Appendix E3: Geohydrology · Lephalale Coal & Power Project – Groundwater Assessment PAGE 4 Disclosure of Vested Interest • I do not have and will not have any vested interest

Appendix E3: Geohydrology

Lephalale Coal Mines (Pty)

Ltd

Lephalale Coal & Power Project

Groundwater Impact Assessment

27 June 2017

Lephalale Coal & Power Project – Groundwater Assessment

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LEPHALALE COAL & POWER PROJECT

GROUNDWATER IMPACT ASSESSMENT

a report for

LEPHALALE COAL MINES (PTY) LTD

Compiled by

Lucas Smith

Principal Hydrogeologist. M.Sc. Pr. Sci. Nat.

181 Lisdogan Street, Arcadia, Pretoria, 0083


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Declaration of Independence

I, Lucas Smith, declare that –

General declaration:

• I act as the independent Hydrogeology practitioner in this application;

• I will perform the work relating to the application in an objective manner, even if this results

in views and findings that are not favourable to the applicant;

• I declare that there are no circumstances that may compromise my objectivity in performing

such work;

• I have expertise in conducting hydrogeological impact assessments, including knowledge of

the Act, Regulations and any guidelines that have relevance to the proposed activity;

• I will comply with the Act, Regulations and all other applicable legislation;

• I have no, and will not engage in, conflicting interests in the undertaking of the activity;

• I undertake to disclose to the applicant and the competent authority all material

information in my possession that reasonably has or may have the potential of influencing -

any decision to be taken with respect to the application by the competent authority; and -

the objectivity of any report, plan or document to be prepared by myself for submission to

the competent authority;

• I will ensure that information containing all relevant facts in respect of the application is

distributed or made available to interested and affected parties and the public and that

participation by interested and affected parties is facilitated in such a manner that all

interested and affected parties will be provided with a reasonable opportunity to participate

and to provide comments on documents that are produced to support the application;

• I will provide the competent authority with access to all information at my disposal

regarding the application, whether such information is favourable to the applicant or not;

• All the particulars furnished by me in this form are true and correct;

• I will perform all other obligations as expected from a hydrogeological practitioner in terms

of the Act and the constitutions of my affiliated professional bodies; and

• I realise that a false declaration is an offence in terms of regulation 71 of the Regulations

and is punishable in terms of section 24F of the NEMA.


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Disclosure of Vested Interest

• I do not have and will not have any vested interest (either business, financial, personal or

other) in the proposed activity proceeding other than remuneration for work performed in

terms of the Regulations.

HYDROGEOLOGICAL CONSULTANT: ASST (Pty) Ltd

CONTACT PERSON: Lucas Smith

Tel: +27 12 342 8033

Email: [email protected]

SIGNATURE:


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Executive Summary

Kongiwe Environmental (Pty) Ltd has been appointed by Lephalale Coal Mines (Pty) Limited

(LCM) to undertake the Environmental Impact Assessment process as part of the Mining Right

Application, and other Environmental Authorisations required for the proposed Lephalale Coal &

Power Project (Mine and IPP plant). It is noted that the economic base case includes the supply

of the coal to an IPP on site, but alternative markets and optimisation options are being

investigated. The applications at this stage will only be made for the mining section;

applications for the IPP will be done in the future once the detailed design of the IPP plant has

progressed.

This report presents the groundwater impact assessment associated with the LCPP. The

groundwater impact assessment focused on the following objectives:

• Define the current groundwater use in the LCPP area;

• Define the aquifers underlying the LCPP area, as well as current groundwater table

depth, groundwater quality, and flow characteristics;

• Develop a numerical model that will be used to define groundwater related impacts and

groundwater inflow into the open cast mining areas;

• Define the radius of influence that will be created by mine dewatering, plus the extent

of possible contamination originating from the proposed pit areas and mine

infrastructure;

• Define the acid rock drainage potential associated with the local geology and coal

seams; and

• Assess whether pit decant will occur during the operational phase and post closure.

The LCPP is predominantly in the A42J quaternary catchment, forming part of the Limpopo

Water Management Area. The main drainage associated with the A42J quaternary catchment is

the Mokolo River, located approximately 14 kilometres west from the LCPP area. The Lephalala

River is located approximately 17 km east from the study area (A50H quaternary catchment)

and originates in the Sandrivier Mountains. The area between the Mokolo River and Lephalala

River, where the LCPP is located, is described as an endoreic area (does not produce surface

runoff) because of the semi-arid climatic conditions and shallow topographic gradient. Several

rural communities are located along the Lephalala River; these include Ga-Seleka, Witpoort,

Mokuranyane and Ga-Shongwane. These communities reply heavily on groundwater for water

supply. The groundwater impact assessment indicates that these communities plus the river

systems are not at risk.

The Lower Ecca sandstone is considered to be the main water bearing formation in the area, as

well as the intercept of linear geological features. The main water strikes are between 70 m and

82 m below ground level (bgl). The fractured aquifers in the area can be classified as confined

aquifers based on the rest groundwater level depths versus water strike depths. Most of the

water strikes were found outside the coal horizons; those observed in the coal horizons only

produced seepage water. The east-west trending faults in the south of the project area seem to


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be preferred groundwater flow paths / higher yielding aquifer units. The main water strikes in

borehole RHP03 (highest blow yield borehole at 25,000 L/h) were in the mudstone; 79 m and

109 m bgl and indicate the intercept of a fractured zone (fault) below the interbedded coal

sequence.

Land owner communications indicate low borehole yields for the northern portion of the study

area, but the farms along the south have higher yielding boreholes; these include the farms

Pretoria, Garibaldi and Weltevreden. This potentially relates to east-west trending faults

identified in the area.

The upper coal seams are found from approximately 18 to 26 m bgl across the proposed mining

footprint area. Borehole RHP06 at Garibaldi only intercepted coal at 64 m bgl. Borehole RHP05

on the farm Pretoria intercepted no coal, but water yielding granite was intercepted at 50 m bgl,

and in borehole RHP03 at 112 m bgl. The water strike in borehole RHP05 (at 50 m bgl) was at

the contact zone between the Karoo formations and the granite. The weathered granite could

be a potential target for water supply drilling.

The groundwater table in the Alomfraai, Middelboomspunt and Weltevreden Portion 1 farms

indicates a higher elevation compared to the Stellenbosch, Sebright, Billiards and Rondeboschje

farms (lower elevations). This confirms a regional groundwater flow direction in a north-

westerly direction.

Groundwater quality assessments indicated that groundwater in the area shows fluoride,

sodium and chloride enriched water. The current groundwater quality is variable; depending on

whether the borehole intercepted the coal horizons. Based on the SANS241 drinking water

guidelines and on the sampled borehole water, the groundwater is not fit for human

consumption (unless treated), predominantly because of high fluoride concentrations and

isolated occurrences of nitrate and Total Organic Carbon. All measured metals and sulphate

were present in concentrations below the SANS241 guideline limits.

The coal and mudstone / shale / sandstone horizons sampled for standard ABA analysis are

deemed to be potentially acid generating. Based on the results from the total concentration

analysis:

• TCT0 threshold value for barium was exceeded in Samples 9, 10, 11, 12 and 13;

• The TCT0 threshold value was exceeded for lead in Sample 11; and

• The TCT0 threshold value for fluoride was exceeded in all samples.

Based on the total concentration and leachable concentration results the waste will be classified

as a Type 3 waste and the liner design must be according to Class C landfill requirements.

The impact of pit dewatering during the construction of the box cut suggests that groundwater

levels may be lowered by up to 25 m inside the box cut. The resultant cone of depression will be

controlled by the geological units and the presence of faulting. It is estimated that the zone of

influence will not extend further than 500 m from the box cut. Boreholes HONI1 and HONI2 fall


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within the delineated dewatering cone. It is estimated that groundwater levels in HONI1 may be

lowered by more than 7 m and in HONI2 by approximately 2 m. The impact may reduce the

performance of the boreholes, but there is insufficient information to confirm this anticipated

impact. It is estimated that groundwater would seep into the box cut at an average rate of

approximately 100 m3/d.

During the operational phase, groundwater will continue to seep into the mining void as mining

progresses. The shape of the cone of depression will be controlled by the geology and the

presence of faults. Due to the low transmissivities of the host rock, the cone of depression is

not expected to extend further than 2 km from Pit 1 and 1.5 km from Pit 2; 13 private boreholes

fall within this zone of influence. It is shown that groundwater levels in boreholes BILL2, BILL3,

BOTM4, Groot2 and STEL1 may be lowered by less than 2 m. This impact will most probably not

be significant, as borehole performance and use should not be affected under these

circumstances. Groundwater levels may be lowered by up to 10 m in boreholes HONI3, HONI4

and BILL4. This lowering in groundwater level is expected to affect borehole performance,

especially during the dry season. Mine dewatering may result in a lowering in groundwater

levels in boreholes ROND5, HONI3 and WELT1 by up to 20 m. It is anticipated that groundwater

supply from these boreholes would be severely affected and that the boreholes will most likely

dry up with time. Boreholes HONI1, HONI2 and Groot1 will be destroyed during mining.

It is shown that the rate at which groundwater should seep into Pit 1 will increase from around

100 m3/d during operations in Cut 1 (box cut) to approximately 1,100 m3/d at the end of life of

the pit (Cut 8). Once mining at Pit 2 commences, the volume of groundwater seeping into Pit 1

will reduce. Towards the end of life of the mining operations, the volume of groundwater

seepage to Pit 1 is expected to be around 600 m3/d. The volume of seepage to Pit 2 is expected

to start at approximately 350 m3/d and increase to around 890 m3/d at the end of life of the

operations. In total, the maximum volume of groundwater seepage to both pits is calculated to

be around 1,580 m3/d.

The simulations indicate that groundwater levels would recover within 18 to 20 years after

mining ceases at Pit 1 and within 22 to 35 years at Pit 2. Whether the pits will decant in future,

will depend on how well backfilling and rehabilitation of the pits are achieved upon mine

closure. Simulations suggest that decant can be expected if the rate of recharge to the pits

exceed 5% of MAP after rehabilitation. One decant position is indicated for Pit 1, which is

situated on the south-western highwall, at 873 m above mean sea level (amsl). Decant will take

place if water levels inside the pits rise to above this elevation.

Two possible decant locations were identified for Pit 2, on the north-western highwall. The

decant elevation is 874 m amsl for this pit. If the rate of recharge to the pits cannot be kept

below 5% of MAP post rehabilitation, decant will commence 18 to 35 years after closure from

the pits, as indicated on Figure 18. The volume of decant is estimated to be between 40 and

150 m3/d at Pit 1 and 30 and 120 m3/d at Pit 2.

The model was run for a period of 100 years after mining ceases. During this period,

groundwater levels will recover for the first 20 to 30 years. Thereafter, the plume is expected to


PAGE 8

migrate in a westerly direction. During this period, the contamination is not expected to

migrate more than 900 m from the mining area. This is due to the low transmissivities of the

Ecca sediments.

The potential for local groundwater resources to supply a portion of the water required by the

proposed mine cannot be ruled out; however this could only be achieved by intersecting highly

productive fracture systems, removed from the mine dewatering impact zone. It seems likely

that for the Project demand to be sustained, water will have to be imported from outside the

immediate area (RHDHV, September 2016). The MCWAP-2A project will provide 75 to 100

million m3/annum to the Lephalale and Steenbokpan areas, by laying a new pipeline from the

Crocodile River.

RHDHV indicated the following water demands:

• LCPP daily domestic water demand – 150 kl/d (150 m3/d);

• CHPP operational water demand – 2,635 kl/d (2,635 m3/d);

• IPP operation water demand – 4,110 kl/d (4,110 m3/d);

• Dust suppression – 288 kl/d (288 m3/d).

• Total demand = 7,183 kl/d (7,183 m3/d).

In total, the maximum volume of groundwater seepage to both pits is calculated to be around

1,580 m3/d (range: 1,398 to 1,737 m3/d).

The model indicated that the sustainable borehole yields calculated from the aquifer tests will

probably not be sustainable in the long-term when the impact of mine dewatering is also taken

into consideration. Model simulations indicate that the boreholes could probably only be

pumped at around 43 m3/d (0.5 L/s) continuously over the life of the operations. This is

significantly less than what is indicated by the aquifer tests. The aquifer testing and software

interpretations can however not take the impact of mine dewatering and the simultaneous

pumping of the two boreholes over a period of 42 years into consideration. Borehole

abstraction could potentially support office and dust suppression requirements, but large-scale

abstraction would not be possible or sustainable.

Potential wellfield considerations should include water supply sources further from the pits and

outside the mine dewatering zone of influence.

The Anglo Coal Bed Methane Operation is located approximately 20 km north-northwest of

Lephalale and 23 km west of the LCPP site and could potentially be a water supply resource.

Waste water from local municipal water treatment facilities could represent an option. LCM has

already expressed a commitment to obtaining water from the MCWAP-2A.


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1 Table of Contents

1 Introduction ...................................................................................................................... 1

1.1 Groundwater Study Objectives ................................................................... 2

1.2 Compliance Framework .............................................................................. 2

1.2.1 Applicable National Legislation .................................................................. 2

1.2.2 IFC Performance Standards ........................................................................ 2

1.3 Groundwater Assessment Team ................................................................. 3

1.4 Report Structure .......................................................................................... 3

2 Environmental Setting ...................................................................................................... 4

2.1 Catchment ................................................................................................... 4

2.2 Climate, Rainfall and Groundwater Recharge ............................................ 5

2.3 Geology ........................................................................................................6

2.4 Hydrogeology .............................................................................................. 8

3 Groundwater Assessment .................................................................................................9

3.1 Literature Review ........................................................................................9

3.1.1 Historical Exploration Activities .................................................................9

3.1.2 Background Information .............................................................................9

3.2 Current Groundwater Use ......................................................................... 10

3.2.1 Groundwater Quality ................................................................................ 14

3.3 Geophysical Survey ..................................................................................... 21

3.4 Drilling Programme................................................................................... 23

3.4.1 Drilling Results .......................................................................................... 24

3.5 Aquifer Testing .......................................................................................... 27

3.6 Geochemical Evaluation ............................................................................ 34

3.6.1 Laboratory Tests ........................................................................................ 35

3.6.2 Laboratory Results ..................................................................................... 36

3.7 Waste Classification .................................................................................. 41

3.7.1 Waste Assessment Methodology .............................................................. 41

3.7.1 Assessment Results.................................................................................... 45

4 Conceptual Groundwater Model ....................................................................................46


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4.1 Potential Pathways and Receptors ........................................................... 49

4.2 Priority Contaminants .............................................................................. 49

4.3 Potential Pollution Source Identification ................................................ 49

5 Numerical Model ............................................................................................................. 50

5.1 Key Assumptions and Literature Based Data Inputs ............................... 50

5.2 Description of the Model ........................................................................... 51

5.3 Model Input Files and Integration ............................................................ 53

5.4 Calibration Results .................................................................................... 53

5.5 Model Sensitivity ....................................................................................... 56

5.6 Assessment Uncertainties ......................................................................... 57

5.7 Defining the Groundwater Impacts .......................................................... 57

5.7.1 Scenario Testing ........................................................................................ 57

5.7.2 Simulation Results .................................................................................... 60

6 Groundwater Impact Assessment ................................................................................... 75

6.1 Activity Description .................................................................................. 75

7 Cumulative Impacts ........................................................................................................ 81

8 Water Demand ................................................................................................................ 81

8.1 Water Supply Options ............................................................................... 82

8.1.1 Groundwater from the Pit ......................................................................... 83

8.1.2 Production Boreholes ................................................................................ 83

8.1.3 Outside Sources .........................................................................................84

8.1.4 Mokolo and Crocodile Water Augmentation Project (MCWAP)............84

9 Groundwater Management Plan.....................................................................................84

9.1 Groundwater Management Objectives ....................................................84

9.1.1 Construction Phase ...................................................................................84

9.1.2 Operational Phase ..................................................................................... 85

9.1.3 Groundwater Closure Objectives ............................................................. 86

9.2 Groundwater Management Implementation Plan .................................. 86

9.2.1 Management of Groundwater Availability .............................................. 86

9.2.2 Management of Groundwater Quality .................................................... 86


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10 Groundwater Monitoring .......................................................................... 87

10.1 Groundwater Monitoring Objectives ....................................................... 87

10.2 Proposed Groundwater Monitoring Programme .....................................88

10.3 Groundwater Monitoring Reporting ....................................................... 90

10.4 Quality Assessment and Control ............................................................. 90

11 Conclusions ............................................................................................... 92

12 Recommendations ..................................................................................... 97

13 References ................................................................................................. 99

APPENDIX A ......................................................................................................................... 101

APPENDIX B .........................................................................................................................102

APPENDIX C ......................................................................................................................... 103

APPENDIX D ........................................................................................................................ 104

APPENDIX E ..........................................................................................................................105

APPENDIX F ......................................................................................................................... 106

APPENDIX G .........................................................................................................................107

APPENDIX H ........................................................................................................................ 108

2 List of Tables

Table 1. LCPP Hydro-chemical results ........................................................................................ 20

Table 2. Proposed drilling localities ........................................................................................... 22

Table 3. Proposed core drilling localities .................................................................................... 24

Table 4. Drilling summary of new boreholes .............................................................................. 26

Table 5. Core drilling summary .................................................................................................. 27

Table 6. Aquifer test programme summary ............................................................................... 32

Table 7. Geochemistry sample selection .................................................................................... 34

Table 8. Acid Base Accounting results ........................................................................................40

Table 9. Waste type and disposal classification* ........................................................................ 42


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Table 10. LCPP sample results, TCT limits .................................................................................. 43

Table 11. LCPP sample results, LCT limits ................................................................................... 44

Table 12. 2017 Aquifer test parameter estimation (ASST)* ........................................................46

Table 13. Groundwater level measurements used ..................................................................... 47

Table 14. Pathways and receptors ............................................................................................ 49

Table 15. Sulphate concentrations from leach tests (mg/L) ...................................................... 49

Table 16. Contaminant transport advection parameters ............................................................ 53

Table 17. Calibration criteria ..................................................................................................... 53

Table 18. Steady state calibration results .................................................................................. 54

Table 19. Calibrated aquifer parameters ................................................................................... 55

Table 20. Mining schedule ......................................................................................................... 58

Table 21. Pumping borehole details .......................................................................................... 58

Table 22. Simulation periods .................................................................................................... 60

Table 23. Private boreholes affected by mine dewatering ......................................................... 62

Table 24. Estimated groundwater seepage volumes (m3/d) ....................................................... 65

Table 25. Expected increase in sulphate concentrations in boreholes ........................................ 75

Table 26. Significance rating methodology ................................................................................ 77

Table 27. Groundwater Impact Assessment summary .............................................................. 80

Table 28. Proposed monitoring programme ............................................................................. 90

3 List of Figures

Figure 1. Lephalale rainfall. Station 0674341 8 ............................................................................6

Figure 2. Correlation between surface level and groundwater levels .......................................... 13

Figure 3. Piper diagram ............................................................................................................. 18

Figure 4. LCPP Stiff diagrams ................................................................................................... 19

Figure 5. Class C landfill site liner requirements (NEM:WA, 2008) .............................................. 45

Figure 6. Regional geology .........................................................................................................48

Figure 7. Model grid .................................................................................................................. 52

Figure 8. Steady state calibration: simulated vs measured head ................................................ 55

Figure 9. Sensitivity analysis ...................................................................................................... 56


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Figure 10. Mining layout used during simulations ...................................................................... 59

Figure 11. Simulated cone of depression: Construction Phase ................................................... 63

Figure 12. Simulated cone of depression: Operational Phase .....................................................64

Figure 13. Groundwater seepage volumes ................................................................................. 65

Figure 14. Simulated drawdown as a result of groundwater abstraction ................................... 68

Figure 15. Cumulative impact of groundwater abstraction and mine dewatering ..................... 69

Figure 16. Rate of groundwater level recovery for Pit 1 ............................................................. 70

Figure 17. Rate of groundwater level recovery for Pit 2 .............................................................. 71

Figure 18. Decant assessment ................................................................................................... 73

Figure 19. Simulated sulphate plume 100 years after mine closure ........................................... 74

Figure 20. Proposed additional monitoring borehole locations ................................................. 89


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Abbreviations

Abbreviation Description

ABA Acid Base Accounting

AEL Atmospheric Emissions Licence

AG Acid Generating

AMD Acid Mine Drainage

ARD Acid Rock Drainage

ASST Applied Scientific Services and Technologies (Pty) Ltd

CoC Chemicals of Concern

CV Curriculum Vitae

DMR Department of Mineral Resources

DWAF Department of Water Affairs and Forestry (now DWS)

DWS Department of Water and Sanitation

EA Environmental Authorisations

EC Electrical Conductivity

EHS Environment Health and Safety

EIA Environmental Impact Assessment

EMP Environmental Management Plan

GPS Global Positioning System

HDV Heavy Duty Vehicle

IFC International Finance Corporation

iLeh Irene Lea Environmental & Hydrogeology

IPP Independent Power Producer

IWULA Integrated Water Use Licence Application

km kilometre

LCM Lephalale Coal Mines (Pty) Limited

LCPP Lephalale Coal and Power Project

LDV Light Duty Vehicle

L/s Litre per second

L/h Litre per hour

m metre

m3 cubic metre

m3/day cubic metre per day


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MAE Mean Annual Evaporation

m amsl metres above mean sea level

MAP Mean Annual Precipitation

m bgl metres below ground level

MCWAP Mokolo Crocodile Water Augmentation Project

meq/L milli-equivalents per litre

MGH Masimong Group Holdings

mg/ℓ milligrams per litre

ml millilitre

mm millimetre

mm/a millimetre per annum

MPRDA Mineral and Petroleum Resources Development Act

MRA Mining Right Application

mS/m milli Siemens per metre

NAG Net Acid Generating

NEMA National Environmental Management Act, 1998

NEM:AQA National Environmental Management: Air Quality Act

NEM:WA National Environmental Management: Waste Act, 2008

NGA National Groundwater Archive

NHRA National Heritage Resources Act

NNP Nett Neutralising Potential

NWA National Water Act

PAF Potential Acid Forming

PCD Pollution Control Dam

Ptn Portion

PFS Pre-feasibility Study

PR Prospecting Right

RHDHV Royal Haskoning DHV

ROM Run of Mine

SANAS South African National Accreditation System

SANS South African National Standards

SPLP Synthetic Precipitation Leaching Procedure

s Specific yield


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S Storativity

TCLP Total Concentration Leach Procedure

TDS Total Dissolved Solids

TOC Total Organic Carbon

T Transmissivity

WHO World Health Organisation

WRD Waste Rock Dump

XRD X-ray Diffraction

XRF X-ray Fluorescence

WMA Water Management Area


PAGE 1

1 Introduction

Lephalale Coal Mines (Pty) Limited (LCM) (a member of the Masimong Group Holdings (MGH)

Group), proposes to develop a new Open Pit Coal Mine and Independent Power Producer (IPP)

plant approximately 25 kilometres (km) northeast of the town of Lephalale (Plan 1, Appendix A).

The project is known as the Lephalale Coal and Power Project (LCPP) and is 10 km north of the

R518 provincial road which links Lephalale and Marken. LCM holds the Prospecting Rights (PR)

for the 12 farms making up the project area (Plan 2, Appendix A):

• Prospecting Right LP 30/5/1/1/2/1359PR: farms Honingshade 427 LQ, Garibaldi 480 LQ,

Pretoria 483 LQ, Wellington 432 LQ, Forfarshire 419 LQ, Stutgard 420 LQ, Billiards 428

LQ, Franschoek 207 LQ; and

• Prospecting Right LP 30/5/1/1/2/1046PR: farms Grootgenoeg 426 LQ, Weltevreden 482

LQ, Sebright 205 LQ, Botmansdrift 423 LQ.

The LCPP resource will be mined using open pit strip mining, which is preferred because the

initial box cut lies close to the surface (approximately 11 metres in depth). The pits extend to a

depth of 70 metres (m) in Pit 1 and 65 m in Pit 2, and there is a low strip ratio and low dip

(approximately 2°). This mining approach is considered standard for the so-called barcode coals

in this part of the Waterberg Coalfield, is well understood in Southern Africa, and is suitable for

the large near-surface coal deposits found in the Waterberg Coalfield.

The Pre-Feasibility Study (PFS) (RHDHV, September 2016) recommends the use of hydraulic

excavators, combined with appropriately matched mining trucks for overburden, inter-burden

and ROM production, coupled with complementary ancillary mining equipment. The coal will be

processed on site, which will include washing, crushing and screening. Mine waste rock will be

stored on site or will be backfilled into the pit. Discard from the plant will also be stored on site.

Kongiwe Environmental (Pty) Ltd has been appointed by LCM to undertake the Environmental

Impact Assessment (EIA) process as part of the Mining Right Application (MRA), and other

Environmental Authorisations (EA’s) required for the proposed Mine and IPP plant. It is noted

that the economic base case provides for the sale of the coal through the IPP, but alternative

markets and optimisation options are being investigated. Importantly, the applications at this

stage will only be made for the mining section; applications for the IPP plant will be done in the

future once the detailed design of the IPP plant has progressed.

