Jones & Wagener - jaws.co.za DEIR... · Jones & Wagener Engineering & Environmental Consultants ......

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Jones & WagenerEngineering & Environmental Consultants59 Bevan Road PO Box 1434 R ivonia 2128 South Africa

tel : 00 27 11 519 0200 www.jaws.co.za email: [email protected]

SOUTH32 SA COAL HOLDINGS SOUTH AFRICA (PTY) LIMITED

SPECIALIST SURFACE WATER REPORT FOR SOUTH32 CSA WOLVEKRANS COLLIERY NORTH:

LIFE OF ASSET EXPANSION AND DISPATCH RIDER PROJECT

Report No.: JW119/15/E812 - Rev 0

July 2016

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DOCUMENT APPROVAL RECORD

Report No.: JW119/15/E812 - Rev 0

ACTION FUNCTION NAME DATE SIGNATURE

Prepared Engineer C Williamson 08-06-2015

Prepared Engineer M Veeragaloo 12-08-2015

Reviewed Environmental Scientist

T Hopkins 11-07-2016

Approved Engineer M Palmer 29-07-2016

RECORD OF REVISIONS AND ISSUES REGISTER

Date Revision Description Issued to Issue Format No. Copies

08-06-2015 A -D Internal Review

M Palmer

T Hopkins

Word.doc 1

29-07-2016 E Client Review South32 Word.doc 1

05-10-2016 0 Final T Hopkins Word.doc 1

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SPECIALIST DECLARATION

I, Malini Veeragaloo, hereby declare that:

� I act as the independent specialist 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 the specialist report relevant to this application, 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 not, 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.

� All the particulars furnished by me in this form are true and correct.

� I realise that a false declaration is an offence in terms of regulation 48 and is punishable in terms of section 24F of the Act.

A signed specialist declaration is attached in Appendix C. A detailed CV of the author is included in Appendix D.

EXECUTIVE SUMMARY

South 32 Coal Holdings South Africa (Pty) Limited (South32 CSA) is proposing to extend the existing approved opencast mining operations boundaries at its Wolvekrans Colliery North Section, for the Hartbeesfontein and Goedehoop Sections. In addition, South32 CSA proposes to mine the No. 1, No. 2 and No. 4 seams using underground mining techniques at the proposed Dispatch Rider section, which is located in the south of the Hartbeesfontein opencast section. The underground section will be accessed through the existing Driefontein previously opencast mined out area.

There are a number of key components associated with the proposed project, these include:

• Extension of the approved opencast coal mining pit boundaries within the Hartbeesfontein and Goedehoop Sections (Life of Asset (LoA) mining expansion).

• Underground mining in the south of the Hartbeesfontein Section (called the Dispatch Rider project) which entails the following: o Change the mining method of the existing EMP approved opencast area (pit DW)

to underground mining, o Undermine the adjacent property to the east (the Dispatch Rider Prospecting Area

is located to the east of the existing approved mining rights area. South32 CSA has submitted an application to renew the prospecting rights on the farm), and

o Development of infrastructure in support of Dispatch Rider.

Jones & Wagener (Pty) Ltd (J&W) were appointed by South32 CSA to carry out the specialist surface water assessment for South32 CSA’s LoA extension and Dispatch Rider Project for Wolvekrans Colliery North section, as input into the application for environmental authorisation.

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The R35 provincial road passes through Wolvekrans Colliery, while the N4 national road lies to the north of the Goedehoop section’s northern boundary. The town of Middelburg lies approximately 20 km to the north of the mine.

The proposed project is located within the existing Wolvekrans Colliery mining rights boundary, with the exception of a portion of the area to be mined to the east of the Hartbeesfontein Section, as part of the Dispatch Rider underground mining operation.

Proposed opencast mining operations are planned on the Hartbeesfontein and Goedehoop Sections of Wolvekrans Colliery, while underground mining is planned at Dispatch Rider, in the south of the Hartbeesfontein Section.

Study Approach

This surface water study entails a review characterising the surface water regime at the site and the catchment in which it resides, in terms of surface water quality and quantity.

A site wide mine water balance model for the overall Wolvekrans Colliery North Section was developed to determine the quantity of water that will need to be managed over the life of mine (LOM). The water balance was used to assess the size of the existing PCDs, so as to comply with GN R704 and to ensure a risk of spill of less than 2% for any given year.

Thereafter an assessment of the impacts of the project on surface water, in terms of both quality and quantity, was conducted, as well as an assessment of the mitigation of the impacts.

Project Description

In 2002 the then Middelburg Mine’s coal reserves were estimated at 297 million tons (Jones and Wagener, 2002). Currently, opencast mining is undertaken at Wolvekans Colliery North Section, with a production rate of approximately 7 million tons run of mine (ROM) per year at Middelburg Colliery (AGES, 2013). The mine supplies coal to the Duvha Power Station, as well as the export market.

The opencast mining method that is currently employed is opencast strip mining. This involves the removal of topsoil, overburden drilling and blasting, overburden removal coal drilling and blasting and coal removal. Once the coal has been removed spoils are levelled and the topsoil is replaced and the area re-vegetated

South32 CSA is currently applying for environmental authorisation for changes to the mine plan, as well as for additional proposed activities. Wolvekrans Colliery North Section consists of the Hartbeesfontein, Goedehoop, as well as Bankfontein Sections. Mining at Bankfontein has, however, ceased.

South32 CSA proposes to mine the coal remnants at the Hartbeesfontein and Goedehoop Sections using opencast mining, as well as to mine the No. 1, No. 2 and No. 4 coal seam using underground mining in the south of the Hartbeesfontein Section, known as Dispatch Rider. This is expected to extend the life of mine (LOM) to 2039.

No shafts will be sunk for the Dispatch Rider project. The adjacent highwall of the old Driefontein opencast pit will be used to gain access to the underground.

Mining is to commence with No. 2 seam, followed by No. 4 seam and lastly No. 1 seam coal.

Infrastructure

The following existing infrastructure can be found within the study area:

• The Spookspruit and Niekerkspruit river diversions. • Haul roads, service and access roads. • Six Eskom power lines and associated infrastructure (i.e. substations).

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• The Duvha-Hendrina water pipeline, as well as various other pipelines across the site. • Overland conveyor from the North Plant to the rapid load-out silo, as well as conveyor

from Klipfontein to the North Plant. • Workshops, offices and stores.

• Wash bays. • Filling station. • Diesel and oil storage tanks.

• Sewage Treatment Plant. • Potable water treatment plant. • Two middlings dumps. • Slurry dam.

• PCDs and associated water management infrastructure (e.g. canals). • Pits and ramps and associated mining infrastructure. • Coal washing and middlings plant.

The following infrastructure is proposed for Wolvekrans Colliery North Section:

• Additional and extended opencast pits.

• Likely overburden and topsoil stockpiles at GP Pit (not part of this application) • Silt traps. • Dirty water drains and sumps.

• Clean water diversion canals. • Access roads and haul roads.

The infrastructure required in support of the Dispatch Rider section will include the following:

• Adit with two incline conveyors. • Conveyor between coal stockpiles. • Ventilation.

• Three coal stockpiles. • Two sumps for the collection of contaminated runoff. • “Jo-Jo” water tanks for potable water.

• “Jo-Jo” tanks to store washbay water. • 6 Ml steel tank for the storage of raw water, filtration unit and treated water tanks (two

3 Ml tanks). • 33 kV power line (diverted from existing power line). • Break test ramp. • Refuelling area. • Control room. • Underground Machine Parking Platform.

• Heavy machine loading and storage area Platform. • Light masts (50m). • Washbay. • Security fence and access control. • Pipelines. • Haul roads and LDV access roads. • Conservancy tanks. • Communication tower. • Transformer bay slab. • LDV and public parking areas.

• Refuge bays (position to be confirmed but should be placed within the dirty footprint). • Stone dust silos (position to be confirmed but should be placed within the dirty

footprint).

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Water Supply

Two types of water are required on the site, namely potable water and process water. Maximising the reuse of dirty water on the site is part of the water management philosophy at Wolvekrans Colliery. Thus, all process water is, and will continue to be drawn from the pollution control dams and voids.

Raw water supply to the mine is from the Duvha-Hendrina pipeline, which is sourced from the Komati-Usutu Government Water Scheme. Part of the mine’s bulk water supply is received through the Usutu-Vaal Government Water Scheme via the Olifants River (AGES, 2013).

Mine impacted water is treated at the Middelburg Water Reclamation Plant (MWRP) to suitable quality for discharge into the Niekerkspruit, or is re-mineralised before being pumped to Wolvekrans Colliery for potable water use.

Waste Management

Mine residue was historically disposed of at above ground slurry dams and discard dumps. However, once the capacity of these above ground facilities was used up, the mine received permission from the then Department of Minerals and Energy (DME), now the Department of Mineral Resources (DMR), to place the discard within the ramps, associated with the opencast workings, as backfill.

Currently, course discard is still disposed of in this way. This method of disposal is both cost effective, with respect to managing the residue, as well as simultaneously providing an effective means of backfilling and closing up the old final voids. This practice is expected to continue for the remainder of the life of the plant at the North Section.

Two middlings dumps exist on the site. These were constructed next to the plant area before deposition within the ramps. Approximately 25 million tons of discard was placed in these dumps. These dumps are now closed. However, the possibility of reclamation of the dumps has not been excluded.

Historically, thickener underflow material was pumped to two storage dams that were constructed within the old workings of the pit at North Section. However, once the capacity of the dams was reached, a new slurry disposal facility was constructed. This facility is located approximately 700 m west-south-west of the North Plant. Water is returned from the facilities, via penstocks, to Dam 3. The facility consists of three compartments, which are used sequentially. In 2013, it was estimated that the current facility had a remaining life of 12 years AGES (2013).

Storm water management

In terms of the proposed water management, the water make from Goedehoop North and Hartbeesfontein opencast will be pumped either to the existing Goedehoop PCD or Dam 5 PCD, whereas water make from Goedehoop South pits will be pumped to the Klipfontein pipeline to the MWRP. Water make from Dispatch Rider UG will be pumped to H3/ H4 void before being pumped to Dam 5 PCD.

The surplus water make will be pumped to the MWRP and treated for discharge. Post closure, the opencast pit will be allowed to fill to an environmentally safe level below decant elevation. The water level will be monitored and maintained at or below the environmentally safe level by pumping to the MWRP.

The current and proposed storm water management is detailed in Section 4.5.2 of this report.

Clean storm water will be diverted around dirty areas to minimise the generation of dirty water. Dirty storm water will be contained in an in-pit sump from where it will be pumped to either Goedehoop Dam or Dam 5 PCD for re-use or to be treated at the approved MWRP, before being released further downstream. The storm water management systems will be designed to

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accommodate at least the 1:50 year event without spilling, in line with current South African legislation.

Water balance

A site wide mine water balance model was developed to determine the quantity of water that will need to be managed at the Wolwekrans Colliery North Section over the life of mine (LOM).

Important assumptions, limitations and information used are indicated in Section 5.2.

Water Make

The total mine water make is expected to increase from a current water make of 15 000 m3/day to a maximum of 52 000 m3/day for average rainfall, with an average water make over the life of mine (i.e. 2015-2039) of 29 200 m3/day.

The post closure water make over the life of mine (2015-2039) is estimated to be 29 300 m3/day.

