimmed to the required widths, cross-

sections, surface finishes and levels as specified on the drawings and specifications. Where not specifically stated, the vertical tolerance is to be within ± 10mm.

39.2. The width of the formation measured from the final staked centre line shall in no case be less than the specified dimension. The tolerance on the depth and location of trenches shall be ± 10mm.

39.3. The Contractor shall provide and have available at all times during the contract working hours, the necessary staff and equipment to ensure that the correct setting out of the Works is maintained continuously throughout construction. Should any errors in setting out of the Works occur, such errors shall be corrected, and any necessary adjustments shall be carried out to the satisfaction of the Company Representative, at the Contractor’s cost. No payment will be made for extra material placed on the embankment as part of over-construction to the final design geometry by the Contractor, that is not required to be corrected.

40. MEASUREMENT AND PAYMENT

40.1. The Contractor shall construct the Works as detailed in the Contract Documents and the Schedule of Quantities at the prices quoted at the rates quoted or for Lump Sum for specific items as detailed in the Schedule of Quantities.

40.2. The prices quoted in the Schedule of Quantities shall be exclusive of GST.

40.3. The latest relevant Australian Standards shall be applied to all Works covered within the Tender Document.

40.4. The Contractor is to be aware that the Australian Standard 1181-1982 “Method of Measure of Civil Engineering Works and Associated Building Works”, states that slopes

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of cut and fill are measured net on plan area, unless the slope is greater than 1V:10H (Vertical: Horizontal), then that portion of the Works shall be measured on the net slope area. The Contractor is deemed to have taken this into account when establishing the Tender Sum.

40.5. The unit rates set out in the Schedule of Quantities shall be deemed to include the cost of complying with all conditions, obligations, and liabilities described in the Contract Documents, and the supply of all supervisory input, incidental plant, equipment, labour, and materials indicated or implied in these Documents. The descriptions entered against the items in Schedule of Quantities are intended only to identify the items. Reference must be made to the entire Schedule of Quantities, Specifications, and Drawings for a full description of the Works and liabilities covered by the prices entered against each item.

40.6. The appropriate unit rates include all costs such as wharfage, demurrage, delivery to site, storage, overhead charges, compliance testing and profit.

40.7. The unit rates and totals shown in the Schedule of Quantities are to be in Australian dollars (AUD) and cents.

40.8. All items shall be paid for according to the agreed quantities for each item and as approved by the Company Representative. Units of measurement shown in the unit column of the Schedule of Quantities have been abbreviated as follows:

ea each km linear kilometre m linear metre mP

2P square metre

mP

3P cubic metre

tonne or t metric tonne LS lump sum.

40.9. The measurement of any volumes will be in bank cubic metre volume measured as

compacted in place in the Works. Measurement of areas shall be net areas.

40.10. Any rates stated in the Schedule of Quantities shall be applied to any additions or deletions from the Contract Works and, where Works of a different nature or type are specified, these rates shall be used where possible, or shall form the basis of any rates agreed between the Company Representative and the Contractor.

40.11. All quantities are to be rounded up or down to the nearest whole number and quoted rates are to be to the nearest cent per unit.

40.12. The units of measure for items shall be based on the units listed in the Schedule of Quantities included in the Contract fee schedule. Regardless of quantity claimed, the

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measurement for payment is made to the specified pay limits, with exception where additional work has been directed by the Company Representative.

40.13. The Contractor is responsible for surveying of the Works before and after construction to determine the quantity of each unit for payment. The Contractor shall provide, where requested, additional calculations and explanations of figures to the satisfaction of the Company Representative to demonstrate how each quantity has been calculated.

40.14. The Company Representative may, at his own cost, perform additional surveys of the Works to provide a check of the Contractor’s measurements. In the event of a discrepancy between the two surveys, the Company Representative survey shall take precedence.

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PART B: PE LINER INSTALLATION

41. PE LINER MATERIALS

41.1. General

All liner materials must strictly comply with the requirements of this Specification. For all materials, a certificate of such compliance shall be provided to the Company Representative before the materials are incorporated into the work at least 14 days prior to commencement of the work.