This report presents the groundwater impact assessment. An understanding of the

hydrogeological environment is essential to understand the impact of the operations on the

receiving environment, and to help design a dewatering system and groundwater management

plan that reduces or removes the risk of slope instability and adverse operating conditions

occurring.


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1.1 GROUNDWATER STUDY OBJECTIVES

The groundwater impact assessment focused on the following objectives:

• Define the current groundwater use in the LCPP area;

• Define the aquifers underlying the LCPP area, as well as current groundwater table

depth, groundwater quality, and flow characteristics;

• Develop a numerical model that will be used to define groundwater related impacts and

groundwater inflow into the open cast mining areas;

• Define the radius of influence that will be created by mine dewatering, plus the extent

of possible contamination originating from the proposed open cast areas and mine

infrastructure;

• Define the acid rock drainage (ARD) potential associated with the local geology and coal

seams;

• Assess whether pit decant will occur during the operational phase and post closure; and

• Recommend a groundwater monitoring network that will effectively monitor the

groundwater quality and level changes.

1.2 COMPLIANCE FRAMEWORK

1.2.1 Applicable National Legislation

The following applications will be made to the Department of Mineral Resources (DMR): Mining

Right Application (MRA) in terms of the Minerals and Petroleum Resource Development Act,

2002 (Act No. 28 of 2002) (MPRDA); Application for EA for listed activities triggered in Listing

Notices GN R983, 984 and 985 and in accordance with the Environmental Impact Assessment

(EIA) Regulations, 2014, promulgated in terms of National Environmental Management Act,

1998 (Act No. 107 of 1998) (NEMA); and Application for listed waste activities in terms of GN R.

921 of the National Environmental Management: Waste Act, 2008 (Act No. 59 of 2008), as

amended (NEM:WA).

In addition, applications will also be made to the following competent authorities: Application

for an Atmospheric Emission Licence (AEL), in terms of the National Environmental

Management: Air Quality Act, 2004, (Act 39 2004) (NEM: AQA); an Integrated Water Use Licence

(IWUL) in terms of the National Water Act, 1998 (Act 36 of 1998), as amended (NWA); and

relevant permit applications will also be made in terms of sections 34, 35 and 36 of the National

Heritage Resources Act, 1999 (Act No. 25 of 1999) (NHRA).

1.2.2 IFC Performance Standards

The International Finance Corporation (IFC) Performance Standards are an international

benchmark for identifying and managing environmental and social risks and has been adopted

by many organizations as a key component of their environmental and social risk management.

The IFC’s Environmental, Health and Safety (EHS) Guidelines provide technical guidelines with

general and industry-specific examples of good international industry practice to meet IFC’s

Performance Standards. In many countries, the scope and intent of the IFC Performance


PAGE 3

Standards is addressed or partially addressed in the country’s environmental and social

regulatory framework.

The financial institution is required to verify, as part of its environmental and social due

diligence process, that the commercial client complies with the IFC Performance Standards. To

do so, the financial institution needs to be knowledgeable of the environmental and social laws

of the country in which it operates and compare the regulatory requirements against those of

the IFC Performance Standards to identify gaps. A good understanding of both sets of

requirements, as well as potential gaps ensures that the financial institution will effectively

identify and assess the key environmental and social risks and impacts that might be associated

with a financial transaction.

The groundwater impact assessments will be undertaken to South African Best Practice

Guidelines and more specific, guidelines defined by the Department of Water and Sanitation

(DWS). The groundwater numerical flow and transport model will support the groundwater

impact assessment; defining potential groundwater quality and quantity impacts; including

impacts on the local communities, towns and surface water resources.

The water quality assessment was based on South African National Standard (SANS) 241-1:2015,

Drinking Water Guideline. Reference was also made to DWS, Domestic Use water quality

guideline.

1.3 GROUNDWATER ASSESSMENT TEAM

The following hydrogeologists are involved in the LCPP groundwater assessment:

• Lucas Smith (MSc Geohydrology) Pr.Sci.Nat:

o Project hydrogeologist.

o Field work, data analysis, interpretations, and reporting.

• Irene Lea (MSc Geohydrology) Pr.Sci.Nat:

o Numerical model and groundwater impact assessment.

Curriculum Vitae (CVs) are appended to Appendix B.

1.4 REPORT STRUCTURE

The report is structured as follow:

• Section 2 – Environmental Setting.

• Section 3 – Groundwater Assessment.

• Section 4 – Conceptual Groundwater Model.

• Section 5 – Numerical Model.

• Section 6 – Groundwater Impact Assessment.

• Section 7 – Cumulative Impacts.

• Section 8 – Water Demand.

• Section 9 – Groundwater Management Plan.


PAGE 4

• Section 10 – Groundwater Monitoring.

• Section 11 – Conclusions.

• Section 12 – Recommendations.

Appendices:

• Appendix A: Project maps.

• Appendix B: Curriculum Vitae.

• Appendix C: National Groundwater Archive Data.

• Appendix D: 2017 Hydrocensus Data.

• Appendix E: Water Laboratory Certificates.

• Appendix F: Borehole Logs.

• Appendix G: Geochemistry Laboratory Certificates.

• Appendix H: IAP Comments and Response.

2 Environmental Setting

The LCPP is situated in the Waterberg Coalfield, approximately 25 km northeast from Lephalale.

The topography is generally flat, with no prominent topographic features in the project area.

Hills are present south of the R518 Marken road, as well as to the south-west; the most

prominent being Tafelkop in the south, rising approximately 220 m above the average surface

elevation in the area. There is a gentle slope towards the north and northwest, regionally

draining towards the Mokolo River located to the west of the project area. The surface

elevation varies from 943 metres above mean sea level (m amsl) in the south to 869 m amsl in

the north, and 840 m amsl in the northwest.

The general topography and main drainage of the study area are illustrated in Plan 3 (Appendix

A).

2.1 CATCHMENT

The LCPP is in the A42J quaternary catchment, with two small portions of the LCM PR area in the

A42H and A50H quaternary catchments respectively; all forming part of the Limpopo Water

Management Area (WMA:1). The proposed mining area falls predominantly in the A42J

catchment. The farm Franschhoek 207 LQ and the northern portions of the farm Sebright 205

LQ are in quaternary catchment A50H (Plan 3, Appendix A). The southern portion of the farm

Pretoria 483 LQ is in the A42H quaternary catchment.

The main drainage is the Mokolo River located approximately 14 km west from the LCPP area.

The Mokolo River has various tributaries including the Sand River and the Grootspruit that

originate in the Waterberg mountain range and flow into the Mokolo River upstream of the

Mokolo Dam. Other tributaries include the Tambotie River, Poer se Loop and the Rietspruit that

join the Mokolo River downstream of the Mokolo Dam. The non-perennial Duikerspruit; a


PAGE 5

tributary of the Mokolo River is located approximately 16 km south from the LCPP area (Plan 3,

Appendix A).

The Lephalala River is located approximately 17 km east from the study area and originates in

the Sandrivier Mountains that form part of the Waterberg mountain range.

The Mokolo and Lephalala Rivers discharge into the Limpopo River located approximately 80 km

north. The area between the Mokolo River and Lephalala River is described as an endoreic area

(does not produce surface runoff) in the Limpopo WMA Water Resource Situation Analysis

Report (DWAF, July 2003), because of the semi-arid climatic conditions and shallow topographic

gradient.

The Mokolo Dam is in the Mokolo catchment, which provides water for a multitude of uses, the

most important being the supply to the Matimba Power Station and Exxaro’s Grootegeluk Coal

Mine. Water use in the catchment broadly includes 87% for agricultural activities and 13% for

the industrial, mining, power generation and domestic water supply service sectors (e.g.

Municipalities). Irrigation is currently the largest water user in this catchment (Department

Water Affairs, March 2012).

2.2 CLIMATE, RAINFALL AND GROUNDWATER RECHARGE

The project site is in the Northern Arid Bushveld climatic region; characterized by warm

summers (October to April) and mild, dry winters (May to September). Maximum temperatures

are usually experienced in January and minimum temperatures occur on average in July (DWAF,

July 2003). Monthly temperatures vary, with the average maximum temperatures ranging from

30°C to 36°C and the minimum temperatures between 3°C and 7°C.

The Lephalale area is situated in a semi-arid climate zone, characterised by summer rainfall with

an average annual rainfall of approximately 400 millimetres (mm) and an annual evaporation

higher than 2,000 mm, making local groundwater resources highly vulnerable to droughts (VSA

Leboa Consulting, January 2010). The peak rainfall months are January and February.

During drier years, the annual rainfall in the Limpopo WMA ranges generally between 100 and

200 mm in the extreme north, with most of the catchment ranging between 200 and 400 mm,

increasing up to 600 mm in the south.

Based on the monthly rainfall distribution for the Limpopo WMA, a Mean Annual Precipitation

(MAP) of 409 mm/a was calculated, with a maximum annual rainfall of 696.1 mm/a and a

minimum of 116.5 per annum over the 103-year period (DWAF, July 2003). In accordance with

the rainfall patterns, the relative humidity is higher in summer than in winter.

Rainfall data collected from the South African Weather Service is presented in Figure 1. The

data presents the rainfall in Lephalale (station 06743418) over the past 3 years (January 2014 to

December 2016), with an average rainfall of 378 mm per annum. Year 2014 recorded an annual


PAGE 6

rainfall total of 511 mm and subsequently 2015 and 2016 only received 291 mm and 332 mm

per annum respectively.

Figure 1. Lephalale rainfall. Station 0674341 8

2.3 GEOLOGY

(Referenced from – HASKONINGDHV UK LTD, 16 September 2016: Pre-Feasibility Study for

Lephalale Coal & Power Project. I&BPB4509R001D01)

The Waterberg Coalfield extends approximately 85 km west from the town of Lephalale and has

a 40 km north-to-south extent. The Coalfield is bounded by faults along its northern and

southern limits and is divided into two principal areas by the Daarby fault. The two areas consist

of a shallow western area where surface mining methods can extract the coal; and a deep north-

eastern area. The Waterberg Coalfield is characterised by high ash, low calorific value, and

thermal coal suitable for electricity generation.

The Waterberg Coalfield covers approximately 3,400 km2 and in the northwest, beyond the

border with Botswana, the Waterberg becomes the Mmamabula Coalfield which maintains the

same overall characteristics.

The primary coal seams within the Waterberg form part of the Ecca Group and were deposited

between 300 million (Late Carboniferous) and 180 million (Middle Jurassic) years ago. The Ecca


PAGE 7

Group Coal Measures are said to comprise over one third of the coal reserves within the

Southern Hemisphere and a significant reserve of South Africa is known to be present within the

Waterberg, understood to contain over 75 Bt of in-situ Inferred Resources, comprising over 50%

of the remaining mineable coal in South Africa.

The Ecca Group is contained within the Permian Karoo Supergroup, the dominant lithology in

southern Africa, covering approximately two-thirds of the country. The Karoo includes

sedimentary formations comprising a combination of interbedded sandstone and greyish,

carboniferous shale, and underlain by the glacial strata of the Dwyka Formation (Late

Carboniferous).

The Karoo of the Waterberg region differs from that of the main Karoo basin in the Highveld-

Witbank region in that the Waterberg region is characterised by the overlying coal bearing

sequence of the additional Volksrust Formation of the Mid-Late Permian. Locally, the Vryheid

and Volksrust Formations are referred to as the Grootegeluk and Swartrant Formations.

Local coal units are described using a recognised naming convention founded during

establishment of the Grootegeluk Mine in the 1980s. Seams are numbered from Zone 11 at the

top of the sequence to Zone 1 at the base. Each Zone has characteristic lithological features and

recognisable geophysical signatures, and coal qualities.

The productive series is hosted by the Ecca Group, which is subdivided into the Volksrust and

Vryheid Formations. Coal Zones 1 to 11 are contained within these two formations, with the

Volksrust comprising the upper Zones (5 to 11) and the Vryheid comprising the lower Zones (1

to 4).

The potentially productive region of the Waterberg is bounded by two large east-west striking

faults (Zoetfontein fault in the north and Eenzaamheid fault in the south), forming a series of

partially uplifted horst structures which, in areas, allow coal to be exploited at relatively shallow

depths. The central uplifted block is further traversed by the Daarby fault which, whilst

depicting varying strike orientation, is generally seen to trend northwest to southeast. The fault

has vertical throw of between 250 m and 400 m and is downthrown to the northeast. Many

potential faults with approximately east-west and northeast-southwest orientations have been

identified within the LCPP area (Plan 4, Appendix A). In the LCPP study area the Daarby fault

traverses the farms Wellington, Rondeboschje, Wolvendraai and Pretoria.

The geological structure of the LCPP deposit suggests that it is positioned on the eastern limit of

the Waterberg Coalfield. This is further supported by previous interpretations that show the

depth of cover (overburden) beneath the farms of the LCPP increases approximately west. The

coal bearing strata of the LCPP indicate a sub-horizontal structure with shallow dips towards the

west and southwest away from the basin margin. Granite outcrops can be found on the eastern

boundary of the proposed mining footprint area.


PAGE 8

2.4 HYDROGEOLOGY

The Ecca sandstone is considered to be the main water bearing formation in the area from

which farm supplies are generally drawn, as well as the intercept of linear geological features.

The regional groundwater flow is likely to be controlled by the dip of the strata and the

predominantly east-west trending faults, as well as porous flow processes in the weathered

material and fracture flow processes within the coal measures and sandstone / mudstone. The

groundwater table in the project area follow the topography. Historically, no groundwater

sampling has been undertaken and subsequently no information was available to assess the

seasonal trends and quality of groundwater in the area (RHDHV, September 2016). The LCPP

specialist groundwater assessment included an assessment of the current groundwater quality

(Section 3.2.1).

Groundwater recharge is only likely to occur at a time when there is enough rainfall to allow

localised runoff and pooling of water. The frequency of such events is low. According to VSA

Leboa Consulting (January 2010) most of the groundwater recharge occurs remote to the

Lephalale area, potentially from the foothills of the Waterberg Mountains, which could be the

main source of groundwater to the LCPP study area.

According to RHDHV (September 2016) borehole yields in the Limpopo Region are frequently

under 86 m3/day (1 L/s) in the Karoo siltstone, but may be up to 216 m3/day in similar age

sandstone (approximately 2.5 L/s). The Waterberg formations have steep topography and show

generally poor capability to produce huge amounts of groundwater, unless boreholes intersect

the northeast or southeast trending geological structures (Digby Wells Environmental, 2014).

The borehole yields for the Karoo and Waterberg sediments differ slightly. Only 10% of all

boreholes yield more than 2 L/s from both geological units.

The Department of Water and Sanitation initiated a groundwater assessment in Lephalale in

2009 (VSA Leboa Consulting, January 2010). The main purpose was to establish if groundwater

was a viable option for production purposes in the Lephalale area. The study concluded that a

volume of 1.4M m3/a could be obtained from eight boreholes located in a 10-km radius in town.

The Department of Water and Sanitation was using seven of the boreholes for water level

monitoring purposes (quarterly measurements), but one was later damaged during road

construction activities. The following conclusions were made:

• Confined and semi-confined, deep aquifers are present, linked with fracturing,

horizontal bedding plains and alluvial deposits; associated with the Waterberg Group;

• Three exploration boreholes can be drilled and one may result in a production borehole

of 21,600 L/h, on average;

• Borehole depths varied between 250 m and 300 m;

• Seven production boreholes can potentially supply 1M m3/a;

• The current exploration boreholes at Lephalale can access 1.4M m3/a groundwater from

the Waterberg aquifer;

• Production boreholes should be placed at least 2 km apart; and


PAGE 9

• Water quality constraints include high concentrations of Na, Cl and F. No treatment is

required for industrial use; however, treatment or blending will be required for

domestic use.

Most groundwater samples in quaternary catchment A42J show chloride enriched water.

Changes in the ratios of Ca, Mg and Na indicate that the groundwater may be subjected to

cation exchange processes.

3 Groundwater Assessment

3.1 LITERATURE REVIEW

Available geological and hydrogeological reports were reviewed during the LCPP groundwater

investigation to gain a better understanding of the local geological and hydrogeological

characteristics. The available information was used to help define the groundwater impact

assessment scope of work.

3.1.1 Historical Exploration Activities

The central farms of the LCPP have been subjected to three principal phases of mineral

exploration (RHDHV, September 2016):

• Phase 1: Historical: Honingshade, Garibaldi and Pretoria - Little is known regarding the

full extent or specification of historical drilling within the LCPP farms. Previous studies

refer to the drilling of 18 boreholes at the farms Honingshade (9 boreholes), Garibaldi (8

boreholes) and Pretoria (1 borehole).

• Phase 2: Pre-LCM: Grootgenoeg and Weltevreden - Beacon Rock Corporate Services on

behalf of Thandululo Coal Mining (Pty) Ltd. In 2009, 48 diamond core holes of 60.3 mm

diameter were drilled on the Grootgenoeg and Weltevreden farms. Of these, 20 were

drilled as twinned boreholes to obtain additional sampling material for further coal

quality analysis.

• Phase 3: 2010 to 2012: Honingshade, Garibaldi and Pretoria – P.C. Meyer Consulting

(Pty) Ltd, on behalf of LCM. The drilling programme included 66 boreholes (43 diamond,

23 percussion) on the farms Honingshade (20 diamond), Garibaldi (8 diamond, 23

percussion) and Pretoria (15 diamond).

3.1.2 Background Information

The following reports were reviewed to gain a better understanding of the local geology,

hydrogeology, and catchment characteristics:

• Department Water Affairs, March 2012. Classification of Significant Water Resources in

the Mokolo and Matlabas Catchment: Limpopo Water Management Area (WMA) and

Crocodile (West) and Marico WMA: WP 10506. Information Analysis Report: Mokolo


PAGE 10

and Matlabas Catchments: Limpopo WMA Final Report No.

RDM/WMA1,3/00/CON/CLA/0112B. Directorate: Water Resource Classification.

• Department Water Affairs and Forestry, July 2003. Limpopo Water Management Area.

Water resources situation assessment. Main Report.

• Digby Wells Environmental, February 2014. Fatal Flaw and Screening Assessment -

Lephalale Coal Project.

• Digby Wells Environmental, January 2015. Dedi Coal Water Supply Option Analysis.

Phase 1 Assessment Report.

• Digby Wells Environmental, September 2016. Exxaro Coal (Pty) Ltd Grootegeluk Short-

Term Stockpiles Amendment Project – Phase 2 Stockpile Expansion.

• HASKONINGDHV UK LTD, 16 September 2016. Pre-Feasibility Study for Lephalale Coal &

Power Project. I&BPB4509R001D01.

• VSA Leboa Consulting, January 2010. Hydrogeological Assessment and Aquifer Recharge

Potential within the Lephalale (Ellisras) Local Municipality Area. Report Nr: PWMA

01/A42/00/02209_01. Directorate: Water Resource Planning Systems (WRPS). Final

Report.

The National Groundwater Archive (NGA) was accessed during the baseline assessment to

identify existing borehole and aquifer information for the LCPP project area. The NGA search

indicated 52 boreholes located in the Dedicoal prospecting right areas, as well as on adjacent

farms (Appendix C).

The NGA borehole information indicates:

• The borehole coordinates as listed on the NGA are not always accurate as most

boreholes were not found at the listed coordinates. Borehole localities previously

plotted by hand or coordinates measured from 1:50 000 topographical maps could be

the reason for this. The use of different coordinate systems / datums (without good

references) can also result in inaccurate coordinates. The LCPP project hydrogeologist

reverted to using the knowledge of the land owners and farm workers to locate all

existing boreholes (Appendix D);

• Recorded groundwater levels on the NGA vary between 4.5 metres below ground level

(m bgl) on the farm Wolvendraai and 117 m bgl on the farm Forfarshire; and

• Only 4 borehole yields are recorded, and vary between 0.3 L/s and 2.7 L/s.

3.2 CURRENT GROUNDWATER USE

A hydrocensus was conducted across the LCM prospecting right area by Digby Wells

Environmental, during November 2014. During the survey they identified 28 boreholes, located

predominantly in the central, southern and far north-eastern farm portions.

Twenty-one of the identified boreholes were in use, primarily for stock and game watering, plus

domestic use. At the time, the deepest measured groundwater level in the area was 45 metres

below ground level (m bgl) on the farm Pretoria; closest to surface was 7 m bgl on Weltevreden.


PAGE 11

ASST repeated the hydrocensus during March and April 2017 to include the proposed mining

footprint area, farms associated with the LCM prospecting right areas, as well as adjacent

properties. The hydrocensus concentrated on identifying existing boreholes throughout the

project area to enhance the knowledge of the groundwater system and current groundwater

use.

During the 2017 hydrocensus 57 boreholes were identified (Plan 5, Appendix A). Farms

surveyed included:

• Stellenbosch 203 LQ;

• Sebright 205 LQ;

• Franschhoek 207 LQ;

• Trompettersfontein 422 LQ;

• Botmansdrift 423 LQ;

• Honingshade 427 LQ;

• Billiards 428 LQ;

• Rondeboschje 429 LQ;

• Grootgenoeg 426 LQ;

• Middelboomspunt 425 LQ;

• Alomfraai 484 LQ;

• Weltevreden 482 LQ;

• Garibaldi 480 LQ;

• Wolvenfontein 481 LQ; and

• Pretoria 483 LQ.

The 57 boreholes identified included:

• 2 open exploration boreholes with small diameter steel casing inserted;

• 48 boreholes in use:

o 40 fitted with submersible / sun pumps;

o 7 fitted with windpumps;

• 6 open boreholes not in use;

• 1 hand-dug pit on the farm Middelboomspunt;

• Groundwater level measurements were possible from 34 boreholes; pumping

equipment blocked the rest; and

• Collection of 5 groundwater samples for water quality analysis from:

o Pretoria 483 LQ;

o Garibaldi 480 LQ;

o R/E Weltevreden 482 LQ;

o Portion 1 of Grootgenoeg 426 LQ; and

o R/E Sebright 205 LQ.


PAGE 12

During the hydrocensus the following information was collected for each borehole:

• Borehole position (X, Y, Z-coordinates);

• Information relating to equipment installed;

• Borehole construction details;

• Borehole yield – if known by the land owner;

• Groundwater level, if possible; and

• Current use.

A summary of the boreholes identified during the 2017 hydrocensus is available in Appendix D.

All coordinates were taken with a hand-held Garmin GPS (Global Positioning System) (UTM

ZONE 35; Units, Metres).

It is recommended to have all future monitoring and production boreholes, as well as private

boreholes surveyed with a differential GPS system to ensure accurate reporting of the

groundwater levels. Hand-held GPS systems have a coordinate accuracy of approximately 5 m

whereas the differential GPS systems record the coordinates, and more importantly the

elevation with accuracy better than five centimetres.

Water levels were measured by using a dip meter to measure the distance from the mouth of

the borehole (borehole collar elevation) to the groundwater table depth in the borehole. The

height of the borehole collar was subtracted from the measured water level to define a water

level below surface (measured in m bgl) (Appendix D). The m bgl measurement was subtracted

from the borehole’s surface elevation to define metres above mean sea level (m amsl) for all

water table measurements.

The groundwater level below surface varied between a maximum depth of 53 m bgl on the farm

Stellenbosch, and 3 m bgl on the farm Alomfraai, Ptn 2. If the groundwater levels are measured

against elevation above sea level then the highest water elevations can be found on the farms

Pretoria and Alomfraai (south-eastern areas) and the lowest water table elevations on the farms

Billiards and Rondeboschje (northwest); indicating a regional groundwater flow from southeast

to northwest. The farm portions located along the upper regions of the quaternary catchments,

i.e. Pretoria, Alomfraai and Sebright indicate deeper groundwater levels (below surface)

compared to the other farms located deeper within the quaternary catchment (towards the

west and northwest).

The correlation between topography and groundwater elevation is approximately 80%, as

shown in Figure 2. The depth to groundwater table correlates well with the surface elevations,

indicating that on a regional scale groundwater flow follows topography. Many of the boreholes

in the area are equipped with solar pumps. The pumps automatically switch on and off based

on the level of the water table in relation to the pump inlet, or based on demand from surface.

The green dots on Figure 2 represent boreholes that were switched off during the hydrocensus

to allow for water level measurements, and there for the variance. The groundwater table


PAGE 13

recovers very slowly and subsequently some of the measured water levels do not represent

actual rest water levels.

Figure 2. Correlation between surface level and groundwater levels

No time series groundwater level data were available to determine seasonal changes in the

groundwater levels. A comparison between the 2017 groundwater levels and the water table

depths recorded during the Digby Wells hydrocensus (November 2014) indicates that there has

been no significant change in the water levels across the area over the past 2.5 years. The level

measurements were however done during different seasons and will therefore not be an

accurate groundwater level comparison. There appears to be no groundwater flow barriers in

the area.

Detailed information in terms of borehole construction and yields are not available for most of

the identified boreholes. The information provided by the land owner or farm workers

indicated low borehole yields for most of the LCPP project area. Verbal communication

indicates that the farms along the south present higher yielding boreholes; these include the

farms Pretoria, Garibaldi and Weltevreden. This potentially relates to the east-west trending

faults (including the Daarby fault) in the area.

