PROJECT: VOORSPOED MINE PIT CLOSURE STUDY · PROJECT: VOORSPOED MINE – PIT CLOSURE STUDY 2015/2016 7 VSM is preparing to consult with the authorities to propose and negotiate a

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PROJECT: VOORSPOED MINE – PIT CLOSURE STUDY

Date: Technical Memo submitted: 25 November 2015

Final Document submitted: 21 June 2016

To: Hans Kgasago

Company: Voorspoed Mine

Client P/O 41006144750

From: E-TEK Consulting & Redco

Project No: E-TEK :187.3

Report number: E-TEK 10079

7 Solomon Str, Potchefstroom, 2531

PO Box 19144, Noordbrug, 2522

Tel office: +27 18 294 3652

Mobile: +27 83 446 6154

E-mail: [email protected]

mailto:[email protected]

PROJECT: VOORSPOED MINE – PIT CLOSURE STUDY 2015/2016

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TABLE OF CONTENTS

1. PURPOSE OF DOCUMENT ........................................................................................................................ 6

2. BACKGROUND ........................................................................................................................................... 6

3. SCOPE OF WORK ....................................................................................................................................... 7

4. ALTERNATIVES CONSIDERED ................................................................................................................. 7

5. DISCUSSION AND CLARIFICATION OF ALTERNATIVES ...................................................................... 8

5.1. BASIS OF ESTIMATE FOR THE COSTING OF SCENARIOS ......................................................... 8

5.2. SCENARIO 1: RESOURCE COVER, CONCRETE WALL AND ENVIROBERM .............................. 8

5.2.1. Specifications ......................................................................................................................... 8

5.2.2. Cost: Scenario 1 ................................................................................................................... 11

5.2.3. Feasibility / construction risks ............................................................................................... 12

5.2.4. Water balance ...................................................................................................................... 13

5.3. SCENARIO 2: RESOURCE COVER, RESHAPE TOP BENCH TO 18°, CONCRETE WALL AND ENVIROBERM ........................................................................................................................................... 14

5.3.1. Specifications ....................................................................................................................... 14

5.3.2. Cost: Scenario 2. .................................................................................................................. 17


5.3.4. Water balance ...................................................................................................................... 18

5.4. SCENARIO 3: PARTIAL IN-FILL – ANGLE OF REPOSE, CONCRETE WALL AND ENVIROBERM ........................................................................................................................................... 19

5.4.1. Specifications ....................................................................................................................... 19

5.4.2. Cost: Scenario 3 ................................................................................................................... 21


5.4.2. Water balance ...................................................................................................................... 22

5.5. SCENARIO 4: PARTIAL IN-FILL – RESHAPED TO 18°, CONCRETE WALL AND ENVIROBERM ........................................................................................................................................... 22

5.5.1. Specifications ....................................................................................................................... 22

5.5.2. Cost: Scenario 4 ................................................................................................................... 25


5.5.4. Water balance ...................................................................................................................... 26

5.6. SCENARIO 5: RESOURCE COVER, CONCRETE WALL, ENVIROBERM AND OPTIMISE CATCHMENT ............................................................................................................................................. 26

5.6.1. Specifications ....................................................................................................................... 26

5.6.2. Cost: Scenario 5 ................................................................................................................... 29


5.6.4. Water balance ...................................................................................................................... 30

5.7. SCENARIO 6: COMPLETE IN-FILL WITH ALL AVAILABLE MRD MATERIAL .............................. 31

5.7.1. Specification ......................................................................................................................... 31

5.7.2. Cost: Scenario 6 ................................................................................................................... 33


6. BENEFICIAL LAND USE OF THE FARM INCLUDING THE OPEN PIT ................................................. 34

7. ENHANCED SCENARIO 7: ALTERNATIVE LAND USE OF THE PIT .................................................... 35


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7.1. SCENARIO 7: RESOURCE COVER, ACCESS ROUTE, FENCE, ENVIROBERM AND OPTIMISE CATCHMENT ............................................................................................................................................. 35

7.1.1. Specifications ....................................................................................................................... 35

7.1.2. Cost: Scenario 7 ................................................................................................................... 38


7.1.4. Water balance ...................................................................................................................... 39

8. RISK ASSESSMENT AND COST-BENEIFT ANALYSIS ......................................................................... 39

8.1. METHODOLOGY AND APPROACH ............................................................................................... 39

8.2. OUTPUTS OF RISK ASSESSMENT................................................................................................ 40

9. STANDARD OPERATING PROCEDURE FOR SITE-WIDE CLOSURE .................................................. 47

ANNEXURE A: RISK ASSESSMENT AND COST-BENEFIT ANALYSIS ..................................................... 48

ANNEXURE B: STANDARD OPERATING PROCEDURE FOR CLOSURE ................................................. 49

ANNEXURE C: PRESENTATION OF OPEN PIT CLOSURE SCENARIOS AND COSTS ............................ 50


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FIGURES

Figure 1: Model of the final pit and waste rock dump at life of mine ...........................................................................6

Figure 2: Typical details of the reinforced concrete wall and enviroberm .................................................................10

Figure 3: Scenario 1 – Layout illustrating the concepts (no water) ...........................................................................10

Figure 4: Scenario 1 – Cross section A-A indicates the concepts and estimated pit lake level, NGL and ZOR .......11

Figure 5: Scenario 1 – Cross section B-B indicates the concepts and estimated pit lake level, NGL and ZOR .......11

Figure 6: Modelled rate of rise of the pit lake (108 ha catchment) ............................................................................14

Figure 7: Scenario 2 – Layout illustrating the concepts (no water) ...........................................................................15

Figure 8: Scenario 2 – Layout after filling with water ................................................................................................16

Figure 9: Scenario 2 – Cross section A-A indicates the concepts and estimated pit lake level, NGL and ZOR .......16

Figure 10: Scenario 2 – Cross section B-B indicating the concepts and estimated pit lake level, NGL and ZOR ....17

Figure 11: Scenario 3 – Layout illustrating the concepts (no water) .........................................................................20

Figure 12: Scenario 3 – Layout after filling with water ..............................................................................................20

Figure 13: Scenario 3 – Cross section A-A indicating the concepts and estimated pit lake level, NGL and ZOR ....21




Figure 17: Scenario 4 – Cross section A-A indicating the concepts and estimated pit lake level NGL and ZOR .....24






Figure 23: Modelled rate of rise of the pit lake (increased catchment to 180 ha) .....................................................31

Figure 24: Scenario 6 – Layout illustrating the concepts ..........................................................................................32

Figure 25: Scenario 6 – Cross-section A-A indicating the concepts .........................................................................32

Figure 26: Scenario 6 – Cross-section B-B indicating the concepts .........................................................................33





Figure 31: Risk summary for Accessibility to the Open pit ........................................................................................41

Figure 32: Risk summary for Open pit sidewall stability ...........................................................................................42

Figure 33: Risk summary for impact on Water resources .........................................................................................43

Figure 34: Risk summary for impact on Land capability and End land use ..............................................................44

Figure 35: Risk summary for impact on Natural resources .......................................................................................45

Figure 36: Risk summary for impact associated with Government and stakeholders ..............................................46


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TABLES

Table 1: Scenario 1 – Detail of cost estimate. ..........................................................................................................12

Table 2: Scenario 2 – Detail of implementation cost estimate ..................................................................................17





Table 7: Enhanced Scenario 7 – Detail of cost estimate. .........................................................................................38


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1. PURPOSE OF DOCUMENT

Basis of design, discussions and estimated cost for the implementation of the Voorspoed Mine (VSM)

pit closure alternatives (technical component), including the associated risks and standard operating

procedures for site-wide closure.