Materials not protected against solar radiation shall be stored under cover to prevent damage by solar radiation. Materials and equipment damaged prior to, and/or during installation must not be used and must be replaced at the Contractor’s expense.

Production samples of materials shall be provided to the Company Representative and will be held throughout the period of the contract for the purpose of providing a reference against which all subsequent items may be gauged for compliance with this Specification.

The PE membrane liner shall be a new (virgin), ‘First’-quality product designed specifically for the purpose of hydraulic containment and of the thickness specified. The membrane shall be uniform, free of holes, blisters, bubbles, gels, nicks, cuts, undispersed raw materials, or any sign of contamination by foreign matter.

The PE liners (HDPE, LDPE, LLDPE, etc.) shall comply with the following minimum (or maximum where marked *) test values shown in Table 42-1..

Textured PE liner shall be double sided co-extruded textured either black or white surfaced. The PE liner material physical properties shall comply with Table 42-1.

.

42. QUALITY CONTROL

The liner shall be monitored throughout the manufacturing process for product integrity and consistency. Manufacturer shall test rolls in accordance with Table 42-2 for the following physical properties and at the following minimum frequency or per batch of resin, whichever results in the greatest number of tests.

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Table 42-1: Materials specifications

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Table 42-2: Liner QC testing frequency

Notes : (1) Of 10 readings; 8 out of 10 must be 0.18 mm, and lowest individual reading must be 0.13 mm; also see Note 6. (2) Alternate the measurement side for double sided textured sheet (3) Machine direction (MD) and cross machine direction (XMD) average values should be based on 5 test specimens each direction. Yield elongation is calculated using a gage length of 33 mm Break elongation is calculated using a gage length of 50 mm

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(4) The SP-NCTL test is not appropriate for testing geomembranes with textured or irregular rough surfaces. Test should be conducted on smooth edges of textured rolls or on smooth sheets made from the same formulation as being used for the textured sheet materials. The yield stress used to calculate the applied load for the SP-NCTL test should be the manufacturer’s mean value via MQC testing. (5) Other methods such as D 1603 (tube furnace) or D 6370 (TGA) are acceptable if an appropriate correlation to D 4218 (muffle furnace) can be established. (6) Carbon black dispersion (only near spherical agglomerates) for 10 different views: 9 in Categories 1 or 2 and 1 in Category 3 (7) The manufacturer has the option to select either one of the OIT methods listed to evaluate the antioxidant content in the geomembrane. (8) It is also recommended to evaluate samples at 30 and 60 days to compare with the 90-day response. (9) The condition of the test should be 20 hr. UV cycle at 75°C followed by 4 hr. condensation at 60_C. (10) Not recommended since the high temperature of the Std-OIT test produces an unrealistic result for some of the antioxidants in the UV exposed samples. (11) UV resistance is based on percent retained value regardless of the original HP-OIT value. (12) NA – not applicable for the type of material.

Certified test results shall be submitted to and approved by the Company Representative at least 14 days prior to geomembrane delivery to site. The Contractor shall submit a list which indicates date of production, plant location, resin batch number, manufacturing line number and identification number and square meter of each geomembrane roll. Rolls shall be listed in the order of production with the status of the roll (rejected or approved for shipment). All rolls shall be included in the list whether approved for shipment.

42.1. Resin

Resin used in the manufacture of geosynthetics shall be virgin first quality single source, compounded polyethylene resin manufactured specifically for the purpose of producing PE liners. A statement from the Manufacturer on the origin and type of the resin and supporting base resin density and OIT test results shall be provided and shall be reported to the Company Representative. There shall be no intermixing with other resin types. Reclaimed polymer shall not be added to the resin. The manufacturer may recycle edge trim from the roll being produced. Edge trim shall be returned immediately to the process but shall not exceed 2% of the total resin required. Edge trim which has been stored or sourced from other manufacturing lines shall not be recycled.

PE resin shall meet the requirements as listed in Table 42-3.

Table 42-3: Resin specifications

1 Base resin density without carbon black added

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Manufacturers Quality Control data and Certified test results for all rolls to be delivered to the site shall be submitted to and approved by the Company Representative at least 14 days prior to shipping the liner to the site.