The mine water make for each opencast pit and underground area is tabulated in Table 5.4.1(a) below.

The combined water make is shown in Figure 5.4.1(a). This figure presents the total mining water make over the life of the mine, showing the predicted seasonal variation in water make.

Water Balance Flow diagrams

The schematic water balance diagram is presented in Figures 5.4.4(a) and (b) for the average water flows over the LOM.

Figure 5.4.1(a): Graphical presentation of average daily water make during the operational phase of mining showing the expected seasonal variation in water make

0

10000

20000

30000

40000

50000

60000

70000

80000

Av

era

ge

da

ily v

olu

me

(m

3/d

ay)

Year analysed

Middelburg North water balance for surface water study - Rainfall used: Average

Summer Period

Winter Period

Annual Average

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Water management and storage requirements

Goedehooop Dam and Dam 5 PCD are the main PCDs for the Wolvekrans Colliery North Section and all surplus dirty water generated at the mine is pumped to these dams.

In order to not infinitely accumulate water, it is necessary that the average inflow into the mine is balanced with the mine water usage or treatment. In the event that the inflows exceed the usage or outflow from the mine it is necessary to store the surplus water that is not used. Therefore, in order to limit the dirty water storage requirements to a reasonable volume the average outflows need to equal the average inflows. If the average inflows are not matched by the average outflows, water will simply accumulate over time and an infinite storage volume will be required.

Due to the size of Goedehoop Dam, it is expected that the dam has sufficient capacity to handle surplus water for average rainfall conditions, while pumping at the prescribed rate of 12Ml/day to the MWRP for treatment. However, at Dam 5 PCD, under average rainfall conditions, the amount of surplus water needed to be sent to the MWRP far exceeds the 7.5Ml/day allowed. It is expected that, under average rainfall conditions, a peak pumping rate of 25.5Ml/day and an average pumping of 17Ml/day is required from Dam 5 PCD to the MWRP in order to ensure a 2% or lower risk of spill in any one year. This implies that the MWRP treatment capacity would have to increase.

Table 5.4.5(a) below shows, the expected volume of water that will need to be pumped to the MWRP to prevent spillage of dirty water from Goedehoop Dam and Dam 5 PCD under average rainfall conditions.

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Table 5.4.1(a): Expected mine water make for average rainfall

Mining section

Average water make over LOM of the pits

and Underground areas

(m3/day)

Maximum annual water make

(m3/day)

Post closure water make

(m3/day)

Opencast:

GP 731* 956* 537*

GN 9419* 13975* 4349*

GWAB 260* 398* 232*

GW 4339* 8350* 1832*

GO 88* 129* 78*

GZ 148* 254* 200*

GD 700* 745* 533*

HN 16631* 29879* 10483*

Goedehoop North old workings

1525* 1699* 673*

Goedehoop South old workings

3439* 3459* 2987*

Hatbeesfontein old workings

10923* 11029* 7710*

Bankfontein old workings 644* 648* 648*

Underground:

Dispatch Rider 99* 190* 190*

*Note that the averages given in the table above will differ from the flow diagram as the above numbers are averages over the LOM of each individual pit and underground area. (i.e. it is the average over the Life of Pit or underground). The flow diagram will contain the averages over the entire LOM (i.e. 2015-2039)

Table 5.4.5(a) Pumping rate required over the LOM, under average rainfall conditions

Dam

Peak pumping rate to MWRP for treatment under average rainfall

(over the LOM)

(m3/day)

Average pumping rate to MWRP for treatment under average rainfall

(over the LOM)

(m3/day)

Goedehoop Dam 12 000 6 000

Dam 5 PCD 25 500 17 000

Extreme Rainfall Conditions

Based on the water balance modelling, it was found that, under extreme rainfall conditions, a pumping rate of 25.5 Ml/day from Dam 5 PCD to the MWRP was insufficient to ensure a risk of spill of 2% or lower in any one year. Therefore, it is expected that an additional buffer storage capacity of 18 million m3 coupled with an additional water use of 3 000 m3/day is required to ensure a 2% or lower risk of spill in any one year.

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At Goedehoop Dam, under extreme rainfall conditions, water pumped will need to be re-directed to an alternative storage area of 3 million m3 to ensure a 2% or lower risk of spill in any one year at Goedehoop Dam.

The entire daily rainfall record was run over the LOM in order to evaluate the maximum amount of water that would need to be pumped to the MWRP over a year, as well as the maximum pumped to the MWRP on any given day for treatment from Goedehoop Dam and Dam 5 PCD in order to ensure a 2% or lower risk of spill.

The required maximum volume of water that will need to be pumped for treatment over a year, as well as for a given day, for extreme events ensuring a 2% risk of spill is detailed in Table 5.4.5(b) below.

Table 5.4.5(b) Pumping rate required over the LOM to MWRP

From

Max amount of water to be pumped to

MWRP for treatment over a year

(Ml/year)

Max amount of water to be pumped to MWRP for treatment over a day

(m3/day)

GN704 compliance

Goedehoop Dam, Dam 5

PCD and Goedehoop

South pits via Klipfontein line

18400 Ml/yr 96700 m3/day 2% risk of Spill

Conclusion

The water balance modelling indicates the following:

• The Goedehoop Dam will cater for both surface runoff reporting to the dam, as well as pit water, with surplus water being pumped to MWRP for treatment, with a risk of spill less than 2%, for average rainfall.

• Under extreme rainfall conditions, water pumped to Goedehoop Dam will need to be re-directed to an alternative storage area of 3 million m3 to ensure a 2% or lower risk of spill in any one year at Goedehoop Dam.

• Dam 5 PCD will require an increased pumping rate of 25.5 Ml/day to the MWRP under average rainfall and under extreme rainfall water will need to be re-directed to an alternate buffer storage area of 18 million m3 coupled with a water use of 3 000 m3/day for extreme rainfall in order to ensure a 2% or lower risk of spill in any one year at Dam 5 PCD.

• Increased pumping from Goedehoop Dam and Dam 5 PCD to the MWRP would require an increased treatment rate and therefore capacity at the MWRP.

• It is recommended that the old workings adjacent to the new pits be dewatered prior to the mining of the new pits in order to provide buffer capacity for the summer months and extreme events, as well as reduce the expected steady state seep volume reporting to the new pits from the old pits. In addition to this, further potential optimisation of the buffer storage can be achieved if the potential water storage capacities of all the pits are known, thereby potentially allowing for the temporary storage of water in these pits during wet periods, with subsequent reduced pumping to Dam 5 PCD. The potential storage capacities of the pits, at a safe level below decant, will need to be determined and the water balance reassessed based on the storage capabilities of the pits.

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• During the decommissioning phase, all pits will be backfilled without a final void, rehabilitated and made free-draining. The water level in the workings should be actively managed to ensure they remain below the decant elevation.

• The post closure mine water make will be pumped from the mine workings to the Goedehoop Dam and Dam 5 PCD and from there to the MWRP for treatment.

• The assumptions upon which this water balance is based require careful verification, particularly with regard to the groundwater make on site.

• The water balance will need to be refined as the mine design develops and the results presented here should be viewed as preliminary, for input to the mine design process.

Impact assessment

The major concerns with regard to the Wolvekrans Colliery North project’s surface water impacts revolve around the effective separation of clean and dirty water, effective isolation of the pits, adequate sizing of the dirty water pumping, diversion and containment facilities and effective use of dirty water so that the impact on the clean catchment remains minimal. The impact assessment is detailed in Section 8 and is indicated in Table 8.4 of this document.

With majority of the operations being opencast mining, the potential impact on the surface water quality and quantity is significant. The project also has the potential to contribute significantly to the cumulative impacts in the catchment, as it is situated amongst a number of other mining activities.

The Wolvekrans Colliery North and South form a large portion of surface disturbance in relation to the other activities in the area that could potentially impact on surface water. The Wolvekrans Colliery North extension area is small in relation to the existing Wolvekrans Colliery North and South mining area, however it adds to the surface disturbance of Wolvekrans Colliery as a whole with a moderate to high impact on Pans in the area.

There are other existing coal mining operations in the region, namely Black Wattle Colliery to the north, as well as Mavela Colliery and Muhanga Mine on the banks of the Spookspruit downstream of the MWRP, but these are small in relation to Wolwekrans Colliery.

Therefore, there are numerous coal mines in the Olifants River catchment, both upstream and downstream of the mine, as well as surrounding agricultural activities, power stations and industrial areas that also potentially impact on the water quality and quantity in the catchment. Wolvekrans Colliery does form a large portion of this area.

The cumulative impact of the Wolvekrans Colliery North mining operation extension, with the mitigation measures described in the impact assessment, is considered to be medium to high in relation to the current and anticipated future activities in the area, as the catchment is already impacted by mining activities. The cumulative impact of all of the coal mines in the area has resulted in a regional crisis in terms of water quality and quantity. Every new mine contributes to the further reduction and / or deterioration of the water resources in the Mpumalanga region and it is essential that good water management be implemented at Wolvekrans Colliery North to prevent further contributions to the existing impacts in the catchment.

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SOUTH32 SA COAL HOLDINGS SOUTH AFRICA (PTY) LIMITED SPECIALIST SURFACE WATER REPORT FOR SOUTH32 CSA WOLVEKRANS COLLIERY NORTH: LIFE OF ASSET EXPANSION AND DISPATCH RIDER PROJECT REPORT NO: JW119/15/E812 - Rev 0 CONTENTS PAGE

1. INTRODUCTION 2

1.1 Background 2

1.2 Terms of reference 3

1.3 Study area 3

1.4 Approach and methodology 4

2. LEGISLATIVE ASPECTS 8

2.1 Regulatory requirements 8

2.2 Applicable legislation, policies and/or guidelines 8

3. DETAILS OF THE APPLICANT AND ENVIRONMENTAL ASSESSMENT PRACTITIONER 10

3.1 Details of the applicant 10

3.2 Details of the environmental consultant 10

3.3 Details of the surface water specialists 10

4. DESCRIPTION OF THE PROJECT 12

4.1 Project location 12

4.2 General description 12

4.3 Surface infrastructure 13

4.4 Solid waste – water management 18

4.5 Liquid waste – water management 19

4.6 Watercourse alterations 26

5. WATER BALANCE 28

5.1 Computational methodology 28

5.2 Assumptions, information used and limitations 28

5.3 Rainfall data 31

5.4 Water balance modelling 32

5.5 Post closure water balance 43

5.6 Conclusion 44

6. BASELINE ENVIRONMENTAL DESCRIPTION 46

6.1 Regional climate 46

6.2 Catchment description 46

6.3 Rainfall and evaporation 48

6.4 Surface water quantity 53

6.5 Surface water quality 59

6.6 Surface water users 86

7. CONSIDERATION OF ALTERNATIVES 88

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7.1 Clean water management 88