Figure 1: Model of the final pit and waste rock dump at life of mine

2. BACKGROUND

VSM is in the process of planning for mine closure in accordance with the Anglo American Mine

Closure Toolbox (MCT). The current life of mine (LOM) is 2021 and according to the MCT, a mine

needs to aim at developing a Final closure plan within the last five years of operation.

At the time of submission of certain amendments to the Environmental Management Programme

(EMPr), the Department of Mineral Resources (DMR) approved the EMPr subject to certain

suspensive conditions. One condition was that VSP had to backfill all open excavations to natural

ground level (NGL), including the open pit.

High level modelling and cost estimation indicated that backfilling of the pit would result in excessive

costs that were not economically viable. Furthermore, the department was expecting more from the

mining company than what could be considered proportional to the benefits that could be achieved

by mining.


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VSM is preparing to consult with the authorities to propose and negotiate a commitment to implement

a feasible pit closure option that would comfortably fit into the physical and social setting into which

the mine lease area was transformed during mining activities. The chosen option will be aligned with

the agreed final land uses as far as possible and address the identified risks associated with closure.

3. SCOPE OF WORK

E-TEK was appointed to assist VSM with the following:

Establishment of open pit closure scenarios or alternatives for VSM (Sections 4 to 7 of this report);

The identification of the associated risks as well as a cost-benefit analysis (Section 8 of this report,

as well Annexure A);

Developing a site wide closure Standard Operating Procedure (SOP) for the implementation of

the closure plan and closure application process for the entire mine. This document was completed

in November 2015 and is referred to as the Voorspoed Mine Closure SOP, which includes the

Mine closure Legal compliance assessment checklist (Section 9 as well as Annexure B); and

Presentation of the various open pit closure scenarios to DMR (Annexure C)

4. ALTERNATIVES CONSIDERED

The following alternatives for closure of the pit have been identified after the screening of alternatives

and consultation with the client. Refer to Section 5 for detailed descriptions of the alternatives:

OPTION DESCRIPTION OF SCENARIO COMMITMENT

Scenario 1 Cover the remaining resource in the pit

Construct a concrete wall around the pit rim, outside the calculated

zone of relaxation (ZOR)

Construct an enviroberm outside of the concrete wall

Scenario 2 Cover the remaining resource in the pit


ZOR


Reshape the top bench to 18 degrees (°)

Scenario 3 Fill pit partially

Slope of infilling at angle of repose – from pit rim to pit floor

Construct a concrete wall and enviroberm as per Scenario 1

Scenario 4 Fill pit partially

Reshape slope infilling to 18° from pit rim to pit floor

Construct a concrete wall and enviroberm as per Scenario 1

Scenario 5 Optimise runoff catchment to increase volume of water stored in the

pit lake

Cover the remaining resource in the pit


ZOR


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OPTION DESCRIPTION OF SCENARIO COMMITMENT


Scenario 6 Complete infill of pit with all mineral resource deposit (MRD) material

available

Enhanced Scenario 7 Optimise runoff catchment to increase volume of water stored in the

pit lake

Cover the remaining resource in the pit

Demolish haul roads below the final pit lake level

Keep only 1 access route from the pit perimeter to the final pit lake

level (Other entrances and switch backs demolished)

Construct a fence all around the pit rim, outside the calculated ZOR

Construct an enviroberm outside of the fence

Excavate a trench around the enviroberm

5. DISCUSSION AND CLARIFICATION OF ALTERNATIVES

5.1. BASIS OF ESTIMATE FOR THE COSTING OF SCENARIOS

Rates used were based on market-related and industry norm rates. The rates are subject to

change upon final design.

It was assumed that the implementation of chosen scenarios will be implemented after mine

closure and not during the operational phase (There can be a significant savings if certain actions

are implemented as an operational cost).

Higher unit rates and preliminary and general costs (P&Gs) for certain items can be expected in

the event of the implementation being done during the operational phase. This is due to regulated

access and expected health and safety requirements.

Quantities and rates were based on conceptual designs and modelling done by the client and

E-TEK and subject to change.

P&Gs and contingencies have been included at indicative values. Detail planning is required,

which will inform the implementation plan, e.g. project duration and whether it will be implemented

as a standalone contract or part of other closure actions.

Allowances where made for P&Gs based on the overall estimated project value.

The costing was done based on current (2015) rates. No inflation factors have been applied.

5.2. SCENARIO 1: RESOURCE COVER, CONCRETE WALL AND ENVIROBERM

Refer to Figure 2, Figure 5 and Table 1.

5.2.1. Specifications

5.2.1.1 Resource cover

Cover the remaining visible resource at the bottom of the pit with a layer of imported waste rock

to a depth of approximately 10 m above the resource. This should discourage illegal miners from


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entering the pit, thereby reducing the risk of illegal mining during the period that the pit lake is

forming.

o Load, haul, dump and spread material sourced from the waste rock dump (WRD). Access the

pit via the existing pit ramps.

Utilise equipment with suitable braking and emergency stop systems.

o Compact to specifications.

5.2.1.2 Concrete wall

Construct a reinforced concrete wall around the entire pit rim approximately 10 m outside the ZOR

of the pit. The ZOR boundary will be delineated by the client.

o The primary function of the reinforced concrete wall is to create a sustainable barrier that will

minimise the risk of access to the pit after closure.

Total length of the reinforced concrete wall will be ±4,070 m.

o Excavate topsoil and incompetent material from the foundation footprint to a minimum

specification of 0.5 x 0.8 m. Rework and compact the in situ material where needed.

o Import suitable waste rock and compact as a base layer up to a depth of 500 mm below NGL

where over excavation has occurred.

o Cast a reinforced concrete strip foundation with construction joints as specified. Install

reinforcement starter bars for the wall to be cast.

o Cast the reinforced concrete wall, in two lifts, on the prepared foundation. The final height of

the concrete wall should be 2.4 m above NGL.

o Backfill and profile the immediate area adjacent to the wall. Slope the terrain away from the

wall to avoid future ponding of runoff water against the foundation of the concrete wall.

5.2.1.3 Enviroberm

Construct an enviroberm approximately 10 m outside the reinforced concrete wall.

o Construct the enviroberm only on the northern and western sides of the pit perimeter and abut

against the WRD on the northern and southern sides. The WRD on the eastern side will fulfil

the same function as the enviroberm.

o The primary function of the enviroberm is to screen the pit perimeter, i.e. for aesthetic reasons

and as a storm water diversion berm where required.

Construction method:

o Excavate the berm’s foundation footprint to a minimum depth of 300 mm and place excavated

material close by to utilise as growth medium after the construction of the enviroberm.

o Load and haul the required material from the WRD, spread in layers, shape and compact to

specifications.

o The specifications of the enviroberm:

Total length: ±1,570 m

Height: minimum of 2 m above NGL

Crest width: ±5 m

Side slopes no steeper than 1:5 to ensure long-term stability

o Spread and profile the excavated material over the enviroberm to serve as a growth medium.

o Ameliorate and vegetate the cover layer.


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Vegetate with indigenous vegetation, i.e. diversity of grass, tree and shrub species on the

crest.

Figure 2: Typical details of the reinforced concrete wall and enviroberm

Figure 3: Scenario 1 – Layout illustrating the concepts (no water)


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Figure 4: Scenario 1 – Cross section A-A indicates the concepts and estimated pit lake level, NGL and ZOR

Figure 5: Scenario 1 – Cross section B-B indicates the concepts and estimated pit lake level, NGL and ZOR

5.2.2. Cost: Scenario 1

The cost estimate to implement Scenario 1 is indicated in Table 1 below.