42.2. Extrudate Material Requirement

The extrudate rod or bead shall be high quality polyethylene and shall be of the same formulation and same supplier as the resin used to produce the geomembrane. All additives shall be thoroughly dispersed throughout the extrudate rod or bead. There shall be no contamination by foreign matter in the extrudate rod or bead.

42.3. Roll Identification

Liner shall be supplied in rolls of a minimum width of 6.5 metres with no longitudinal joints in the width. As a minimum, each roll shall be labelled as follows:

a) roll number;

b) name of Manufacturer;

c) batch number of raw materials;

d) date of manufacture;

e) material thickness;

f) roll length and area;

g) product type and grade; and

h) reference to manufacturer's quality assurance report.

42.4. Liner Samples The Contractor shall submit for approval by the Company Representative samples of liner material and field seams prior to the start of construction. The Contractor shall submit 200mm x 250mm samples of liner materials which have been made in conformance with this Specification.

42.5. Quality Control Procedures Manual The liner Installer shall submit a Quality Control Procedures Manual to the Company Representative at least two weeks prior to the commencement of any installation of any PE geomembrane liner on the site (Hold Point). The Manual shall include:

• The Installers organisational structure and personnel, qualifications and experience of the proposed installation personnel;

• Inspection and Test Plans (ITP’s);

• A detailed Work Methos Statement for each facility;

• A liner panel layout drawing;

• Trial weld procedures;

• Storage and handling procedures; Measures to minimise wrinkling of the liner;

• Welding procedures, including equipment make and model;

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• Weld repair procedures;

• Non-destructive testing procedures;

• Destructive testing procedures;

• Pro-forma sheets for recording of installation and test results;

• Deployment equipment and procedures;

• Procedures to be employed during deployment and welding of geomembrane liners on slopes;

• Safety equipment;

• Any additional information specific to the project conditions that may be requested by the Company Representative.

The Contractor(s) shall submit to the Company Representative on a weekly basis all quality documentation and test results etc. indicated in the Quality Control Procedures Manual to demonstrate compliance with the quality system for the project and to demonstrate compliance with this specification.

Copies of these records and tests, as well as all corrective actions taken when results are unsatisfactory, shall be presented to the Company Representative in writing within one day following an inspection, test or action.

Final completion will not be certified until all records have been submitted. Records shall include the following:

a) Contractor’s panel layout drawing showing panel numbers and joint numbers, to be marked up progressively with the roll number used for each panel, and with the locations of samples taken for destructive testing;

b) manufacturer's roll production test reports for all rolls used in the work;

c) subgrade certification reports;

d) daily vacuum box or joint inflation test reports referenced to joint numbers;

e) daily test weld field test reports referenced to joint numbers, equipment identification, and operator, and including weather conditions and any adjustments to equipment controls;

f) destructive test field report and record of submission for laboratory testing referenced to joint number; and

g) laboratory test reports to be available within two weeks of testing. record drawing indicating liner seam locations, destructive test locations, cap strip locations as well as patches and all repairs for the liner system.

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43. LINER WARRANTY

43.1. Manufacturer’s Certification

The Contractor shall submit, to the Company Representative for approval, written Manufacturer's Certification that the liner material:

a) conforms to the material requirements of these Specifications;

b) is similar to and of the same formulation as that for which certification is submitted; and

c) has been demonstrated by actual usage to be satisfactory for the intended application.

Manufacturer's certification shall include the minimum average roll values for material to be furnished on this project. The Contractor shall obtain the Company Representative’s approval of the liner and all other materials to be used, prior to shipment to the site. The Contractor will not be allowed to unload or store on site, any material that is delivered prior to obtaining such approval.

43.2. Material Warranty The liner manufacturer shall furnish a written liner warranty for a period of 20 years. The warranty shall be against manufacturing defects or workmanship and against deterioration due to ozone, ultraviolet light rays, and/or other normal weather aging. The warranty shall be limited to replacement of material only.

43.3. Installer Warranty The Geomembrane Installer shall guarantee the geomembrane installation against defects in the installation and workmanship for 1 year commencing with the date of final acceptance. A written liner warranty will be required.