7.2 Minimising the generation of dirty water make 88

7.3 Maximising the reuse of dirty water 88

7.4 Implementing treatment where required 88

7.5 Alternatives in terms of process development 88

7.6 Infrastructure alternatives at Dispatch Rider 88

8. ENVIRONMENTAL IMPACT ASSESSMENT AND MITIGATION MEASURES 90

8.1 Introduction 90

8.2 Impact assessment methodology and rating system 90

8.3 Activities to be undertaken at Wolvekrans Colliery North that could potentially affect surface water 90

8.4 Surface water impact assessment and mitigation measures 93

8.5 Cumulative impacts 94

9. FINANCIAL PROVISION 116

10. SUMMARISED WATER MANAGEMENT PLAN 117

10.1 Construction Phase 117

10.2 Operational Phase 118

10.3 Decommissioning 120

10.4 Post Closure 121

11. MONITORING AND AUDITING 122

11.1 Water quality monitoring 122

11.2 Water quantity monitoring (water balance monitoring) 124

11.3 Data management and reporting 126

11.4 Performance assessment/ audit 127

12. EMERGENCY AND REMEDIATION PROCEDURE 128

13. CONCLUSION 129

14. REFERENCES 131

APPENDICES

Appendix A

WATER QUALITY RESULTS

Appendix B

IMPACT ASSESSMENT RATING CRITERIA

APPENDIX C


APPENDIX D

CV’S

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List of Tables Table 5.4.1(a): Expected mine water make for average rainfall .......................... viii Table 3.1(a): Applicant details. ......................................................................... 10

Table 3.2(a): Environmental consultant details. ................................................ 10

Table 3.3(a): Specialist consultant contact details ............................................ 10

Table 3.3(b): J&W team members and relevant experience ............................. 11

Table 4.1(a): Towns surrounding Middelburg North Mine ................................. 12

Table 4.2(a): Anticipated LOM for Middelburg Colliery LoA expansion and Dispatch Rider project ................................................................. 13

Table 4.5.5(a): Existing dirty water storage facilities ............................................ 25

Table 5.4(a): Anticipated LOM for Middelburg Colliery LoA expansion and Dispatch Rider project ................................................................. 33

Table 5.4.1(a): Expected mine water make for average rainfall ........................... 36

Table 5.4.2(a): Water use at Middelburg North .................................................... 37

Table 6.1(a) Long-term minimum, maximum and mean temperature for eMalahleni for the period 2008 – 2010 (Synergistics, 2012). ....... 46

Table 6.3.1(a): Key data for selected rainfall stations (ICFR database) ............... 49

Table 6.3.1(b): Average monthly rainfall depth for the Vandyksdrift rainfall record (0478546_W) and evaporation depths (from WR90) .................... 51

Table 6.3.3(a): Statistical rainfall extremes for Vandyksdrift rainfall station (from WRC K5/1060) ............................................................................ 52

Table 6.4.1(a): Mean Annual Runoff (MAR) for catchment areas at Wolvekrans Colliery North section .................................................................. 54

Table 6.4.2(a): Computed dry weather flows of the affected rivers at MMS North 54

Table 6.4.3(a): Peak flows (m3/s) for various recurrence intervals ( from 2002 EMPR) ......................................................................................... 56

Table 6.4.3(b): Peak flows (m3/s) for various recurrence intervals ....................... 56

Table 6.5.1(a) List of surface water monitoring locations .................................... 59

Table 11.1.1(a): Details of surface water quality monitoring locations .................. 122

Table 11.1.2(b): Proposed Surface water quality sampling and analysis ............. 123

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List of Figures Figure 5.4.1(a): Graphical presentation of average daily water make during the

operational phase of mining showing the expected seasonal variation in water make ................................................................. vi

Figure 1.1(a): Regional Locality Plan ................................................................... 5

Figure 1.3(a): Study area ..................................................................................... 6

Figure 1.3(b): LoA Plan Layout ............................................................................ 7

Figure 4.3.1(a): Existing surface infrastructure...................................................... 16

Figure 4.3.1(b): Proposed surface infrastructure at Dispatch Rider ....................... 17

Figure 4.5.2(a): Schematic storm water management at the LoA areas ................ 21

Figure 4.5.2(b): Schematic storm water management at Dispatch Rider............... 22

Figure 5.4.1(a): Graphical presentation of average daily water make during the operational phase of mining showing the expected seasonal variation in water make ................................................................ 34

Figure 5.4.1(b): Individual opencast water make for opencast pits GP, Bankfontein, GWAB and GW ........................................................................... 34

Figure 5.4.1(c): Individual opencast water make for opencast pits GO, GZ, GD and HN ............................................................................................... 35

Figure 5.4.1(d): Individual opencast water make for historic opencast pits (Goedehoop North and South and Hartbeesfontein) and GN pit .. 35

Figure 5.4.1(e): Individual opencast water make for Dispatch Rider Underground 36

Figure 5.4.3(a): Schematic water balance diagram – average flows over Life of Mine (2015-2039) ................................................................................. 39

Figure 5.4.3(b): Schematic water balance diagram – average flows over Life of Mine (2015-2039 .................................................................................. 40

Figure 6.2.1(a): Location of site in relation to its catchment .................................. 47

Figure 6.3.1(a): Rainfall mass plot for the rainfall record ....................................... 50

Figure 6.3.1(b): Rainfall record for Vandyksdrift .................................................... 51

Figure 6.3.2(b): Mean monthly rainfall and evaporation for Vandyksdrift ............... 52

Figure 6.3.3(a): Top 100 one day ranked rainfall peaks ........................................ 53

Figure 6.4.1(a): Catchment boundaries and nodes ............................................... 55

Figure 6.5.1(a): Surface water monitoring locations .............................................. 63

Figure 6.5.2(a): Location of site in relation to the Catchment Management Units .. 64

Figure 11.1.1(a): Water quality monitoring locations ............................................. 125

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Abbreviations used

BEE Black Economic Empowerment

BEEH Bio-resources Engineering and Environmental Hydrology

BPG Best Practise Guidelines

DNWRP Directorate National Water Resource Planning

DM District Municipality

DMR Department of Mineral Resources

DRH Direct Run-off Hydrograph

DTM Digital Terrain Model

DWA Department of Water Affairs

DWAF Department of Water Affairs and Forestry

DWS Department of Water and Sanitation

DWF Dry Weather Flow

EC Electrical Conductivity

EIA Environmental Impact Assessment

EIR Environmental Impact Report

EMP Environmental Management Program

EMPR Environmental Management Program Report

ERA Environmental Risk Assessment

GA General Authorisation

GN Government Notice

GNR Government Notice Regulation

HCV High Calorific Value

HDPE High Density Polyethylene

ICFR Institute for Commercial Forestry Research

IWULA Integrated Water Use Licence Application

IWWMP Integrated Water and Waste Management Plan

J&W Jones & Wagener

MDEDET Mpumalanga Department of Economic Development, Environment and Tourism

LCV Low Calorific Value

LM Local Municipality

LoA Life of Asset

mamsl metres above mean sea level

MAP Mean Annual Precipitation

MAR Mean Annual Runoff

MR Minimum Requirements

MU Management Unit

xvi

MWRP Middelburg Water Reclamation Plant

NDA National Department of Agriculture

NEMA National Environmental Management Act

NEM:WA National Environmental Management: Waste Act

NWA National Water Act, 1998 (Act 36 of 1998)

PCD Pollution Control Dam

PP Public Participation

RDF Recommended Design Flood

RMF Regional Maximum Flood

ROM Run Of Mine

RWQO Receiving Water Quality Objectives

SANCOLD South African National Commission on Large Dams

SAWS South African Weather Service

SCS Soil Conservation Services

SDF Standard Design Flood

SEF Safety Evaluation Flood

South32 CSA South32 Coal Holdings South Africa

SS Suspended Solids

SWMP Storm Water Management Plan

TDS Total Dissolved Solids

WR05 Surface Water Resources of South Africa 2005

WR90 Surface Water Resources of South Africa 1990

WRC Water Resource Commission

WTP Water Treatment Plant

Jones & WagenerEngineering & Environmental Consultants59 Bevan Road PO Box 1434 R ivonia 2128 South Africa

tel : 00 27 11 519 0200 www.jaws.co.za email: [email protected]

SOUTH32 SA COAL HOLDINGS SOUTH AFRICA (PTY) LIMITED SPECIALIST SURFACE WATER REPORT FOR SOUTH32 CSA WOLVEKRANS COLLIERY NORTH: LIFE OF ASSET EXPANSION AND DISPATCH RIDER PROJECT REPORT NO: JW119/15/E812 - Rev 0

1. INTRODUCTION

1.1 Background

Wolvekrans Colliery is situated approximately 20 km south of Middelburg in the Mpumalanga Province. The Mining Complex is owned by South32 SA Coal Holdings (Pty) Ltd (CSA) formerly known as BHP Billiton Energy Coal South Africa (Pty) Limited, ("BECSA").

South32 CSA proposes to extend the existing approved opencast mining operations boundaries at its Wolvekrans Colliery North section, for the Hartbeesfontein and Goedehoop sections. In addition, South32 CSA proposes to mine the No. 1, No. 2 and No. 4 seam coal using underground mining techniques at the proposed Dispatch Rider section, which is located in the south of the Hartbeesfontein opencast section. The underground section will be accessed through the existing Driefontein previously opencast mined out area.

The location of Wolvekrans Colliery and the various mining sections that form part of this project are illustrated in the regional location map shown in Figure 1.1(a).

There are a number of key components associated with the proposed project, these include:

� The extension of the approved opencast coal mining pit boundaries within the Hartbeesfontein and Goedehoop sections (Life of Asset (LOA) mining expansion).

� Underground mining in the south of the Hartbeesfontein section (called the Dispatch Rider project), with associated infrastructure development. The underground mining section will extend to the east to the Dispatch Rider Prospecting Rights area.

Jones & Wagener (Pty) Ltd (J&W) were appointed to carry out the specialist surface water assessment for South32 CSA’s LoA extension and Dispatch Rider Project for Wolvekrans Colliery North section, as input into the application for environmental authorisation.

This report details the surface water specialist study for Wolvekrans Colliery North section’s Hartbeesfontein and Goedehoop Sections, with focus on the construction and operation of the proposed LoA extension and Dispatch Rider Project.

The purpose of the document is to assess the current surface water conditions on the site, to quantify the possible impacts of the proposed mining and related activities of the proposed project, and to develop mitigation measures for the site.

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Report JW119/15/E812 - Rev 0

E812_REP-01_rev0_mvmp2CEW_MMS_North_20161005_snopsis.docx Jones & Wagener (Pty) LtdEngineering & Environmental Consultants

1.2 Terms of reference

The terms of reference for the specialist surface water study are summarised below. Specific components to be addressed include the following:

1.2.1 Baseline assessment

The objective of the baseline study is to characterise the surface water regime at the site and the catchments in which it resides in terms of surface water quality and quantity. Information for the baseline assessment was abstracted from the consolidated EMP submitted in 2013 for the Wolvekrans Middelburg Complex.

In addition, as part of the baseline assessment, a floodline determination was conducted for the site, along the Vaalbankspruit and along the Spookspruit diversion. This included the floodline hydrology and the determination of the 1:50 and 1:100 year floodlines.

Please note that the surface water study does not include the delineation of sensitive areas such as pans and wetlands, or the assessment of aquatic ecology. Information regarding the aquatic ecology, pans and wetlands is included in separate specialist studies.

1.2.2 Site water management

This includes the compilation of a conceptual surface water management plan to mitigate the identified impacts, as well as the development of a surface water monitoring protocol. This includes the provision of information on the management of surface water around the planned activities, as well as the identification of pollution point sources.

The objective is to ensure compliance with legislation in terms of the management of both storm water and water affected by planned activities. The separation of clean and dirty water, with the diversion of clean water around dirty areas and the containment of dirty water on site, is necessary in order to achieve compliance.