860

870

880

890

900

910

920

930

940

950

820 840 860 880 900 920 940

Wat

er E

leva

tio

n (

mam

sl)

Surface Elevation (mamsl)

Water level vs Surface Elevation


PAGE 14

Several rural communities are located along the Lephalala River; these include Ga-Seleka,

Witpoort, Mokuranyane and Ga-Shongwane. These communities reply on groundwater for

water supply. They are located approximately 10 km to 15 km east of the proposed mining

development.

3.2.1 Groundwater Quality

Five groundwater samples were collected during the 2017 hydrocensus. The water samples

were submitted to Aquatico Laboratories in Pretoria for analysis; Aquatico is a SANAS accredited

laboratory (South African National Accreditation System). The water samples were analysed for

basic inorganic parameters and the results were compared against the SANS 241:2015 Drinking

Water Standards. It is recommended that all identified boreholes, actively used for domestic

and agricultural purposes be sampled before the construction phase to update the baseline

assessment and build a water quality database for the area. The database will help the client

identify water quality and level trends in the area, and will serve as reference to identify and

quantify potential impacts on private boreholes.

Groundwater samples were also collected from 9 boreholes during the 2017 aquifer testing

programme. The results have been included in this section (Table 1).

All water samples were taken in accordance with the Department of Water and Sanitation’s

(DWS) Water Sampling Guide. Samples were collected from boreholes across the project area

to ensure a good representation of groundwater qualities.

Samples were taken using single valve, decontaminated bailers or from pumps and taps in the

case of boreholes which were equipped and in use. Sterilized 500 millilitre (ml) sample bottles

were used and filled to the top. Samples were stored in a cooler box during the site surveys.

Samples were submitted to Aquatico Laboratory in Pretoria for chemical analysis that included

the following elements:

• Total Dissolved Solids as TDS • Electrical Conductivity in mS/m

• Nitrate and Nitrite as N • pH value

• Chlorides as Cl • Aluminium as Al

• Total Alkalinity as CaCO3 • Ammonium as NH4

• Fluoride as F • Cadmium as Cd

• Sulphate as SO4 • Copper as Cu

• Total Hardness as CaCO3 • Nickel as Ni

• Calcium as Ca • Zinc as Zn

• Magnesium as Mg • Lead as Pb

• Sodium as Na • Total Chromium

• Potassium as K • Total Organic Carbon

• Iron as Fe • Manganese as Mn


PAGE 15

Water quality data are presented by means of tables, and Piper and Stiff diagrams. The Piper

(Figure 3) and Stiff diagrams (Figure 4) were created using the WISH software.

Piper Diagram

The Piper Diagram uses the relationship of chemical parameters to classify water samples

according to their dominant cations and anions, as well as allowing for the grouping of water

according to hydrogeological facies. The Piper Diagram uses concentrations calculated in meq/L

to represent a percentage of the total cations or anions. The cations and anions of each sample

are plotted on the respective triangular plot and the points are then projected onto the central

diamond graph (Figure 3). Depending on where the sample point falls on the diamond graph,

basic assumptions can be attributed to the sample, and for this reason the diamond graph is

divided into quarters. Displaying numerous water qualities of the same sample on one plot

gives an understanding of the changes occurring over time, whilst displaying multiple samples

together provides a basis for comparison.

The left quarter in a Piper Diagram represents freshly recharged water, dominated by calcium-

magnesium-bicarbonate signature. The right quarter is associated with stagnant or slow-moving

groundwater and is dominated by sodium and chloride. The bottom quarter is typical of

dynamic groundwater flow and is dominated by sodium and bicarbonates; and the top quarter

typically indicates contamination, and is dominated by sulphate.

Stiff Diagrams

Stiff diagrams (Figure 4) are graphical presentation of the general chemistry of water. A

polygonal shape is created from four parallel horizontal axes extending on either side of a

vertical axis. Cations are plotted on the left of the vertical axis and anions are plotted on the

right (Fetter, 1994). The diagrams can be relatively distinctive for showing water composition

differences or similarities. One feature is the tendency of a pattern to maintain its characteristic

shape as the sample becomes diluted. It may be possible to trace the same types of

groundwater contamination from a source by studying the patterns.

The water quality results are presented in Table 1. The laboratory certificates are attached in

Appendix E.

Based on Figure 3 and Figure 4 the dominant cations in the groundwater samples are sodium

(Na) and magnesium (Mg), with the dominant anions being chloride (Cl) and bicarbonate (HCO3).

The ion distribution is clear in the Stiff diagrams (Figure 4), with the general water facies of the

LCPP project area predominantly represented by Na-HCO3 and Na-Cl water types.

High sodium and chloride values are typical of Waterberg Coalfield (Karoo) aquifers, with low

recharge and long residence times. The boreholes plotting in the right quarter of the Piper

Diagram with a Na-Cl dominant facies, could potentially be associated with the deeper more

stagnant groundwater, with the coal seams contributing to higher TDS and EC values. The


PAGE 16

elevated F, Cl and Na concentrations are naturally occurring ions in the groundwater and are

associated with the Karoo formations and their mineralogy.

Based on the water quality results (Table 1), the following conclusions were drawn:

• Chronic Health effects:

o Fluoride – fluoride is present in high concentration (between 2 and 7.4 mg/L) in

almost all sampled boreholes, except for GARI2 and RHP01. The measured

concentrations exceed the SANS241 chronic health limit of 1.5 mg/L. Fluoride

concentrations are associated with leaching of fluoride containing minerals from

the Karoo formations and often exceed the SANS241 chronic health limit. It is a

relatively stable anion and removal can be achieved through adsorption in a bed

of activated alumina; removal in ion exchange columns along with other anions;

and removal in membrane processes such as reverse osmosis and electro-

dialysis, together with virtually all other ions.

o Total Organic Carbon – a high TOC value (10.2 mg/L) was measured for borehole

HONI2. In groundwater, the main natural sources of organic matter include

organic matter deposits such as buried peat, kerogen and coal; soil and

sediment organic matter; and organic matter present in water infiltrating into

the subsurface from rivers or dams / pans. Borehole HONI2 is located adjacent

to a small pan and together with the coal seams might explain the high TOC

value.

• Acute Health effects:

o Nitrate – Borehole GARI2 yielded a high nitrate concentration (44.8 mg/L);

potentially because of animal movement in the area. Mineral deposits of

nitrates are rare due to the high water-solubility of nitrates, but nitrate is

abundant in soils and in aquatic environments, particularly in association with

the breakdown of organic matter and eutrophic conditions. A source of nitrates

in natural water results from the oxidation of plant and animal debris and of

animal and human excrement.

• Aesthetic effects:

o Sodium and Chloride concentrations are elevated for boreholes GROOT3, HONI2

and RHP01. Elevated Sodium and Chloride concentrations are common in the

Waterberg area and often exceed the SANS241 guideline limits. Water

measuring high sodium and chloride concentrations is often associated with

deep, stagnant groundwater resources, and low recharge. The 3 boreholes are

in the central parts of the proposed mining footprint area and yield low

quantities of water and recovery of the water levels were very slow after

completion of the aquifer tests.

o Manganese – Manganese is a relatively abundant element, constituting

approximately 0.1% of the earth's crust. Six boreholes measured manganese

concentrations that could present aesthetic concerns (Table 1). Manganese

tends to precipitate out of solution to form a black hydrated oxide which is


PAGE 17

responsible for the staining problems often associated with manganese-bearing

water.

o Ammonia - Ammonia is not toxic to man at the concentrations likely to be found

in drinking water, but does exert other effects. Elevated concentrations of

ammonia can compromise the disinfection of water and give rise to nitrite

formation in distribution systems, which may result in taste and odor problems.

A high ammonia concentration was measured in borehole RHP01. Ammonia is

also found in runoff from agricultural lands, where ammonium salts have been

used for fertilizers and this could be the reason for the elevated concentration

found in borehole RHP01. Old agricultural lands characterize the area.

• Scaling effects – high concentrations of calcium were measured in most boreholes.

Scaling occurs in water heating appliances such as kettles and geysers and results in low

efficiencies and the partial obstruction of pipes. High concentrations of calcium also

impair the lathering of soap.

Based on the SANS241 drinking water guideline and on the sampled borehole water, the

groundwater is not fit for human consumption (unless treated); predominantly because of high

fluoride concentrations and isolated occurrences of nitrate and TOC. All measured metals and

sulphate were present in concentrations below the SANS241 guideline limits.


PAGE 18

20%

40%

60%

80%

20%40%60%80%

20%

40%

60%

80%

20%

40%

60%

80%

20% 40% 60% 80%

20%

40%

60%

80%

20%

40%

60%

80%

20%

40%

60%

80%

ALOM4 BILL8 GARI2 GROOT3 HONI2 PRET3 RHP01 RHP02 RHP03 RHP04 RHP05 RHP06 SEBR1 WELT4

Chloride

Sulphate

Tot

al Al

kalin

ity

Sodium & Potassium

Mag

nesiu

m

Calcium

AnionsCations

LCPP - Piper Diagram

Figure 3. Piper diagram


PAGE 19

Figure 4. LCPP Stiff diagrams

ALOM420170530 - 14h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

BILL820170531 - 11h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

GARI220170328 - 10h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

GROOT320170329 - 15h30

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

HONI220170806 - 18h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

PRET320170328 - 14h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

RHP0120170527 - 17h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

RHP0220170527 - 22h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

RHP0320170526 - 18h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

RHP0420170506 - 19h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

RHP0520170530 - 17h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

RHP0620170706 - 00h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

SEBR120170330 - 08h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

WELT420170329 - 10h00

Cl

Alk

SO4

Na+K

Ca

Mg

15 meq/l 15

STIFF Diagrams

Table 1. LCPP Hydro-chemical results

Parameter pH EC TDS Ca Mg Na K TOC Cl SO4 NO3-N F Al Fe Mn Ammonia

as N

Cr Cu Ni Zn Cd Pb

Unit mS/m mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L

SANS241

Standard

Limits

≥5-

≤9.7

Aesthetic

≤170

Aesthetic

≤1200 -- --

Aesthetic

≤200 --

Chronic

health

≤10

Aesthetic

≤300

Acute

health

≤500

Acute

health

≤11

Chronic

health

≤1.5

≤0.3

Chronic

health

≤2

Chronic

health

≤0.4

Aesthetic

≤1.5

Chronic

health

≤0.05

Chronic

health

≤2

Chronic

health

≤0.07

Aesthetic

≤5

Chronic

health

≤0.003

Chronic

health

≤0.01

-- -- -- -- -- -- -- -- -- Aesthetic

≤250 -- -- --

Aesthetic

≤0.3

Aesthetic

≤0.1 -- -- -- -- -- -- --

DWS Drinking

Standards

No

health.

Scaling

intensifies

from

32mg/L

Diarrhoea

and

scaling

issues

from

70mg/L

No

aesthetic

or health

effects

below

50mg/L

ALOM4 8.2 80.9 463.0 61.7 17.8 78.8 7.4 1.7 96.3 21.9 5.5 2.7 <0.002 <0.004 <0.001 0.057 <0.003 <0.002 <0.002 <0.002 <0.002 <0.004

BILL8 7.7 144.0 929.0 94.6 39.6 181.0 18.6 2.1 89.2 111.0 4.5 2.0 <0.002 <0.004 <0.001 0.201 <0.003 0.055 <0.002 0.232 <0.002 <0.004

GARI2 8.6 103.0 739.0 94.4 62.5 72.5 7.9 1.7 90.0 20.4 44.8 0.7 <0.002 <0.004 <0.001 0.156 <0.003 <0.002 <0.002 <0.002 <0.002 <0.004

GROOT3 8.6 187.0 1227.0 172.0 47.1 244.0 5.7 1.2 556.0 62.2 0.4 2.4 <0.002 <0.004 0.17 0.361 <0.003 <0.002 <0.002 <0.002 <0.002 <0.004

HONI2 8.05 100.0 683.0 11.6 4.7 242.0 7.5 10.2 143.0 7.6 1.4 7.4 1.1 0.18 0.019 0.202 <0.003 <0.002 <0.002 <0.002 <0.002 <0.004

PRET3 8.64 99.8 616.0 81.6 34.6 118.0 4.6 1.5 182.0 26.9 1.8 2.9 <0.002 <0.004 <0.001 0.07 <0.003 <0.002 <0.002 <0.002 <0.002 <0.004

RHP01 7.3 207.0 1404.0 172.0 47.9 248.0 19.4 5.1 403.0 175.0 0.3 1.3 <0.002 <0.004 0.21 3.34 <0.003 0.049 <0.002 0.077 <0.002 <0.004

RHP02 7.9 135.0 866.0 113.0 24.7 160.0 6.3 2.1 206.0 139.0 0.3 3.4 <0.002 <0.004 0.26 0.473 <0.003 0.038 <0.002 0.026 <0.002 <0.004

RHP03 8.3 120.0 730.0 86.5 19.5 156.0 5.2 1.8 195.0 86.1 0.3 3.7 <0.002 <0.004 0.12 0.138 <0.003 0.011 <0.002 0.583 <0.002 <0.004

RHP04 7.79 103.0 743.0 87.2 21.0 144.0 6.9 1.4 196.0 77.5 <0.194 3.3 <0.002 <0.004 0.23 0.192 <0.003 0.155 <0.002 0.162 <0.002 <0.004

RHP05 8.4 86.2 486.0 46.4 12.6 121.0 3.6 2.2 134.0 28.7 0.2 3.9 <0.002 <0.004 0.10 0.075 <0.003 <0.002 <0.002 0.008 <0.002 <0.004

RHP06 8.35 89.4 605.0 60.3 22.7 127.0 7.9 1.2 137.0 41.3 <0.194 2.6 0.017 <0.004 0.053 0.536 <0.003 <0.002 <0.002 <0.002 <0.002 <0.004

SEBR1 8.6 75.7 457.0 39.3 19.0 117.0 2.4 1.3 96.7 45.7 4.1 3.1 <0.002 <0.004 <0.001 0.829 <0.003 <0.002 <0.002 <0.002 <0.002 <0.004

WELT4 8.6 106.0 681.0 89.9 20.5 153.0 5.9 1.1 166.0 79.3 0.6 3.3 <0.002 <0.004 <0.001 0.052 <0.003 <0.002 <0.002 <0.002 <0.002 <0.004


PAGE 21

3.3 GEOPHYSICAL SURVEY

A ground geophysical investigation was conducted to identify regional geological structures,

which could act as preferential groundwater flow paths and potentially good water yielding

aquifers. The ground surveys have been used in conjunction with the available remote

sensing images and geological maps.

The geophysical investigation was conducted during April 2017 by ASST. The following

techniques were applied:

• EM 34–3 electromagnetic (EM) system, with a coil spacing of 20 m and 40 m, and a

station spacing of 10 m; and

• Magnetic survey with a GEM Walking Mag. With the Walking Mag the operator is

equipped with a GEM unit that automatically samples during the walking process.

This gives a continuous record of the ground over which the survey is being

conducted.

Most of the target areas were focused along the fault zones in the southern and central

parts of the proposed footprint area (Plan 4, Annexure A). The drilling programme would

assess the water yielding potential of the aquifers in the area and therefore accurate

placement of the boreholes was important.

Line orientation was predominantly in a north-south or NW- SE direction (Plan 4, Annexure

A); the reason being that most of the identified linear structures (potential faults) strike east-

west. The survey included 10 survey lines, and line and station coordinates were marked in

the field using a differential GPS.

Based on the interpretation of the geophysical data, 26 potential drilling targets were

identified (Table 2). Six boreholes were selected from this list for the LCPP groundwater

drilling programme. The selected borehole targets would serve to:

• Identify the geological formations underlying the project area, as well as

characterize the linear geological structures;

• Obtain information on the baseline groundwater quality;

• Investigate the hydraulic properties of the intersected geology and associated

aquifer systems; and

• Act as monitoring boreholes should the development proceed.


PAGE 22

Table 2. Proposed drilling localities

Traverse ID EAST SOUTH Farm

Traverse1_bh1 591544,4921 7392085,956

Garibaldi

Traverse1_bh2 591555,0545 7391951,459

Traverse1_bh4 590963,2819 7392683,441

Traverse1_bh5 590861,5604 7392788,408

Traverse2_bh1 595755,4313 7392449,233

Pretoria

Traverse2_bh2 595743,0852 7391980,601

Traverse2_bh3 595727,445 7392072,684

Traverse2_mag 595471,7508 7391419,037

Traverse2_mag2 595406,0771 7391247,845

Traverse3_mag 597791,3759 7390860,552

Traverse3_bh 597828,0058 7390920,286

Traverse4_mag 594976,9288 7389947,036

Traverse4_bh1 594623,971 7390551,522

Traverse4_bh2 594534,4718 7390658,59

Traverse5_mag 592864,0206 7393247,298

Weltevreden

Traverse5_bh1 592167,4819 7393932,833

Traverse5_bh2 592097,0066 7394029,133

Traverse5_mag2 592466,752 7393597,648

Traverse6_mag 592609,5185 7395605,432

R/E Grootgenoeg

Traverse6_bh1 592614,3459 7395592,311

Traverse6_bh2 592831,4582 7394799,87

Traverse6_bh3 592669,6721 7395388,889


PAGE 23

Traverse ID EAST SOUTH Farm

Traverse7_mag 594276,6248 7397440,986

Grootgenoeg Ptn 1

Traverse7_bh 594237,4717 7397556,74

Traverse8_mag 594785,7678 7403609,864

R/E Sebright

Traverse8_mag2 594782,9352 7403569,757

3.4 DRILLING PROGRAMME

Based on the geophysical survey results, communication with RHDHV and an understanding

of the local geology, ASST identified 6 suitable drilling positions for groundwater

characterisation, groundwater monitoring and possible water supply boreholes (Table 4).

Five additional localities were identified for the core drilling programme by RHDHV (Table 3).

The percussion and core drilling programmes were carried out during April and May 2017.

Core drilling was carried out by Ubuntu Rock Drilling and the percussion drilling by GPJ

Bezuidenhout Projects. Drilling supervision was undertaken by Peet Meyer Consulting,

RHDHV and ASST.

The borehole depths were based on the proposed depth of the open-cast areas. It is

important to assess the full extent of the geological horizons to be penetrated by the open

pit mining operations, to help define geological and hydrogeological properties and define

geological conditions below the pit floor. The boreholes were positioned relatively close to

the proposed pits and mine infrastructure areas.

Identifying the aquifer yield potential of the underlying formations was one of the objectives

of the drilling programme. The results of the drilling programme, plus the outcome of the

aquifer testing programme were used to determine whether local aquifers could potentially

serve as water supply to the mine. The drilling of a deep percussion borehole (approx. 300

m deep) was included in the drilling programme to determine whether high yielding

resources like that found in Lephalale are present within the LCPP area.

The 6 percussion boreholes included (Plan 6, Appendix A):

• One deep-aquifer characterisation borehole (approximately 300 m deep) to

investigate the deeper fractured aquifer’s water yielding potential, on the farm

Garibaldi; and

• Five groundwater characterisation / monitoring boreholes (approx. 120 m deep) to

assess the underlying groundwater status and occurrence.

Data collected include the geological succession, water strike depth, the cumulative final

blow yield and final rest water level, as well as the collection of percussion drill samples at

one metre intervals. A summary of the results is presented in Table 4 and Table 5.


PAGE 24

Core drilling was included in the drilling programme to obtain sample material for acid rock

drainage (ARD) analysis. Five core holes were drilled (Table 3 and Plan 6, Appendix A);

positioned within the footprints of the proposed opencast pit areas (Pit 1 and Pit 2).

Table 3. Proposed core drilling localities

Farm BHID Easting Northing Elevation Depth to base of coal (mbgl)

Botmansdrift RHD01 93102.4 -601057.5 873.9 54.4

Honingshade RHD02 93102.0 -602866.5 875.3 42.1

Grootgenoeg RHD03 92034.4 -604331.4 868.4 68.3

Grootgenoeg RHD04 92367.2 -606128.0 872.2 85.8

Weltevreden RHD05 93231.0 -608344.6 885.4 82.0

3.4.1 Drilling Results

The geological profiles intercepted by the percussion and core drilling programmes are

presented in Appendix F.

The new LCPP percussion boreholes – targeting linear geological features – produced blow

yields between 800 litres per hour (L/h) and 25,000 L/h (Table 4). This includes the deep

borehole (RHP06), where the water strikes were deeper than 100 m below surface (deepest

at 230 m bgl). The deep borehole (267 m deep) yielded a final blow yield of 2,500 L/h. In

general, borehole yields throughout the project area are low, indicating no major aquifer

systems.

From Table 4 it can be concluded that the high yielding formations / aquifers seem to be the

intercept of linear geological features below the water table. Most of the main water strikes

were between 70 m and 82 m bgl. The deepest water strike was at 230 m bgl in borehole

RHP06. The shallow weathered zone, the small fractures in the coal seams and the

geological contacts only yielded seepage water.

The fractured aquifers in the area can be classified as confined aquifers based on an

assessment of the rest groundwater level depths versus water strike depths. All rest water

levels were located at a shallower depth compared to the water strike depths (Table 4).

Most of the water strikes were found outside the coal horizons; those observed in the coal

horizons only produced seepage water. The east-west trending faults in the south of the

project area seem to be preferred groundwater flow paths / higher yielding aquifer units.

The main water strikes in borehole RHP03 (highest blow yield borehole at 25,000 L/h) were

in the mudstone; 79 m and 109 m bgl. The geological samples indicated that the borehole

intercepted a fractured zone (fault) below the interbedded coal sequence.


PAGE 25

Based on the percussion and core drilling results the top of the coal seams are found from

approximately 18 to 26 m bgl across the proposed mining footprint area. Borehole RHP06 at

Garibaldi only intercepted coal at 64 m bgl (Plan 6, Appendix A). Borehole RHP05

intercepted no coal, but granite was intercepted at 50 m bgl, as well as in borehole RHP03 at

112 m bgl. Granite outcrops are visible on the farms to the east of the proposed pit areas,

e.g. at Middelboomspunt and Alomfraai. The water strike in borehole RHP05 (at 50 m bgl)

was at the contact zone between the Karoo formations and the granite; the borehole yielded

a blow yield of approximately 8,000 L/h. The weathered granite could be a potential target

for water supply drilling. Infill drilling is recommended to assess the occurrence and depth

of the granite underlying the proposed plant, infrastructure and IPP plant areas. Monitoring

boreholes across the dip along the western contact of the granite are recommended to

monitor possible pollutant movement along this boundary.

The depth of weathering (highly weathered material) varies between 7 and 23 m bgl; on

average, the depth of weathering is approximately 13 m bgl.

The recorded groundwater levels vary between 7 and 41 m bgl. Boreholes on the

Grootgenoeg and Weltevreden farms indicate water levels closer to surface compared to the

rest of the area, with PRET3 measuring a water level depth of 41 m bgl. On average, most of

the boreholes indicate a water level depth of approximately 25 to 30 m bgl. If the

groundwater levels are presented as metres above mean sea level then the groundwater

table in the Alomfraai, Middelboomspunt and Weltevreden (Ptn 1) farms indicate a higher

elevation compared to the Stellenbosch, Sebright, Billiards and Rondeboschje farms (lower

elevations). This confirms a regional groundwater flow direction in a north-westerly

direction.

The 2017 drilling programme yielded two boreholes with high blow yields (8,000 L/h to

25,000 L/h). The other four boreholes yielded between 800 and 2,500 L/h each; confirming

the low average yield for the area.


PAGE 26

Table 4. Drilling summary of new boreholes

Borehole ID RHP01 RHP02 RHP03 RHP04 RHP05 RHP06

Bo

reh

ole

Loca

tio

n

(UTM

)

35

Easting 92706.8 92204.4 92901.2 90897.9 95793.7 91581.1

Northing -605653.4 -607110.0 -607795.8 -608254.9 -608594.2 -608957.6

Elevation 873.2 874.0 879.7 874.7 908.8 883.7

Bo

reh

ole

Dat

a

Borehole Depth (m) 151 181 116 166 80 270

Blow Yield (L/h) 800 1,000 25,000 1,000 8,000 2,500

Water Strike depth (m) 82 81, 164 79, 109 -- 50 70, 230

Static Water Level (m bgl) 25.7 30.4 28.2 32.6 35.7 35.0

Geology

Coal seams from 18 m with mudstone

interburden below

Coal seams from 24 m with

mudstone interburden

below

Coal seams from 26 m with mudstone

interburden below. Granite from 112 m

Coal seams with mudstone

interburden

Mudstone with granite from 48m

Deep overburden. Coal seams from 63 m with mudstone

interburden

Depth of Weathering 11 m 22 m 23 m 12 m 10 m 13 m


PAGE 27

Table 5. Core drilling summary

Farm BHID Easting Northing Elevation Hole

Depth (m)

Geology

Botmansdrift RHD01 93102.4 -601057.5 873.9 55 Coal seams from 18 m with mudstone interburden below

Honingshade RHD02 93102.0 -602866.5 875.3 70 Coal seams from 15 m with mudstone interburden below

Grootgenoeg RHD03 92034.4 -604331.4 868.4 61 Coal seams from 16 m with mudstone interburden below

Grootgenoeg RHD04 92367.2 -606128.0 872.2 64 Coal seams from 19 m with mudstone interburden below

Weltevreden RHD05 93231.0 -608344.6 885.4 70 Coal seams from 20 m with mudstone interburden below

3.5 AQUIFER TESTING

Following completion of the drilling programme, an aquifer test programme was initiated to

determine the hydrogeological characteristics of the local aquifers. This includes:

• Borehole drawdown and recovery characteristics.