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Table 1: Scenario 1 – Detail of cost estimate.

5.2.3. Feasibility / construction risks

The following construction activities may pose significant challenges and risks:

o Cover resource:

Non-compliance with regulations and Anglo American plc (AA) health and safety

(H&S) requirements, i.e. the existing policies for safety may not allow the activity to

continue (risk too high);

Compliance with regulations and Anglo American plc (AA) health and safety (H&S)

requirements, i.e. the compliance may introduce excessive measures and costs to

mitigate the safety risk;

Hauling down gradient into the pit may cause brake failures with subsequent fatal

accidents;

Ramp instability and premature failure during construction;

Pit instability – falling rocks and objects, and slope failure may make the pit

inaccessible or cause serious injuries;

Traffic control in the pit will be required to prevent accidents, but this will slow down

production;

Dozer working in confined area while reshaping the cover layer;

Flooding of the pit during construction will temporarily stop backfilling, increase risk

of slope and ramp failures and risk of skidding; and

Inadequately skilled supervision and operators will increase the risk of serious

accidents and reduce production rates.

o Construction of reinforced concrete wall:

Non-compliance and compliance with H&S;

Scenario 1: Description Notes Unit Qty Rate Cost Sub-Total

1 Resource cover at bottom and construct concrete wall and enviroberm around pit

1.1 Construct Enviroberm m 1 570 6 293 650

1.1.1 Prepare foundations Excavate foundation footprint; minimum depth of

300mm; stockpile nearby to utilize as growth medium

after construction of the enviroberm

m3 11 775 42.50R 500 438

1.1.2 Load & haul Load and haul material from WRD; spread and compact in

layers according to specificationsm3 58 875 95.00R 5 593 125

1.1.3 Spread growth

medium

Spread stripped topsoilm3 11 775 8.50R 100 088

1.1.4 Ameliorate and

vegetate

Supply and spread Ameliorate; Supply and spread

indigenous vegetation, i.e. diversity of grass species and

trees and shrubs on crest, thorny / hedge plant

ha 4 25 000.00R 100 000

1.2 Construct Concrete

Wallm 4 070 18 447 682

1.2.1 Excavate foundations Excavate topsoil and incompetent material from

foundation footprint to a minimum depth of 0.5m.

Assume 20% increase due to trench topography.

m3 1 954 85.00R 166 056

1.2.2 Prepare foundations Rework and compact insitu material; Import suitable

waste rock & compact as base layer up to a depth of

500mm where needed (20% of foundatrion length)

m3 326 95.00R 30 932

1.2.3 Cast reinforced - strip

foundation

Including concrete, reinforcement, formwork & labour

m3 977 4 670.00R 4 561 656

1.2.4 Cast reinforced - wall Cast wall in two lifts; Rate including concrete,

reinforcement, formwork & labourm3 2 930 4 670.00R 13 684 968

1.2.5 Backfill Backfill & compact around foundation m3 407 10.00R 4 070

1.3 Resource Cover 8 372 500

1.3.1 Load & haul Haul down ramp; low production; 3km m3 85 000 90.00R 7 650 000

1.3.2 Spread and compact Spread m3 85 000 8.50R 722 500

Sub total 33 113 832

P&G's@ 35% 11 589 841

Contingencies @ 10% 3 311 383

Total ex VAT 48 015 056


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Non-compliance with SABS standards as per scope of work (SOW); and

Inadequately skilled supervision and artisans.

o Construction of enviroberm:


Non-compliance with SABS standards as per SOW;

Inadequately skilled supervision and operators; and

Inadequately skilled supervision and labour of subcontractors. (Amelioration and

vegetation establishment).

Residual risks after the above mitigation measures have been implemented are provided in the

accompanying risk assessment report.

5.2.4. Water balance

A basic water balance was developed for the pit to assess the likelihood of a pit lake forming and the

extent to which the water level will rise projected over time. The results have been supplied to the

client as an interactive spreadsheet.

Dewatering rates and rainfall records for the corresponding period were obtained from the client

for 2012 to 2015 and used to calibrate the model.

Physical properties of rock formations were obtained from the latest Itasca Groundwater Report

(2014).

It was assumed that mining and dewatering will cease in 2021. The results of the analysis indicate

the following:

o A pit lake will form over time mostly due to the inflow from runoff from the pit catchment (108

ha) during rainfall events, i.e. the pit side slopes as well as the area between the pit perimeter

and the reinforced concrete wall.

o There is a 50% probability that the pit level will reach levels between 1,263 and 1,269 mamsl

at the end of 2071.Refer to Figure 6.

o The pit will then store between 8,900,000 m3 and 9,600,000 m3 water.

o Groundwater inflow contributes to about 38% of the annual inflow into the pit at end of LOM

and will decrease to less than 20% after 50 years, i.e. when the water level reaches 1,263

mamsl.

o The pit water levels will fluctuate between 1,260 and 1,265 mamsl if water is abstracted from

the pit lake at a rate of 100,000 to 180,000 m3/annum.

o The current allocation of irrigation water by the department of water and sanitation (DWS) to

farmers is approximately 7,700 m3/ha/annum Using the allocation as a benchmark, it could be

assumed that a farmer could irrigate between 13 and 23 ha of agricultural crops sustainably

from the pit lake.


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Figure 6: Modelled rate of rise of the pit lake (108 ha catchment)

5.3. SCENARIO 2: RESOURCE COVER, RESHAPE TOP BENCH TO 18°,

CONCRETE WALL AND ENVIROBERM

Refer to Figure 2, Figure 7 to Figure 10 and Table 2




to a depth of approximately 10 m. This should discourage illegal miners from entering the pit,

thereby reducing the risk of illegal mining during the period that the pit lake is forming.

Specifications as per Scenario 1 (p. 8).


Construct a reinforced concrete wall around the total pit perimeter approximately 10 m outside the

ZOR of the pit. The ZOR will be delineated by the client.

The primary function of the reinforced concrete wall is to create a sustainable barrier to minimise

the risk of access to the pit after closure.


5.3.1.3 Enviroberm


Construct the enviroberm only on the northern and western side of the pit perimeter and abut

against the WRD on the northern and southern sides. The WRD on the eastern side will fulfil the

same function as the enviroberm (Figure 7).

The primary function of the enviroberm is to screen the pit perimeter, i.e. for aesthetic reasons and

to act as a storm water diversion berm where required.


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5.3.1.4 Top bench reshape.

Reshape only the top bench around the pit perimeter to 18° by cutting back material and placing

it outside the pit perimeter.

This material could be used for the construction of the enviroberm.

The main function of the reshaped top bench will be to improve the aesthetic quality of the pit rim.

(Unstable material is removed and vegetation will establish).

o Cut back and place the material outside pit ZOR.

o Utilise the excavated material to construct the enviroberm.

o Supply and spread ameliorate and supply and spread indigenous vegetation, i.e. diversity of

grass, tree and shrub species.



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Figure 8: Scenario 2 – Layout after filling with water

Figure 9: Scenario 2 – Cross section A-A indicates the concepts and estimated pit lake level, NGL and ZOR


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Figure 10: Scenario 2 – Cross section B-B indicating the concepts and estimated pit lake level, NGL and ZOR

5.3.2. Cost: Scenario 2.

The cost estimate to implement Scenario 2 is summarised in Table 2.