1.2.3 Water balance for the mine

This includes the compilation of a site water balance and water flow diagrams for the mine, including the proposed mining areas and associated infrastructure.

The objective of the water balance is to quantify the water make over the life of the mine, during operations and post closure.

1.2.4 Impact assessment

This includes an assessment of the impact of the project and its components on surface water in the study area, in terms of both water quality and water quantity.

In addition, this includes the formulation of proposed mitigation measures for significant impacts, as well as monitoring required to measure the success of the mitigation measures, once implemented. The residual impact after implementation of the mitigation measures was also quantified.

1.3 Study area

The study area is indicated in Figure 1.3(a), with the Life of Mine (LOM) plan indicated in Figure 1.3(b). The R35 provincial road passes through Wolvekrans Colliery, while the N4 national road lies to the north of the Goedehoop section’s northern boundary. The town of Middelburg lies approximately 20 km to the north of the mine.

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The proposed project is located within the existing Wolvekrans Colliery mining rights boundary, with the exception of a portion of the area to be mined to the east of the Hartbeesfontein section, as part of the Dispatch Rider underground mining operation.

Proposed opencast mining operations are planned on the Hartbeesfontein and Goedehoop sections of Wolvekrans Colliery, while underground mining is planned at Dispatch Rider, in the south of the Hartbeesfontein section.

A full description of the hydrological setting of the site is given in Section 6.

1.4 Approach and methodology

The following actions were taken as part of the surface water specialist study for this project:

Information received from South32 CSA, was reviewed and relevant issues were noted.

� Rainfall data was obtained from the Institute for Commercial Forestry Research (ICFR) database and the South African Weather Service (SAWS) and processed for use in the hydrological calculations and water balance modelling.

� Topographical maps and satellite imagery (Google Earth) were reviewed to assess catchment conditions and to delineate the catchments within the study area.

� Peak flood flows at relevant locations within the study area were estimated for various recurrence intervals using a number of methodologies applicable to South African conditions.

� Water quality data received from South32 CSA was reviewed, collated and assessed.

� A site-specific water balance model was developed to:

� Estimate the site water surplus/deficit, water make over the life of mine and surplus water generation.

� To assess the storage and water treatment requirements and to provide input to the water management strategy for the mine.

� The site water management was assessed in terms of the current legislation and a preliminary storm water management plan was compiled.

� Sketches and a description of the pollution control strategies around the various point sources were compiled.

� The potential impacts associated with the proposed mining and related activities were assessed according to the methodology stipulated by the lead environmental consultant (J&W). Impacts were assessed for the construction, operational, decommissioning and post closure phases. Potential impacts were detailed, then mitigation measures described, with residual impacts then being assessed.

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Figure 1.1(a): Regional Locality Plan

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Figure 1.3(a): Study area

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Figure 1.3(b): LoA Plan Layout

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2. LEGISLATIVE ASPECTS

2.1 Regulatory requirements

A detailed legal assessment is discussed in the EMPR amendment compiled by J&W. The Acts and Regulations that pertain to the surface water for mining projects include:

� The Constitution of the Republic of South Africa (Act 108 of 1996).

� The Mineral and Petroleum Resources Development Act (Act 28 of 2002).

� The National Water Act, Act 36 of 1998 (hereafter referred to as NWA).

� The National Environmental Management Act, Act 107 of 1998 (hereafter referred to as NEMA).

� National Environmental Management: Waste Act, 2008 (Act 59 of 2008) (NEM:WA).

� Government Notice (GN) 704 of 4 June 1999: Regulation on use of water for mining and related activities aimed at the protection of water resources (hereafter referred to as GN704).

� Government Notice (GN) R139 of 24 February 2012: Regulations regarding the safety of dams in terms of Section 123(1) of the NWA.

� Government Notice (GN) R991 of 18 May 1984: Requirements for the purification of waste water or effluent.

� GN 399 dated 26 March 2004: General Authorisations in terms of Section 39 of the NWA: S21(a) and (b) water uses, as extended in GN 970 dated 30 November 2012: Extension of time period for General Authorisations in terms of Section 39 of the NWA: S21(a) and (b) water uses – until withdrawn by Notice in the Government Gazette.

� GN 1199 dated 18 December 2009: Replacement of General Authorisation in terms of Section 39 of the NWA: S21(c) and (i) water uses

� Government Notices (GN) R982 to 985 of December 2014: Listed activities in terms of NEMA.

� Government Notice (GN) R636 of August 2013: National norms and standards for disposal of waste to landfill, in terms of NEM: WA.

� The Minister of Water and Sanitation published, the classes and resource quality objective of water resources for the catchments of the Olifants River catchment in GN 466 on 22 April 2016. This is done in terms of S13(4) of the NWA. The purpose is to ensure ecological sustainability by taking into consideration the social and economic needs of competing interests of all who rely on the water resources.

2.2 Applicable legislation, policies and/or guidelines

The following DWAF Best Practice Guideline (BPG) documents are relevant to this project:

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series A: Best Practice Guideline A2: Water Management for Mine Residue Deposits, July 2008

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series A: Best Practice Guideline A4: Pollution Control Dams, August 2007

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� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series A: Best Practice Guideline A6: Water Management for Underground Mines, July 2008

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series G: Best Practice Guideline G1: Storm Water Management, August 2006

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series G: Best Practice Guideline G2: Water and Salt Balances, August 2006

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series G: Best Practice Guideline G3: Water Monitoring Systems, July 2007

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series G: Best Practice Guideline G4: Impact Prediction, December 2008

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series G: Best Practice Guideline G5: Water Management Aspects for Mine Closure, December 2008

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series H: Best Practice Guideline H1: Integrated Mine Water Management, December 2008

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series H: Best Practice Guideline H2: Pollution Prevention and Minimization of Impacts, July 2008

� Best Practice Guidelines for Water Resource Protection in the SA Mining Industry, Series H: Best Practice Guideline H3: Water Reuse and Reclamation, June 2006.

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3. DETAILS OF THE APPLICANT AND ENVIRONMENTAL ASSESSMENT PRACTITIONER

3.1 Details of the applicant

Table 3.1(a) below provides the details for the applicant responsible for the environmental applications for the proposed project.

Table 3.1(a): Applicant details.

Project applicant:

South32 SA Coal Holdings (Pty) Ltd

Trading name (if any):

South32 SA Coal Holdings (Pty) Ltd

Contact person: Mr Clinton Lee

Postal address: P.O Box 61820, Marshalltown, 2107

Email: [email protected] Tel: 013 643 3825 Fax:

3.2 Details of the environmental consultant

The details of the Environmental Assessment Practitioners responsible for the IWULA in respect of this project are provided in Table 3.2(a) below.

Table 3.2(a): Environmental consultant details.

Environmental consultant Jones & Wagener (Pty) Ltd

Contact person: Tolmay Hopkins

Postal address: PO Box 1434, Rivonia, 2128

Email: [email protected] Tel: 011 519 0200 Fax: 011 519 0201

3.3 Details of the surface water specialists

The details of the Surface Water Specialist responsible for the Specialist Surface Water Study in respect of this project are provided in Table 3.3(a) below. Details of the J&W project team members and their relevant experience are provided in Table 3.3(b).

Table 3.3(a): Specialist consultant contact details

Specialist consultant Jones & Wagener (Pty) Ltd

Contact person: Mr Michael Palmer

Postal address: PO Box 1434, Rivonia, 2128

Email: [email protected] Tel: 011 519 0200 Fax: 011 519 0201

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Table 3.3(b): J&W team members and relevant experience

Name Email address Experience Responsibility

Caroline Williamson [email protected] BSc (Eng) 4 years

experience Surface Water Specialist

Report

Malini Veeragaloo [email protected] BSc (Eng) 9 years

experience Water Balance and Surface

Water Specialist Report

Michael Palmer [email protected] Pr Eng, MSc Eng Civil

17years experience

Project Director

Review of: Surface Water Specialist Report

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4. DESCRIPTION OF THE PROJECT

The overall project is described in the main EIR. Aspects relevant to the surface water component are detailed in the sections that follow.

4.1 Project location

Wolvekrans Colliery North is situated approximately 20 km south of Middelburg, in the Mpumalanga province. It is situated within the Steve Tshwete Local Municipality, in the Nkangala District Municipality.

Table 4.1(a) documents the towns surrounding the North Section of the Wolvekrans Colliery, as per AGES (2013).

Table 4.1(a): Towns surrounding Middelburg North Mine

Town Approximate distance (km) Direction

eMalahleni (previously Witbank) 30 km North West

Middelburg 25 km North East

Van Dyks Drift 17 km South

Bethal 70 km South

Pullenshope 70 km South East

Hendrina 70 km South East

4.2 General description

In 2002 the then Middelburg Mine’s coal reserves were estimated at 297 million tons (Jones and Wagener, 2002). Currently, opencast mining is undertaken at Wolvekans Colliery North section, with a production rate of approximately 7 million tons run of mine (ROM) per year at Middelburg Colliery (AGES, 2013). The mine supplies coal to the Duvha Power Station, as well as the export market.

The opencast mining method that is currently employed is opencast strip mining. This involves the removal of topsoil, overburden drilling and blasting, overburden removal coal drilling and blasting and coal removal. Once the coal has been removed spoils are levelled and the topsoil is replaced and the area re-vegetated

South32 CSA is currently applying for environmental authorisation for changes to the mine plan, as well as for additional proposed activities. Wolvekrans Colliery North section consists of the Hartbeesfontein, Goedehoop, as well as Bankfontein Sections. Mining at Bankfontein has, however, ceased.

South32 CSA proposes to mine the coal remnants at the Hartbeesfontein and Goedehoop sections using opencast mining, as well as to mine the No. 1, No. 2 and No. 4 coal seam using underground mining in the south of the Hartbeesfontein section, known as Dispatch Rider. This is expected to extend the life of mine (LOM) to 2039.The main components of the proposed expansion project are:

� Extension of the approved opencast coal mining pit boundaries within the Hartbeesfontein and Goedehoop sections (Life of Asset (LoA) mining expansion).

� Underground mining in the south of the Hartbeesfontein section (called the Dispatch Rider project) which entails the following:

� Change the mining method of the existing EMP approved opencast area (pit DW) to underground mining,

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� Undermine the adjacent property to the east (the Dispatch Rider Prospecting Area is located to the east of the existing approved mining rights area. South32 CSA has submitted an application to renew the prospecting rights on the farm), and

� Development of infrastructure in support of Dispatch Rider.

No shafts will be sunk for the Dispatch Rider project. The adjacent highwall of the old Driefontein opencast pit will be used to gain access to the underground.

Mining is to commence with No. 2 seam, followed by No. 4 seam and lastly No. 1 seam coal.

The anticipated Life of Mine Plan (LOM) for the proposed LoA extension is detailed in Table 4.2(a).

Table 4.2(a): Anticipated LOM for Middelburg Colliery LoA expansion and Dispatch Rider project

Section Location Mining Method Life of reserve

(years)

GP New Mini Pit Opencast 2033-2039

GN Goedehoop North Opencast 2019-2022

GWAB

Goedehoop South

Opencast 2022-2023, 2026-2027

GO Opencast 2033-2037

GZ Opencast 2033-2039

GW Opencast 2033-2039

GD Opencast 2028-2030

HN

Hartbeesfontein

Opencast 2028-2034

Dispatch Rider

Bord and Pillar Underground

2015-2030

4.3 Surface infrastructure

The surface infrastructure that can be found at Wolvekrans Colliery North comprises roads, railway lines, powerlines, pipelines and conveyors, as well as water and waste management infrastructure, offices and workshops. This section briefly discusses the existing infrastructure that can be found, as well as the proposed surface infrastructure.