44. LINER PANEL LAYOUT DRAWING

The Contractor shall prepare liner panel layout drawings allocating a logical sequence of numbers to panels and joints. Three copies shall be submitted to the Company Representative as part of the overall procedure for approval (Hold Point). The panel layout should minimise the number of panels and the length of joints. Joints shall be oriented perpendicular to the batter slopes not across the batter slope wherever practical. No horizontal joint should be located within 1.5m of a batter toe line. Horizontal joints should be staggered across each width of roll. The panel layout may be varied in the field from that shown on the drawings only with the approval of the Company Representative. In addition to the panel layout drawing and in accordance with the Construction Procedure, refer to Section 5.2, the following should be included:

a) proposed starting position for the placement of the PE liner;

b) panel numbering system;

c) panel diagram showing panel dimensions and panel layout proposed to be used to a suitable scale;

h) relevant experience of geomembrane installer; and

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d) typical installation rates (m²/day) for both cell floor and side slopes.

45. AREAS TO BE LINED

45.1. Surface Preparation

The Contractor shall ensure that all surfaces to be lined including corners and around penetrations shall be finished smooth and free of all rocks, stones, sticks, roots, sharp objects and debris of any kind or any object which may damage the liner. The surface shall be rolled with a smooth drum roller to provide a firm unyielding compacted subgrade for the liner prior to placing of the liner (Hold Point).

Where a suitable surface cannot be achieved by treatment of the in-situ material, an imported smoothing fine course fill shall be placed. The smoothing fine course shall consist of a sandy clay material which shall be free of organic matter and coarse or sharp particles. The smoothing course shall be the minimum thickness necessary to maintain 150 mm minimum cover over irregularities or protrusions in the sub-grade formation unless shown otherwise on the Drawings. The surface shall be watered and rolled with a smooth drum roller to obtain a smooth uniform finish.

The upstream top corner of the anchor trench shall be rounded to avoid damage to the geomembrane liner. No loose soil or water will be permitted in the anchor trench. Anchor trenches are to be inspected and signed off by the Company Representative prior to installation of the geomembrane (Hold Point).

The Geomembrane Installer Supervisor shall provide daily written subgrade acceptance certifications to the Company Representative for the surface to be covered by the geomembrane in that day’s operation (Hold Point). The surface shall be maintained in a manner, during installation, to ensure subgrade suitability.

All subgrade damaged by construction equipment and deemed unsuitable for geomembrane deployment shall be repaired prior to placement of the geomembrane. All repairs shall be approved by the Company Representative and the Geomembrane Installer Supervisor (Hold Point). Surfaces to be lined shall be flat on any plane within ±50mm vertical tolerance in any area of 10mP

2P. All intersections between planes shall be

made along straight lines.

45.2. Maintenance Where surface finishing is completed ahead of liner installation, the surface shall be maintained until immediately prior to liner installation. This surface will need to be re- inspected again by the Company Representative and approved prior to installation of the liner (Hold Point). Sufficient equipment shall remain on the site until and during installation to enable reinstatement of the surface in the event of damage due to inclement weather. Any reinstatement work shall be at the expense of the Contractor. The Company Representative reserves the right to instruct the Contractor to perform remedial work to satisfy the criteria.

46. LINER INSTALLATION

Liner installation shall be performed in accordance with the International Association of Geosynthetic Installers HDPE and LLDPE Geomembrane Installation Specification. Rolls of liner shall be handled and securely stored to prevent damage prior to installation.

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Geomembrane shall be unrolled in a controlled manner directly into the final position. The method of unrolling shall not cause scratches or crimps in the material, nor shall it disrupt the integrity of the finished sub-grade.

The liner should be placed in a relaxed state such that the material can respond to thermal changes without excessive buckling, wrinkling or tensioning. No geomembrane material shall be unrolled and deployed if the material temperatures are lower than 0°C unless otherwise approved in writing by the Company Representative. Typically, only the quantity of geomembrane that will be anchored and seamed together in one day should be deployed.

In general, seams shall be orientated parallel to the line of maximum slope. In corners and odd shaped geometric locations, the total length of the field seam shall be minimized. Seams shall not be located at low points in the subgrade unless geometry requires seaming at such locations and if approved by the Company Representative.