Table 2: Scenario 2 – Detail of implementation cost estimate


The following construction activities provide significant challenges and risks:

o Cover resource:





2 Resource cover at bottom & Reshape top bench to 18°; construct concrete wall and enviroberm around pit

2.1 Construct Enviroberm m 1 570 5 704 900

2.1.1 Prepare foundations Excavate topsoil from foundation footprint; minimum

depth of 300mm; stockpile nearby to utilize as growth

medium after construction of the berm

m3 11 775 42.50R 500 438

2.1.2 Load & haul Load and haul material from top bench cut back; spread

and compact in layers according to specificationsm3 58 875 85.00R 5 004 375

2.1.3 Spread growth

medium

Spread stripped topsoilm3 11 775 8.50R 100 088


vegetate

Supply and spread required ameliorants; Supply and

spread indigenous vegetation seed. i.e. diversity of grass

species, trees and shrubs on crest, thorny / hedge plants. ha 4 25 000.00R 100 000


Wall

See details above - Scenario 1m 4 070 4 532.60R 18 447 682 18 447 682

2.3 Resource Cover See details above - Scenario 1 m3 85 000 98.50R 8 372 500 8 372 500

2.4 Reshape Top Bench Cut back and place outside pit ZOR; utilize cut material to

construct Enviro bermm3 86 000 18.00R 1 548 000 1 548 000

2.5 Ameliorate and

vegetate

Supply and spread required ameliorants; Supply and

spread indigenous vegetation seed. i.e. diversity of grass

species, trees and shrubs on crest, thorny / hedge plants. ha 7 25 000.00R 175 000 175 000


P&G's@ 35% 11 986 829




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accidents;





production;








Non-compliance with SABS standards as per SOW; and





Inadequately skilled supervision and operators;


vegetation establishment.

o Reshape top bench to 18°:

Non-compliance and compliance with H&S (risk too high to allow operation or require

excessive measures and costs to mitigate);

Inadequately skilled supervision and operators will increase the risk of equipment falling

down the bench;

Pit rim instability (top bench) can cause premature failure during operations;

Movement of hauling team (trucks, operators and supervision) in close proximity of

unprotected pit rim can increase the pit rim instability;

Correct sizing of the plant for the operation (breaking force); and

Work on the top bench will have to be delayed while backfilling is in progress, because

risk of injuries due to falling material into the pit is increased if activities run simultaneously




Refer to Scenario 1 water balance (p. 13).


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5.4. SCENARIO 3: PARTIAL IN-FILL – ANGLE OF REPOSE, CONCRETE WALL AND

ENVIROBERM

Refer to Figure 2, Figure 11 to Figure 14 and Table 3.


5.4.1.1 Backfilling

Partially backfill the pit with material from the WRD. Leave the backfilled material at the angle of

repose and fill until the pit side slopes are covered.

End-tipping around the pit perimeter can be done at several positions simultaneously, thereby

increasing production.

Slope the backfilled material from the modified pit rim outwards to reduce any inflow of runoff.

The plan area of the pit will be reduced to approximately 43 ha.

5.4.1.2 Concrete wall.


ZOR of the pit; the ZOR will be delineated by the client.




5.4.1.3 Enviroberm.


Construct the enviroberm only on the northern and western side of the pit perimeter and abut







20




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Figure 13: Scenario 3 – Cross section A-A indicating the concepts and estimated pit lake level, NGL and ZOR



The cost estimate to implement scenario 2 is summarised in Table 3.




o Filling pit partially (end tipping from pit perimeter):


3 Partial Infill at angle of repose construct concrete wall and enviroberm around pit

3.1 Construct Enviroberm See details above in Scenario 1 m 1,570 4,100.00R 6,437,000 6,437,000

3.2 Construct Concrete Wall See details above in Scenario 1m 4,070 4,600.00R 18,722,000 18,722,000

3.3 Partial Infill @ 35deg Fill in from pit perimeter; Load and haul; dump & dozer over

end of fillm3 21,000,000 38.00R 798,000,000 798,000,000

Sub total 823,159,000

P&G's@ 6% 49,389,540

Contingencies @ 10% 82,315,900

Total ex VAT 954,864,440


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Implementation over long-term period extends decommissioning period and

increases chances for construction risks.







Pit rim instability - top bench failure during construction;

Pit instability – failure within ZOR during construction;

Slumping of deposited material into pit during deposition; and

Inadequately skilled supervision and operators.









Inadequately skilled supervision and labour of subcontractors.(Amelioration and

vegetation establishment.


accompanying risk assessment report


The catchment of the partially backfilled pit is reduced (from 108 ha for Scenario 1 to approximately

43 ha for Scenario 3), due to the backfilled material sloping away from the pit. This will reduce inflow

to the pit. This scenario was not modelled in detail, but the final pit lake volume and levels were

estimated based on the results of the model for Scenario 1. The pit formed by the backfilled material

will have a different stage curve. It was estimated that the water level could rise up to approximately

1,270 mamsl.

5.5. SCENARIO 4: PARTIAL IN-FILL – RESHAPED TO 18°, CONCRETE WALL AND

ENVIROBERM

Refer to Figure 15 to Figure 18 and Table 4.


5.5.1.1 Backfilling

Partially backfill the pit with material from the WRD. Leave the backfilled material at the angle of

repose and fill until the pit side slopes are covered.


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End-tipping around the pit perimeter can be done at several positions simultaneously, thereby

increasing production.

Slope the backfilled material from the modified pit rim outwards to reduce any inflow of runoff.

The plan area of the pit will remain approximately 63 ha.

Ameliorate and vegetate the reshaped pit slopes and surrounding areas.

5.5.1.2 Concrete wall and enviroberm.

The 18° slopes will be stable and safe; therefore, there is no need to construct a concrete wall or

enviroberm to address any possible risk due to slope failure. The pit lake that will form will however

introduce a safety risk due to the possibility of drowning. Construct a reinforced concrete wall to

reduce the possibility of access to the pit.

5.5.1.3 Revegetation

The slopes can be rehabilitated to reduce the visual impact of the bare pit side slopes.



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Figure 17: Scenario 4 – Cross section A-A indicating the concepts and estimated pit lake level NGL and ZOR


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The cost estimate to implement scenario 4 is summarised in Table 4.


The same approach for the costing was used as for Scenario 1.

The rate for importing fill material is for the shorter haul distance to the pit perimeter.

Scenario 4 has the additional cost for reshaping the dumped material in the pit to 18° in a balanced

cut and fill action



o Filling pit partially:










4 Partial Infill at 18°

4.1 Construct Enviroberm See details above in Scenario 1 m 1,570 4,100.00R 6,437,000 6,437,000

4.3 Construct Concrete Wall See details above in Scenario 1m 4,070 4,600.00R 18,722,000 18,722,000

4.4 Partial Infill @ 35deg Fill in from pit perimeter; Load and haul; dump & dozer over

end of fillm3 28,000,000 38.00R 1,064,000,000 1,064,000,000

4.5 Reshape Infill to 18deg Balanced cut & fill to 18deg; estimate 30% of fill material to be

reshapedm

3 8,400,000 18.50R 155,400,000 155,400,000

4.6 Ameliorate and

vegetate

Supply and spread required ameliorants; Supply and spread

indigenous vegetation seed. i.e. diversity of grass species, trees

and shrubs.

ha 66 25,000.00R 1,645,000 1,645,000

Sub total 1,246,204,000

P&G's@ 6% 74,772,240


Total ex VAT 1,445,596,640


26





o Reshape slope to 18°:



Correct sizing of the plant for the operation;

Synchronisation of operations (reshaping while hauling & dumping); and


vegetation establishment


accompanying risk assessment report


The catchment of the partially backfilled pit is reduced, from 108 ha for Scenario 1 to approximately

68 ha for Scenario 4, since diversion berms or paddocks will divert or contain storm water and

prevent it from entering the pit.