4.3.1 Mine plan and site layout

The existing infrastructure is shown in Figure 4.3.1(a), with the proposed infrastructure at Dispatch Rider, shown in Figures 4.3.1(b).

4.3.1.1. Existing infrastructure

The following existing infrastructure can be found within the study area:

� The Spookspruit and Niekerkspruit river diversions.

� Haul roads, service and access roads.

� Six Eskom power lines and associated infrastructure (i.e. substations).

� The Duvha-Hendrina water pipeline, as well as various other pipelines across the site.

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� Overland conveyor from the North Plant to the rapid load-out silo, as well as conveyor from Klipfontein to the North Plant.

� Workshops, offices and stores.

� Wash bays.

� Filling station.

� Diesel and oil storage tanks.

� Sewage Treatment Plant.

� Potable water treatment plant.

� Two middlings dumps.

� Slurry dam.

� PCDs and associated water management infrastructure (e.g. canals).

� Pits and ramps and associated mining infrastructure.

� Coal washing and middlings plant.

4.3.1.2. Proposed infrastructure

The following infrastructure is proposed for Wolvekrans Colliery North:

� Additional and extended opencast pits.

� Likely overburden and topsoil stockpiles at GP Pit (not part of this application)

� Silt traps.

� Dirty water drains and sumps.

� Clean water diversion canals.

� Access roads and haul roads.

� The infrastructure required in support of the Dispatch Rider section will include the following:

� Adit with two incline conveyors.

� Conveyor between coal stockpiles.

� Ventilation.

� Three coal stockpiles.

� Two sumps for the collection of contaminated runoff.

� “Jo-Jo” water tanks for potable water.

� “Jo-Jo” tanks to store washbay water.

� 6 Ml steel tank for the storage of raw water, filtration unit and treated water tanks (two 3 Ml tanks).

� 33 kV power line (diverted from existing power line);

� Break test ramp.

� Refuelling area.

� Control room.

� Underground Machine Parking Platform.

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� Heavy machine loading and storage area Platform.

� Light masts (50m).

� Washbay.

� Security fence and access control.

� Pipelines.

� Haul roads and LDV access roads.

� Conservancy tanks.

� Communication tower.

� Transformer bay slab.

� LDV and public parking areas.

� Refuge bays (position to be confirmed but should be placed within the dirty footprint).

� Stone dust silos (position to be confirmed but should be placed within the dirty footprint).

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Figure 4.3.1(a): Existing surface infrastructure

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Figure 4.3.1(b): Proposed surface infrastructure at Dispatch Rider

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4.3.2 Project schedule

Detailed in the main EIR.

4.3.3 Sources of Water

Two types of water are required on the site, namely potable water and process water. Maximising the reuse of dirty water on the site is part of the water management philosophy at Wolvekrans Colliery. Thus, all process water is, and will continue to be drawn from the pollution control dams and voids.

Raw water supply to the mine is from the Duvha-Hendrina pipeline, which is sourced from the Komati-Usutu Government Water Scheme. Part of the mine’s bulk water supply is received through the Usutu-Vaal Government Water Scheme via the Olifants River (AGES, 2013).

Mine impacted water is treated at the Middelburg Water Reclamation Plant (MWRP) to suitable quality for discharge into the Niekerkspruit, or is re-mineralised before being pumped to Wolvekrans Colliery for potable water use.

4.3.3.1. Potable water

Potable water for domestic use is sourced from the Usuthu Main Water Supply and supplied to the various workshops and offices around the mine. The water is treated in a potable water treatment plant with a design capacity of 2400 m3/day. The plant makes use of a flocculation process, including a clarifying cone and sand filter bed. After flocculation, water is pumped to a chlorine content tank and held there in order to achieve an acceptable water quality (AGES, 2013).

4.3.3.2. Process water

Process water is required as supply for mineral processing at the North Plant. This is estimated at 6 Ml/day and after expansion 8 Ml/day, as per the 2006 EMP. Historically, additional make-up water for the plant requirements was sourced from the Duvha-Hendrina pipeline but due to improvements at the plant, make-up water is generally not required and all water is sourced from the PCDs (i.e. mine affected water).

Water is also used for dust suppression around the mine, which is estimated as follows:

� 2 Ml/day is supplied from the Bankfontein void for roads.

� 0.5 Ml/day supplied from Goedehoop Dam for ramps.

� 0.5 Ml/day supplied from Goedehoop North voids for hauls roads.

� An amount of 4 Ml/day is also pumped from the G1 void to forced evaporators.

(Reference: Water balance discussion meeting held 10 July 2015, Document: E812-10_Min01_r0mv-Water BalDiscussion_20150710))

4.4 Solid waste – water management

Solid waste is generated at various locations across the mine, including, but not limited to, the offices, workshops and the North Plant. The sections that follow detail the various waste streams and the waste management at the mine, as it pertains to surface water management.

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4.4.1 Disposal of general waste

Wolvekrans Colliery disposes its general waste at the Middelburg municipal landfill site. This landfill site is licensed and after each disposal the mine receives a safe disposal certificate.

4.4.2 Disposal of hazardous waste

Wolvekrans Colliery contracts a registered waste company to remove and dispose of hazardous waste generated at the mine complex. The waste is taken to the Holfontein Hazardous waste site, a licensed facility, and safe disposal certificates are received for each waste disposal.

Medical waste is stored on site, at the Naledi Village Clinic, and thereafter removed by an external waste contractor employed by the mine.

4.4.3 Disposal of mine residue

Mine residue was, historically, disposed of at above ground slurry dams and discard dumps. However, once the capacity of these above ground facilities was used up, the mine received permission from the then Department of Minerals and Energy (DME), now the Department of Mineral Resources (DMR), to place the discard within the ramps, associated with the opencast workings, as backfill.

Currently, course discard is still disposed of in this way. This method of disposal is both cost effective, with respect to managing the residue, as well as simultaneously providing an effective means of backfilling and closing up the old final voids. This practice is expected to continue for the remainder of the life of the plant at the North Section.

Two middlings dumps exist on the site. These were constructed next to the plant area before deposition within the ramps. Approximately 25 million tons of discard was placed in these dumps. These dumps are now closed. However, the possibility of reclamation of the dumps has not been excluded.

Historically, thickener underflow material was pumped to two storage dams that were constructed within the old workings of the pit at North Section. However, once the capacity of the dams was reached, a new slurry disposal facility was constructed. This facility is located approximately 700 m west-south-west of the North Plant. Water is returned from the facilities, via penstocks, to Dam 3. The facility consists of three compartments, which are used sequentially. In 2013, it was estimated that the current facility had a remaining life of 12 years AGES (2013).

4.5 Liquid waste – water management

4.5.1 Domestic waste water management

Domestic waste water generated from the mine’s office complex, as well as from Naledi village, is treated by the sewage plant at Wolvekrans Colliery. The plant is a batch treatment plant, with a capacity of 24 million litres per month. Once the waste water has been treated it is discharged into Dam 2 for reuse at the plant (AGES, 2013).

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4.5.2 Storm water management

4.5.2.1. Background

An effective surface water management system will be essential to ensure efficient mining and to protect the natural water resource during the construction, operation and post closure phases of the mine. This will entail management of dirty water generated through the mining process (including the mine water make and run-off from mine infrastructure areas), as well as handling of clean water flowing towards the mining area.

Water management measures that are required will include the diversion of clean runoff from upstream of the mining areas around the site, and the containment of dirty runoff from the site in the water management (pollution control) dams (Goedehoop Dam and Dam 5 being the main pollution control dams (PCDs) to which all surplus dirty water is pumped and from which surplus water is pumped to the MWRP), with the exception of Goedehoop South LOM pits where water from the pits will be pumped directly to the MWRP, via the Klipfontein pipeline. These measures need to be designed to accommodate events up to at least the 1:50 year event, in line with GN R7041.

Storm water that is generated around the mining area consists of clean and dirty runoff. This includes:

� Clean runoff from clean catchments draining towards the mining activities and infrastructure. Measures will be implemented to ensure that significant clean catchments are diverted away from the workings. Clean water diversions and flood protection measures will be designed to accommodate at least the 1:50 year event.

� Dirty runoff will be generated in the opencast and mine, as well as Dispatch Rider infrastructure areas. Measures will be implemented to contain this runoff by directing it to the pollution control dams. At the proposed pit extension area, dirty runoff reporting to the pit will be collected in an in-pit sump from where it will be pumped to either Goedehoop Dam, Dam 5 PCD or in the case of Goedehoop South LOM pits to the Klipfontein pipeline before being directed to the MWRP. At Dispatch Rider dirty runoff, as well as underground water make will be directed to an underground sump from where water will be pumped to H3/ H4 void before being pumped to Dam 5 PCD and ultimately directed to the MWRP. The dirty water management system, including the pollution control dams, needs to be designed in accordance with GN R704 to accommodate the 1:50 year event as a minimum (i.e. 2% risk of spillage) with a minimum of 800 mm freeboard.

Storm water management measures are discussed in more detail below.

A layout of the proposed surface water management infrastructure is shown in Figures 4.5.2(a) and (b) for the LoA areas and Dispatch Rider and are discussed in more detail below.

1 Government Notice 704 (GN R704) of 1999, in terms of the National Water Act, Act 36 of 1998 (Department of

Water Affairs and Forestry)

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Figure 4.5.2(a): Schematic storm water management at the LoA areas

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Figure 4.5.2(b): Schematic storm water management at Dispatch Rider

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4.5.2.2. Storm water management in clean areas

In line with best practice and the requirements of the National Water Act (Act 36 of 1998) (NWA), contaminated storm water runoff volumes will be minimised by preventing runoff from clean areas from entering the dirty areas. This will be achieved by means of clean water diversion canals that will collect clean runoff and divert it around the dirty areas.

All clean water diversions will be designed to accommodate the peak flow expected for at least a 1:50 year event.

Please refer to Figures 4.5.2 (a) and (b).

Opencast pits

Runoff from clean catchments draining towards the mining areas will be diverted around the mining area, minimising clean runoff into the opencast workings and onto the mine infrastructure areas. These will be in the form of clean water cut-off canals and berms. Clean water diversions and flood protection measures will be designed to accommodate at least the 1:50 year event within the excavated canal with flood events of at least the 1:100 year being accommodated on the flood protection berm.

Overburden stockpiles

South32 CSA plans to avoid the establishment of new overburden stockpiles on surface by backfilling adjacent voids with the boxcut overburden material from the new pits. However, there is likely to be an overburden stockpile at the proposed pit GP in the north of the Goedehoop area. The need for overburden stockpiles at other pits is still to be confirmed and was not available at the time of writing. The stockpiles will therefore not form part of this application.

The overburden material has the potential to contain carbonaceous material and therefore potential to generate poor quality runoff due to contact of the water with carbonaceous material.

Runoff from clean catchments draining towards the overburden stockpiles will be diverted around the stockpiles by means of a diversion berm.

Topsoil stockpiles

Topsoil is considered clean and therefore no specific storm water management infrastructure is proposed.