• Aquifer hydraulic parameters:

o Transmissivity (T) defined as the product of the average hydraulic

conductivity (K) and the saturated aquifer thickness. It is a measure of the

rate of flow under a unit hydraulic gradient through a cross-section of unit

width over the whole saturated thickness of the aquifer. The unit of

measurement is m2/day.

o Aquifer storage, either storativity (confined storage) or specific yield

(unconfined storage). Storativity (S) is the volume of water released from

storage per unit surface area per unit change in head. It is a dimensionless

quantity. Specific yield (s) is a ratio between 0 and 1 indicating the amount

of water released due to drainage, from lowering the water table.

• Characterisation of aquifer flow boundaries such as low permeable, no-flow or

recharge boundaries. No-flow or low permeable boundaries refer to a lower

transmissive structure (e.g. fracture with a lower conductance or low permeable

dyke) or aquifer boundary (limit of aquifer – no-flow boundary) that results in an

increase in groundwater drawdown during borehole abstraction. Recharge

boundaries relate often to leakage from surface water bodies.

The aquifer testing included existing private boreholes within the LCPP project area. The

private boreholes were selected to identify current borehole yields in the area, identify

borehole yield trends and to improve on the understanding of aquifer behaviour; this

information is fed into the numerical groundwater flow model. Sixteen private boreholes


PAGE 28

were tested on the farms Honingshade, Billiards, Grootgenoeg, Weltevrede, Alomfraai,

Pretoria and Wolvendraai.

Boegman Borehole Testing was subcontracted to carry out the aquifer testing during May

and June 2017. Aquifer testing was undertaken on the following boreholes (refer to Table 6

and Plan 5 and Plan 6 – Appendix A):

• The six new boreholes drilled on the farms Weltevreden, Garibaldi and Pretoria; and

• 16 private boreholes across the LCPP project area.

Prior to the aquifer test, static groundwater levels are measured in the pumping and

observation boreholes to enable drawdown calculations during test pumping. Pumped

water was released via a discharge pipe, at least 100 m from the test borehole, to avoid

rapid recharge from the discharged water. During the test, the abstraction rate is

continuously monitored by means of electronic flow meters and calibrated by measuring the

time it takes to fill a container of known volume, with a stopwatch.

The pumping test programme included the following different tests:

• Firstly, a step drawdown test (SDT) is performed. During the SDT the borehole is

pumped at a constant discharge rate for 30 minutes, where after the step is

repeated at a progressively higher discharge rate. During the SDT the drawdown

over time is recorded in pumping and observation boreholes. The advantage of this

test is that the pumping rate for any specific drawdown can easily be determined

from the relationship between laminar and turbulent flow. After the test stopped,

residual drawdown is measured until approximately 90% recovery of the water level

has been reached. The discharge rate for the constant discharge test (see below) is

calculated from the interpretation of the time drawdown data generated during the

SDT.

• The constant discharge test (CDT) follows the SDT. During a CDT a borehole is

pumped for a predetermined time at a constant rate. During the CDT test the

drawdown over time is recorded in the pumping and observation boreholes.

Discharge measurements are taken at predetermined time intervals to ensure that

the constant discharge rate is maintained throughout the test period. Any changes

in discharge rate are recorded. The duration of CDT at LCPP varied from 12 to 24

hours, depending on the yield of the borehole. During CDT, the aquifer needs to be

stressed sufficiently to identify boundary effects that may impact on long-term

aquifer utilization.

• The recovery test (RT) follows directly after pump shut down, at the end of the SDT

and CDT. The residual drawdown over time (water level recovery) is measured in

production and observation boreholes until approximately 90% recovery is reached.

Aquifer parameters and sustainable borehole yields can be derived from the time

drawdown data of the CDT and recovery tests by application of a variety of analytical

methods.

• Yield tests or maximum drawdown tests are short duration pumping tests

(approximately 2 to 4 hours long) performed to define an approximate yield of a

borehole. These tests are often performed instead of the usual step drawdown or

calibration tests. During this test, the water level inside the borehole is drawn down


PAGE 29

to the approximate position of the pump, close to the bottom of the borehole. The

abstraction rate is then continually adjusted until the drawdown stabilizes just above

the pump inlet level. The water level is kept at this maximum drawdown level for a

period of approximately 2 to 4 hours. This abstraction rate is then adopted as an

approximate yield of the borehole.

The pumping test data was interpreted by using several analytical methods, i.e. Flow

Characteristic; Cooper Jacob and Theis. The following software was used for test pumping

data analysis:

• The Flow Characteristic Method or FC Method, (Van Tonder et al, 2001). The FC

method uses the first and second order derivatives interpreted from time drawdown

data (during test pumping), available drawdown, boundary conditions and recharge

to derive sustainable borehole yields. The method is suited for characterising

fractured rock aquifers; and

• AquiferTest Pro, internationally recognized test pumping analysis software,

distributed by Waterloo Hydrogeologic. Theis-related analytical methods were used.

The Theis method is a curve-fitting method developed for primary aquifers.

However, in most cases it provides an acceptable first approximation of fractured

aquifer hydraulic parameters.

The pumping test data was used to calibrate the groundwater numerical model.

Groundwater samples were collected during the pumping test programme (Table 1). A

summary of the test programme is given in Table 6.

Most of the boreholes tested indicate a low water yield, plus slow recovery. It is

recommended to conduct at least 48-hour constant discharge tests on boreholes earmarked

for future production purposes. Monitoring boreholes are also required around each

production borehole to ensure an accurate assessment of the long-term use and the

borehole’s recharge characteristics.

The recovery of the groundwater table after abstraction is a good indicator of the aquifer

yield potential. The volume of abstracted water should not exceed the rate of recovery of

the system, to ensure that the aquifer is not dewatered, which might have a significant

impact on other groundwater users within the same hydrogeological system.

The recovery test data for the tested boreholes indicate that the recovery of boreholes

located in the mudstone, shale and sandstone is slow and that full recovery (100%) is often

not achieved within the predetermined testing timeframe. The recovery rate is related to

groundwater recharge / flow. The different recovery rates were as follow:

• Recovery tempo on the 6 new boreholes:

• RHP01 6.5 hr - 38%

• RHP02 4 hr - 51%

• RHP03 7.5 min - 100%

• RHP04 10 hr - 95%

• RHP05 6 hr - 90% / 13 hr - 100%

• RHP06 6.6 hr - 85%


PAGE 30

• Short duration yield test recovery rates (abstraction rates and duration were not the

same - Table 6):

• ALOM4 77 min - 87%

• ALOM6 15 min - 63%

• BILL1 14 min - 89%

• BILL3 55 min - 93%

• BILL8 72 min - 90% / 83 min 100%

• Groot3 22 min - 99%

• Groot4 38 min - 99%

• HONI2 105 min - 99%

• HONI3 71 min - 71%

• HONI4 15 min - 84%

• PRET3 25 min - 90% / 41min 100%

• ROND2 56 min - 17%

• ROND4 30 min - 80%

• WELT6 43 min - 99%

• WOLV1 36 min - 99%

• WOLV2 1 min - 100%

The low borehole yields, fast water level drawdown and slow recovery observed during the

aquifer testing indicate low transmissivity (T) aquifers with low recharge. The average T-

value calculated from the recovery data was 0.2 m2/d.

The main water strikes in borehole RHP03 (highest yielding borehole in the area) were in the

mudstone; 79 m and 109 m bgl. The geological samples indicate that the borehole

intercepted a fracture zone (fault) below the interbedded coal sequence. Two 24-hour

aquifer tests were performed on borehole RHP03. During the first 24-hour test the water

table drew down to the coal seam where it stabilised at 65 m below surface, at a rate of

14,500 L/h. The pumping level remained in the coal seam up to the end of the test; an

indication that the coal seam could potentially be an open / permeable system. The test was

repeated at 17,000 L/h to ensure full drawdown and “dewatering” of the coal seam.

Drawdown was steady and indications are that this fault zone could be a potential water

supply target. Recovery of the water table, after pump switch off, was 100% within 7

minutes; the only fractured system / aquifer in the area to recovery this fast.

Other boreholes with relatively good recovery rates (100% recovery within approximately 30

minutes) include:

• GROOT3 and GROOT4 on Portion 1 of the farm Grootgenoeg;

• PRET3 on the farm Pretoria;

• WELT6 on Portion 1 of the farm Weltevreden; and

• WOLV1 and WOLV2 on Wolvendraai.

These boreholes are all potentially located on the east-west fault systems extending through

the southern and central portions of the mining footprint area, and yield between 4,500 and

10,000 L/h each.


PAGE 31

Sustainable abstraction rates are low compared to the blow or tested yields (Table 6); in

most cases for the LCPP area the sustainable rate is approximately 15% that of the tested

rate. The numerical modelling (Section 5.7) confirmed the recommendations for a low

sustainable yield / use of the borehole. Blow yields are only a rough indication of potential

borehole yield and aquifer tests are often short duration tests to stress a borehole and its

associated aquifer systems and get an indication of aquifer properties and possible long-

term yield. The test data is interpreted by software and the calculated sustainable

abstraction rate is based on continuous pumping 24 hours a day and therefore the

difference in yields. Groundwater recharge is also worked into the calculations. Thus, to

ensure the sustainable use of a borehole, the recommended yields will be lower compared

to yields used during the tests.

In summary: The 22 tested boreholes cumulatively yield approximately 81,500 L/h or 81.5

m3/hr. Based on this first order aquifer yield assessment and the mine’s water requirement

(6,747 m3/day) the local groundwater resources would not be a viable source of water to

supply the mining operations or the proposed IPP plant. This initial groundwater assessment

indicates that groundwater resources could potentially satisfy the mine’s dust suppression

and domestic requirements (1.55k L/d and 0.15k L/d respectively). Additional groundwater

exploration studies across a wider area and focussed on the east-west faults could

potentially deliver the 110 m3/hr required for operational demand, but with the low

recharge in the area and slow recovery, the effective spacing and use of the production

boreholes would be of great importance. A much greater area could also be impacted by

the wellfield abstraction.


PAGE 32

Table 6. Aquifer test programme summary

Constant drawdown yield tests on 6 new

boreholes - 24 hours test

BH

Depth

Water

Level

(m bgl)

Blow

Yield

(L/h)

Test

Yield

(L/h)

Test

Duration

Sust.

Yield

L/h)

Water

Strikes

(m bgl)

Pump

Depth

(m bgl)

Avail

Drawdown

Max

Drawdown

Recovery

RHP01 151m 25.7m 800 50 1.5h. 3

steps

----- 82 120m 94.3m 85.46m 6.5hr - 38%

RHP02 181m 30.4m 1000 300 4hr 20min 36 81, 164 85m 54.6m 49.66m 4hr - 51%

RHP03 116m 28.2m 25000 14500 24hr 9360 79, 109 85m 56.8m 37.85m 7.5min - 100%

RHP03_repeat 116m 26.0m 25000 17000 24hr 5040 79, 109 115m 89.0m 49.05m 7min - 99.9%

RHP04 166m 32.6m 1000 700 13hr

40min

108 ----- 120m 87.4m 62.35m 10hr - 95%

RHP05 80m 35.7m 8000 6000 24hr 1440 50 62m 26.3m 17.09m 6hr - 90% / 13hr

100%

RHP06 270m 35.0m 2500 550 12hr 72 70, 230 120m 85.0m 57.87m 6.6hr - 85%

Short duration yield tests on existing

private boreholes - 2 to 4 hours test

ALOM4 130m

plus

58.6m ----- 1200 53min ----- ----- 130m 71.4m 67.58m 77min - 87%

ALOM6 13m 3.0m ----- 10 20min dry ----- 12m 9.0m 9.0m 15min - 63%

BILL1 73.4m 35.6m ----- 5500 54min ----- ----- 72m 36.4m 34.10m 14min - 89%


PAGE 33

BILL3 ----- 27.4m ----- 1100 42min ----- ----- 86m 58.6m 55.53m 55min - 93%

BILL8 125.5m 25m ----- 1500 41min ----- ----- 100m 75m 67.50m 72min - 90% /

83min 100%

Groot3 104m 9.2m ----- 7000 55min ----- ----- 101m 91.8m 55.47m 22min - 99%

Groot4 100m 13.0m ----- 4500 38min ----- ----- 98m 85.0m 83.44m 38min - 99%

HONI2 85m 50.0m ----- 400 39min ----- ----- 82m 35.0m 27.49m 105min - 99%

HONI3 130m+ 23.0m ----- 1600 40min ----- ----- 118m 95.0m 94.5m 71min - 71%

HONI4 117m 30.0m ----- 5000 60min ----- ----- 116m 86.0m 31.20m 15min - 84%

PRET3 148m 41.4m ----- 4500 53min ----- ----- 110m 68.6m 65.10m 25min - 90% /

41min 100%

ROND2 130m 24.6m ----- 150 36min ----- ----- 100m 75.4m 67.50m 56min - 17%

ROND4 230m 26.7m ----- 4000 20min ----- ----- 120m 93.3m 77.3m 30min - 80%

WELT6 93m 7.4m ----- 7000 40min ----- ----- 90m 82.6m 38.68m 43min - 99%

WOLV1 116m 13.0m ----- 3500 80min ----- ----- 115m 102.0m 99.42m 36min - 99%

WOLV2 53m 19.5m ----- 10000 30min ----- ----- 50m 30.5m 0.94m 1min - 100%


PAGE 34

3.6 GEOCHEMICAL EVALUATION

The geological formations and coal seams in the LCPP project area were subjected to geochemical

assessments to determine their leach and acid generation potential. The samples were submitted

for static leachate tests and the analysis were performed according to the National Environmental

Management: Waste Act, 2008 (NEM:WA) guidelines and regulations for waste classification. The

laboratory results have been used to determine the mineral composition of the sample, what

elements could potentially leach from the coal or waste material during storage on surface or within

the pit, and define the liner requirements for the storage of the material on surface.

Mining and ore processing expose sulphates and metals in the geological formations to water and

oxygen, producing low pH waters often associated with heavy metal contamination. Fifteen (15)

geological core samples were submitted for geochemical laboratory tests to define the mineral

composition and to determine the potential for acid generation or neutralisation. Core samples

were taken at different depths to ensure a representative analysis of the proposed mining zone;

including the overburden, interburden and coal horizons (Table 7).

Table 7. Geochemistry sample selection

Hole Geochem Sample No.

From (m)

To (m)

Thickness (m)

Comment

RHD02 1 42.28 42.76 0.48 Interburden (mudstone) from below geological Sample 15 and the main interbedded coal sequence

RHD02 2 30.22 30.74 0.52 From geological Sample 10 (mudstone and coal)

RHD02 3 29.25 30.04 0.79 From geological Sample 9 (coal)

RHD02 4 14.30 14.75 0.45 Overburden (mudstone) above first coal

RHD05 5 33.81 34.57 0.76 From geological Sample 14 (coal)

RHD05 6 28.16 28.71 0.55 From geological Sample 10 (mudstone and coal)

RHD01 7 Mixed interval 0.54 From geological Sample 10 (mudstone and coal)

RHD01 8 Mixed interval 0.62 From geological Sample 8 (coal)

RHD03 9 23.0 23.50 0.50 Overburden (mudstone) Sample 7/13

RHD03 10 24.96 25.50 0.54 From geological Sample 7/14 (coal)


RHD04 12 20.50 21.50 1.0 Overburden (mudstone)



RHD04 15 31.72 32.5 0.78 Interburden (mudstone) from below geological Sample 15 and the main interbedded coal sequence


PAGE 35

3.6.1 Laboratory Tests

All samples were sent to Waterlab (Pty) Ltd for analysis. Tests included:

• XRD and XRF analysis;

• Acid-Base Accounting (ABA), Net Acid Generation (NAG);

• Sulphur Speciation;

• TCLP extraction; and

• Aqua regia digestion.

Leachate tests are done to simulate the heavy metal and anion leachate potential of coal, host rock /

waste material, with the solution type and pH based on the guidelines. Total Concentration values

were determined by aqua regia digestion and analysis with ICP methods to determine the chemical

make-up of the material before being leached.

Evaluation of a material’s potential to generate or neutralise acid and leach metals or salts are

determined by two types of tests, static and kinetic tests. Static tests enable a basic evaluation of

the material in terms of its potential to produce ARD and to identify elements that may leach from

sample. Kinetic testing (not conducted during this phase) supports the static test findings, but at a

high level of confidence and provides an indication of the time scale associated with the leaching.

3.6.1.1 XRD and XRF

XRD is used to determine the mineralogical composition of the material. XRF is typically used for

bulk analyses of larger fractions of geological materials. It is widely used for analysis of major and

trace elements in rocks, minerals, and sediment.

3.6.1.2 ABA and NAG

Acid-Base Accounting (ABA) measures the acid and alkaline-producing potential of geological

samples to determine if the waste material will produce acid and leach metals. It defines the acid-

neutralising potential and acid-generating potential of rock samples; the difference is calculated and

reported as the Net Neutralising Potential (NNP). The NNP is compared with a predetermined set of

values to divide samples into categories that either require, or do not require further laboratory test

work.

ABA includes Nett Acid Generation (NAG) tests that evaluate the nett acid generation and

neutralising potential of the material.

3.6.1.3 Leachate Tests and Total Element Analysis

As part of the LCPP assessment, leach tests (TCLP) were undertaken by performing a 1:20 (solid-

liquid) aqueous extraction with distilled water. The tests are commonly used as a preliminary

screening process to identify potential chemicals of concern (CoC). The synthetic precipitation

leachate procedure (SPLP), at a low pH and of longer duration (kinetic tests) are recommended

before mining commences to better define the acid producing / neutralising and leach potential of

the various geological samples.


PAGE 36

3.6.1.4 Sulphur Analysis

Sulphide minerals are the primary sources of acidity and leaching of trace metals, and their

measurement is a requirement for acid drainage chemistry prediction. For sustainable long-term

acid generation, at least 0.3% Sulphide–S is needed. Values below this can yield acidity.

3.6.2 Laboratory Results

The laboratory results were assessed against the guidelines as set out in the NEM:WA to determine

the potential environmental risks, as well as to determine the waste type and liner requirements. All

results are presented in Appendix G and are summarised in the following sub-sections.

3.6.2.1 Sample Mineralogy

Dominant minerals in the samples (XRD analysis) include kaolinite and quartz. The quartz, clay and

carbon minerals are characteristic of the area. Pyrite minerals were recorded and the content varies

between zero and 2.95%. The presence of pyrite in the samples indicates a potential for the

material to generate acid. The presence of gypsum, dolomite and calcite indicate the potential for

some degree of acid neutralisation.

The XRF results show high SiO2 and Al2O3 content – potentially kaolinite.

3.6.2.2 ABA and NAG

The following guidelines were used to assess the acid or neutralising potential of the LCPP samples;

the results are presented in Table 8. Net Neutralising Potential (NNP) is classified according to the

following:

• If NNP (NP – AP) < 0, the sample has the potential to generate acid.

• If NNP (NP – AP) > 0, the sample has the potential to neutralise acid produced.

• Any sample with NNP < 20 is potential acid-generating, and any sample with NNP > -20

might not generate acid (Usher et al., 2003).

• NNP values between –20 and 20 kg/ton CaCO3 are in the grey range of uncertainty, kinetic

tests may be needed.

• If the NNP is greater than 20 kg/ton CaCO3, it is generally accepted that the material is non-

acid producing.

• If the NNP is less than –20 kg/ton CaCO3, it is generally accepted that the material is acid

producing.


PAGE 37

Classification according to the Neutralising Potential Ratio (NPR)

Potential for ARD Initial NPR Screening

Criteria Comments

Likely < 1:1 Likely AMD generating

Possibly 1:1 – 2:1 Possibly AMD generating if NP is insufficiently reactive or is

depleted at a faster rate than sulphides

Low 2:1 – 4:1

Not potentially AMD generating unless significant preferential

exposure of sulphides along fracture planes, or extremely

reactive sulphides in combination with insufficiently reactive NP

None >4:1 No further AMD testing required unless materials are to be used

as a source of alkalinity

Classification according to the Sulphur Content (%S) and Neutralising Potential Ratio (NPR)

For sustainable long-term acid generation, at least 0.3% Sulphide-S is needed. Values below this can

yield acidity, but it is likely to be only of short-term significance. From this, and using the NPR

values:

• Samples with less than 0.3% Sulphide-S are regarded as having insufficient oxidisable

Sulphide-S to sustain acid generation.

• NPR ratios of >4:1 are considered to have enough neutralising capacity.

• NPR ratios of 3:1 to 1:1 are consider inconclusive.

• NPR ratios below 1:1 with Sulphide-S above 3% are potentially acid-generating (Waterlab

test certificates).

The classification of the material is done according to the following:

TYPE I Potentially Acid Forming Total S(%) > 0.25% and NP:AP ratio 1:1 or less

TYPE II Intermediate Total S(%) > 0.25% and NP:AP ratio 1:3 or less

TYPE III Non-Acid Forming Total S(%) < 0.25% and NP:AP ratio 1:3 or greater


PAGE 38

Based on the results presented in Table 8, the following were concluded from the ABA and NAG

tests results:

• Paste pH:

o The coal sample associated with RHD04 indicated a paste pH of 4.7. The rest of the

pH values were between 5.3 and 7.6.

o A pH of < 4.0 is considered potentially acid forming (PAF) and contain significant

acidic Sulfate salts that will produce acid upon exposure to water. Samples with a

paste pH of 4.0 to 5.0 are also considered PAF, but have a lower stored acidic salt

content. In the field, both lithologies are likely to generate ARD upon exposure to

water.

o Paste pH values higher than pH 5.0 indicate a short-term acid neutralizing capacity.

• Sulphur content:

o The sulphur content of only 4 of the 15 samples is below the 0.3% benchmark and is

unlikely to generate acid sustainably (Table 8); these mostly relate to overburden

and interburden samples, including the two samples collected from below Zone 15.

It is also due to the low S-values that these 4 samples have a classification of TYPE II.

The rest of the samples have a sulphur content above 0.3% and are likely to

generate acid, unless the formation’s neutralising potential is enough to buffer any

acid that could be generated;

• Nett Neutralization Potential:

o All samples except Sample 11 have a NNP value less than zero and is therefore

potentially acid generating.

o The following NNP values are less than -20 kg/ton CaCO3 and will likely generate

acid:

▪ Sample 3, RHD02, Coal seam, Zone 9.

▪ Sample 4, RHD02, Overburden (mudstone).


▪ Sample 6, RHD05, Mudstone - Coal, Zone 10.

▪ Sample 8, RHD01, Mixed Interval Coal, Zone 8.

▪ Sample 13, RHD04, Coal seam, Zone 8/11.


• Neutralizing Potential Ratio:

o According to the NPR results all samples are likely to generate AMD.

• Based on the ABA results presented above the following rock classifications are done:

o TYPE I – Potentially Acid Forming formation:

▪ Samples 2 to 8;

▪ Sample 10; and

▪ Samples 12 to 14.

▪ These include two overburden samples and the rest are coal or coal /

mudstone mixtures (Zone 10).

o TYPE II – Intermediate risk:

▪ Sample 1;

▪ Sample 9;

▪ Sample 11; and

▪ Sample 15.


PAGE 39

▪ These samples relate to overburden and interburden material, except for

Sample 11 (coal seam). Samples 1 and 15 were taken from below Zone 15.

• The geological formations sampled during the LCPP groundwater assessment are deemed to

be potentially acid generating.

3.6.2.3 TCLP Tests

From the TCLP leachate results the following can be concluded:

• Fluoride concentrations exceed the TCT0 limit in all samples;

• Barium was identified in high concentrations (exceeding the TCT0 limit) in geochem samples

9, 10, 11 and 12;

• Lead exceeded the TCT0 limit for geochem sample 11;

• In terms of the Leachable Concentrations (LC) most parameters are within the LCT0

guideline values, with only mercury leaching out (0.01mg/L) above the recommended 0.006

mg/L in Sample 5, RHD05, coal seam; and

• Although the leachate from the static tests is relatively clean, a long-term acid producing

potential and oxidation can lead to an increase in leachable elements. It is recommended

that the coal and waste material be submitted for long term kinetic tests, as well as SPLP

tests with an acidic solution of pH 4 or 5.

Sampling was limited to five core drill holes. It is recommended that additional samples be taken

across the project area, focussing on the proposed pit areas to provide a more complete

understanding of the acid generating potential for the area; analysis should include SPLP and kinetic

testing.