This will reduce inflow to the pit. This scenario was not modelled in detail, but the final pit lake

volume and levels were estimated based on the results of the model for Scenario 1.

The pit formed by the backfilled material will, however, have a different stage curve. It was

estimated that water levels could rise up to about 1,347 mamsl.

5.6. SCENARIO 5: RESOURCE COVER, CONCRETE WALL, ENVIROBERM AND

OPTIMISE CATCHMENT

Refer to Figure 2, Figure 19 to Figure 22 and Table 5.




to a depth of approximately 10 m. This should discourage illegal miners from entering the pit,

thereby reducing the risk of illegal mining during the period that the pit lake is forming.




ZOR of the pit.; the ZOR will be delineated by the client.





27

5.6.1.3 Enviroberm


Construct the enviroberm only on the northern and western sides of the pit perimeter and abut






Reshape surrounding areas during final rehabilitation or construct collection drains from

surrounding areas to increase the catchment reporting to the pit lake. There are many different

alternatives to consider but the following rehabilitated areas were added to the catchment:

o Slope of lowest lift of the WRD on the south side of the pit and the area between the toe of the

slope and the concrete wall;

o Slope of lowest lift of the WRD on the east side of the pit and the area between the toe of the

slope and the concrete wall; and

o A portion of the rehabilitated footprint of the plant area.



28




29



The cost estimate for the implementation of Scenario 5 is the same as that of Scenario 1, as there

are no additional actions required. This is reflected in Table 5.



The following construction activities may pose significant challenges and risks (similar to

Scenario 1):

o Cover resource:








accidents;





production;


5 Resource cover at bottom, optimise catchment and construct concrete wall and enviroberm around pit

5.1 Construct Enviroberm See details above in Scenario 1 m 1 570 4 008.69R 6 293 650 6 293 650


Wall

See details above in Scenario 1m 4 070 4 532.60R 18 447 682 18 447 682

5.3 Resource Cover See details above in Scenario 1 m3 85 000 98.50R 8 372 500 8 372 500


P&G's@ 35% 11 589 841




30










o Construction enviroberm:






o Changes to storm water management infrastructure:

Access of humans and animals to the open pit through unprotected storm water

structures in the concrete wall; and

Non-compliance with SABS standards as per SOW.


A basic water balance was developed for the pit to assess the likelihood of a pit lake inform over time

and the extent to which the water level will rise. Scenario 5 was modelled to investigate the increased

yield when the catchment of the pit is increased, i.e. runoff from areas that were outside the “normal”

catchment is routed to the pit lake. The results were also provided to the client as an interactive

spreadsheet.

Dewatering rates and rainfall records for the corresponding period were obtained from the client

for 2012 to 2015 and were used to calibrate the model.

Physical properties of rock formations were obtained from the latest Itasca Groundwater Report

(2014).

It was assumed that mining and dewatering will cease in 2021. The results of the analysis indicate

the following:

o A pit lake will form over time mostly due to the inflow from runoff from the pit catchment (188

ha) during rainfall events, i.e. the pit side slopes as well as the area between the pit perimeter

and the reinforced concrete wall.

o There is a 50% probability that the pit level will reach levels between 1,278 and 1,283 mamsl

at the end of 2071.

o The pit will then store between 10,780,000 m3 and 11,480,000 m3 water.

o Groundwater inflow is about 32% of the annual inflow into the pit at end of LOM and will

decrease to less than 13% after 50 years, i.e. when the water level reaches 1,270 mamsl.

o The pit water levels will fluctuate between 1,260 and 1,265 mamsl if water is abstracted from

the pit lake at a rate between 120,000 and 220,000 m3/annum.


31

o The current allocation of irrigation water by DWS to farmers is approximately 7,700 m3/annum

Using the allocation as a benchmark, it could be assumed that a farmer could irrigate between

15 and 28 ha of agricultural crops sustainably from the pit lake

Figure 23: Modelled rate of rise of the pit lake (increased catchment to 180 ha)

5.7. SCENARIO 6: COMPLETE IN-FILL WITH ALL AVAILABLE MRD MATERIAL

Refer to Figure 24 to Figure 26 and Table 6.

5.7.1. Specification

Fill the entire pit void with all available material from MRDs.

o Place the coarse residue deposit (CRD) material in the bottom of the pit. The conveyor system

can possibly be reversed to increase the work rate. This will give time for the fine residue

deposit (FRD) material to dry out.

o Place the FRD material on top of the CRD material after the material has dried out sufficiently

in order to be handled safely.

o Place the WRD material up to the NGL before commencing with the profiling of a dome over

the backfilled pit.

o Compaction of the backfilled material is not considered, since it will reduce the work rate, but

more so as it is impractical when end-tipping from the pit perimeter.

Fill the pit to approximately 20 m above the NGL to form a dome shape that is free-draining and

that will allow for future settlement of the backfilled material.

Ameliorate and vegetate the backfilled pit dome.

1080

1130

1180

1230

1280

20

21

20

22

20

23

20

24

20

26

20

27

20

28

20

29

20

31

20

32

20

33

20

34

20

36

20

37

20

38

20

39

20

41

20

42

20

43

20

44

20

46

20

47

20

48

20

49

20

51

20

52

20

53

20

54

20

56

20

57

20

58

20

59

20

61

20

62

20

63

20

64

20

66

20

67

20

68

20

69

20

71

Elev

atio

n (

mam

sl)

Min 25% 50% 75% Max


32

Figure 24: Scenario 6 – Layout illustrating the concepts

Figure 25: Scenario 6 – Cross-section A-A indicating the concepts


33

Figure 26: Scenario 6 – Cross-section B-B indicating the concepts


The cost estimate to implement Scenario 6 is summarised in Table 6.


The same approach for the costing was used as for Scenario 1, except that the rate for importing

fill material is for the shorter haul distance to the pit perimeter. Scenario 6 has the additional cost

for reshaping the dumped material above the NGL in a dome shape.



o Fill pit:













o Reshape dome to specification:


6 Complete Infill with all MRD material

6.1 Complete Infill Fill in from pit perimeter; Load and haul; dump & dozer over

end of fill; shape final levels above NGLm

3 62,240,000 42.00R 2,614,080,000 2,614,080,000

6.2 Ameliorate and

vegetate

Supply and spread required ameliorants; Supply and spread

indigenous vegetation seed. i.e. diversity of grass species, trees

and shrubs

ha 77 25,000.00R 1,915,000 1,915,000

Sub total 2,615,995,000

P&G's@ 6% 156,959,700


Total ex VAT 3,034,554,200


34



Correct sizing of the plant for the operation;

Synchronisation of operations (reshaping while hauling & dumping); and





6. BENEFICIAL LAND USE OF THE FARM INCLUDING THE OPEN PIT

The scenarios presented above will mitigate the prominent closure risks to varying degrees. All are

associated with a cost which is directly related to the magnitude of intervention investigated.

The cost associated with Scenarios 3, 4 and 6 is exorbitant and cannot be justified when considering:

The NPV of the entire operation.

The benefit to be gained from the money spent after implementing the said scenarios.

Scenarios 1, 2 & 5 provided the more feasible alternatives, but the strict specifications for some

aspects (e.g. concrete wall) inflate the costs resulting in an unrealistically high expense in relation to

the degree that the specific risks can be addressed (e.g. illegal access) and the benefit to be gained.