Shaft complex infrastructure area

No shafts will be sunk for the Dispatch Rider project. The adjacent high wall of the old Driefontein opencast pit will be used to gain access to the underground.

The shaft infrastructure area will be located on a partially rehabilitated mined-out area to the north west of an area that has been used for the disposal of slurry. The site drains in a south westerly direction towards the Boesmanskransspruit. Clean runoff draining towards the mine infrastructure area will be diverted by means of a clean water diversion canals and berms, constructed around the northern and north eastern boundaries of the mine infrastructure area. Clean catchment areas at and around the adit area will also be diverted by means of clean water canals and berms. Adequate energy dissipation and erosion protection will be provided at the discharge points. The storm water management at the shaft area can be seen in Figure 4.6.2(b).

24



Pollution control dams

There are no proposed PCDs for the extension project, as all dirty water generated in the opencast pits will be pumped to existing PCDs (either the existing Goedehoop PCD or Dam 5 PCD) or directly to the MWRP.

4.5.2.3. Storm water management in dirty areas

The dirty water containment facilities will be designed to ensure a risk of spill of dirty water to the environment of not more than once in 50 years (a 2% or lower risk in any one year). Infrastructure that will be provided to ensure the containment of contaminated water is described in the sections that follow, and is illustrated in Figures 4.5.2(a) and (b).

Opencast areas

Storm water runoff from the opencast pit areas (spoil heaps, un-rehabilitated spoils, pits and ramps, etc.) will be collected in the active opencast pits and managed as part of the mine water make. Water make from the pit will be pumped either to Goedehoop PCD or Dam 5 PCD on surface.

Overburden stockpile

As far as is practicable, overburden will be disposed of in-pit. All runoff and seepage from the overburden will be contained within the opencast workings, to be managed along with the opencast pit water make. It is envisaged that this will be possible at the majority of the opencast operations. However, there is likely to be an overburden stockpile at the proposed Pit GP in the north of the Goedehoop area.

The overburden material has the potential to contain carbonaceous material and therefore the potential to generate poor quality runoff due to contact of the water with carbonaceous material.

Storm water runoff from the overburden stockpiles will be collected via perimeter drains and directed to Goedehoop Dam.

Pollution control dams

There are no proposed new PCDs.

At Dispatch Rider clean catchments have been diverted away from the dirty areas and the dirty runoff directed towards two sumps one on surface and one underground. The surface sump would drain to the underground sump. Water from the underground sump will be pumped to the H3/H4 void before being pumped to existing Dam 5 PCD.

Dispatch Rider infrastructure area

In order to minimise the dirty water footprint of the mine infrastructure area, various catchment areas within the shaft area that could be considered clean, were delineated by the design engineers. These areas will be provided with a separate storm water drainage system and allowed to drain to the environment.

Storm water runoff from the remainder of the site will be considered dirty. These areas include:

� Stockpile area.

� Refuelling area.

25



� Heavy machine loading/storage area.

� Underground machine parking.

� Adit etc.

The clean areas delineated by the design engineers can be seen in Figure 4.5.2(b). It should be noted that the water balance presented in Section 5 assumes that this internal clean and dirty storm water management is implemented.

Storm water runoff from the dirty areas will be conveyed via a dedicated storm water system comprising concrete lined channels and pipes to the underground sump.

The storm water channels and pipes will be sized to prevent the spillage of dirty water to clean areas (i.e. beyond the mine surface infrastructure boundaries) for events up to at least the 1:50 year recurrence interval (a 2% or lower risk of spill in any one year).

An underground sump will be constructed as a containment facility for mine water make pumped from the underground workings. A second sump will be constructed to temporarily store dirty storm water run-off from the infrastructure area, from where it will be pumped to the underground sump. From the underground sump, water will be pumped to the H3/H4 void before being pumped to Dam 5 PCD and ultimately to the MWRP for treatment.

4.5.3 Mine water management

The water make from Goedehoop North and Hartbeesfontein opencast will be pumped either to the existing Goedehoop PCD or Dam 5 PCD whereas water make from Goedehoop South pits will be pumped to the Klipfontein pipeline to the MWRP. Water make from Dispatch Rider UG will be pumped to H3/ H4 void before being pumped to Dam 5 PCD.

The surplus water make will be pumped to the MWRP and treated for discharge to the Spookspruit. Post closure, the opencast pit will be allowed to fill to an environmentally safe level below decant elevation. The water level will be monitored and maintained at or below the environmentally safe level by pumping to the MWRP.

4.5.4 Water storage facilities

4.5.4.1. General description of dams

Existing dams

Currently there are a number of dirty water storage facilities at Wolvekrans Colliery North section. These are detailed in Table 4.5.5(a).

Table 4.5.5(a): Existing dirty water storage facilities

Dam Capacity (m3)

Dam 1 160 000

Dam 2 315 000

Dam 3 62 000

Dam 4 156 000

Dam 5 580 000

Dam 6 162 000

Dam 7 226 000

26



Dam Capacity (m3)

Dam 8 191 000

Dam 9 78 000

Dam 10 210 000

Dam 25

(This dam forms part of Goedehoop Dam) 120 000

Dam 26 82 000

Dam 27 28 000

Dam 28 32 000

Goedehoop Dam 1 800 000

Proposed dams

No new surface water dams are proposed as part of the LoA extension but two dirty water sumps are proposed at Dispatch Rider project.

4.5.5 Polluted water treatment facilities

4.5.5.1. Mine water treatment

All surplus dirty water generated at Wolvekrans Colliery North section will be collected in either the Goedehoop PCD or Dam 5 PCD and then pumped to the MWRP, where the water will be treated to meet the interim Resource Water Quality Objectives (RWQO), for discharge to the Spookspruit.

The MWRP is a membrane based desalination process based on the High Recovery Reverse Osmosis (HiPRO®) process. The first phase, treating up to 20 000 m3/day (20 Mℓ/d) is operational and the treatment capacity will be increased to 30 000 m3/day (30 Mℓ/d), as the need arises.

4.5.5.2. Sewage water treatment

Sewage generated at Wolvekrans Colliery North section is treated at the Middelburg Colliery sewage plant. This plant has a treatment capacity of 24 million litres of sewage per month. Treated water is discharged into Dam 2 for reuse at the processing plant (AGES, 2013).

4.6 Watercourse alterations

The Spookspruit has been permanently diverted on Bankfontein Farm. Originally there was a temporary alteration in the river course for the purpose of underground mining, however a permanent diversion was implemented to prevent flood and normal stream flow from entering the open pit during mining operations (AGES, 2013). The reference number for the application of the Section 20 permit for this diversion is B187/1/210/6.

The Niekerkspruit, a minor tributary of the Spookspruit, was diverted in 1982 around the plant and workshops area and past the contaminated water dams (Dams 1 to 5) at Hartebeestfontein (AGES, 2013). This was done in order to separate clean and dirty water.

Mining will take place in close proximity to pans and watercourses as part of the LoA extension and Dispatch Rider project as can be seen in Figure 4.6(a). Therefore, Section 21 (c) and (i) water uses will need to be applied for.

27



Figure 4.6(a): Water uses associated with proposed mining extension

28



5. WATER BALANCE

The objective of the water balance modelling is to estimate the volumes of water that will be generated by the proposed activities, including effluent water and surface runoff from the dirty areas. This is assessed together with the water demands on the site to determine whether the site will operate with a water surplus or deficit and to determine the storage capacity required to ensure legal compliance in terms of prevention of spills from the site. The water balance modelling is therefore a key input to the overall water management strategy for the site.

5.1 Computational methodology

Daily rainfall data from the South African Weather Service (SAWS) rainfall stations 0478292 Langsloot and 0478303 Secunda (as detailed in Section 6), together with monthly evaporation data estimated from the “Surface Water Resources of South Africa 2005” (WRC, 2005), also known as WR05, were input to a hydrological model based on the Soil Conservation Services (SCS) method to determine runoff on a daily basis using antecedent conditions. The method (as adapted to South African conditions by Schmidt & Schulze) is believed to be highly suitable for the site, having been developed in catchments with areas of approximately 8 km2, and smaller.

The seepage and groundwater recharge inflows were derived by Exigo through groundwater modelling conducted as part of the geohydrological assessment. These rates of inflow were then brought into the J&W water balance model, where extreme rainfall impacts and surface water make were assessed. The water use and storage requirements to ensure a 2% or lower risk of spilling in any one year were subsequently computed.

The surface runoff areas were measured from layout and surface topography drawings provided by South32 CSA. Water consumption information related to the mining operation was also provided by South32 CSA. This data was entered into the water balance model.

The overall water balance for the Wolvekrans Colliery North section was subsequently calculated.

5.2 Assumptions, information used and limitations

5.2.1 Assumptions and information used

The following activities are included:

� The Life of Mine for additional opencast areas extends from 2019 to 2039 with the Dispatch Rider underground section extending from 2015 to 2030.

� Water used for dust suppression on surface and underground has been accounted for.

� Potable water use at the offices and change house, as drinking water for approximately 350 people, amounts to 70m3/day and will be supplied from Wolvekrans Colliery North section.

� Measured potable water flows were provided by South32 CSA.

� Domestic waste water generated from the mine’s office complex, as well as from Naledi village, is treated by the sewage plant at Wolvekrans Colliery North section. The plant is a batch treatment plant, with a capacity of 24 million litres per month. Once the waste water has been treated it is discharged into Dam 2 for reuse at the plant (AGES, 2013).

29



� Surplus water at Goedehoop Dam and Dam 5 PCD will be pumped to the Middelburg Water Reclamation Plant (MWRP).

� Existing haul roads will be used to transport coal from the active pits to the coal processing area at the North Plant. From here an existing conveyor will convey coal to the loadout silo.

� No shafts will be sunk for the Dispatch Rider project. The adjacent high wall of the Driefontein old opencast pit will be used to gain access to the underground.

The following key assumptions and information have been used:

� Runoff from the external catchment, draining towards opencast workings and mine surface infrastructure area, will be diverted, minimising the volume of water reporting to the PCDs.

� Overburden material will be handled in-pit, i.e. no overburden stockpiles have been modelled.

� Runoff and seepage from all dirty areas around the coal processing plant, including the old coal discard facilities, drain into Dam 5 PCD.

� Runoff from offices, workshops, hard park, pipe store yard, ROM infrastructure area and the North Plant area drain to Dam 5 PCD.

� Water make from Dispatch Rider will be collected in an underground sump before being pumped to H3/H4 void.

� Water make from the expanded Goedehoop North pits will be pumped to Goedehoop Dam.

� Water make from expanded Hartbeesfontein pit will be pumped to Dam 5 PCD.

� Water make from the expanded Goedehoop South pits will be pumped to the MWRP via the Klipfontein line.

� Bankfontein pit is rehabilitated and has been allowed to fill up. Water is abstracted from this pit for dust suppression of haul roads.

� A new pipeline has recently been constructed to transfer surplus water from the South Plant to Hartbeesfontein voids E6, H3 and H4, ultimately for treatment at the MWRP. The volume of water to be transferred via this pipeline was not available at the time of writing and has been excluded from the water balance.

� Based on the MWRP Surface Water Specialist Report (i.e. Report No. JW92/11/B478-Rev2, July 2011), the maximum allowed flows which Goedehoop Dam and Dam 5 PCD are allowed to pump to the MWRP are 12Ml/day and 7.5Ml/day respectively. This has been taken into account in the modelling.