The liner shall not be allowed to “bridge over” voids or low areas in the subgrade. The geomembrane shall rest in intimate contact with the subgrade. Temporary loading such as sandbags or tyres shall be placed on the liner to prevent wind damage during and after installation. It should be noted that this temporary loading should be of a suitable construction to prevent against damage of the liner. The Contractor shall be required to ensure that the spacing of these sandbags/tyres are appropriately designed (this could include tying the sandbags/tyres together in a horizontal and vertical direction) to prevent against uplift and potential damage of the liner.

All personnel working on the liner surface shall wear soft-soled shoes and shall not engage in any activity which may damage the liner. Machinery other than joint welding machinery shall not be operated on the liner.

47. JOINING OF LINERS

47.1. General

Joining of liners shall be carried out strictly in accordance with the manufacturer's written instructions and GRI GM 19. The Contractor shall provide a complete description of the processes to be used and shall identify the equipment proposed for accomplishing the joining.

No geomembrane material shall be seamed when the sheet temperature is below 0°C and above 75 °C as measured by an infrared thermometer or surface thermocouple unless otherwise approved by the Company Representative.

Fishmouths or excessive wrinkles at the seam overlap shall be minimized and when necessary cut along the ridge of the wrinkles back into the panel to effect a flat overlap. The cut shall be terminated with a keyhole cut (nominal 10 mm diameter hole) to minimize crack/tear propagation. The overlay shall subsequently be seamed. The keyhole cut shall be patched with an oval or round patch of the same base geomembrane material extending a minimum of 150 mm beyond the cut in all directions.

47.2. Personnel The Contractor shall nominate a Project Joint Welding Supervisor before commencing work and shall demonstrate that the Company Representative has a proven background

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in installation of lining systems and materials similar to those specified. All personnel employed in welding shall be competent and experienced in the use of the equipment.

The Contractor shall ultimately be responsible for ensuring the quality assurance programme is followed. The Company Representative shall be notified to be able to inspect Welds in accordance with the requirements of this specification.

47.3. Joint Welding Equipment Only specialised purpose-designed equipment approved by the liner manufacturer and the Company Representative shall be used. For long run work the machine shall be mounted on a carriage to operate at controlled speed. In all cases the temperature at the point of fusion shall be monitored and controlled with an interlock to the drive mechanism so that welding is stopped if the temperature falls outside the range at which satisfactory welding can be achieved.

Where the welding procedure includes provision for heated extrudate to be incorporated in the weld, any degraded extrudate, which has been overheated or heated and cooled in the barrel, shall be purged with fresh material prior to the resumption of welding.

Equipment shall be maintained on a regular basis to ensure efficient performance throughout.

The field tensiometer (NATA certified) shall have a current certificate of calibration in accordance with the manufacturer’s calibration recommendations (Hold Point).

47.4. Joint Strength Requirements Each test specimen should fail in the parent material and not in the weld as demonstrated by test welds and destructive test samples in accordance with Section 13. Breadth and depth of fusion between sheets shall be as required to meet these criteria. Where extrudates are included in the weld the extrudate material after fusion shall be fully compatible physically and chemically with the liner material.

The liner material shall not be overheated during welding so that crystallisation, oxidation, perforation, or degradation of the liner does not occur.

47.5. Weather Conditions Welding shall not be commenced or continued during rain, fog, excessive winds, or ambient temperatures outside the range of 10°C to 40°C and relative humidity is more than 80% or in accordance with the manufacturer guidelines. The joints adjacent to the corners of the ponds and the toe of the batters shall be made during the coolest part of the day and shall not be made when the liner is exposed to direct sunlight.

47.6. Liner Preparation The surface of the liner to be welded shall be clean, dry and free from any foreign matter and contaminants such as chemicals, hydrocarbons, clay, sand, etc. Where the liner manufacturer's instructions require the surfaces to be abraded prior to welding, this shall be carried out no more than one hour prior to welding, using appropriate mechanical abrading equipment recommended by the manufacturer. Care shall be taken to restrict grinding to the immediate area of the joint, and to avoid overgrinding which may reduce the effective liner thickness adjacent to the joint.