The client therefore embarked on a further phase of the study to reduce costs while aiming to achieve

an enhanced end land use of which the open pit plays a make or break role in achieving a sustainable

end land use after closure.

This entails the optimization of the pit as reservoir and the utilization of the water source to support

the development of higher value agricultural and industrial business enterprises. The feasibility and

details of the suggested ventures is outside the scope of this study, but the following possibilities,

multiple variations and combinations thereof need to be considered:

Intensive & extensive animal farming;

Intensive & extensive animal feed production;

Cash crops under irrigation;

Green houses with hydroponics,

Aqua culture;

Generation of electricity by using concentrated sunlight to heat water;

Other.

Further reasoning for reducing the strict and expensive access control measures in the previous

scenarios:

Access control can never be accepted to be absolute or guaranteed – practically any passive

barrier can be crossed in some or other way. Rather remove the attraction to illegal entrants.

The site will be managed as an ongoing business after closure and access can be actively

controlled by the operators / owners of the enterprise.

Focus therefore needs to be on discouraging illegal mining per se above all other risks which are

costly to mitigate.


35

7. ENHANCED SCENARIO 7: ALTERNATIVE LAND USE OF THE PIT

7.1. SCENARIO 7: RESOURCE COVER, ACCESS ROUTE, FENCE, ENVIROBERM

AND OPTIMISE CATCHMENT

Enhanced Scenario 7 has been investigated as an extension to Scenario 5.

Refer to:



Figure 29: Scenario 7 – Cross section A-A indicating the concepts and estimated pit lake level,

NGL and ZOR

Figure 30: Scenario 7 – Cross section B-B indicating the concepts and estimated pit lake level,

NGL and ZOR


7.1.1.1 Resource cover / Access control

Cover the remaining visible resource at the bottom of the pit with a layer of rock blasted from the

nearest bottom benches to a depth of approximately 10 m. Sterilisation of the resource in the pit

will discourage illegal miners from entering the pit, thereby reducing the risk of illegal mining during

the period that the pit lake is forming. The blasting of the bottom benches will be done before

removing the required equipment from the pit bottom at LoM. The cost is therefor considered to

be an operational cost. No allowance for this item is required for scheduled mine closure.

Other specifications as per Scenario 1 and 2 (p. 8) except that the concrete wall is substituted with

a security fence and the design of the trench has been changed. (Refer to § 7.1.1.2 and

§ 7.1.1.3).

Decommission the haul road switchback indicated in Figure 28 above the final estimated resting

water level in the pit. Access along the existing ramps to the bottom of the pit will then be

inaccessible during the period that the pit lake is forming.

The top four benches of the open pit where designed to fail spontaneously and thus need no

further intervention. This will discourage access to the pit floor from the pit perimeter, because this

zone is expected to be difficult to navigate (The haul road should remain stable). The failure

boundary is still within the ZOR which is considered when placing further infrastructure (such as a

fence).

7.1.1.2 Security Fence

Construct a security fence around the entire pit rim approximately 10 m outside the ZOR of the pit.

The ZOR boundary will be delineated by the client.

o The primary function of the fence is to create a visible barrier that will further minimise the risk

of uncontrolled access to the pit after closure.

Total length of the fence will be ±4070 at a height of 2.4m.


36

7.1.1.3 Enviroberm and trench

Excavate the trench approximately 15 m outside the security fence. Leave the excavated sides

vertical to allow natural failure of trench sides. Construction the enviroberm using the excavated

material from the trench. The toeline of the enviroberm must be a minimum of 5m from the trench.

Covering the enviroberm with a 1m deep waste rock layer.

Construct the enviroberm only on the northern, western and southern sides of the pit perimeter

and abut against the WRD on the northern and southern sides. The WRD on the northern to

southern sides (clockwise) will fulfil the same function as the enviroberm (Figure 27).




Reshape surrounding areas during final rehabilitation and construct collection drains from

surrounding areas to increase the catchment of runoff reporting to the pit. There are many different

alternatives to consider but the following rehabilitated areas were added to the catchment to

increase the runoff volume reporting to the pit:

o Slope of lowest lift of the WRD on the south side of the pit and the area between the toe of the

slope and the fence;

o Slope of lowest lift of the WRD on the east side of the pit and the area between the toe of the

slope and the fence; and

o A portion of the rehabilitated footprint of the plant area.



37





38


Table 7: Enhanced Scenario 7 – Detail of cost estimate.


The following construction activities may pose significant challenges and risks (similar to

Scenario 1):

o Cover resource:

Non-compliance with regulations and Anglo American plc (AA) health and safety (H&S)

requirements, i.e. the existing policies for safety may not allow the activity to continue (risk

too high);


requirements, i.e. the compliance may introduce excessive measures and costs to mitigate

the safety risk;


Pit instability – falling rocks and objects, and slope failure may make the pit inaccessible

or cause serious injuries;


production;


Dozer working on the ramps while reshaping the switch backs and entrances.

Flooding of the pit during construction will temporarily increase risk of slope and ramp

failures and risk of skidding; and

Inadequately skilled supervision and operators will increase the risk of serious accidents

and reduce production rates.

o Construction of fence:

Enhanced Scenario (7):Description Notes Unit Qty Rate Cost Sub-Total

7 Resource cover at bottom and construct fence, enviroberm and trench around pit

7.1 Construct Enviroberm & Trench m 2 220 8 075 400

7.1.1 Prepare foundations Excavate berm foundation footprint; minimum depth of

300mm; stockpile nearby to utilize as growth medium

after construction of the enviroberm (Can be considered

operational cost)

m3 16 650 42.50R 707 625

7.1.2 Load & haul Utilise excavated material from trench; Load and haul

additional material from WRD; spread and compact in

layers according to specifications (Can be considered

operational cost)

m3 83 250 85.00R 7 076 250

7.1.3 Spread growth

medium

Spread stripped topsoil (Can be considered operational

cost) m3 16 650 8.50R 141 525


vegetate

Supply and spread Ameliorate; Supply and spread

indigenous vegetation, i.e. diversity of grass species and

trees and shrubs on crest, thorny / hedge plant (Can be

considered operational)

ha 6 25 000.00R 150 000

7.2 Install Security Fence m 4 070 1 648 350

7.2.1 Fence as per Quote Security fence 2.4m high; diamond mesh 50mmx2.5mm

galvanised; flatwrap 500 razorwire; posts 101mm x 2mm

every 30m; standards every 5.5m; with 8m gate; including

erection

m 4 070 405.00R 1 648 350

7.3 Resource Protection 8 422 500

7.3.1 Cover resource Cover resource at bottom of pit @ 10m deep with waste

rock; blast nearest ramps at cessation of miningm3 85 000 98.50R 8 372 500

7.3.2 Decommission

switchbacks

Blast switchbacks above final pit lake water levelsum 1 50 000.00R 50 000

7.3.3 Reshape top benches Reshape top 4 benches to discourage access; no active

works required - benches are desiged to failm3 1 -R 0


P&G's@ 35% 6 351 188




39










o Changes to storm water management infrastructure:

Non-compliance with SABS standards as per SOW.


A basic water balance was developed for the pit to assess the likelihood of a pit lake forming over

time and the extent to which the water level will rise. Scenario 5 was modelled to investigate the

increased yield when the catchment of the pit is increased, i.e. runoff from areas that were outside

the “normal” catchment is routed to the pit. The results were also provided to the client as an

interactive spreadsheet.