� Pumping protocols used in the water balance modelling, upon consultation with South32 CSA, were based on a 450 mm diameter pipe pumping from the pits to Goedehoop Dam or Dam 5 PCD for 12 hours a day.

� The opencast and underground mining areas used for the modelling were based on the latest LOM plans received from South32 CSA (file names “LoA PPP_opencast.dwg; North Amendment_GW_GWABadjusted_23_11_2015; Dispatch S1 Period Progress.dwg; Dispatch S2 Period Progress.dwg; Dispatch S4 Period Progress.dwg”).

� Dust suppression application rates at Wolvekrans Colliery North section were based on information provided by South32 CSA, as indicated in Table 5.2.1(a) below.

30



� Other uses and losses are given in Table 5.2.1(a) below.

� The surface water inflows to the PCDs have been estimated, based on the surface runoff model.

� The layout drawings used to delineate the various sub-catchments on the mine surface infrastructure site were provided by South32 CSA.

� The capacities of the PCDs were taken from the consolidated EMP and the 2002 EMP and are given in Table 5.2.1(b) below:

� Groundwater inflows to the opencast and underground were obtained from Exigo, file name “LOM_Groundwaterinputs_rgmv.xls”.

� Decant elevations and time to decant in each of the pits were obtained from Exigo, report name “J_W_South32_NS_GWmodel20160630-G14/081/3”

� Exigo also included the following in their groundwater modelling: “Dewatering of the Bank Colliery was included in the groundwater model as it has been confirmed by South32 to occur. Complete dewatering down to the 2 seam floor of the Bank Colliery underground plan as available was simulated, but the assumption made with regards to possible flooding and sealing of mined-out compartments and dewatering volumes has to be kept in mind.” Therefore there are uncertainties with regards to the groundwater and therefore the expected groundwater volumes should be reassessed.

Table 5.2.1(a) List of water uses and losses received from South32 CSA

Water Use Volume (m3/day) Source

Dispatch Rider

Dust suppression on Surface 135

South32 CSA (Darren Pietersen)

Dust suppression Underground 80

Ventilation loss 92.6

Service water suppled from H3/H4 void 126

Drinking water (potable water) for 350 people

70

Other areas

Dust suppression from Bankfontein Void for roads

2000

Water balance discussion meeting held 10 July 2015, Document : E812-10_Min01_r0mv-Water

BalDiscussion_20150710

Dust suppression from Goedehoop Dam for Ramps

500

Dust suppression from Goedehoop voids for haul roads

500

Water used from G1 void for evaporators

4000

Fire suppression Ad-hoc

31



Table 5.2.1(b) Dam Capacities

Dam Capacity (m3) Source

Dam 1 160 000 Consolidated EMP and 2002 EMP

Dam 2 315 000

Dam 3 62 000

Dam 4 156 000

Dam 5 580 000

Dam 6 162 000

Dam 7 226 000

Dam 8 191 000

Dam 9 78 000

Dam 10 210 000

Dam 25

(This dam forms part of Goedehoop Dam)

120 000

Dam 26 82 000

Dam 27 28 000 2002 EMP

Dam 28 32 000 2002 EMP

Goedehoop Dam 1 800 000 Consolidated EMP and 2002 EMP

Sumps at Dispatch Rider (combined) 19 300 J&W

5.2.2 Limitations

By their nature, models are theoretical estimates of natural phenomena that are too complex to be derived exactly. It is inevitable that there will be variations in the actual flows when compared to the predicted flows. This can only be addressed by the recalibration of modelled data with measured data, from which more reliable estimates of extreme and average water make and runoff volumes can be developed.

5.3 Rainfall data

The water balance modelling requires historical daily rainfall data from a gauge in close proximity to the site. It is important that the rain gauge has a long record, and within that record contain rainfall events that correspond to at least the 1:50 year event, since the legal requirement is that a mine should not spill dirty water to the environment more than once in 50 years (a 2% risk of spilling in any one year). The duration of the event can vary, and in most of the larger mines, the critical event is not the 24 hour event, but rather above average rainfall over a period of several months, typically with several extreme rainfall events occurring during a wetter than average period.

For the Vandyksdrift station (please refer to Section 6 for further detail), there are no events that has been recorded at the station, which are in excess of the 1:50 year event, making this record unsuitable for the water balance assessment. Therefore for the water balance modelling Langsloot/Secunda gauge was used.

The rainfall data from the Langsloot and Secunda rainfall stations was evaluated and found to have reliable data, with reasonably representative extremes for the duration of the record. The records were found to have similar characteristics and were combined

32



to create a rainfall record spanning from 1914 to 2008, a record length of 95 years. The statistical extremes for the combined rainfall record are presented in Table 5.3(a).

Table 5.3(a) Statistical rainfall extremes for Langsloot/Secunda rainfall station

Event Rainfall depth (mm)

1 day 2 day 3 day 7 day 1 month Annual

1:2 yr 59 81 96 143 184 689

1:10 yr 88 117 132 182 246 886

1:20 yr 105 136 150 196 274 946

1:50 yr 132 166 178 215 314 1052

1:100 yr 157 194 202 230 346 1111

1:200 yr 188 226 230 244 382 1174

1:250 yr* 205 245 250 253 400 1190

Max Recorded 175 196 196 212 368 1068

5.4 Water balance modelling

Wolvekrans Colliery North section comprises of four historic opencast areas, namely Goedehoop North Pits, Goedehoop South Pits, Hartbeesfontein Pit as well as a rehabilitated pit known as Bankfontein Pit.

The Wolvekrans Colliery North Extension Project consists of the extension of the Goedehoop North, Goedehoop South and Hartbeesfontein opencast areas as well as a new underground area known as Dispatch Rider.

As per discussion with South32 it is important to note that the mining at Goedehoop North will not be a continuation from the current voids and new boxcuts will be created. The water makes of the old and new pits will therefore be separate and therefore, no pre-mining dewatering will be required.

The LOM schedule for these proposed LoA pits and underground areas can be seen in Figures 1.3 (b) above.

The LOM schedule for each pit and underground area are provided in Table 5.4(a) below.

33



Table 5.4(a): Anticipated LOM for Middelburg Colliery LoA expansion and Dispatch Rider project

Section Location Mining Method Life of reserve

(years)

GP New Mini Pit Opencast 2033-2039

GN Goedehoop North Opencast 2019-2022

GWAB

Goedehoop South

Opencast 2022-2023, 2026-2027

GO Opencast 2033-2037

GZ Opencast 2033-2039

GW Opencast 2033-2039

GD Opencast 2028-2030

HN

Hartbeesfontein

Opencast 2028-2034

Dispatch Rider

Bord and Pillar Underground

2015-2030

5.4.1 Water make

From Figure 5.4.1(a) below, the total mine water make is expected to increase from a current water make of 15 000 m3/day to a maximum of 52 000 m3/day for average rainfall, with average water make over the life of mine (i.e. 2015-2039) of 29 200 m3/day.

The post closure water make over the life of mine (2015-2039) is estimated to be 29 300 m3/day.

The mine water make for each opencast pit and underground area is tabulated in Table 5.4.1(a) below.

The combined water make is shown in Figure 5.4.1(a). This figure presents the total mining water make over the life of the mine, showing the predicted seasonal variation in water make. There spikes in the seasonality due to spikes in groundwater inflows to the opencast pits. The individual contributions from the opencast and underground sections are shown in Figures 5.4.1(b) to (d)

The total post closure water make for average rainfall are given in Table 5.4.1(a).

34



Figure 5.4.1(a): Graphical presentation of average daily water make during the operational phase of mining showing the expected seasonal variation in water make

Figure 5.4.1(b): Individual opencast water make for opencast pits GP, Bankfontein, GWAB and GW

0

10000

20000

30000

40000

50000

60000

70000

80000

Av

era

ge

da

ily v

olu

me

(m

3/d

ay)

Year analysed

Middelburg North water balance for surface water study - Rainfall used: Average

Summer Period

Winter Period

Annual Average

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

2016 2021 2026 2031 2036 2041 2046

Ave

rag

e d

aily

vo

lum

e (

m3/d

)

Years

Water make for OC 1 to OC 4

OC1_GP pit OC2_Bankfontein pit OC3_GWAB pit OC4_GW pit

35



Figure 5.4.1(c): Individual opencast water make for opencast pits GO, GZ, GD and HN

Figure 5.4.1(d): Individual opencast water make for historic opencast pits (Goedehoop North and South and Hartbeesfontein) and GN pit

0

5000

10000

15000

20000

25000

30000

35000

2016 2021 2026 2031 2036 2041 2046

Ave

rage

da

ily v

olu

me (

m3/d

)

Years


OC5_GO pit OC6_GZ pit OC7_GD pit OC8_HN pit

0

2000

4000

6000

8000

10000

12000

14000

16000

2016 2021 2026 2031 2036 2041 2046

Avera

ge d

aily

volu

me (

m3/d

)

Years


OC9_GNHistoric pit OC10_GHSouthHistoric OC11_HN Historic pit OC12_GN pit

36



Figure 5.4.1(e): Individual opencast water make for Dispatch Rider Underground

Table 5.4.1(a): Expected mine water make for average rainfall

Mining section

Average water make over LOM of the pits

and Underground areas

(m3/day)

Maximum annual water make

(m3/day)

Post closure water make

(m3/day)

Opencast:

GP 731* 956* 537*

GN 9419* 13975* 4349*

GWAB 260* 398* 232*

GW 4339* 8350* 1832*

GO 88* 129* 78*

GZ 148* 254* 200*

GD 700* 745* 533*

HN 16631* 29879* 10483*

Goedehoop North old workings

1525* 1699* 673*

Goedehoop South old workings

3439* 3459* 2987*

Hatbeesfontein old workings

10923* 11029* 7710*

0

50

100

150

200

250

2016 2021 2026 2031 2036 2041 2046

Ave

rage d

aily

volu

me (

m3/d

)

Years

Water make for Dispatch Rider

Dispatch Rider UG

37



Bankfontein old workings 644* 648* 648*

Underground:

Dispatch Rider 99* 190* 190*

*Note that the averages given in the table above will differ from the flow diagram as the above numbers are averages over the LOM of each individual pit and underground area. (i.e. it is the average over the Life of Pit or underground). The flow diagram will contain the averages over the entire LOM (i.e. 2015-2039)

5.4.2 Water Use and losses

The water uses and losses at Wolvekrans Colliery North, as modelled in the water balance, are indicated below in Table 5.4.2(a).

Table 5.4.2(a): Water use at Middelburg North

Water use Quantity

(m3/day) Source

Dispatch Rider Dust suppression on surface 135

South32 Darren

Dust suppression Underground 80 Ventilation loss 92.6

Service water suppled from H3/H4 void

126

Drinking water (potable water) for 350 people

70

Other Areas Dust suppression from Bankfontein Void for roads

2000

Water balance discussion meeting held 10 July 2015,

Document : E812-10_Min01_r0mv-Water

BalDiscussion_20150710

Dust suppression from Goedehoop Dam for Ramps

500

Dust suppression from Goedehoop voids for haul roads

500

Water used from G1 void for evaporators

4000

Fire suppression Ad-hoc

5.4.3 Surplus water

The operating philosophy at the Wolvekrans Colliery North section mining operation involves the pumping of all surplus dirty water make to either Goedehoop Dam or to Dam 5 PCD and from there water is pumped to the MWRP for treatment. Therefore, over the LOM, the surplus water make (which includes the surface water make) for average rain will need to be pumped to the MWRP and treated to ensure a 2% or lower risk of spill in any one year.