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47.7. Joint Lap

The minimum lap of adjacent liner sheets shall be 100mm, unless specified as greater by the liner manufacturer or the welding equipment supplier. "Fish mouths" along the joint should be minimised, but should they occur the material shall be cut, overlapped, and welded normal to the joint.

47.8. Fusion Welding (Primary Welds) Seam welding of PE liners shall be accomplished primarily by fusion welding using either a hot wedge or hot air welder.

The joint shall consist of a double weld produced by surface fusion with an air gap between. Pressure nipping rollers shall press the molten surfaces together immediately behind the hot air or hot wedge welder to complete the weld.

47.9. Extrusion Welding (Secondary Welds) Extrusion welding shall be used where fusion welding is not possible such as at pipe penetrations, patched, repairs, and short (less than a roll width) runs of seams.

Fusion welding shall be achieved by fusion of an extrudate on to the top surface of both sheets at the lap. The depth and width of engagement of the extrudate shall be as required to achieve the strength requirements. The means of deposition of the extrudate shall provide for full integration with the surface of the sheets, so that the weld becomes homogeneous with the liner.

47.10. Connections at Penetrations and to Structure Connections to liner penetrations and adjoining structures shall be made in accordance with the details shown on the construction drawings. Connections shall be at least equivalent in strength to the normal lap joints and the security of containment shall not be diminished. Local stresses in the liner at connections shall be minimised (Hold Point).

Penetrations shall be constructed from the base geomembrane material, flat stock, prefabricated boots and accessories as shown in the construction drawings.

47.11. Anchorage

Anchor trenches shall be excavated in accordance with the details on the construction drawings and shall be kept well drained to avoid softening during rain periods and maintained to not dry, desiccate and crack. Trenches shall be filled in early morning when the liner is at maximum contraction. Filling shall be carried out in a planned, logical sequence to avoid overstressing of the liner.

Fill Material for the anchor trench shall be Zone 2B material unless specified otherwise.

The fill material shall be compacted to 95% SMDD, as determined by AS 1289. The compacted anchor trench fill shall be tested for moisture content and maximum dry density at the rate of one test per 100m of trench.

48. INSPECTIONS, TESTING AND REPAIR

All areas found to be defective shall be repaired at the expense of the Contractor. The Company Representative shall be notified of defective areas prior to the repair taking

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place (Hold Point). The Contractor shall ensure a plan is marked up showing the locations of repairs made and the type of repair made. The marked-up drawing shall be handed to the Company Representative at completion and agreed upon with the Contractor.

48.1. Visual Inspections The entire surface of every sheet of liner material shall be inspected by the Contractor during placing to identify any tears, abrasions, indentations, cracks, thin areas, or other defects.

Any defects such as holes, tears, blisters, lamination, undispersed raw materials or visible non-uniformity or contamination by foreign matter which in the opinion of the Company Representative is detrimental to the long service life required of the membrane liner, shall be grounds for rejection of the membrane liner material.

Where additional faults are found, the Company Representative reserves the right to reject the roll.

The Contractor shall replace any rejected rolls and repair any defects to the Company Representative's satisfaction at the Contractor’s expense.

48.2. Field Seam Testing All field seams shall be subjected to both non-destructive and destructive field testing. Additionally, representative samples of field seams shall be taken for laboratory testing by an independent, appropriately qualified geosynthetic laboratory. The following tests shall be carried out at the specified frequencies. Testing of each length of seam shall be carried out within 48 hours of its completion.

48.2.1. Test Welds (In Field) Test welds shall be made as follows:

a) prior to commencement of each shift

b) following any break in operation; and

c) following any significant adjustment to welder controls. Test seams shall be made by each welding technician and tested in accordance with ASTM D4437 at the beginning of each seaming period. Test seaming shall be performed under the same conditions and with the same equipment and operator combination as production seams. The test seam shall be approximately 3.3 m long for fusion welding and 1 meter long for extrusion welding with the seam centred lengthwise. At a minimum, tests should be made by each technician once 4-6 hours; additional tests may be required with changes in environmental conditions.