PAGE 40

Table 8. Acid Base Accounting results

Acid – Base Accounting Modified Sobek (EPA-600)

Sample Identification

Sample 1 RHD02

Interburden, Mudstone

Sample 2 RHD02

Mudstone + Coal

Sample 3 RHD02

Coal

Sample 4 RHD02

Overburden, Mudstone

Sample 5 RHD05

Coal

Sample 6 RHD05

Mudstone + Coal

Sample 7 RHD01

Mudstone + Coal

Sample 8 RHD01

Coal

Paste pH 7.4 5.3 5.6 6.7 7.2 7.2 6.0 6.8

Total Sulphur (%) (LECO) 0.11 0.52 1.04 1.82 3.73 1.01 0.44 3.2

Acid Potential (AP) (kg/t) 3.44 16 33 57 117 32 14 100

Neutralization Potential (NP) 2.93 2.21 0.750 8.75 5.6 6.81 0.75 4.39

Nett Neutralization Potential (NNP) -0.505 -14 -32 -48 -111 -25 -13 -96

Neutralizing Potential Ratio (NPR) (NP:AP) 0.853 0.136 0.023 0.154 0.048 0.216 0.055 0.044

Rock Type II I I I I I I I

Acid – Base Accounting Modified Sobek (EPA-600)

Sample Identification

Sample 9 RHD03

Mudstone, Obdn

Sample 10 RHD03

Mudstone parting / coal

Sample 11 RHD03

Coal

Sample 12 RHD04

Overburden

Sample 13 RHD04

Coal

Sample 14 RHD04

Coal

Sample 15 RHD04

Interburden

Paste pH 6.1 7.6 7.4 5.7 5.6 4.7 7

Total Sulphur (%) (LECO) 0.17 0.84 0.14 0.34 1.55 2.83 0.13

Acid Potential (AP) (kg/t) 5.31 26 4.38 11 48 88 4.06

Neutralization Potential (NP) 1.72 15 4.63 0.750 8.25 1.24 -0.948

Nett Neutralization Potential (NNP) -3.59 -11 0.25 -9.88 -40 -87 -5.01

Neutralizing Potential Ratio (NPR) (NP:AP) 0.324 0.573 1.06 0.071 0.170 0.014 0.233

Rock Type II I II I I I II


PAGE 41

3.7 WASTE CLASSIFICATION

Fifteen geological samples were analysed in accordance with the NEM:WA Regulations (2013).

According to the NEM:WA mine waste is listed under Schedule 3, under the category Hazardous

Waste; and is considered to be hazardous unless the applicant can prove that the waste is non-

hazardous.1 As waste rock are considered to be waste, they are regulated (August 2013) by:

• GNR 634 (23 August 2013): Waste Classification and Management Regulations – talks to

SANS 10234 and talks to the requirements for disposal, record keeping.

• GNR 635 (23 August 2013): National Norms and Standards for the assessment of Waste for

Landfill Disposal – Assessment of waste prior to landfilling. Prescribes limits relating to

chemical composition of wastes from lab testing such as LCT (Leachable Concentration

Threshold).

• GNR 636 (23 August 2013): National Norms and Standards for Disposal of Waste to Landfill –

aligns waste classification and character to simplified basal lining systems (containment)

being Class A, B, C and D versus Type 0 to 4.

According to these regulations, waste must be classified in accordance with GHS - SANS 10234

“South African National Standard Globally Harmonized System of Classification and Labelling of

Chemicals (GHS)”; within 180 days of generation. Classification guidelines are used to determine the

waste category, as well as liner design specifications associated with each category.

3.7.1 Waste Assessment Methodology

Total Concentration Threshold limits are subdivided into three categories:

• TCT0 limits based on screening values for the protection of water resources, as contained in

the Framework for the Management of Contaminated Land (DEA, March 2010);

• TCT1 limits derived from land remediation values for commercial/industrial land (DEA,

March 2010); and

• TCT2 limits derived by multiplying the TCT1 values by a factor of 4, as used by the

Environmental Protection Agency, Australian State of Victoria.

Leachable concentrations were determined by following the Australian Standard Leaching Procedure

for Wastes, Sediments and Contaminated Soils (AS 4439,3-1997), as specified in the NEM:WA

Regulations (2013). The procedure recommends the use of reagent water for leaching of non-

putrescible material that will be mono-filled. A leachate of 1:20 solids per reagent water was used.

Leachable Concentration Threshold (LCT) limits are subdivided into four categories:

• LCT0 limits derived from human health effect values for drinking water, as published by the

Department of Water and Sanitation (DWS), South African National Standards (SANS), World

Health Organization (WHO) or the United States Environmental Protection Agency (USEPA);

• LCT1 limits derived by multiplying LCT0 values by a Dilution Attenuation Factor (DAF) of 50,

as proposed by the Australian State of Victoria;

• LCT2 limits derived by multiplying LCT1 values by a factor of 2; and

1 Proposed changes to these Regulations that would allow for the management of residue stockpiles and residue deposits after a risk assessment, rather than automatic categorisation as hazardous waste, were gazette in GN R1440 of 25 N0vember 2016. These revised Regulations are however not yet in force.


PAGE 42

• LCT3 limits derived by multiplying the LCT2 values by a factor of 4.

GN R634 identifies waste classes (Waste Types 0 to 4) ranging from high risk to low risk. Waste is

classified by comparing the total and leachable concentration of elements and chemical substances

in the waste material to TCT and LCT limits as specified in the National Norms and Standards for

Waste Classification, and the National Norms and Standards for Disposal to Landfill (Table 9).

Table 9. Waste type and disposal classification*

Type of Waste Element or chemical substance concentration

Type 0 LC > LCT3 OR TC > TCT2

Type 1 LCT2 < LC ≤ LCT3 OR TCT1 < TC ≤ TCT2

Type 2 LCT1 < LC ≤ LCT2 AND TC ≤ TCT1

Type 3 LCT0 < LC ≤ LCT1 AND TC ≤ TCT1

Type 4 LC ≤ LCT0 AND TC ≤ TCT0 for metal ions and inorganic anions

AND all chemical substances are below the total concentration

limits provided for organics and pesticides listed

Disposal Requirements

Type 0 Not allowed. The waste must be treated first and then re-tested to determine the risk profile for disposal.

Type 1 Class A or Hh:HH

Type 2 Class B or GLB+

Type 3 Class C or GLB+

Type 4 Class D or GSB-

*DEA. Waste Classification and Management Regulations and Supporting Norms & Standards


PAGE 43

Table 10. LCPP sample results, TCT limits

Total Concentration Thresholds (mg/kg) Measured Total Concentrations (mg/kg)

Parameter Unit TCT0 TCT1 TCT2

Sample 1

RHD02

Sample 2

RHD02

Sample 3

RHD02

Sample 4

RHD02

Sample 5

RHD05

Sample 6

RHD05

Sample 7

RHD01

Sample 8

RHD01

Sample 9 RHD03

Sample 10

RHD03

Sample 11

RHD03

Sample 12

RHD04

Sample 13

RHD04

Sample 14

RHD04

Sample 15

RHD04

Interburden,

Mudstone

Mudstone +

Coal

Coal Overburden,

Mudstone

Coal Mudstone + Coal

Mudstone + Coal

Coal Mudstone, Obdn

Mudstone parting /

coal

Coal Overburden Coal Coal Interburden

As, Arsenic mg/kg 5.8 500 2000 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 4.00 4.00 4.80

B, Boron mg/kg 150 15000 6000 23 46 117 66 66 89.2 <10 <10 18 30 <10 <10 33 35 20

Ba, Barium mg/kg 62.5 6250 25000 <10 12 45 28 21 <10 <10 45 374 97 317 71 62 25 13

Cd, Cadmium mg/kg 7.5 260 1040 6.00 4.40 1.60 5.20 4.00 2.00 1.20 4.40 2.80 3.20 4.40 4.00 4.00 4.80 4.00

Co, Cobalt mg/kg 50 5000 20000 <10 <10 <10 29 <10 <10 <10 20 <10 <10 <10 <10 <10 <10 <10

Cr Total, Chromium Total mg/kg 46000 800000 N/A 45 41 <10 36 18 37 31 29 42 12 41 36 18 12 35

Cu, Copper mg/kg 16 19500 78000 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 9.60

Hg, Mercury mg/kg 0.93 160 640 <0.400 <0.400 <0.400 <0.400 <0.400 <0.400 <0.400 0.400 <0.400 <0.400 <0.400 <0.400 <0.400 <0.400 <0.400

Mn, Manganese mg/kg 1000 25000 100000 54 59 <10 12 46 166 49 98 113 114 46 212 <10 <10 <10

Mo, Molybdenum mg/kg 40 1000 4000 <10 <10 <10 22 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

Ni, Nickel mg/kg 91 10600 42400 20 16 11 46 18 18 17 22 <10 <10 <10 <10 <10 <10 <10

Pb, Lead mg/kg 20 1900 7600 9.20 <4.00 <4.00 5.60 7.20 <4.00 <4.00 <4.00 18 <4.00 28 10 10 4.00 16

Sb, Antimony mg/kg 10 75 300 <8.00 8.40 <8.00 <8.00 <8.00 9.20 8.40 <8.00 <8.00 <8.00 <8.00 <8.00 <8.00 <8.00 <8.00

Se, Selenium mg/kg 10 50 200

<4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 <4.00 4.40 <4.00 <4.00 <4.00 <4.00

V, Vanadium mg/kg 150 2680 10720 88 58 <10 30 <10 48 31 14 30 <10 36 <10 <10 <10 68

Zn, Zinc mg/kg 240 160000 640000 46 61 41 130 49 63 46 38 56 16 35 45 38 86 38

Cr(VI), Chromium (VI) Total [s] mg/kg 6.5 500 2000 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5

Total Fluoride [s] mg/kg mg/kg 100 10000 40000 222 270 155 330 175 240 261 282 299 168 277 276 196 182 299

Total Cyanide as CN mg/kg mg/kg 14 10500 42000 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05


PAGE 44

Table 11. LCPP sample results, LCT limits

Leachable concentration threshold (mg/L) Measured Leachable concentration of samples (mg/L)

Parameter Unit LCT0 LCT1 LCT2 LCT3

Sample 1

RHD02

Sample 2

RHD02

Sample 3

RHD02

Sample 4

RHD02

Sample 5

RHD05

Sample 6

RHD05

Sample 7

RHD01

Sample 8

RHD01

Sample 9

RHD03

Sample 10

RHD03

Sample 11

RHD03

Sample 12

RHD04

Sample 13

RHD04

Sample 14

RHD04

Sample 15

RHD04

Interburden, Mudstone

Mudstone + Coal

Coal Overburden, Mudstone

Coal Mudstone + Coal

Mudstone + Coal

Coal Mudstone, Obdn

Mudstone parting /

coal

Coal Overburden Coal Coal Interburden

As, Arsenic mg/ℓ 0.01 0.5 1 4 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

<0.010 <0.010 <0.010 <0.010 <0.010 <0.010

B, Boron mg/ℓ 0.5 25 50 200 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 0.027 <0.025 0.041

0.028 0.030 0.026 0.026 0.026 <0.025

Ba, Barium mg/ℓ 0.7 35 70 280 <0.025 <0.025 <0.025 <0.025 <0.025 0.041 <0.025 0.058 <0.025

<0.025 <0.025 <0.025 <0.025 <0.025 <0.025

Cd, Cadmium mg/ℓ 0.003 0.15 0.3 1.2 <0.003 <0.003 <0.003 <0.003 <0.003 <0.003 <0.003 <0.003 <0.003

<0.003 <0.003 <0.003 <0.003 <0.003 <0.003

Co, Cobalt mg/ℓ 0.5 25 50 200 <0.025 <0.025 <0.025 0.067 <0.025 <0.025 <0.025 <0.025 <0.025

<0.025 <0.025 <0.025 <0.025 <0.025 <0.025

Cr Total, Chromium Total

mg/ℓ 0.1 5 10 40 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025

<0.025 <0.025 <0.025 <0.025 <0.025 <0.025

Cr(VI), Chromium (VI)

mg/ℓ 0.05 2.5 5 20 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

Cu, Copper mg/ℓ 2.0 100 200 800 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

Hg, Mercury mg/ℓ 0.006 0.3 0.6 2.4 <0.001 <0.001 <0.001 0.002 0.010 <0.001 <0.001 0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Mn, Manganese mg/ℓ 0.5 25 50 200 <0.025 <0.025 <0.025 <0.025 0.148 0.137 <0.025 0.035 <0.025 0.028 <0.025 <0.025 <0.025 <0.025 <0.025

Mo, Molybdenum mg/ℓ 0.07 3.5 7 28 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025

Ni, Nickel mg/ℓ 0.07 3.5 7 28 <0.025 <0.025 <0.025 0.037 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025

Pb, Lead mg/ℓ 0.01 0.5 1 4 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

Sb, Antimony mg/ℓ 0.02 1.0 2 8 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 <0.020

Se, Selenium mg/ℓ 0.01 0.5 1 4 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

V, Vanadium mg/ℓ 0.2 10 20 80 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025

Zn, Zinc mg/ℓ 5.0 250 500 2000 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 0.080 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025 <0.025

Total Dissolved Solids*

mg/ℓ 1000 12 500 25 000 100 000 12 20 <10 56 64 16 24 50 42 30 <10 26 32 38 20

Chloride as Cl mg/ℓ 300 15 000 30 000 120 000 <2 <2 <2 <2 2 2 <2 <2 3 2 <2 2 <2 <2 <2

Sulphate as SO4 mg/ℓ 250 12 500 25 000 100 000 <2 5 <2 24 19 4 11 13 4 4 2 3 5 14 <2

Nitrate as N mg/ℓ 11 550 1100 4400 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Fluoride as F mg/ℓ 1.5 75 150 600 0.7 0.5 0.3 0.9 0.4 0.5 0.2 0.4 0.7 0.4 0.7 0.6 0.3 <0.2 0.6

Total Cyanide as CN mg/ℓ 0.07 3.5 7 28 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

pH mg/ℓ 6.4 5.2 5.6 7.1 7.5 7.2 6.1 7.2 5.4 7.2 6.9 5.7 5.1 4.2 6.1


PAGE 45

3.7.1 Assessment Results

Results of the TCT and LCT analysis are shown in Table 10 and Table 11 respectively, and compared

to threshold concentrations published in the NEM:WA, Waste Classification and Management

Regulations.

3.7.1.1 Total Concentrations

Based on the total concentration analysis (Table 10):




3.7.1.2 Leachable Concentrations

Based on the leachable concentration analysis (Table 11) all results are below the LCT0 threshold

values except for elevated mercury (Hg) identified for geochem sample 5.

3.7.1.3 Classification

Based on the total concentration results only (Table 10), the waste will be classified as a Type 3

waste and the liner design must be according to Class C landfill requirements (Figure 5). This is

based on TCT0 threshold values exceeded for barium, lead and fluoride, but still below TCT1 values.

Figure 5. Class C landfill site liner requirements (NEM:WA, 2008)

Based on the leachable concentrations only, the samples are classified as a Type 3 waste, and should

be also disposed of at a site designed according to Class C liner requirements (Figure 5).

For the LCPP project, a Class C landfill will be required for disposal of the waste material based on

the Total and Leachable Concentration results.


PAGE 46

4 Conceptual Groundwater Model The results of the fieldwork programmes were used to construct a conceptual model that feeds into

the numerical model. The components considered as part of a conceptual model are listed in Table

12; also refer to Section 2.4.

Two aquifers are included in the evaluation, namely an upper weathered aquifer and a deeper

fractured rock aquifer associated with the Waterberg Coalfield. The coal seams form part of the

Ecca Group of the Karoo Supergroup and dip in a westerly direction across the footprint area. The

formations comprise a combination of sandstone, shale and coal seams, with granite identified

towards the east and southeast. The Ecca sediments are underlain by Dwyka Formation tillite. The

regional geological setting for the area under consideration for the groundwater model is presented

in Figure 6.

Results from the exploration borehole drilling programme (Table 4 and Table 5) indicate that the

average depth of weathering varies between 7 and 23 m bgl; on average, the depth of weathering is

approximately 13 m bgl. This depth was used to delineate the base of the weathered aquifer during

simulations.

East-west striking faults are present in the southern and central parts of the study area (Figure 6)

(1:250 000 geological map). These include the Daarby Fault situated south of the footprint area and

Zoetfontein fault to the north. Many sub-parallel faults are present, which originates from tectonic

processes. The Daarby Fault has a vertical throw of 250 to 400 m (RHDHV, 2016). To the southwest

of the fault, coal seams are within 200 m of the surface. In other areas, the coal was displaced to

much greater depths.

ASST completed a fieldwork programme between March and June 2017. The results of aquifer tests

completed on newly drilled monitoring boreholes (RHP-series) and the hydrocensus boreholes are

summarised in Table 12. This information forms the basis of the conceptual model used during

numerical modelling.

Table 12. 2017 Aquifer test parameter estimation (ASST)*

Borehole T (m2/d) K (m/d) S (-)

RHP01 - - -

RHP02 1.04E-2 – 8.76E-3 5.2E-4 – 4.38E-4 1.2E-3

RHP03 1.43E+1 – 7.18E0 8.41E - 2.51E-4 1.28E-1 – 7.13E-1 RHP04 - - -

RHP05 2.63E-3 – 8.76E-3 1.31E-4 – 3.04E-7 4.38E-4 – 5.29E-4

BILL1 9.35E-4 4.67E-5 3.11E-5 * Results obtain with Aquifer Test Pro software

The results of the aquifer tests indicate that the Ecca shale transmissivities (T) are low, which means

that groundwater would flow at a slow rate through the formations. The transmissivity of the fault

immediately south of Pit 2 is higher than that of the host rocks, as indicted by the results of the

aquifer test for RHP03. The transmissivity of the fault further south, as well as that for the

northeast-southwest trending fault is comparable to that of the Ecca shale, as indicated by the

results for boreholes RHP05 and RHP02 respectively.

Two of the private boreholes, PRET1 and PRET2, were potentially drilled into the Daarby Fault.

Groundwater level measurements from these boreholes will be used during the calibration process

to estimate the aquifer parameters for this fault. Groundwater level measurements used during the


PAGE 47

numerical model were obtained from the 2017 hydrocensus completed by ASST. These are

presented in Table 13.

Table 13. Groundwater level measurements used

Borehole ID X-Coordinate Y-Coordinate Elevation (mamsl) SWL (m) SWL (mamsl) ALOM1 99486 -2606541 934 24.4 909.6

ALOM3 99351 -2605914 928 17.8 910.2

BILL2 90130 -2605094 872 31.1 841.0

BILL3 90189 -2604915 871 27.6 843.4

BILL4 90682 -2604437 872 16.5 855.5 BOTM1 95561 -2602408 894 18.1 875.9

BOTM2 95889 -2602244 896 47.9 848.2

GARI1 91264 -2608511 883 18.9 864.1

Groot2 93144 -2605183 886 26.9 859.1

Groot3 94651 -2605258 896 12.1 883.9 Groot4 94502 -2604378 893 13.0 880.1

HONI2 93293 -2602408 881 29.7 851.3

HONI3 94009 -2602691 885 37.5 847.5

HONI4 91383 -2602512 876 31.3 844.7

MIDD3 96696 -2604885 908 9.5 898.5

PRET1 94338 -2609003 912 18.9 893.2 ROND1 89682 -2606661 868 25.7 842.4

SEBR1 94545 -2597663 877 43.3 833.7

SEBR4 94482 -2597568 877 37.9 839.1

SEBR6 95462 -2598517 879 30.1 848.9

SEBR7 96748 -2597389 871 23.0 848.1 STEL2 89386 -2600227 881 53.4 827.6

WELT2 94188 -2606034 892 15.5 876.5

WELT5 95327 -2605825 909 24.7 884.3

WELT6 95830 -2605856 904 6.9 897.1

WOLV1 90733 -2610746 887 13.0 874.0 WOLV2 90603 -2611097 886 19,5 866.5

RHP01 92707 -2605651 882 25.7 856.3

RHP02 92204 -2607109 881 30.4 850.6

RHP03 92901 -2607795 888 28.2 859.8

RHP05 95794 -2608594 909 35.7 873.3

The information presented indicates that the average depth to groundwater is 26 m below surface.

This implies that the weathered aquifer would on average be dry. It is possible that the weathered

aquifer will carry water in low-lying areas or where perched aquifer conditions occur. The extent to

which this is the case in the project area is not known, as none of the boreholes available specifically

targeted the shallow weathered aquifer.


PAGE 48

Figure 6. Regional geology


PAGE 49

4.1 POTENTIAL PATHWAYS AND RECEPTORS The potential pathways and receptors identified for the project are listed in Table 14.

Table 14. Pathways and receptors

Pathways Receptors

Runoff Mokolo and Lephalala Rivers

Seepage Private boreholes

Various faults (Figure 6)

4.2 PRIORITY CONTAMINANTS Sulphate was chosen as potential contaminant during simulations, as it is an indicator element of the

impact of coal mining on groundwater quality. The results of the leach tests on overburden and coal

samples suggest that low concentrations of sulphate will initially leach from the material, as

indicated in Table 15.

Table 15. Sulphate concentrations from leach tests (mg/L)

Element

Sample 1 RHD02

Sample 2

RHD02

Sample 3

RHD02

Sample 4

RHD02

Sample 5

RHD05

Sample 6

RHD05

Sample 7

RHD01

Sample 8

RHD01 Inter-

burden, Mudstone

Mudstone + Coal

Coal Over-burden,

Mudstone Coal

Mudstone + Coal

Mudstone + Coal

Coal

Sulphate <2 5 <2 24 19 4 11 13

The result of the Acid Base Accounting analyses completed on the same sample set suggests that

acidification of water is possible at the operations (Section 3.6.2). Experience in similar

environments suggests that sulphate concentrations in leachate from the mine will be above those

reported in the leach tests in Table 15.

No discard is currently available for analysis and since sulphate concentrations are expected to

increase above those reflected in Table 15, simulations will be undertaken as a percentage variation

from the source value. To achieve this, a percentage value of 100% will be assigned to each source.

The model will calculate the resultant dilution of the source term as the plumes move through the

aquifers, and the results will be reported as a percentage of the source term.

When field-measured leachate quality or monitoring information becomes available, the

percentages can be multiplied with the monitoring data to obtain actual sulphate concentrations.

4.3 POTENTIAL POLLUTION SOURCE IDENTIFICATION

The potential sources to groundwater contamination considered as part of this assessment include:

• The two pits;

• The waste rock dump;

• The discard dump; and

• The Plant area.


PAGE 50

5 Numerical Model Irene Lea Environmental and Hydrogeology (iLEH) completed the numerical flow and contaminant

transport model for the EIA phase of the groundwater specialist study.

The numerical groundwater model that was constructed for the project helps to determine the

hydrogeological impacts associated with the proposed LCPP. The objectives of the numerical

modelling to be completed as part of this assessment are as follows:

• Construct and calibrate a numerical groundwater flow and contaminant transport model for

the sub-catchment in which the project is situated;

• Use the model to complete a groundwater impact assessment for the project, including the

impact on both groundwater levels and quality. Specific focus will be placed on

understanding the impact of mining on existing private groundwater use;

• Evaluate the long-term impact of mining on groundwater levels and quality; and

• Make recommendations to augment the groundwater monitoring programme following the

outcome of the assessment, if required.

5.1 KEY ASSUMPTIONS AND LITERATURE BASED DATA INPUTS

The numerical model is based on the following assumptions:

• Aquifer parameters were inferred from aquifer tests data as presented by ASST. Aquifer

parameters used to construct the numerical model are presented in Table 12.

• MODFLOW, the modelling software used during simulations, assumes that aquifers are

continuous porous media. For this reason, average aquifer parameters are assigned during

simulations. The heterogeneous nature of a fractured rock aquifer is therefore

approximated by a homogenous porous flow field. This is the nature of all groundwater

modelling software and not just of MODFLOW.

• The position and extent of the faults were inferred either from the 1:250 000 geological map

(Figure 6) or from information made available by RHDHV.

• The source characterisation used for the project was inferred from leach tests undertaken

on overburden material and coal samples. The results indicate low concentrations of

sulphate in leachate draining from overburden and the coal. Sulphate is an indicator

element of the impact of coal on groundwater quality. No discard was available for sampling

and analysis. In the absence of this information, contaminant transport simulations were

undertaken in terms of a percentage of source concentrations, which was assumed to be

100%. This does not provide an absolute concentration, but rather an indication of how

possible contamination will be diluted as it moves through the aquifers with time.

• Only advective transport of contaminants was simulated. Assumptions made regarding

advection, are presented in Table 15. While it is acknowledged that attenuation will take

place in the soils, there is currently insufficient information available to quantify the extent

to which this takes place. As such, simulations are based on the precautionary principle and

take the worst-case scenario into consideration by assuming that contamination will move at

the same rate as the groundwater flow velocity.

• The extent of the numerical model is based on natural groundwater barriers, as discussed

below. These include the delineation of the quaternary catchments, water divides, as well as

rivers and streams.


PAGE 51

5.2 DESCRIPTION OF THE MODEL

The numerical modelling was undertaken according to accepted industry principles and standards,

including the Department of Water and Sanitation’s Best Practice Guideline for Impact Prediction

(DWS BPG G4, 2008).