The estimated final level of the pit lake (1280mamsl) will be above the level where remaining traces

of kimberlite is exposed in the pit sidewalls (1198mamsl). There is a 50% chance that the elevation

of 1200 mamsl will be reached between 2032 and 2034. A pit lake level of 1200 mamsl can be

reached quicker by supplementing the natural ingress of water due to rainfall with additional water

with the existing water allocation from the Renoster River Weir. The WUL for this water use is valid

until 2029 on condition it is used for mining related purposes – which it will be. The allocation is

220,000m3/month. The required volume to reach 1198 mamsl is

3,4 million m3 of water. With current allocation from the Renoster River, this can be reached within

1.5 years excluding the rainfall and runoff.

8. RISK ASSESSMENT AND COST-BENEIFT ANALYSIS

8.1. METHODOLOGY AND APPROACH

The focus of the Risk Assessment was to follow a risk-based approach in order to assist the decision-

making process in determining the most feasible open pit closure scenario for closure.

The identified risks were captured in a dedicated spreadsheet that reflects all the respective risks for

each of the open pit closure scenarios. These risks were individually evaluated and ranked for each

of the closure scenarios, before and after implementation of the rehabilitation closure criteria. The

Anglo American 5x5 closure risk matrix was used. Refer to Annexure A of this report for the risk

matrix and different criteria used to determine the risks. The identified risks were rated according to

“probability / likelihood” and “consequence of occurrence”.

To determine the possible consequence, different criteria were used for each of the following

aspects:

Safety


40

Occupational Health

Environment

Financial

Legal & Regulatory

Social / Community

Reputation

8.2. OUTPUTS OF RISK ASSESSMENT

The Risk assessment was done in the format of an Interactive spreadsheet with the following Index

(refer to Annexure A):

Open pit closure scenarios: Schematic illustration of the different open pit closure scenarios.

Risk matrix: The 5 x 5 risk matrix as per the Anglo American Toolbox.

Risk assessment tool: Detailed list of all risks associated with the different Open Pit Closure

Scenarios, including Low and Medium Risks.

Accessibility to open pit: Summary of risks associated with the risk aspect.

Pit sidewall stability: Summary of risks associated with the risk aspect.

Water resources: Summary of risks associated with the risk aspect.

Land capability and End land use: Summary of risks associated with the risk aspect.

Natural resources: Summary of risks associated with the risk aspect.

Government and stakeholders: Summary of risks associated with the risk aspect.

Cost-benefit analysis: A summary of all residual risks which are associated with the different

closure scenarios as well as the associated costs for the implementation of the different scenarios.

It is important to read all of the abovementioned components of the Risk assessment in correlation

with each other. The following is a summary of the output of the Risk assessment tool.


41

Figure 31: Risk summary for Accessibility to the Open pit

Voorspoed Open Pit Closure Risk Assessment

SCENARIO 1

SCENARIO 2

SCENARIO 3

SCENARIO 4

SCENARIO 5

SCENARIO 6

SCENARIO 7

SAFETY OCCUPATIONAL HEALTH ENVIRONMENTAL FINANCIAL LEGAL & REGULATORY SOCIAL / COMMUNITY REPUTATION

PRE-MITIGATION NONE 21 (H) 24 (H) 17 (S) 17 (S) 23 (H) 21 (H) 24 (H)

SCENARIO 1 9 (M) 9 (M) 9 (M) 5 (L) 9 (M) 9 (M) 9 (M) UNLIKELY



SCENARIO 4 6 (M) 6 (M) 6 (M) 3 (L) 6 (M) 6 (M) 6 (M) RARE


SCENARIO 6 #N/A #N/A #N/A #N/A #N/A #N/A #N/A NO RISK


PRE-MITIGATION NONE 23 (H) 23 (H) 25 (H) 20 (S) 23 (H) 25 (H) 25 (H)

SCENARIO 1 9 (M) 9 (M) 9 (M) 9 (M) 9 (M) 9 (M) 9 (M) UNLIKELY


SCENARIO 3 3 (L) 3 (L) 3 (L) 3 (L) 3 (L) 3 (L) 3 (L) RARE





COVER RESOURCE, 1 ACCESS ROUTE, INCREASE CATCHMENT, FENCE & BERM

RISK RELATED ASPECT: ACCESSIBILITY TO OPEN PIT

MITIGATION MEASURES

RISK CATEGORY

SCENARIO

COVER RESOURCE, WALL & BERM

RESHAPE TOP BENCH 18°, COVER RESOURCE ,WALL & BERM

PARTIAL IN-FILL AT ANGLE OF REPOSE , WALL & BERM

PARTIAL IN- FILL AT 18°, WALL & BERM

COVER RESOURCE, INCREASE CATCHMENT, WALL & BERM

COMPLETE, IN-FILL ALL MRD MATERIAL

RESIDUAL RISK /

IMPACTS AFTER IMPLEMENTATION OF THE

MANAGEMENT MEASURES

Illegal mining due to access to potential resource.

Possibility of human and animal injury or death due to

uncontrolled access to the pit (falling down steep slopes or

drowning).

RISK STATEMENT

Risk MatrixPit side wall stability Risk Assessment Tool

Accessibility to open pit

Water resources

Land capability

& ELU

Index

Open Pit Closure Scenarios

Natural resources

Government &

Stakeholders

Cost-Benefit Analysis


42

Figure 32: Risk summary for Open pit sidewall stability


SCENARIO 1

SCENARIO 2

SCENARIO 3

SCENARIO 4

SCENARIO 5

SCENARIO 6

SCENARIO 7


PRE-MITIGATION NONE 21 (H) 23 (H) 20 (S) 17 (S) 20 (S) 21 (H) 21 (H)

SCENARIO 1 13 (S) 13 (S) 13 (S) 8 (M) 13 (S) 13 (S) 13 (S) POSSIBLE


SCENARIO 3 8 (M) 8 (M) 8 (M) 8 (M) 8 (M) 8 (M) 8 (M) POSSIBLE




SCENARIO 7 5 (L) 5 (L) 5 (L) 5 (L) 9 (M) 9 (M) 9 (M) UNLIKELY

PRE-MITIGATION NONE 23 (H) 23 (H) 23 (H) 17 (S) 23 (H) 21 (H) 21 (H)



SCENARIO 3 8 (M) 8 (M) 8 (M) 8 (M) 8 (M) 8 (M) 8 (M) POSSIBLE




SCENARIO 7 5 (L) 5 (L) 5 (L) 5 (L) 9 (M) 9 (M) 9 (M) UNLIKELY

RISK RELATED ASPECT: PIT SIDE WALL STABILITY








RESIDUAL RISK /


MANAGEMENT MEASURES

Failure of the open pit side walls, resulting in possible

instability of surrounding areas e.g. remaining infrastructure and

residue deposits (under-estimating the extent of the zone of

relaxation)

Failure of the open pit side walls, resulting in human and animal

injury or death (under-estimating the extent of the zone of

relaxation)

RISK STATEMENT SCENARIO MITIGATION MEASURES

RISK CATEGORY



Water resources

Land capability

& ELU

Index


Natural resources

Government &

Stakeholders



43

Figure 33: Risk summary for impact on Water resources


SCENARIO 1

SCENARIO 2

SCENARIO 3

SCENARIO 4

SCENARIO 5

SCENARIO 6

SCENARIO 7


PRE-MITIGATION NONE #N/A #N/A 18 (S) 5 (L) 8 (M) 5 (L) 5 (L)