Two 25 mm wide specimens shall be die-cut by the Geomembrane Installer from each end of the test seam. These specimens shall be tested by the Geomembrane Installer using a field tensiometer testing both tracks for peel strength and direct shear strength tests. The weld will be considered acceptable if the test piece fails in the un-welded liner away from the joint. If the field test fails then further test welds shall be made after appropriate adjustment of the welder controls and retested until an acceptable weld is obtained.

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Field test results shall be recorded, and test pieces marked and stored. The Company Representative reserves the right to take further test pieces from the test welds for independent tests offsite.

The acceptance criteria for peel and shear strength testing are as specified below or as recommended by the manufacturer of the liner. The Company Representative will be required to agree to the alternative acceptance criteria prior to commencement of the work. The minimum acceptance criteria for a 1.5mm liner are as follows:

a) Peel Strength (fusion weld) > 15.9kN/m

b) Peel Strength (extrusion weld) > 13.6kN/m

c) Shear Strength (fusion and extrusion welds) > 21kN/m

48.2.2. Non-Destructive Testing (In Field)

48.2.2.1. Air Pressure Testing: Double fusion seams with and enclosed channel shall be air pressure tested by the Geomembrane Installer in accordance with ASTM D5820 and ASTM D4437.Every liner joint shall be subject to close visual inspection and to continuous non-destructive testing.

Double-welded joints shall be subject to air pressure testing. The testing shall be achieved by inflation of the space between the welds to approximately 210kPa pressure or in accordance with the manufacturers recommended pressure and following the 2 minute ‘relaxing period’ (whereby the air temperature and pressure stabilises), the air pressure will be monitored for 5 minutes and the pressure loss recorded.

The acceptance criteria for loss of pressure are as specified below or as recommended by the manufacturer of the liner. The Company Representative will be required to agree to the alternative acceptance criteria prior to commencement of the works. If pressure loss does not exceed 28 kPa after 5 minutes, the seam shall be considered leak tight.

48.2.2.2. Vacuum Testing: For single welded joints testing shall be achieved using vacuum testing. Vacuum testing shall be performed by the Geomembrane Installer in accordance with ASTM D4437 and ASTM D5641.

The vacuum pump shall be charged, and the tank pressure adjusted to approximately 35 kPa. The acceptance criteria are as specified: if no bubbles appear while the vacuum is held for 5 seconds then the joint is satisfactory.

48.2.2.3. Spark Testing: Where field non-destructive testing cannot be performed, seams shall be field spark tested by standard holiday leak detectors in accordance with ASTM D6365. Spark testing shall be performed in areas where both air pressure testing and vacuum testing are not possible.

Equipment for Spark Testing shall be comprised of but not limited to a hand-held holiday spark tester and conductive wand that generates a high voltage. The testing activities shall be performed by the Geomembrane Installer by placing an electrically conductive tape or wire beneath the seam prior to welding. A trial seam containing a non-welded segment shall be subject to a calibration test to ensure that such a defect (non-welded

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segment) will be identified under the planned machine settings and procedures. Upon completion of the weld, the spark tester shall be held approximately 25 mm above the weld moving slowly over the entire length of the weld in accordance with ASTM D6365. If there is no spark the weld is considered to be leak free.

48.2.3. Destructive Testing (In Field & In Laboratory) Samples for destructive testing may be taken from finished joints at locations as directed by the Company Representative at a frequency of up to one sample per 150 metres of seam length or another predetermined length in accordance with ASTM D6392. The sample shall be taken by the Geomembrane Installer from a location specified by the Company Representative.

If any samples fail field testing, then additional samples may be taken to define the extent of sub-standard joint. Destructive testing of the joints must be carried out on a continuous basis and not at the end of the works.

Each sample shall be 1000 mm long parallel to the joint by 300mm wide, with the joint central in width. The sample shall be cut into three equal sections and distributed as follows:

a) field test sections for five peel tests and five shear strength tensiometer tests to be made, as described above;

b) independent test section for five peel tests and five shear strength tests to be performed at an offsite testing laboratory; and

c) record section to be marked and submitted to the Company Representative with the corresponding field test report, and with reference to submission of the independent test specimen.