The numerical model for the project was constructed using Processing MODFLOW Pro, a pre- and

post- processing package for MODFLOW and MT3DS. MODFLOW is a modular three-dimensional

groundwater flow model and MT3DS a modular three-dimensional solute transport model published

by the United States Geological Survey. MODFLOW and MT3DS use 3D finite difference

discretization and flow codes to solve the governing equations. MODFLOW and MT3DS is a widely

used simulation code, which is well documented. MODFLOW is used to simulate groundwater flow

rate and direction. MT3DS is superimposed on the MODFLOW simulation results and is used to

predict the rate and direction of contaminant movement in the aquifers.

The model area was refined into block cells of 10 m x 10 m around the project area (Figure 7). The

finer grid allowed more detailed simulations around the areas of interest. Towards the model

boundaries and away from the area of interest, the model grid size increases to 400 m. The Moloko

River along the western model boundary was simulated as a constant head boundary in the upper

layer. The eastern boundary was included as general head boundary during simulations. The rest of

the model boundaries were included as no-flow boundaries.

Two layers were included in the model. The upper layer presents the weathered aquifer to a depth

of 24 m below surface. The second layer represents the fractured rock aquifer. The upper layer was

simulated as an unconfined aquifer. The second layer was simulated under confined conditions. All

units used during simulations were presented in metres (length) and days (time).


PAGE 52

Figure 7. Model grid


PAGE 53

5.3 MODEL INPUT FILES AND INTEGRATION

The conceptual model discussed in Section 4 was used to construct the numerical model for the

project area. The initial aquifer parameters used are presented in Table 12. These were gradually

adjusted during calibration, as discussed below.

The geometry of the numerical model, based on the conceptualisation of the aquifers, is presented

in Figure 7. The model zones used during simulations are based on the geological map presented in

Figure 6.

The topographical surface was interpolated from the Digital Terrain Model (DTM) (i.e. the surface

topography) and incorporated into the model to ensure that the elevations used to simulate the

Moloko River and the general head boundary conditions reflects the topography. The initial water

levels in the model layers of the model were kriged from available information, as presented in Table

13.

The MT3DS contaminant transport model advection input parameters are indicated in Table 16.

Table 16. Contaminant transport advection parameters

PERCEL WD DCEPS NPLANE NPL NPH

0.75 0.5 10-5 2 1 8 NPMIN NPMAX SRMULT NLSINK NPSINK DCHMOC

2 8 1 2 8 0.0001

It was assumed that horizontal and vertical transverse dispersivity is 0.1; that the effective molecular

diffusion coefficient is 8.64E-5 m2/d and that the longitudinal dispersivity is 50 to 100 m.

No chemical reaction was taken into consideration during simulations.

5.4 CALIBRATION RESULTS

Calibration of a numerical model refers to the demonstration that the model is capable of

reproducing field-measured data, which are the calibration values. Calibration is achieved when a

set of parameters, boundary conditions, source terms and stresses are found that produce simulated

heads and concentrations that match field measured data within the calibration criteria set for the

project. This is an important step in the modelling project, which ensures that model results are

reliable. The calibration criteria set for the project are presented in Table 17.

Table 17. Calibration criteria

Requirement Acceptability criteria Compliance

Calibration error <5m for water level measurements taken Complied with (see discussion below)

Calibration 80% of data points complies with calibration error

Complied with (see discussion below)

Model calibration was undertaken with field-measured groundwater levels obtained from the 2017

hydrocensus. The calibration results are presented in Table 18. It is shown that the calibration

error (the difference between measured and simulated head or groundwater level) is 3.4 m, which is


PAGE 54

less than 5 m for 23 of the 29 data points, which is equivalent to an 80% compliance to the

calibration error.

A 97% correlation was achieved between measured and simulated heads, as demonstrated in Figure

8. The calibration results were used as the starting conditions during simulations, as discussed

below.

Table 18. Steady state calibration results

BH ID Calculated Head (mamsl) Measured Head (mamsl) Error (m) BILL2 843.8456 841 2.85

BILL3 844.7155 843 1.72

BILL4 850.1238 856 5.88

BOTM1 870.5149 876 5.49

BOTM2 847.8295 848 0.17 GARI1 860.428 864 3.57

GROOT2 859.004 859 0

GROOT3 879.0787 884 4.92

GROOT4 876.1266 880 3.87

HONI2 854.0154 851 3.02 HONI3 849.9797 847 2.98

HONI4 849.2011 845 4.20

MIDD3 893.1627 899 5.84

PRET1 888.6443 893 4.36

ROND1 842.4489 842 0.45 SEBR1 840.1077 834 6.11

SEBR4 835.8715 839 3.13

SEBR6 851.7188 849 2.72

SEBR7 846.6465 848 1.35

STEL2 825.2736 828 2.73 WELT2 872.3303 877 4.67

WETL5 877.2468 884 6.75

WELT6 892.7823 897 4.22

WOLV1 872.7573 874 1.24

WOLV2 861.5657 867 5.43

RHP01 861.2424 865 3.76 RHP02 855.213 851 4.21

RHP03 862.4542 860 2.45

RHP05 872.6906 873 0.31


PAGE 55

Figure 8. Steady state calibration: simulated vs measured head

The calibrated aquifer parameters are presented in Table 19. Note that the calibration could only be

completed for geological units represented by dedicated boreholes. Borehole logs are not available

for the private boreholes. For this reason, it was assumed that all boreholes were drilled into the

fractured rock aquifer and could therefore be used to calibrate aquifer parameters for layer 2 of the

model.

Table 19. Calibrated aquifer parameters

Description T (m2/d) K (m/d) Sy (-) S (-) R (% of MAP)

Weathered aquifer NA 0.17 0.108 NA 1

Fine grained sandstone (Trc) 0.20 NA NA 3.17E-4 NA

Red mudstone (Trl) 0.033 NA NA 3.17E-4 NA

Mudstone and shale (Pgr) 0.011 NA NA 3.17E-4 NA

Sandstone and mudstone (Ps) 0.21 NA NA 3.17E-4 NA

Sandstone and mudstone (Tre) 0.12 NA NA 3.17E-4 NA

Gabbro, anorthosite and norite (Vv) 0.102 NA NA 3.17E-4 NA

Daarby Fault 60.0 NA NA 1.43E-3 NA

Other Geological Map Faults 4.80 NA NA 2.43E-2 NA

RHDHV Fault A 0.76 NA NA 6.01E-2 NA

RHDHV Fault B 20.0 NA NA 1.43E-3 NA

RHDHV Fault C 6.30 NA NA 2.43E-2 NA


PAGE 56

Model calibration against the available groundwater level dataset suggests that the transmissivities

(T) and storage coefficients (S) for the various geological components are comparable to that

obtained from the aquifer tests undertaken by ASST. The hydraulic conductivity (K) and specific yield

(Sy) for the weathered aquifer were obtained by running the automated parameter estimation

package of MODFLOW, but are not based on field-measured data. The values obtained are however,

comparable to unconfined weathered aquifers of similar character in the author’s experience.

5.5 MODEL SENSITIVITY A sensitivity analysis was completed on the LCPP model. The purpose of the sensitivity analysis is to

quantify the uncertainty in the calibrated model caused by uncertainty in the estimates of aquifer

parameters, stresses and boundary conditions. The level of heterogeneity of the aquifer material

can never be accurately measured with field data. The uncertainty of the impact of heterogeneity

on simulations is therefore assessed as part of the sensitivity analysis.

The results of a sensitivity analysis can be used to identify data gaps and to plan for additional

fieldwork, including monitoring requirements, once the modelling has been completed.

The comparative sensitivity for the parameters included during calibration is presented in Figure 9.

The comparative sensitivity provides an indication of how sensitive the model is to changes in each

parameter compared to the other parameters tested. A low value indicates a low sensitivity and a

high value a high sensitivity. It is shown that the model is most sensitive to variations in the storage

coefficient of the confined fractured rock aquifers and the transmissivity of the fault furthest south

(Fault A). Data is available to characterise Fault A from one borehole (RHP05). It is however noted

that the fault is south of the mining area and as such is not expected to impact directly on

groundwater flow patterns in the mining area. Borehole RHP05 was however earmarked as a

potential water supply to the project. As such, impact assessments discussed later in this report

regarding groundwater abstraction scenarios may be affected if the calibrated storage coefficient for

this fault varies.

Figure 9. Sensitivity analysis


PAGE 57

5.6 ASSESSMENT UNCERTAINTIES

The accuracy of the modelling project depends on the quality of the input data, the available

information, time available to complete the calibration process and to test the outcome of scenario

modelling. Even with an unchanging environment, impacts are difficult to predict with absolute

certainty. Predictions were calculated with the calibrated flow model, which is a simplified version

of reality. The model represents a tool that can be used to assess the impact of the LCPP on the

aquifers and to identify data gaps. The calibration error is discussed above and is thought to be

acceptable.

The model should be updated and verified with additional monitoring information, as it becomes

available. Uncertainties are approached conservatively, based on the precautionary principle, to

ensure that the predictions and impact assessment in this report addresses the maximum potential

impact of the proposed development. The uncertainties in the model include:

• Uncertainties regarding the storage coefficient for all the geological units: the model is

sensitive to changes in the storage coefficient in the fractured rock aquifer.

• Uncertainties regarding the private borehole pumping rates: It is important to understand

what impact mining and groundwater abstraction at the mining operations will have on

private groundwater use.

• Uncertainties regarding private borehole depth, construction and geology intersected: This

information is not available for the private boreholes. For this reason, it was assumed that

all private boreholes target the fractured rock aquifer.

• Mathematical modelling uncertainties: It is not possible with the available information to

quantify the heterogeneity present in the aquifers simulated. For this reason, there are

inherent uncertainties in the model. The level of confidence in the model can be improved

with the incorporation of additional monitoring data.

The uncertainties listed above can be reduced or eliminated through implementing an on-going

groundwater monitoring programme in the area. This information can be used to improve aquifer

parameter estimation and model calibration. On-site rainfall measurements must also be taken to

ensure that the results of the monitoring programme can be interpreted with certainty. For this

reason, a groundwater monitoring strategy is proposed in Section 10.

5.7 DEFINING THE GROUNDWATER IMPACTS

5.7.1 Scenario Testing

5.7.1.1 Design Criteria

The design criteria incorporated during simulations were taken from the Pre-Feasibility Study

compiled for the operations (RHDHV, 2016). The surface layout and mine plans used during

simulations are presented in Figure 10. The mining components included during the assessment are

indicated on the map. Mining will commence from Pit 1 (north) and will be completed in eight cuts,

as indicated. The time to complete each cut is indicated in Table 20. This information was obtained

from the PFS (RHDHV, 2016). The coal dips in a westerly direction. The depth of mining will

therefore increase towards the west, as indicated by the Zone 5 coal floor contours in Figure 10.

The project will be ramped up over a period of 3 years. The first mining cut will take three years to

complete. It is assumed that the box cut forms part of the first cut. Pit 1 will be mined out over a

period of 31 years.


PAGE 58

Mining from Pit 2 will commence in year 31 at Cut 9. The life of the operations is 42 years, as

indicated.

Table 20. Mining schedule

iCut Timing (years) Total time (years) Pit 0 3 3 1

1 3 6 1

2 4 10 1

3 3 13 1

4 1.5 15 1 5 4 19 1

6 4 23 1

7 2.5 25 1

8 1.5 27 1

9 4.5 31 2 10 3 34 2

11 2.5 37 2

12 1.75 38 2

13 2.5 41 2

14 1 42 2

This groundwater assessment intends to investigate the feasibility of using groundwater to supply

the water demand at the operations. Six new boreholes were drilled for this purpose (the RHP-

series in Table 13). Boreholes RHP03 and RHP05 (Table 21) will most probably be the only boreholes

suitable for groundwater abstraction. The model was used to assess the impact of groundwater

abstraction to determine whether the impact of mine dewatering would affect abstraction trends.

Table 21. Pumping borehole details

BH ID Test yield (l/hr) Sustainable yield (l/hr) Modelled pumping rate (m3/d)

RHP01 50 - 1

RHP02 300 36 1

RHP03 14,500 9,360 225

RHP04 700 - 17 RHP05 8,000 1,440 35

RHP06 550 - 13

5.7.1.2 Simulation Periods Considered

Time periods that were used during simulations are summarised in Table 22. These periods are

based on the objectives of the numerical modelling and the project design criteria listed above. Each

time period was divided into summer and winter rainfall conditions during simulations to allow the

inclusion of seasonality during simulations.


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Figure 10. Mining layout used during simulations


PAGE 60

Table 22. Simulation periods

Stress Period Time Description

1 3 years Ramp up period. It is assumed that no mining will take place.

2 3 years Mining of Cut 1 in Pit 1



5 1,5 years Mining of Cut 4 in Pit 1



9 2.5 years Mining of Cut 7 in Pit 1







16 1 year Mining of Cut 14 in Pit 2

17 100 years

Long-term simulation scenarios:

• Groundwater level recovery around the pit

• Contaminant transport modelling

There are currently no design criteria available to quantify the effect of rehabilitation during the

operational phase. The PFS indicates that rehabilitation will commence three years prior to closure

(RHDHV, 2016). For this reason, the opencast pits were left open during the operational phase.

Backfilling and rehabilitation was only considered during the 100-year long-term scenario. This is

considered a worst-case scenario, which is in line with the precautionary approach followed in

general during scenario testing. The impact of rehabilitation on groundwater will be manifested

through the rate of recharge to the pits. The best-case scenario represents a final rehabilitation

scenario where the rate of recharge through the backfilled and shaped areas reflect ambient

conditions. Several recharge scenarios were however tested in addition, ranging from 5% to 20% of

MAP. The results of these are discussed below.

5.7.2 Simulation Results

5.7.2.1 Construction Phase

The impact of pit dewatering during the construction of the box cut was assessed with the numerical

model. The results of the simulations are presented in Figure 11. It is shown that groundwater

levels may be lowered by up to 25 m inside the box cut. The resultant cone of depression will be

controlled by the geological units and the presence of faulting.

It is estimated that the zone of influence will not extend further than 500 m from the box cut, as

indicated. Private boreholes HONI1 and HONI2 fall within the delineated zone of influence of the


PAGE 61

box cut dewatering cone. It is estimated that groundwater levels in HONI1 may be lowered by more

than 7 m and in HONI2 by approximately 2 m. Depending on the use and pump configuration of the

boreholes, a lowering of 2 m in the groundwater level of HONI2 is not considered significant. The

impact on HONI2 may reduce the performance of the borehole, but there is insufficient information

to confirm this anticipated impact. It is estimated that groundwater would seep into the box cut at

an average rate of approximately 100 m3/d (1.1 L/s).

5.7.2.2 Operational Phase

5.7.2.2.1 Impact: Lowering of Groundwater Levels due to Pit Dewatering


progresses. The rate at which groundwater would seep into the pits will depend on the

transmissivity of the host rock, the presence of water-bearing geological features like faults and

fractures, and the groundwater flow gradient towards the pit. The flow gradient is determined by

the depth of mining, which was interpolated in the model from the coal floor contours.

The model was used to estimate the extent to which pit dewatering would impact on groundwater

levels around the pit. The maximum extent of lowering in groundwater levels (zone of impact) for

the operational phase will develop towards the end of mining, as indicated in Figure 12. It is shown

that the shape of the cone of depression will be controlled by the geology and the presence of faults.

Due to the low transmissivities of the host rock in which the mine is situated, the cone of depression

is not expected to extend further than 2 km from Pit 1 and 1.5 km from Pit 2. The private boreholes

that fall within this zone of influence are listed in Table 23. It is shown that groundwater levels in

five boreholes (BILL2, BILL3, BOTM4, Groot2 and STEL1) may be lowered by less than 2 m. This

impact will most probably not be significant, as borehole performance and use should not be

affected under these circumstances.

Groundwater levels may be lowered by up to 10 m in three boreholes (HONI3, HONI4 and BILL4).

This lowering in groundwater level is expected to affect borehole performance, especially during the

dry season. The extent to which groundwater abstraction will be affected in these boreholes will

depend on the borehole construction, pump installation and the rate at which the boreholes will be

pumped.

Mine dewatering may result in a lowering in groundwater levels in three private boreholes (ROND5,

HONI3 and WELT1) by up to 20 m. It is anticipated that groundwater supply from these boreholes

would be severely affected and that the boreholes will most likely dry up with time.

Three private boreholes (HONI1, HONI2 and Groot1) will be destroyed during mining.


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Table 23. Private boreholes affected by mine dewatering

BH ID Simulated drawdown (m) Drawdown range (m)

BILL2 1.5 <2 BILL3 1.3 <2

BOTM4 1.9 <2

Groot2 1.8 <2

STEL1 1.2 <2

HONI3 4.3 2-5 HONI4 8.3 5-10

BILL4 9.4 5-10

ROND5 12.8 10 - 15

RHP02 14.2 10 - 15

RHP01 14.8 10 - 15 WELT1 16.5 15 - 20

HONI2 20 >20

Groot1 23 >20

HONI1 24 >20


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Figure 11. Simulated cone of depression: Construction Phase


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Figure 12. Simulated cone of depression: Operational Phase


PAGE 65

Figure 13. Groundwater seepage volumes

The rate at which groundwater would seep into the pits was calculated with the aid of the model.

Three scenarios were tested. The minimum seepage rate was calculated by assigning the lowest

transmissivity from the pumping tests to the pit walls. The average and maximum rates represent

seepage volumes under average and maximum transmissivity conditions. The calibrated host rock

and faulting transmissivities were used during all three scenarios. The results of simulations are

show in Table 24 and in Figure 13.

Table 24. Estimated groundwater seepage volumes (m3/d)

Time (yrs) Mining period

Pit 1 Pit 2 Total

Min Ave Max Min Ave Max Min Ave Max

3 Ramp up 0 0 0 0 0 0 0 0 0

6 Cut 1 85 106 126 0 0 0 85 106 126

10 Cut 2 323 356 390 0 0 0 323 356 390 13 Cut 3 433 478 523 0 0 0 433 478 523

15 Cut 4 496 544 594 0 0 0 496 544 594

19 Cut 5 688 756 824 0 0 0 688 756 824

23 Cut 6 819 905 991 0 0 0 819 905 991

25 Cut 7 915 1,007 1,094 0 0 0 915 1,007 1,094 27 Cut 8 986 1,089 1,194 0 0 0 986 1,089 1,194

31 Cut 9 889 990 1,089 283 353 454 1,171 1,343 1,543

34 Cut 10 785 880 977 434 505 602 1,219 1,385 1,580

37 Cut 11 710 798 889 552 626 716 1,262 1,425 1,605

38 Cut 12 654 741 826 648 733 818 1,302 1,473 1,644 41 Cut 13 588 670 749 810 910 988 1,398 1,580 1,737

42 Cut 14 609 641 672 847 892 923 1,457 1,533 1,595


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It is shown that the rate at which groundwater should seep into Pit 1 will increase from around 100

m3/d (range: 85 to 126 m3/d) during Cut 1 (box cut) to approximately 1,100 m3/d (range: 986 to

1,194 m3/d) at the end of life of the pit (Cut 8). The volume of groundwater seepage is determined

by the area that is opened during mining, the depth of mining and the geology intersected.

Once mining at Pit 2 commences, the volume of groundwater seeping into Pit 1 will reduce, as

indicated on Figure 13. Towards the end of life of the mining operations, the volume of

groundwater seepage to Pit 1 is expected to be around 600 m3/d (range: 641 to 672 m3/d). The

volume of seepage to Pit 2 is expected to start at approximately 350 m3/d (range: 283 to 454 m3/d)

and increase to around 890 m3/d (range: 847 to 923 m3/d) at the end of life of the operations.

In total, the maximum volume of groundwater seepage to both pits is calculated to be around 1,580

m3/d (range: 1,398 to 1,737 m3/d).

5.7.2.2.2 Impact: Cumulative impact of groundwater abstraction for mine use

As discussed earlier, local aquifers were assessed as potential water resources available to the

project. The impact of groundwater abstraction from the 6 newly drilled boreholes was assessed

with the model. The results of simulations are presented in Figure 14 and Figure 15.

Figure 14 indicates the cone of depression around all the new boreholes pumped at the sustainable

yields obtained during the 2017 fieldwork phase. The impact of mine dewatering is excluded from

this scenario. The newly drilled boreholes were pumped at their calculated sustainable yields or if

not available, at their test yields during this simulation (Table 21). The results, as shown in Figure 14,

suggests that this pumping configuration is not sustainable. Boreholes RHP03, RHP05 and RHP06

will run dry in the long-term at these yields due to the cumulative impact on each other. The zone of

influence may extend as far as 4 km from the boreholes, affecting private boreholes PRET1, PRET2

and PRET3, as well as WELT2, WELT3 and WELT4, and possibly GARI1 and GARI2. It is thought that

this groundwater abstraction option will result in the drying up of the boreholes listed above, except

for GARI1 and GARI2. As such, it is not recommended that all the new boreholes are pumped

simultaneously over an extended period.

The model was therefore used to run scenarios to test the optimal groundwater abstraction

programme that will be sustainable over the life of the operation, while taking the impact of mine

dewatering into consideration. To achieve this, groundwater was only abstracted from boreholes

RHP03 and RHP05. The model indicated that the sustainable yields calculated from the long-term

aquifer tests will probably not be sustainable in the long-term when the impact of mine dewatering

is also taken into consideration. In fact, the rate of groundwater abstraction had to be reduced

significantly. Additional scenarios can be tested to further optimise this outcome, but model

simulations indicate that the boreholes could probably only be pumped at around 43 m3/d (0.5 L/s)

continuously over the life of the operations. This is significantly less than what is indicated by the

aquifer tests. The aquifer testing and yield calculations can however not take the impact of mine

dewatering and the simultaneous pumping of the two boreholes over a period of 42 years into

consideration. These factors are expected to reduce the sustainable yield of the boreholes, as

indicated.

The combined cone of depression around the mine and the abstraction boreholes is shown in the

Figure 15. The geology, and specifically the faults identified, will control the shape and extent of the

cone of depression, as indicated. Towards the end of life of the operations, groundwater levels may

be lowered to around 70 m in the two boreholes, while pumping continuously. Boreholes RHP03


PAGE 67

and RHP05 are 116 m and 80 m deep respectively. To ensure longevity, the pumps must be installed

as deep as possible into the boreholes.

The modelling results suggest that around 86 m3/d of water in total can be abstracted continuously

over the life of the operations from the two boreholes.

It is however recommended that a more detailed impact assessment is undertaken with the

engineers appointed to the operations to revise the groundwater abstraction regime. Additional

considerations can include developing a pumping regime where the boreholes are switched off for

certain periods, or that additional boreholes are considered for water supply further from the pits

and outside the zone of influence of mine dewatering.

5.7.2.2.3 Impact on Groundwater Quality: Operational Phase

The results of leach tests completed on overburden and coal material indicate low sulphate

concentrations (Table 15). No discard samples were available for analysis at the time of compilation

of this report. Based on similar projects, it is however thought that sulphate concentrations may

increase within the mining area, as discussed earlier in the report, as the Acid Base Accounting

results indicate likely acidification for some of the samples.

During the operational phase, groundwater levels will however be reversed towards the pits, thus

preventing the migration of contaminated water off site. For this reason, it is unlikely that

groundwater contamination would impact on private groundwater users outside the mining

footprint during the operational phase. It is assumed that new monitoring and private boreholes

inside the mining footprint will be maintained and will be used for groundwater monitoring.

Recommendations regarding groundwater monitoring are provided in Section 10.


PAGE 68

Figure 14. Simulated drawdown as a result of groundwater abstraction


PAGE 69

Figure 15. Cumulative impact of groundwater abstraction and mine dewatering


PAGE 70

5.7.2.3 Long-term Impact on Groundwater

5.7.2.3.1 Impact: Recovery of Groundwater Levels after Closure

Once mining and mine dewatering stops, the groundwater levels will start to recover around the

pits. The rate at which this will take place, will depend on the transmissivities of the aquifers, but

most importantly on the quality of backfill and rehabilitation of the pits. The latter will control the

rate of recharge to the pits. Final rehabilitation plans are not available at present. For this reason,

several recharge scenarios were tested with the model to assess the rate of recovery around the pits

post closure, including natural recharge rates, as well as rates of 5, 10, 15 and 20% of MAP over the

surface of the rehabilitated pits. The results are presented in Figure 16 and Figure 17. The

simulations indicate that groundwater levels would recover within 18 to 20 years after mining ceases

at Pit 1 and within 22 to 35 years at Pit 2. At lower recharge rates, the pits would take longer to

recover.

Figure 16. Rate of groundwater level recovery for Pit 1


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Figure 17. Rate of groundwater level recovery for Pit 2

5.7.2.3.2 Impact of Decant

Once groundwater levels have recovered, the possibility of decant from the pits will manifest.

Whether the pits will decant in future, will depend on how well backfilling and rehabilitation of the

pits are achieved upon mine closure. The graphs presented in Figure 16 and Figure 17 indicate that

if the rate of recharge to the pits are reduced to natural rates upon rehabilitation of the two pits,

that water levels inside the pits will not rise above the decant point of each pit. If this cannot be

achieved and more rainwater infiltrates into the pits than what takes place naturally, water levels

inside the pits will rise to above the decant point, which will result in seepage of potentially

contaminated water on surface.

Simulations suggest that decant can be expected if the rate of recharge to the pits exceed 5% of

MAP after rehabilitation. The decant position is governed by the topography around the pits.