SCENARIO 1 #N/A #N/A 18 (S) 5 (L) 8 (M) 5 (L) 5 (L) POSSIBLE


SCENARIO 3 #N/A #N/A 5 (L) 2 (L) 5 (L) 5 (L) 5 (L) UNLIKELY


SCENARIO 5 #N/A #N/A 8 (M) 2 (L) 8 (M) 5 (L) 5 (L) POSSIBLE

SCENARIO 6 #N/A #N/A 1 (L) 1 (L) 3 (L) 3 (L) 3 (L) RARE

SCENARIO 7 #N/A #N/A 8 (M) 2 (L) 9 (M) 5 (L) 5 (L) POSSIBLE

PRE-MITIGATION NONE #N/A 9 (M) 9 (M) 2 (L) 8 (M) 5 (L) 5 (L)

SCENARIO 1 #N/A 5 (L) 9 (M) 2 (L) 5 (L) 5 (L) 5 (L) UNLIKELY


SCENARIO 3 #N/A 8 (M) 13 (S) 2 (L) 8 (M) 8 (M) 8 (M) POSSIBLE

SCENARIO 4 #N/A 8 (M) 13 (S) 2 (L) 8 (M) 8 (M) 8 (M) POSSIBLE


SCENARIO 6 #N/A 12 (M) 17 (S) 2 (L) 8 (M) 8 (M) 8 (M) LIKELY


PRE-MITIGATION NONE #N/A #N/A 20 (S) 5 (L) 8 (M) 5 (L) 5 (L)



SCENARIO 3 #N/A #N/A 8 (M) 2 (L) 5 (L) 5 (L) 5 (L) POSSIBLE

SCENARIO 4 #N/A #N/A 13 (S) 2 (L) 5 (L) 5 (L) 5 (L) POSSIBLE



SCENARIO 7 #N/A #N/A 13 (S) 5 (L) 9 (M) 9 (M) 9 (M) POSSIBLE

Surface water:

Ingress of surface water into the open pit having a negative

effect on surrounding water users and wetland systems

(resulting in reduced local surface water yield)

Assume minimum stormwater diversion structures will be

in place

RISK CATEGORYRESIDUAL RISK /


MANAGEMENT MEASURES

Groundwater:

Impact on local groundwater levels and yield.

Groundwater:

Impact on Groundwater quality


RISK RELATED ASPECT: WATER RESOURCES










Water resources

Land capability

& ELU

Index


Natural resources

Government &

Stakeholders



44

Figure 34: Risk summary for impact on Land capability and End land use


SCENARIO 1

SCENARIO 2

SCENARIO 3

SCENARIO 4

SCENARIO 5

SCENARIO 6

SCENARIO 7


PRE-MITIGATION NONE #N/A #N/A 25 (H) 16 (S) 25 (H) 24 (H) 21 (H)

SCENARIO 1 #N/A #N/A 18 (S) 8 (M) 18 (S) 18 (S) 18 (S) POSSIBLE


SCENARIO 3 #N/A #N/A 24 (H) 12 (M) 24 (H) 24 (H) 21 (H) LIKELY




SCENARIO 7 #N/A #N/A 9 (M) 5 (L) 5 (L) 5 (L) 5 (L) UNLIKELY



MANAGEMENT MEASURES

No beneficial post-closure land use for the open pit

RISK RELATED ASPECT: LAND CAPABILITY & END LAND USE










45

Figure 35: Risk summary for impact on Natural resources


SCENARIO 1

SCENARIO 2

SCENARIO 3

SCENARIO 4

SCENARIO 5

SCENARIO 6

SCENARIO 7


PRE-MITIGATION NONE #N/A #N/A 15 (S) 6 (M) 10 (M) 6 (M) 6 (M)

SCENARIO 1 #N/A #N/A 19 (S) 9 (M) 14 (S) 9 (M) 9 (M) UNLIKELY


SCENARIO 3 #N/A #N/A 24 (H) 17 (S) 21 (H) 17 (S) 17 (S) LIKELY

SCENARIO 4 #N/A #N/A 24 (H) 17 (S) 21 (H) 17 (S) 17 (S) LIKELY


SCENARIO 6 #N/A #N/A 25 (H) 20 (S) 23 (H) 20 (S) 20 (S) ALMOST CERTAIN

SCENARIO 7 #N/A #N/A 14 (S) 5 (L) 9 (M) 5 (L) 5 (L) UNLIKELY



MANAGEMENT MEASURES

Possible resource sterilisation.

RISK RELATED ASPECT: NATURAL RESOURCES











Water resources

Land capability

& ELU

Index


Natural resources

Government &

Stakeholders



46

Figure 36: Risk summary for impact associated with Government and stakeholders


SCENARIO 1

SCENARIO 2

SCENARIO 3

SCENARIO 4

SCENARIO 5

SCENARIO 6

SCENARIO 7


PRE-MITIGATION NONE #N/A #N/A #N/A #N/A 23 (H) 21 (H) 14 (S)

SCENARIO 1 #N/A #N/A #N/A #N/A 17 (S) 17 (S) 17 (S) LIKELY



SCENARIO 4 #N/A #N/A #N/A #N/A 8 (M) 8 (M) 8 (M) POSSIBLE


SCENARIO 6 #N/A #N/A #N/A #N/A 2 (L) 2 (L) 2 (L) UNLIKELY




MANAGEMENT MEASURES

Not meeting the expectations of government and stakeholders

with regards to closure and not obtaining the subsequent

certificate of closure.

RISK RELATED ASPECT: GOVERNMENT & STAKEHOLDERS











Water resources

Land capability

& ELU

Index


Natural resources

Government &

Stakeholders



47

9. STANDARD OPERATING PROCEDURE FOR SITE-WIDE CLOSURE

The purpose of the procedure for site-wide mine closure is to provide a generic description of the

environmental legal framework which is applicable to the mine closure processes, including

legislation, regulations and guidelines as well as the processes to be followed in terms of the

requirements of the legal framework.

The procedure focuses on the generic environmental requirements and processes for site-wide mine

closure and not only the open pit. The Standard operating procedure (SOP) for site-wide closure is

attached in Annexure B.

The SOP was written in accordance with the legal requirements as contained in the legal

requirements’ checklist. The checklist therefore serves as legal reference to the processes found in

the SOP. The SOP gives effect to these requirements and should ideally ensure that an organisation

meets the legal requirements that culminate in the issuing of a closure certificate.

At the time of the submission of the SOP (beginning of November 2015), the client requested that

only the following be considered and that any regulations that were not yet approved be excluded

from this exercise. The processes include:

Application for a closure certificate in terms of the requirements of the Minerals and Petroleum

Resources Development Act (28 of 2002) (MPRDA) and the MPRDA regulations;

Application for environmental authorisation in terms of the National Environmental Management

Act (107 of 1998) (NEMA) and the Environmental Impact Assessment (EIA) Regulations of

December 2014;

The notification and permit application processes in terms of the National Heritage Resources Act

(25 of 1999); and

The notification process in terms of the National Environmental Management Air Quality Act (39

of 2004).

It should however be noted that Regulations 1147: Regulations pertaining to the Financial provision

for prospecting, exploration, mining or production operations came into effect on 20 November 2015,

just after the submission of the abovementioned, and that this should be incorporated and considered

in the update of the SOP.


48

ANNEXURE A: RISK ASSESSMENT AND COST-BENEFIT ANALYSIS


49

ANNEXURE B: STANDARD OPERATING PROCEDURE FOR CLOSURE


50

ANNEXURE C: PRESENTATION OF OPEN PIT CLOSURE SCENARIOS AND

COSTS

Documents

PROJECT: VOORSPOED MINE PIT CLOSURE STUDY · PROJECT: VOORSPOED MINE – PIT CLOSURE STUDY 2015/2016 7 VSM is preparing to consult with the authorities to propose and negotiate a