For field testing, the Geomembrane Installer shall cut 10 identical 25 mm wide replicate specimens from his sample. The Geomembrane Installer shall test five specimens for seam shear strength and five for peel strength. Peel tests will be performed on both inside and outside weld tracks. To be acceptable, 4 of 5 test specimens must pass the stated criteria in section 2.02 with less than 25% separation. If 4 of 5 specimens pass, the sample qualifies for testing by the testing laboratory.

Independent seam testing shall be conducted in accordance with ASTM 5820 or ASTM D4437.

For field seams, if a laboratory test fails, that shall be considered as an indicator of the possible inadequacy of the entire seamed length corresponding to the test sample.

Additional destructive test portions shall then be taken by the Geomembrane Installer at locations indicated by the Engineer; typically, 3 m on either side of the failed sample and laboratory seam tests shall be performed. Passing tests shall be an indicator of adequate seams. Failing tests shall be an indicator of non-adequate seams and all seams represented by the destructive test location shall be repaired with a cap-strip extrusion welded to all sides of the capped area. All cap-strip seams shall be non-destructively vacuum box tested until adequacy of the seams is achieved. Cap strip seams exceeding 50 m in length shall be destructively tested.

The acceptance criteria for peel and sheer strength testing, is as specified in Section 32.15 or as recommended by the manufacturer of the liner.

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48.2.4. Identification of Defects

Panels and seams shall be inspected by the Installer and Owner's Representative during and after panel deployment to identify all defects, including holes, blisters, undispersed raw materials and signs of contamination by foreign matter.

48.2.5. Evaluation of Defects Each suspect location on the liner (both in geomembrane seam and non-seam areas) shall be non-destructively tested using one of the methods described in Section 32.15. Each location which fails non-destructive testing shall be marked, numbered, measured and posted on the daily "installation" drawings and subsequently repaired.

If a destructive sample fails the field or laboratory test, the Geomembrane Installer shall repair the seam between the two nearest passed locations on both sides of the failed destructive sample location.

48.2.6. Post Installation Testing The Contractor shall undertake electrical leak detection testing of the primary liner in accordance with ASTM D6747 as soon as practical after construction. Installation and material defects detected by the electrical testing process shall be covered under the Installer warranty and shall be repaired to the approval of the Company Representative.

48.2.7. Repair Procedures Any portion of the PE liner with a flaw or that fails a non-destructive or destructive test shall be repaired by one of the following methods:

a) Patching for holes, defects or tears 10mm or larger in diameter or length – used to repair large holes, tears, large panel defects, and destructive sample locations that are less than 2mP

2P in total area;

b) Extrusion – used to repair relatively small defects in panels and seams not greater than 10mm in length;

c) Capping – used to repair failed welds or liner seams where welds cannot be non- destructively tested; and

d) Removal – used to replace areas with large defects where the preceding methods are not appropriate. Also used to remove excess material (wrinkles) from the installed liner.

Once the repair has been completed, further non-destructive or destructive testing shall be carried out to ensure the repairs are completed to the requirements of this Specification.

48.2.8. Wrinkles Any wrinkles that can fold over shall be repaired either by cutting out excess material or, if possible, allowing the liner to contract as the temperature decreases. In no case shall material be placed over the liner that could result in the liner folding. All folded liner shall be removed. No material shall be placed in areas where the liner is not in contact with the supporting sub-grade.

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48.2.9. Verification of Repairs on Seams

Each repair shall be non-destructively tested using either vacuum box or spark testing methods. Tests which pass the non-destructive test shall be taken as an indication of a successful repair. Failed tests shall be re-seamed and retested until a passing test result.

The number, date, location, technician and test outcome of each patch shall be recorded.

49. CLEANING UP

On completion of the Liner Installation work on site, the Contractor shall clean up and leave the whole area ready for use by following Contractors to the satisfaction of the Company Representative (Hold Point).

50. ACCEPTANCE CRITERIA

The Company Representative shall release the work as being complete upon the following but not limited to, and in line with the manufacturer’s recommendations:

a) Checks on application and final finish;

b) The installation of PE liners has been completed and signed off

c) Repairs to defects have been completed;

d) Site has been left Clean with no litter; and

e) All required documentation has been provided to the Company Representative in accordance with Section 32.15.

Any work that does not comply shall result in a Non-conformance.