Decant will start at the lowest elevation at each pit, as indicated on Figure 18. One decant position

is indicated for Pit 1, which is situated on the south-western highwall. The elevation of the decant

point is 873 m amsl. If water levels inside the pit rise to above this elevation, decant will take place.

Two possible decant locations were identified for Pit 2, on the north-western highwall. The decant

elevation is 874 m amsl for this pit.

If the rate of recharge to the pits cannot be kept below 5% of MAP post rehabilitation, decant will

commence 18 to 35 years after closure from the pits, as indicated on Figure 18. The volume of

decant is estimated to be between 40 and 150 m3/d at Pit 1 and 30 and 120 m3/d at Pit 2.


PAGE 72

The quality of decant cannot be determined with the available dataset. Based on experience in

similar environments, the water is likely to be acidic with elevated salt and metal concentrations. As

such, it will pose a contamination threat to soil, surface runoff and groundwater.

5.7.2.3.3 Impact: Long-term Risk of Groundwater Contamination

Once groundwater levels have recovered, the possibility exists that contamination from the pits,

waste rock dump, discard dump and the plant may migrate off site. The model was used to calculate

the extent to which this may happen (Figure 19).

As discussed earlier, the contaminant transport model was used to simulate the spread of

contamination as a percentage of the source. All sources (pits, waste rock dump, discard dump and

plant) were assigned a concentration percentage of 100%. The results are presented in 10% contour

intervals.

During simulations, it was assumed that the rate of recharge to the pits is below 5% of MAP and

below 10% of MAP for the rehabilitated mine residue stockpiles. The rate of recharge to the plant

area was assumed to be 1% of MAP, equivalent to the calibrated recharge rate.

The model was run for a period of 100 years after mining ceases. During this period, groundwater

levels will recover for the first 20 to 30 years. Thereafter, the plume is expected to migrate in a

westerly direction. During this period, the contamination is not expected to migrate more than 900

m from the mining area. This is due to the low transmissivities of the Ecca sediments.

The faults may act as preferential flow paths, but to a very limited extent. The plume is not

expected to reach Fault A south of the mining area, nor the Daarby Fault. Very limited preferential

flow is expected along Faults B and C, as indicated, as these faults are up gradient of the pits and

mine residue deposits. Fault C (southwest-northeast striking) may impact on the way potential

contamination migrates from the plant. The plant is however not expected to significantly impact on

groundwater quality in future, as indicated in Figure 19.

The long-term impact of groundwater contamination on existing private boreholes is demonstrated

in Table 25. The table demonstrates the percentage increase in sulphate concentrations compared

to the source terms. It is shown that small increases in sulphate may be seen in boreholes BOTM4,

HONI4, BILL4 and ROND5. Sulphate concentrations are expected to increase by less than 6% in these

boreholes. This will probably not result in the groundwater becoming unfit for use.

Groundwater quality in the rest of the boreholes indicated in Table 25 is however expected to

significantly deteriorate in the long-term and will probably become unfit for use.


PAGE 73

Figure 18. Decant assessment


PAGE 74

Figure 19. Simulated sulphate plume 100 years after mine closure


PAGE 75

Table 25. Expected increase in sulphate concentrations in boreholes

Affected Private Borehole % increase in sulphate concentration

BOTM4 1 HONI4 3

BILL4 4

ROND5 5

RHP02 33

HONI3 37 RHP01 57

WELT1 58

Groot2 90

HONI1 90

HONI2 90 Groot1 100

6 Groundwater Impact Assessment The impact significance rating process serves two purposes: firstly, it helps to highlight the critical

impacts requiring consideration in the management and approval process; secondly, it shows the

primary impact characteristics, as defined above, used to evaluate impact significance.

6.1 ACTIVITY DESCRIPTION

The proposed development includes the following activities:

• Mining

o Box cut

o Open pit

• Residue Stockpiles and Deposits

o Topsoil stockpile

o Discard dump

o Waste tip

o Overburden stockpile

o ROM/ raw material stockpile

• Buildings and Structures

o Fencing

o Gate house complex

o Entrance/ exit and 2 x weighbridges

o Workers under cover waiting areas

o Workers turnstile access control and induction office

o Office complex

o Helicopter landing pad

o Change houses

o Clinic

o Canteen

o Fire control facility

o Solid waste sorting facility

o Gas store

o General workshop


PAGE 76

o Chemical store

o Flammable store

o Hazardous material store

o Electrical workshop

o Instrumentation workshop

o Welding shop

o Combined stores

o Light duty vehicle (LDV)/ heavy duty vehicle (HDV) workshop

o LDV/ HDV wash bay

o LDV/ HDV fuel storage and refuelling

o Oil discard tanks

o Under crane warehouse

o HDV tyre storage

o HDV tyre change assembly station

o HDV tyre change hard stand

• Plant Facilities

o Run of Mine pad

o Single stage wash beneficiation

o Primary crusher

o Conveyors

o Plant motor control centre (MCC) control room

o Transformer bays

o Plant workshop

o Plant coal laboratory

o Plant geology grade control

o Plant office building

• Road Network

o Access roads (R518)

o Internal roads (road width = 7.4 m, road reserve = 15 m)

• Water Supply Network

o Water treatment works (reverse osmosis package plant)

o Waste water treatment works (closed system package plant)

o Sludge and solids collection and disposal

o Pollution control dams/ stormwater retention ponds (combined)

o Raw water dam

o Pipelines

o Pump stations

o Storage tanks

• Electrical Distribution

o Substation and miniature substations (11 kilovolts (kV))

o Uninterrupted power supply (UPS) generators

o 11/ 33 kV switching station

o 33 kV power line

The impact assessment rating will be based on the activities listed above, potential impacts on the

groundwater environment and will be supported by possible mitigation / management measures to

eliminate or reduce the identified impact.


PAGE 77

The impact significance rating system is presented in Table 26 and involves three parts:

• Part A: Define impact consequence using the three primary impact characteristics of

magnitude, spatial scale/ population and duration;

• Part B: Use the matrix to determine a rating for impact consequence based on the

definitions identified in Part A; and

• Part C: Use the matrix to determine the impact significance rating, which is a

function of the impact consequence rating (from Part B) and the probability of occurrence.

Table 26. Significance rating methodology

PART A: DEFINING CONSEQUENCE IN TERMS OF MAGNITUDE, DURATION AND SPATIAL SCALEUse these

definitions to define the consequence in Part B

Impact characteristics Definition Criteria

MAGNITUDE

Major -

Substantial deterioration or harm to receptors; receiving

environment has an inherent value to stakeholders;

receptors of impact are of conservation importance; or

identified threshold often exceeded

Moderate -

Moderate/measurable deterioration or harm to receptors;

receiving environment moderately sensitive; or identified

threshold occasionally exceeded

Minor -

Minor deterioration (nuisance or minor deterioration) or

harm to receptors; change to receiving environment not

measurable; or identified threshold never exceeded

Minor + Minor improvement; change not measurable; or threshold

never exceeded

Moderate + Moderate improvement; within or better than the

threshold; or no observed reaction

Major + Substantial improvement; within or better than the

threshold; or favourable publicity

SPATIAL SCALE OR

POPULATION

Site or local Site specific or confined to the immediate project area

Regional May be defined in various ways, e.g. cadastral, catchment,

topographic

National/

International Nationally or beyond


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DURATION

Short term Up to 18 months

Medium term 18 months to 5 years

Long term Longer than 5 years

PART B: DETERMINING CONSEQUENCE RATING

Rate consequence based on definition of magnitude, spatial extent and duration

SPATIAL SCALE/ POPULATION

Site or Local Regional National/

international

MAGNITUDE

Minor DURATION

Long term Medium Medium High

Medium term Low Low Medium

Short term Low Low Medium

Moderate DURATION

Long term Medium High High

Medium term Medium Medium High

Short term Low Medium Medium

Major DURATION

Long term High High High

Medium term Medium Medium High

Short term Medium Medium High

PART C: DETERMINING SIGNIFICANCE RATING

Rate significance based on consequence and probability

CONSEQUENCE

Low Medium High


PAGE 79

PROBABILITY (of exposure to

impacts)

Definite Medium Medium High

Possible Low Medium High

Unlikely Low Low Medium

A summary of the groundwater impact assessment ratings is presented in Table 27.


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Table 27. Groundwater Impact Assessment summary


PAGE 81

7 Cumulative Impacts The topography in the area is flat with a gentle slope from southeast to northwest. The surface

elevation varies from 943 m amsl in the south to 869 m amsl in the north, and 840 m amsl in the

northwest.

The LCPP is predominantly in the A42J quaternary catchment, forming part of the Limpopo Water

Management Area (WMA:1).

The average depth to groundwater in the fractured rock aquifer underlying the Project area is

approximately 25 to 30 m below surface. This suggests that the deeper, fractured aquifer is most

probably confined and that groundwater levels are below the weathered zone and therefor does not

sustain a shallow weathered aquifer. The sustainable yields for the boreholes in the Project area are

low, which suggest that the aquifers intersected within the Project area are not able to sustain high

abstraction rates for production purposes.

There are no active mines or industrial activities near the proposed LCPP development.

Groundwater is a very valuable and limited resource in this area and it must be managed and

protected to ensure a sustainable resource for all users and the local communities and farming

sector.

Currently, groundwater abstraction for household (private and tourism) and farming use, plus

discharges from sewage systems, plus herbicides and pesticides are the only potential impacts to the

local groundwater environment.

With the addition of mining activities, cumulative impacts will include:

• Decrease in the local groundwater level and possible drying up of private boreholes;

• Deterioration of the current groundwater quality; and

• An increase in acid mine drainage and potential decant post closure.

The outcome of the LCPP groundwater assessment indicates that the mining activities will have an

impact on the receiving environment and that includes 13 private boreholes located in the area

(Table 23). The radius of influence (groundwater level drawdown) could potentially extend

approximately 2 km Pit 1 and 1.5 km from Pit 2 during the operational phase. Model simulations

indicated an even higher impact on the local groundwater resources and users if mine dewatering

plus wellfield abstraction are run at the same time (Figure 15).

Establishing monitoring boreholes (Section 10) around the mining area is required to assess the

implications of dewatering from the LCPP Project on the aquifers near the proposed mine and to

identify if poor quality groundwater related to the mining activities reach a sensitive receptor. The

monitoring data recorded as mining operations progress must be used to update the numerical

model on an annual basis for the first five years of operation. Any additional geological and

hydrogeological information gathered during the development of the mine also needs to be

incorporated into the model updates.

8 Water Demand The potential for local groundwater resources to supply the amount of water required by the

proposed mine cannot be ruled out; however this could only be achieved by intersecting highly


PAGE 82

productive fracture systems backed up by good recharge. It seems likely, that for the project

demand to be sustained, water will have to be imported from outside the immediate area (RHDHV,

September 2016). In the Limpopo WMA, Internal Strategic Perspective mentions that groundwater

resources should be the first option to investigate in terms of water supply. Productive fractures /

aquifer systems (if identified) first need to be tested to determine sustainable production rates and

could potentially only supply water over a short term.

8.1 WATER SUPPLY OPTIONS Water for the LCPP could potentially be sourced from:

• MCWAP2;

• Production boreholes on site;

• Rainwater harvesting;

• Groundwater from the pit;

• Recycled process water; and

• Treated waste water treatment works effluent.

The water usage strategy for the LCPP was designed to operate as a closed water system and

therefore most of the water on site will be captured and re-used where possible, thereby creating a

complete balance.

In terms of the Mokolo catchment no further allocations seem to be possible from surface water

resources without carrying out detailed analyses to verify a sustainable source of supply.

Groundwater is underutilised and should be the first option to supply local requirements, provided

the water quality is acceptable (DWA, 2004).

Water demand calculations done by RHDHV (PFS, 2016) were based on design guidelines and

information received from other PFS disciplines. The calculations resulted in the following demands:

• LCPP daily domestic water demand – 150 kl/d (150 m3/d);

• CHPP operational water demand – 2,635 kl/d (2,635 m3/d);

• IPP operation water demand – 4,110 kl/d (4,110 m3/d);

• Dust suppression – 288 kl/d (288 m3/d).

• Total demand = 7,183 kl/d (7,183 m3/d).

A reverse osmosis package plant has been recommended for the treatment of raw water from the

boreholes. The water treatment was designed to be via a softening stage, filtration stage, reverse

osmosis and finally chemical dosing and the design for the Water Treatment Works (WTW) includes

stainless steel softeners with a brine cleaning tank, a rotary water meter, dosing station, clean in-

place station, filter bank, reverse osmosis bank, and an electrical panel.

Based on the PFS report (RHDHV, 2016) potable water in the MIA and CHPP Area will be supplied by

rainwater (20%) and MCWAP Phase 2 (80%). It was estimated that operational water for the MIA

and CHPP will be sourced from:

• Pit inflow – 80%;

• Rain water – 5%;

• Sewage Effluent – 5%; and

• MCWAP – 20%.


PAGE 83

8.1.1 Groundwater from the Pit

It is estimated that groundwater would seep into the box cut during the construction phase at an

average rate of approximately 100 m3/d. During the operational phase, groundwater will continue

to seep into the mining void as mining progresses. It is shown that the rate at which groundwater

should seep into Pit 1 will increase from around 100 m3/d (range: 85 to 126 m3/d) during Cut 1 (box

cut) to approximately 1,100 m3/d (range: 986 to 1,194 m3/d) at the end of life of the pit (Cut 8).

Once mining at Pit 2 commences, the volume of groundwater seeping into Pit 1 will reduce.

Towards the end of life of the mining operations, the volume of groundwater seepage to Pit 1 is

expected to be around 600 m3/d (range: 641 to 672 m3/d). The volume of seepage to Pit 2 is

expected to start at approximately 350 m3/d (range: 283 to 454 m3/d) and increase to around 890

m3/d (range: 847 to 923 m3/d) at the end of life of the operations.


m3/d (range: 1,398 to 1,737 m3/d) which is approximately 60% the CHPP operational water demand.

This also indicates a higher requirement from the MCWAP supply as assumed in the PFS document if

no other sources are found, e.g. the Anglo Coal Bed Methane supply.

8.1.2 Production Boreholes

The impact of groundwater abstraction from the newly drilled boreholes was assessed with the

numerical model. The newly drilled boreholes were pumped at their calculated sustainable yields or

if not available, at their test yields during this simulation (Table 21). The results suggest that this

pumping configuration is not sustainable. Boreholes RHP03, RHP05 and RHP06 will run dry in the

long-term at these yields. The zone of influence may extend as far as 4 km from the boreholes,

affecting private boreholes PRET1, PRET2 and PRET3, as well as WELT2, WELT3 and WELT4 and

possibly GARI1 and GARI2. It is thought that this groundwater abstraction option will result in the

drying up of the boreholes listed above, except for GARI1 and GARI2. As such, it is not

recommended that all the new boreholes are pumped simultaneously over an extended period.

The model was used to run scenarios to test the optimal groundwater abstraction programme that

will be sustainable over the life of the operation, while taking the impact of mine dewatering into

consideration. To achieve this, groundwater was only abstracted from boreholes RHP03 and RHP05.

The model indicated that the sustainable yields calculated from the long-term aquifer tests will

probably not be sustainable in the long-term when the impact of mine dewatering is also taken into

consideration. In fact, the rate of groundwater abstraction had to be reduced. Additional scenarios

can be tested to further optimise this outcome, but model simulations indicate that the boreholes

could probably only be pumped at around 43 m3/d (0.5 L/s) continuously over the life of the

operations. This is significantly less than what is indicated by the aquifer tests. The aquifer test and

interpretation software can however not take the impact of mine dewatering and the simultaneous

pumping of the two boreholes over a period of 42 years into consideration.

Borehole abstraction could potentially support office and gardening requirements plus dust

suppression, but large-scale abstraction would not be possible or sustainable.

It is however recommended that a more detailed impact assessment is undertaken in terms of

wellfield development. Additional considerations can include water supply sources further from the

pits and outside the zone of influence of mine dewatering.


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8.1.3 Outside Sources

The Anglo Coal Bed Methane Operation is located approximately 20 km north-northwest of

Lephalale and 23 km west of the LCPP site. The Digby Wells (2015) study found that there is a

possibility that approximately 1,000 m³/day could be made available to the industry once certain

challenges with legislation on fracking were overcome.

Waste water from local municipal water treatment facilities could represent an option.

8.1.4 Mokolo and Crocodile Water Augmentation Project (MCWAP)

Several developments are planned and others are likely in the Lephalale area for which additional

water will be required, particularly associated with the exploitation of the coal reserves in the

Waterberg Coalfield. The principal aim of the MCWAP-2A is to provide 75 to 100 million m3/annum

of water to the Lephalale and Steenbokpan areas by laying a new pipeline from the Crocodile River.

The first water from this scheme is not expected before 2022.

The Phase 1 recipients have already been allocated, thus Phase 2A of MCWAP seems a more likely

source of water for the development of the LCPP. Surplus return flows in the Crocodile West/Marico

catchment would be transferred to the Mokolo catchment in the Limpopo WMA using de-gritting

channels with high and low lift pump stations. This will augment the water supply and support

strategic development in the area. The project includes an abstraction point on the Crocodile River

near Thabazimbi. It is not known how much of the transfer has already been allocated, however it is

understood that LCM has already expressed a commitment to obtaining water from the MCWAP 2A.

9 Groundwater Management Plan

9.1 GROUNDWATER MANAGEMENT OBJECTIVES

9.1.1 Construction Phase

The objective during the construction phase is to limit significant impacts on existing private

boreholes. This will be supported by a groundwater monitoring programme.

9.1.1.1 Actions: Construction Phase

The following groundwater management actions are proposed for the construction phase:

• Record the pre-mining yield, borehole depth and groundwater demand associated with each

private borehole identified, even those outside the zone of impact before the construction

phase commences. It is important to record this information prior to mining to ensure that

baseline information is available for each private borehole that is in use;

• Drill additional monitoring boreholes in order to assess all impacts associated with mining

identified as part of this study;

• Implement a quarterly groundwater monitoring programme;

• Implement stormwater management measures to ensure that clean and dirty water is

separated and that dirty water is contained;

• Take additional samples of mine residue deposits (waste rock) for leach tests analysis in

order to improve the understanding of the source term used during contaminant transport

modelling; and


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• Update the existing contaminant transport model with the additional information in order to

complete simulations with field-measured data. This must be done during the first update

of the groundwater model in order to confirm the predictions in this study and to enable

ample time within which to implement the correct remediation measure to minimise long-

term liabilities associated with groundwater contamination.

9.1.2 Operational Phase

The objective during the operational phase is to minimise or prevent the reduction of yield in private

boreholes because of mine dewatering.

9.1.2.1 Actions: Operational Phase

• Maintain the groundwater monitoring programme, as detailed in Figure 20;

• Drill additional monitoring boreholes in order to assess all impacts associated with mining;

• Confirm the yield of privately owned boreholes within the delineated zone of influence

before mining starts, if this has not been done yet, to ensure a reference point for

monitoring;

• Prepare a replacement water supply strategy for private boreholes that may be affected in

anticipation of the potential impacts of mine dewatering;

• Undertake a more detailed assessment of the cumulative impact of groundwater abstraction

on existing private groundwater users;

• Contain dirty water in adequately sized and lined pollution control dams. Prevent dirty

water runoff from leaving the mining area;

• Re-use water collected in the pit and produced in the mining and coal processing activities to

ensure that the intake of borehole or MCWAP water is minimised;

• Ensure that an effective pit dewatering system is in place to ensure that groundwater flow in

the mining area is directed towards the pit and not allowed to freely drain away from the

mining area;

• Adjust the mine’s groundwater abstraction programme to ensure that the impacts on

existing private groundwater use are minimal;

• Develop an effective rehabilitation and closure plan during the operational phase to ensure

that mine closure can be successfully achieved. Groundwater quality impacts often

intensifies post closure when the pit dewatering stops and groundwater can free drain and

follow the regional drainage direction;

• Take additional samples of mine residue deposits (waste rock and discard) for SPLP and

kinetic leach tests analysis to improve the understanding of the source term used during

contaminant transport modelling;

• Update the existing contaminant transport model with the additional information. This

must be done in order to confirm the predictions in this study and to enable ample time

within which to implement the correct remediation measure to minimise long-term

liabilities associated with groundwater contamination; and

• If the mine layout, mine plan and/or schedule changes, the numerical model must be

updated.


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9.1.3 Groundwater Closure Objectives

The objective during the closure phase is to implement the best possible rehabilitation strategy

focussed on reducing the rate of recharge to the pits to near natural conditions. This will reduce the

risk of decant from the pits post closure.

9.1.3.1 Actions: Closure

• Negotiate and get the groundwater closure objectives approved by Government during the

Decommissioning Phase of the project, based on the results of the monitoring information

obtained during the Construction and Operational Phases of the project;

• The monitoring information must be used to update, verify and recalibrate the predictive

tools used during the study. The numerical model must be verified to an adequate level at

least five years before mine closure to simulate the required closure scenarios within

acceptable confidence levels;

• Present the results to Government on an annual basis to determine compliance with the

closure objectives set during the Decommissioning Phase;

• Continue with the pit dewatering to ensure that potential contaminated groundwater flow

in the mining area is directed towards the pit and not allowed to freely drain towards the

local private groundwater users;

• Continue the groundwater level and quality monitoring for a period of at least two years

after mining ceases in order to establish post-closure trends; and

• The volume of decant is estimated to be between 40 and 150 m3/d at Pit 1 and 30 and 120

m3/d at Pit 2. The volume of water will need to be treated to the RWQO prior to discharge.

The mine proposes to have an RO Plant on site, but passive treatment options should also be

considered.

9.2 GROUNDWATER MANAGEMENT IMPLEMENTATION PLAN

9.2.1 Management of Groundwater Availability

• The groundwater that seeps into the pits during the operational phase will be abstracted

and used as part of the mine water demand. This will create a localised cone of depression

around the mining area and will reverse groundwater flow towards the pits. Private

boreholes that fall within the zone of impact were identified in this study.

• Groundwater monitoring will be undertaken in the mine’s monitoring boreholes to generate

a database. The information will be used to evaluate and confirm trends.

• The groundwater flow and contaminant transport model constructed for the project must

be updated and verified on an annual basis for at least the first 5 years and thereafter

possibly every 5- years to ensure that it is at a level of confidence at least 5 years before

mine closure to simulate groundwater closure scenarios.

• Clean surface rainfall runoff will be diverted around mine workings back into the catchment.

This will be achieved through a series of cut-off trenches and berms around the mining area.

• Pit water make will be reused as part of the mine’s water management and use plan.

9.2.2 Management of Groundwater Quality

• Groundwater seepage to the pits will be recycled and used continually as part of the mine

water balance. This will create a localised cone of depression around the mining area as the


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surrounding aquifers are dewatered. This cone of depression will limit the spread of any

potentially contaminated groundwater from the mining area to the surrounding aquifers.

• All dirty water being pumped from the pit should be stored and re-used on the mine to

prevent unnecessary discharge into the natural environment and to reduce the mine’s

operational water requirements. Should the contained water be more than the water use

requirement, it is recommended that the water be recycled or as the last resort be treated

to acceptable levels for the end water use.

• To limit the volume of dirty water to be managed, clean surface runoff will be directed

around the mining area. Should the water need to be discharged into the natural

environment, the RWQO should be met, prior to discharge.

• Groundwater monitoring will continue in the existing monitoring boreholes to populate the

groundwater database. This information must be used to confirm and validate the

information presented in this report as part of the process of negotiating mine closure with

the authorities.

10 Groundwater Monitoring

To prevent groundwater contamination, groundwater management procedures and practices will be

implemented that are in line with accepted practices and in accordance with the requirements of

the Environmental Management Plan (EMP) and Closure Plan for the project. It is recommended

that the groundwater monitoring programme presented here is implemented as part of an

Integrated Waste and Water Management Closure Plan for the project.

10.1 GROUNDWATER MONITORING OBJECTIVES

Groundwater monitoring is directed at measuring compliance to the Environmental Acceptable Level

(EAL) set for the project. The key objectives of the Groundwater Monitoring Programme are

therefore to:

• Develop improved practices and procedures for groundwater protection;

• Detect short and long term trends;

• Recognise changes in groundwater and enable analysis of their causes;

• Measure impacts;

• Check the accuracy of predicted impacts;

• Develop improved monitoring systems; and

• Provide information on the impact of the discard facility on groundwater.

To improve the confidence in the results of the model calibration process, it is recommended that

the groundwater model be verified with monitoring information. Monitoring of groundwater levels

and rainfall will be required to verify the current simulation results. Groundwater monitoring will be

undertaken to establish the extent of contamination in the shallow weathered and deeper fractured

aquifers.

The numerical model constructed for this project must be updated on a regular basis as additional

monitoring information becomes available, at least once every five years, or if the mining methods

or operations change significantly. In this way, all impact predictions will proceed to the level of

detail required for closure.


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10.2 PROPOSED GROUNDWATER MONITORING PROGRAMME

Based on the outcome of model simulations presented in this report, it is recommended that

additional monitoring boreholes are drilled at the operations. The suggested locations of these

boreholes are shown on Figure 20. The proposed groundwater monitoring programme is detailed in

Table 28. All new boreholes should be positioned with geophysical survey methods. Aquifer testing

must be completed on each borehole to establish the aquifer characteristics. This information must

be used to update the existing groundwater model. The following additional boreholes are

recommended:

• MON1: Down gradient of Pit 1, targeting the fault present in the area;

• MON2: Down gradient of the decant point of Pit 2;

• MON3: Down gradient of Pit 2, targeting the fault present in the area;

• MON4: Down gradient of the Discard dump; and

• MON5: Down gradient of the plant, targeting Fault C.


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Figure 20. Proposed additional monitoring borehole locations


PAGE 90

Table 28. Proposed monitoring programme

Monitoring position Sampling interval Analysis Water Quality Standards

Mine monitoring boreholes (RPH-series boreholes) and proposed new boreholes

Quarterly

(Apr, Jul, Oct, Jan)

Full chemical analysis

Groundwater levels

SANS: Drinking Water Standards

(Recommended EAL)

Hydrocensus boreholes within the affected zone

Annually

(April)

Full chemical analysis

Groundwater level

SANS: Drinking Water Standards

(Recommended EAL)

Rainfall Daily at the site No analysis Not Applicable

The length of post-closure monitoring must be negotiated with Government during the

decommissioning phase. It is recommended that the monitoring programme be implemented for a

minimum period of 2 years post closure to establish trends.

10.3 GROUNDWATER MONITORING REPORTING

Annual monitoring reports must be generated and submitted to the Department of Water and

Sanitation. Monitoring reports must contain the following information:

• Monitoring borehole location map;

• Monitoring borehole geology and construction log;

• All coordinates of the groundwater sampling sites;

• Certificates of analysis must be included for quality assurance. Monitoring results will be

compared to South African National Standards (SANS241);

• Time-series graphs for key indicator elements (pH, EC, TDS, F, NO3, SO4 and Fe);

• Trilinear or other analytical groundwater plots;

• A discussion regarding observed trends and potential groundwater contamination; and

• Recommendations regarding possible amendments or additions to the groundwater

monitoring programme, based on trends and other information observed.

An annual groundwater monitoring programme audit must be carried out by an independent party.

10.4 QUALITY ASSESSMENT AND CONTROL

Quality assurance means:

• Developing a system of activities to ensure that measurements meet defined standards

of quality with a stated level of confidence;

• Defining monitoring objectives, quality control procedures to be followed and quality

assessment;

• To define data quality objectives, including accuracy, precision, completeness,

representativeness and comparability; and

• Designing a network, selecting sampling sites, selecting instruments and designing the

sampling system, as discussed above.

Quality control includes preparing record keeping for site operation and equipment maintenance,

equipment calibration, site visit schedules and for data inspection, review, validation and usage. All


PAGE 91

monitoring equipment must be maintained as required, and calibration must be undertaken on a

regular basis.

To ensure that the Groundwater Monitoring Strategy complies with the above, it is important that

analytical laboratories used should be fully accredited for each type of analysis required, to ensure

that accurate analytical methods are used.

While only one or two of the common major ions found in waters may be specified as key indicators,

it is necessary to analyse for the full suite of common ions for quality control purposes and to detect

discrete events and long-term trends in anion composition.

Special attention must be paid to sampling methods and to preservation and handling of samples

prior to analysis. For natural waters (pH >5), all samples must be filtered in the field to <0.45 micron,

as discussed above. pH and conductivity must be measured in the field.

Close attention must be given to siting, logging and construction of monitoring boreholes and

assessment of their condition must be made quarterly.

The following sampling protocol is proposed:

• 500 ml plastic bottles, with a plastic cap and no liner within the cap are required for the

sampling. Sample bottles should be marked clearly with the borehole name, date of

sampling, water level depth and the sampler’s name;

• Water levels should be measured prior to taking the sample, using a dip meter (m bgl);

• Each borehole to be sampled should be purged (to ensure sampling of the aquifer and not

stagnant water in the casing) using a submersible pump or a clean disposable polyethylene

bailer. At least three borehole volumes of water should be removed through purging; or

through continuous water quality monitoring, until the electrical conductivity value

stabilizes;

• The following field measurements should be recorded on a field form for each sampling

point: pH, EC and temperature;

• Samples should be kept cool in a cooler box in the field and kept cool prior to being

submitted to the laboratory; and

• The pH and EC meter used for field measurements should be calibrated daily using standard

solutions obtained from the instrument supplier.


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11 Conclusions

The main drainage in the area is the Mokolo River, located approximately 14 km west from the LCPP

area. The Lephalala River is located approximately 17 km east from the study area (within the A50H

catchment). The area between the Mokolo River and Lephalala River, where the LCPP is located is

described as an endoreic area (does not produce surface runoff) because the semi-arid climatic

conditions and shallow topographic gradient.

Several communities are located along the Lephalala River; these include Ga-Seleka, Witpoort,

Mokuranyane and Ga-Shongwane. These communities reply on groundwater for water supply and

are located approximately 10 km to 15 km east of the proposed mining development. The numerical

model indicated that the mine will have no impact on the communities or their water resources.

The Lower Ecca sandstone is considered to be the main water bearing formation in the area, as well

as the intercept of linear geological features. The regional groundwater flow is likely to be

controlled by the dip of the strata and post-depositional faulting. The water table around the site is

likely to broadly follow the site topography.

According to the RHDHV PFS Report borehole yields in the Limpopo Region are frequently under 86

m3/day (1 L/s) in the Karoo-age siltstone, but may be up to 216 m3/day in similar age sandstone

(about 2.5 L/s) (RHDHV, September 2016). The Waterberg formations generally show poor

capability to produce huge amounts of groundwater, unless boreholes intersect northeast or

southeast trending structures (Digby Wells Environmental, 2014).

During the 2017 hydrocensus 57 boreholes were identified and included:

• 2 open exploration boreholes with small diameter steel casing inserted;

• 48 boreholes in use:

o 40 fitted with submersible / sun pumps;

o 7 fitted with windpumps;

• 6 open boreholes not in use;

• 1 hand-dug pit on the farm Middelboomspunt; and

• Groundwater level measurements were possible from 34 boreholes; pumping equipment

blocked the rest.

The highest water elevations can be found on the farms Pretoria and Alomfraai (south-eastern

areas) and the lowest water table elevations on the farms Billiards and Rondeboschje (northwest);

indicating a regional groundwater flow, from southeast to northwest. The depth to groundwater

table correlates well with the surface elevations; indicating that on a regional scale groundwater

flow will follow topography.

The information provided by the land owners indicated low borehole yields for most of the LCPP

project area. The farms along the south present higher yielding boreholes; these include the farms

Pretoria, Garibaldi and Weltevreden. This potentially relates to the east-west trending faults

identified in the area.


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Based on the groundwater quality results, the following conclusions were drawn in terms of the

baseline water quality:

• Chronic Health effects:

o Fluoride – fluoride is present in high concentration (between 2 and 7.4 mg/L) in all

sampled boreholes, except for GARI2 and RHP01. The measured concentrations

exceed the SANS241 chronic health limit of 1.5 mg/L. Fluoride concentrations are

associated with leaching of fluoride containing minerals from the Karoo formations

and often exceed the SANS241 chronic health limit.

o Total Organic Carbon – a high TOC value (10.2 mg/L) was measured for borehole

HONI2. In groundwater, the main natural sources of organic matter include organic

matter deposits such as buried peat, kerogen and coal; soil and sediment organic

matter; and organic matter present in water infiltrating into the subsurface from

rivers or dams / pans. Borehole HONI2 is located adjacent to a small pan and

together with the coal seams in the area this might be the reason for the high TOC

value.

• Acute Health effects:

o Nitrate – Borehole GARI2 yielded a high nitrate concentration (44.8 mg/L);

potentially because of animal movement in the area.

• Aesthetic effects:

o Sodium and Chloride concentrations are elevated for boreholes GROOT3, HONI2 and

RHP01. Elevated Sodium and Chloride concentrations are common in the Waterberg

area and often exceed the SANS241 guideline limits.

o Manganese – Six boreholes measured manganese concentrations that could present

aesthetic concerns.

o Ammonia - A high ammonia concentration was measured in borehole RHP01.

Ammonia is found in runoff from agricultural lands, where ammonium salts have

been used for fertilizers and this could be the reason for the elevated concentration

found in borehole RHP01. Old agricultural lands characterize the area.

• Scaling effects – high concentrations of calcium were measured in most boreholes.

Based on the SANS241 drinking water guidelines and on the sampled borehole water the

groundwater is thus not fit for human consumption (unless treated); predominantly because of high

fluoride concentrations and isolated occurrences of nitrate and TOC. Measured metals and sulphate

were present on concentrations below the SANS241 guideline limits.

The new LCPP percussion boreholes – targeting linear geological features – produced blow yields

between 800 L/h and 25,000 L/h (Table 4). This includes the deep borehole (RHP06), where the

water strikes were deeper than 100 m below surface (deepest at 230 m bgl). In general, borehole

yields throughout the project area are low, indicating no major aquifer systems in the area.

From Table 4 it can be concluded that the high yielding formations / aquifers seem to be the

intercept of linear geological features below the water table. Most of the main water strikes were

between 70 m and 82 m bgl. The deepest water strike was at 230 m bgl in borehole RHP06. The

shallow weathered zone, the small fractures in the coal seams and the geological contacts yielded

only seepage water. The fractured aquifers in the area can be classified as confined aquifers.


PAGE 94

Based on the percussion and core drilling results the top of the coal seams are found from

approximately 18 to 26 m bgl across the proposed mining footprint area. Borehole RHP06 at

Garibaldi only intercepted coal at 64 m bgl (Plan 6, Appendix A). Borehole RHP05 intercepted no

coal, but granite was intercepted at 50 m bgl, as well as in borehole RHP03 at 112 m bgl. Granite

outcrops are visible on the farms to the east of the proposed pit footprint areas, e.g. at

Middelboomspunt and Alomfraai. The water strike in borehole RHP05 (at 50 m bgl) was at the

contact zone between the Karoo formations and the granite; the borehole yielded a blow yield of

approximately 8,000 L/h. The weathered granite could be a potential target for water supply

drilling.

The depth of weathering (highly weathered material) varies between 7 and 23 m bgl; on average,

the depth of weathering is approximately 13 m bgl.

The low borehole yields, fast water level drawdown and slow recovery observed during the aquifer

testing indicate low transmissivity (T) aquifers with low recharge, as in the case of mudstone, coal

seams and granite. The average T-value calculated from the recovery data was 0.2 m2/d.

The 22 tested boreholes cumulatively yield approximately 81,500 L/h or 81.5 m3/hr. Based on this

first order aquifer yield assessment and the mine’s overall water requirement (6,747 m3/day), the

local groundwater resources would not be a viable source of water to supply the mining operations

or the proposed IPP.

Based on the ABA results the following were concluded:

• Paste pH:

o The coal sample associated with RHD04 indicated a paste pH of 4.7. The rest of the

pH values were between 5.3 and 7.6.

o Samples with a paste pH of 4.0 to 5.0 are considered PAF, but have a lower stored

acidic salt content.

o Paste pH values higher than pH 5.0 indicate a short-term acid neutralization

capacity.

• Sulphur content:

o The sulphur content of only 4 of the 15 samples is below the 0.3% benchmark and is

unlikely to generate acid sustainably (Table 8); these mostly relate to overburden

and interburden samples, including the two samples collected from below Zone 15.

It is also due to the low S-values that these 4 samples have a classification of TYPE II.

The rest of the samples have a sulphur content above 0.3% and are likely to

generate acid, unless the formation’s neutralising potential is enough to buffer any

acid that could be generated;

• Nett Neutralization Potential:

o All samples except Sample 11 have a NNP value less than zero and is therefore

potentially acid generating.

o The following NNP values are less than -20 kg/ton CaCO3 and will likely generate

acid:


▪ Sample 4, RHD02, Overburden (mudstone).


▪ Sample 6, RHD05, Mudstone - Coal, Zone 10.


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▪ Sample 8, RHD01, Mixed Interval Coal, Zone 8.



• Neutralizing Potential Ratio:

o According to the NPR results all samples are likely to generate AMD.

• Based on the ABA results presented above the following rock classifications are done:

o TYPE I – Potentially Acid Forming formation:

▪ Samples 2 to 8;

▪ Sample 10; and

▪ Samples 12 to 14.

▪ These include two overburden samples and the rest are pure coal or coal /

mudstone mixtures (Zone 10).

o TYPE II – Intermediate risk:

▪ Sample 1;

▪ Sample 9;

▪ Sample 11; and

▪ Sample 15.

▪ These samples relate to overburden and interburden material except for

Sample 11 (coal seam). Samples 1 and 15 were taken from below Zone 15.

• The samples collected during the LCPP groundwater assessment, for environmental impact

purposes, are deemed to be potentially acid generating.

Based on the results from the total concentration analysis (Table 10):




Based on the leachable concentration results (Table 11) all results are below the LCT0 threshold

values except for an elevated mercury (Hg) analysis for geochem sample 5.

For the LCPP project, a Class C landfill will be required for disposal of the waste material based on

the Total and Leachable Concentration results.

The impact of pit dewatering during the construction of the box cut was assessed with the numerical

model. It is shown that groundwater levels may be lowered by up to 25 m inside the box cut during

the construction phase. The resultant cone of depression will be controlled by the geological units

and the presence of faulting. It is estimated that the zone of influence will not extend further than

500 m from the box cut. Private boreholes HONI1 and HONI2 fall within the box cut dewatering

cone. It is estimated that groundwater levels in HONI1 may be lowered by more than 7 m and in

HONI2 by approximately 2 m. Depending on the use and pump configuration of the borehole, a

lowering of 2 m in the groundwater level of HONI2 is not considered significant. The impact on

HONI2 may reduce the performance of the borehole, but there is insufficient information to confirm

this anticipated impact. It is estimated that groundwater would seep into the box cut at an average

rate of approximately 100 m3/d.


progresses. The shape of the cone of depression will be controlled by the geology and the presence

of faults. Due to the low transmissivities of the host rock in which the mine is situated, the cone of


PAGE 96

depression is not expected to extend further than 2 km from Pit 1 and 1.5 km from Pit 2. Private

boreholes that fall within this zone of influence are listed in Table 23. It is shown that groundwater

levels in five boreholes (BILL2, BILL3, BOTM4, Groot2 and STEL1) may be lowered by less than 2 m.

This impact will most probably not be significant, as borehole performance and use should not be

affected under these circumstances.

Groundwater levels may be lowered by up to 10 m in boreholes HONI3, HONI4 and BILL4. This

lowering in groundwater level is expected to affect borehole performance, especially during the dry

season.

Mine dewatering may result in a lowering in groundwater levels in boreholes ROND5, HONI3 and

WELT1 by up to 20 m. It is anticipated that groundwater supply from these boreholes would be

severely affected and that the boreholes will most likely dry up with time.

Boreholes HONI1, HONI2 and Groot1 will be destroyed during mining.

It is shown that the rate at which groundwater should seep into Pit 1 will increase from around 100

m3/d during Cut 1 (box cut) to approximately 1,100 m3/d at the end of life of the pit (Cut 8). Once

mining at Pit 2 commences, the volume of groundwater seeping into Pit will reduce, as indicated on

Figure 13. Towards the end of life of the mining operations, the volume of groundwater seepage to

Pit 1 is expected to be around 600 m3/d (range: 641 to 672 m3/d). The volume of seepage to Pit 2 is

expected to start at approximately 350 m3/d (range: 283 to 454 m3/d) and increase to around 890

m3/d (range: 847 to 923 m3/d) at the end of life of the operations.


m3/d (range: 1,398 to 1,737 m3/d).

The numerical model suggests that continuous pumping of the 6 new boreholes is not sustainable.

Boreholes RHP03, RHP05 and RHP06 will pump dry in the long-term at these yields. The zone of

influence may extend as far as 4 km from the boreholes, affecting private boreholes PRET1, PRET2

and PRET3, as well as WELT2, WELT3 and WELT4 and possibly GARI1 and GARI2. It is thought that

this groundwater abstraction option will result in the drying up of the boreholes listed above, except

for GARI1 and GARI2. As such, it is not recommended that all the new boreholes are pumped

together over an extended period.

The model was used to run scenarios to test the optimal groundwater abstraction programme that

will be sustainable over the life of the operation, while taking the impact of mine dewatering into

consideration. To achieve this, groundwater was only abstracted from boreholes RHP03 and RHP05.

The model indicated that the sustainable yields calculated from the aquifer tests will probably not be

sustainable in the long-term when the impact of mine dewatering is also taken into consideration.

The model simulations indicate that the boreholes could probably only be pumped at around 43

m3/d (0.5 L/s) continuously over the life of the operations.

The simulations indicate that groundwater levels would recover within 18 to 20 years after mining

ceases at Pit 1 and within 22 to 35 years at Pit 2. Once groundwater levels have recovered, the

possibility of decant from the pits will manifest. Whether the pits will decant in future, will depend

on how well backfilling and rehabilitation of the pits are achieved upon mine closure.

Simulations suggest that decant can be expected if the rate of recharge to the pits exceed 5% of

MAP, after rehabilitation. The decant position is governed by the topography around the pits.


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Decant will start at the lowest elevation at each pit, as indicated on Figure 18. One decant position

is indicated for Pit 1, which is situated on the south-western highwall. The elevation of the decant

point is 873 m amsl. If water levels inside the pits rise to above this elevation, decant will take place.

Two possible decant locations were identified for Pit 2, on the north-western highwall. The decant

elevation is 874 m amsl for this pit.

If the rate of recharge to the pits cannot be kept below 5% of MAP post rehabilitation, decant will

commence 18 to 35 years after closure from the pits, as indicated on Figure 18. The volume of

decant is estimated to be between 40 and 150 m3/d at Pit 1 and 30 and 120 m3/d at Pit 2.

The model was run for a period of 100 years after mining ceases. During this period, groundwater

levels will recover for the first 20 to 30 years. Thereafter, the plume is expected to migrate in a

westerly direction. During this period, the contamination is not expected to migrate more than 900

m from the mining area. This is due to the low transmissivities of the Ecca sediments.

The potential for local groundwater resources to supply the amount of water required by the

proposed mine is low. Local aquifers could potentially supply domestic requirements. It seems

likely, therefore, that for the Project demand to be sustained, water will have to be imported from

outside the immediate area. The MCWAP 2A project will likely provide 75 to 100 million m3/annum

to the Lephalale and Steenbokpan areas by laying a new pipeline from the Crocodile River. LCM has

registered to receive water from the MCWAP-2A scheme and will most likely supply most of the

operational demands.

12 Recommendations

Based on the information available, it seems unlikely that the mine will be able to operate on local

groundwater resources. Further groundwater investigation in the area is required to identify

sustainable local water resources outside the pit dewatering impact zone to potentially supply

domestic and dust suppression requirements. It is likely that water will need to be imported to

operate the mine. The only viable potential source is MCWAP-2A. It is understood LCM have

already expressed a commitment to obtaining water from the MCWAP-2A. The best available

technology and management practices will be required to minimise water losses and maximise

water recovery.

The weathered granite could be a potential target for water supply. Infill drilling is recommended to

assess the occurrence and depth of the granite underlying the proposed plant, infrastructure and IPP

plant areas. Monitoring boreholes across the dip along the western contact of the granite are

recommended to monitor possible pollutant movement along this boundary.

Most of the boreholes tested indicate a low water yield, plus slow recovery. It is recommended to

conduct at least 48-hour constant discharge tests on boreholes earmarked for future production

purposes. Monitoring boreholes are also required around each production borehole to ensure an

accurate assessment of the long-term use and the borehole’s recharge characteristics.

It is recommended that all identified boreholes, actively used for domestic and agricultural purposes

be sampled before the construction phase to update the baseline assessment and build a water

quality database for the area. The database will help the client identify water quality and level


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trends in the area, and will serve as reference to identify and quantify potential impacts on private

boreholes.

Based on the outcome of model simulations it is recommended that additional monitoring boreholes

are drilled at the operations. The proposed groundwater monitoring programme is detailed in Table

28. The new boreholes should be positioned with geophysical surveying methods. Aquifer testing

must be completed on each borehole to establish the aquifer conditions. This information must be

used to update the existing groundwater model.

It is recommended to have all future monitoring and production boreholes, as well as private

boreholes surveyed with a differential GPS system to ensure accurate reporting of the groundwater

levels. Hand-held GPS systems have a coordinate accuracy of approximately 5 m whereas the

differential GPS systems record the coordinates, and more importantly the elevation with accuracy

better than five centimetres.

Although the leachate from the static tests is relatively clean, a long-term acid producing potential

and oxidation can lead to an increase in leachable elements. It is recommended that the coal and

waste material be submitted for long term kinetic tests, as well as SPLP tests with an acidic solution

of pH 4 or 5.

Geochemistry sampling was limited to five core drill holes. It is recommended that additional

samples be taken across the project area, focussing on the proposed pit areas to provide a more

complete understanding of the acid generating potential for the area.

The numerical model should be updated and verified with additional monitoring information, as it

becomes available. The uncertainties listed in the modelling section can be reduced or eliminated

through implementing an on-going groundwater monitoring programme in the area. This

information can be used to improve aquifer parameter estimation and model calibration. On-site

rainfall measurements must also be taken to ensure that the results of the monitoring programme

can be interpreted with certainty.

Actions listed in Section 9.1 also apply.


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13 References

• Department of Water Affairs and Forestry, 1996. South African Water Quality Guidelines

(second edition). Volume 1: Domestic Use.

• Department Water Affairs, March 2012. Classification of Significant Water Resources in the

Mokolo and Matlabas Catchment: Limpopo Water Management Area (WMA) and Crocodile

(West) and Marico WMA: WP 10506. Information Analysis Report: Mokolo and Matlabas

Catchments: Limpopo WMA Final Report No. RDM/WMA1,3/00/CON/CLA/0112B.

Directorate: Water Resource Classification.

• Department of Water and Environmental Affairs & Water Research Commission, First Edition

2000: Quality of Domestic Water Supplies: Volume 2: Sampling Guide.

• Department Water Affairs and Forestry, July 2003. Limpopo Water Management Area.

Water resources Situation Analysis Report. Main Report.

• Department of Water and Sanitation, BPG G4, 2008. Best Practice Guideline G4: Impact

Prediction, Best Practice Guidelines for Water Resource Protection in the South African

Mining Industry.

• Digby Wells Environmental, February 2014. Fatal Flaw and Screening Assessment - Lephalale

Coal Project.

• Digby Wells Environmental, January 2015. Dedi Coal Water Supply Option Analysis. Phase 1

Assessment Report.

• Digby Wells Environmental, September 2016. Exxaro Coal (Pty) Ltd Grootegeluk Short-Term

Stockpiles Amendment Project – Phase 2 Stockpile Expansion.

• Faure, K., Willis, J.P. & Dreyer, J.C., 1996. The Grootegeluk Formation in the Waterberg

Coalfield, South Africa: facies, paleo-environment and thermal history - evidence from

organic and clastic matter. International Journal of Coal Geology, 29, pp.147–186.

• Fetter C.W., 1993. Applied Hydrogeology. 3rd Edition, MacMillan.

• Gorchev, H.G. & Ozolins, G., 2008. WHO guidelines for drinking-water quality. WHO

chronicle, 38(3), pp.104–8.

• Government Gazette, Notice 615 of 2012. Department of Environmental. Affairs National

Environmental Management: Waste Act, 2008 (ACT No. 59 of 2008). Standard for Disposal

of Waste to Landfill.

• Government Gazette, GNR 634 (23 August 2013): Waste Classification and Management

Regulations.

• Government Gazette, GNR 635 (23 August 2013): National Norms and Standards for the

assessment of Waste for Landfill Disposal.

• Government Gazette, GNR 636 (23 August 2013): National Norms and Standards for Disposal

of Waste to Landfill.

• HASKONINGDHV UK LTD, 16 September 2016. Pre-Feasibility Study for Lephalale Coal &

Power Project. I&BPB4509R001D01.

• Klein, C. & Dutrow, B., 2007. Manual of Mineral Science 23rd ed., John Wiley & Sons, Inc.

• Parsons RP, 1995. A South African aquifer management classification. WRC Report KV

77/95. Water Research Commission, Pretoria.

• SABS, 2015. South African National Standards SANS 241-1:2015. SA Drinking Water

Standards.


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• VSA Leboa Consulting, January 2010. Hydrogeological Assessment and Aquifer Recharge

Potential within the Lephalale (Ellisras) Local Municipality Area. Report Nr: PWMA

01/A42/00/02209_01. Directorate: Water Resource Planning Systems (WRPS). Final Report.


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APPENDIX A

Project Maps


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APPENDIX B

Groundwater Team CVs


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APPENDIX C

National Groundwater Archive data


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APPENDIX D

2017 Hydrocensus data


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APPENDIX E

Water Laboratory Certificates


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APPENDIX F

Geological Profiles – Drilling Programme


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APPENDIX G

Geochem Laboratory Certificates


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APPENDIX H

IAP Comments and Response

Documents

Appendix E3: Geohydrology · Lephalale Coal & Power Project – Groundwater Assessment PAGE 4 Disclosure of Vested Interest • I do not have and will not have any vested interest