The MWRP receives water for treatment from Wolvekrans Colliery North and Klipfontein Section. Wolvekrans Colliery South Section pumps water to Wolvekrans Colliery North.

The total average flows that the MWRP receives from Wolvekrans Colliery(i.e North, South and Klipfontein section) is 30ML/day, with 12Ml/day and 7.5Ml/day coming from Goedehoop Dam and Dam 5 PCD respectively. Therefore, for Wolvekrans Colliery North Section the maximum allowed flows that can be handled from Goedehoop Dam and Dam 5 PCD, at the MWRP, amount to 12Ml/day and 7.5Ml/day respectively.

38



5.4.4 Schematic water balance diagram

The schematic water balance diagram is presented in Figure 5.4.3(a) and (b) for the average water flows over the life of mine.

39



Figure 5.4.3(a): Schematic water balance diagram – average flows over Life of Mine (2015-2039)

40



Figure 5.4.3(b): Schematic water balance diagram – average flows over Life of Mine (2015-2039

41



5.4.5 Water management and storage requirements

5.4.5.1. Water management for average rainfall

Goedehooop Dam and Dam 5 PCD are the main PCDs for the Wolvekrans Colliery North Section and all surplus dirty water generated at the mine is pumped to these dams.

In order to not infinitely accumulate water, it is necessary that the average inflow into the mine is balanced with the mine water usage or treatment. In the event that the inflows exceed the usage or outflow from the mine it is necessary to store the surplus water that is not used. Therefore, in order to limit the dirty water storage requirements to a reasonable volume the average outflows need to equal the average inflows. If the average inflows are not matched by the average outflows, water will simply accumulate over time and an infinite storage volume will be required.

Due to the size of Goedehoop Dam, it is expected that the dam has sufficient capacity to handle surplus water for average rainfall conditions, while pumping at the prescribed rate of 12Ml/day to the MWRP for treatment. However, at Dam 5 PCD, under average rainfall conditions, the amount of surplus water needed to be sent to the MWRP far exceeds the 7.5Ml/day allowed. It is expected that, under average rainfall conditions, a peak pumping rate of 25.5Ml/day and an average pumping of 17Ml/day is required from Dam 5 PCD to the MWRP in order to ensure a 2% or lower risk of spill in any one year. This implies that the MWRP treatment capacity would have to increase.

Table 5.4.5(a) below shows, the expected volume of water that will need to be pumped to the MWRP to prevent spillage of dirty water from Goedehoop Dam and Dam 5 PCD under average rainfall conditions.

Table 5.4.5(a) Pumping rate required over the LOM, under average rainfall conditions

Dam

Peak pumping rate to MWRP for treatment under average rainfall

(over the LOM)

(m3/day)

Average pumping rate to MWRP for treatment under average rainfall

(over the LOM)

(m3/day)

Goedehoop Dam 12 000 6 000

Dam 5 PCD 25 500 17 000

5.4.5.2. Water management for extreme rainfall

Explanatory note on provision for extreme events

South African legislation, detailed in Government Notice 704 of 1999 (GN R704), in terms of the National Water Act, Act 36 of 1998 (NWA), stipulates that dirty water on mining sites needs to be contained for events up to the 1:50 year recurrence interval. The Department of Water and Sanitation (DWS) Best Practice Guideline for water management defines a spill “event” as a series of spills occurring during a given 30 day period.

When determining storage requirements, it is important to understand that a particular recurrence interval does not refer to a single discrete event. For each recurrence interval there is an infinite number of events, depending on the storm duration considered. It is important to determine the appropriate storm duration to use, based on the assessment being carried out. Typically, for peak flow events, shorter duration events (< 24 hours)

42



are considered, as these are of higher intensity and generate greater flow rates. However, for volumetric assessments (sizing of dirty water containment facilities), the duration used could be months, an entire season, or longer, as two or three months of high rainfall, for example, could raise a dam’s water level to such an extent that a subsequent low recurrence interval storm could cause a spill event.

For extreme rainfall there are two considerations:

� Surface water management: The sizing of the PCDs will be driven by the storm water volumes generated on the surface infrastructure during short duration (in the order of one day to a few days) events.

� Mine water balance management: During longer term extreme events (in the order of years), the management of the large volumes of water generated needs to be considered, in terms of available storage and reuse / treatment options.

The risk of spill from a PCD is a function of both dam capacity (for temporary storage of storm water runoff and mine water make) and the rate at which water can be abstracted from the dam for reuse or storage elsewhere. For the purpose of the current water balance modelling, the capacity of Goedehoop Dam and Dam 5 PCD, from the consolidated EMP and 2002 EMP was used. The required abstraction rate from the Goedehoop Dam and Dam 5 PCD, in order to achieve an appropriate risk of spill, was investigated in the water balance model, as well as the additional buffer storage that would be required during extreme rainfall conditions.

The net expected volume of water required to be pumped to the MWRP will vary depending on the nature of the extreme rainfall. As mentioned previously, for the average rainfall assessment, the peak pumping rate out of Dam 5 PCD to the MWRP will have to be increased to 25.5 Ml/day to ensure a 2% or lower risk of spill in any one year, for average rainfall conditions. This means that the MWRP treatment capacity would have to increase.

Based on the water balance modelling, it was found that, under extreme rainfall conditions, a pumping rate of 25.5Ml/day from Dam 5 PCD to the MWRP was insufficient to ensure a risk of spill of 2% or lower in any one year. Therefore, it is expected that an additional buffer storage capacity of 18 million m3 coupled with an additional water use of 3 000m3/day is required to ensure a 2% or lower risk of spill in any one year. In the event that water cannot be used or treated at an additional rate of 3 000m3/day an infinite sized dam will be required.

At Goedehoop Dam, under extreme rainfall water pumped will need to be re-directed to an alternative storage area of 3 million m3 to ensure a 2% or lower risk of spill in any one year at Goedehoop Dam.

It is recommended that the old workings adjacent to the new pits be dewatered prior to the mining of the new pits in order to provide buffer capacity for the summer months and extreme events, as well as reduce the expected steady state seep volume reporting to the new pits from the old pits. In addition to this, further potential optimising of the buffer storage can be achieved if the water storage capacities of all the pits are known, thereby allowing for the temporary storage of water in the pits during wet periods, with subsequently reduced pumping rates to the Dam 5 PCD. The potential storage capacities of the pits, at a safe level below decant, will need to be determined and the water balance reassessed based on the storage capabilities of the pits.

The entire daily rainfall record was run over the LOM in order to evaluate the maximum amount of water that would need to be pumped to the MWRP over a year, as well as the maximum pumped to the MWRP on any given day for treatment from Goedehoop Dam and Dam 5 PCD in order to ensure a 2% or lower risk of spill.

43



The required maximum volume of water that will need to be pumped for treatment over a year, as well as for a given day, for extreme events ensuring a 2% risk of spill is detailed in Table 5.4.5(a) below.

Table 5.4.5(b) Pumping rate required over the LOM to MWRP

From

Max amount of water to be pumped to

MWRP for treatment over a year

(Ml/year)

Max amount of water to be pumped to MWRP for treatment over a day

(m3/day)

GN704 compliance

Goedehoop Dam, Dam 5

PCD and Goedehoop

South pits via Klipfontein line

18400 Ml/yr 96700 m3/day 2% risk of Spill

5.4.5.3. Management during dry periods

During dry periods make-up water, if required, will be drawn from the opencast spoils.

5.5 Post closure water balance

Post closure the existing Wolvekrans Colliery North surface infrastructure will be demolished and removed from the site. The site will be rehabilitated and made free draining, including the pollution control dam and opencast areas.

Post rehabilitation, all surface runoff will be clean, and will be allowed to drain to the receiving environment.

The post closure water make over the LOM is expected to amount to approximately 29 300m3/day.

The estimated time to decant, if the workings are left to fill post closure, has been estimated and is given in Table 5.5(a) below, from the groundwater study, but these values needs to be confirmed.

44



Table 5.5(a) Estimated time to Decant

Section name

Last mining year

Decant volume (m3/d) 25 years

after 2040

Decant volume (m3/d) 75 years

after 2040 Time to decant

(years)

GD 2030 786 827 28

GN 2022 1 420 1 470 8

GO 2037 167 185 40

GP 2039 60 110 13

GW 2039 1 640 1 780 9

GWAB 2027 528 555 31

GZ 2039 378 420 38

HN 2035 10 890 11 960 +/- 6

Goedehoop N+S

Partially Rehabilitated

pits 5 570 5 639 Already Decanting

Dispatch Rider UG 2030 - - -

An environmentally safe water level for the workings (below decant level) will be determined and the water level will be maintained at or below this level by pumping excess water to the MWRP.

5.6 Conclusion

The water balance modelling indicates the following:

� The Goedehoop Dam will cater for both surface runoff reporting to the dam as well as pit water, with surplus water being pumped to MWRP for treatment, with a risk of spill less than 2%, for average rainfall.

� Under extreme rainfall, water pumped to Goedehoop Dam will need to be re-directed to a an alternative storage area of 3 million m3 to ensure a 2% or lower risk of spill in any one year at Goedehoop Dam.

� Dam 5 PCD will require an increased pumping of 25.5Ml/day to the MWRP under average rainfall and under extreme rainfall water will need to be re-directed to an alternate buffer storage area of 18 Million m3 coupled with a water use of 3 000m3/day for extreme rainfall in order to ensure a 2% or lower risk of spill in any one year at Dam 5 PCD.

� Increased pumping from Goedehoop Dam and Dam 5 PCD to the MWRP would require an increased treatment rate and therefore capacity at the MWRP.

� It is recommended that the old workings adjacent to the new pits be dewatered prior to the mining of the new pits in order to provide buffer capacity for the summer months and extreme events, as well as reduce the expected steady state seep volume reporting to the new pits from the old pits. In addition to this, further potential optimization of the buffer storage can be achieved if the potential water storage capacities of all the pits are known, thereby potentially allowing for the temporary storage of water in these pits during wet periods, with subsequent reduced pumping to Dam 5 PCD. The potential storage capacities of the pits, at a safe level below decant, will need to be determined and the water balance reassessed based on the storage capabilities of the pits.

45



� During the decommissioning phase, all pits will be backfilled without a final void, rehabilitated and made free-draining. The water level in the workings should be actively managed to ensure they remain below the decant elevation.

� The post closure mine water make will be pumped from the mine workings to the Goedehoop Dam and Dam 5 PCD and from there to the MWRP for treatment. The expected time to decant for each pit is given in Table 5.5 (a) above. From the table GN and HN pits will start decanting within or immediately after mining. The partially rehabilitated pits have already reached decant elevation.

� The assumptions upon which this water balance is based require careful verification, particularly with regard to the groundwater make on site.

� The water balance will need to be refined as the mine design develops and the results presented here should be viewed as preliminary, for input to the mine design process.

46



6. BASELINE ENVIRONMENTAL DESCRIPTION

The baseline environmental information is important for several reasons. This data forms the basis of the assessment of possible impacts, and the setting of objectives for closure. For surface water it is important that the Mine is able to identify point sources that may be impacting on surface water so that the origin of any future impacts can be identified.

6.1 Regional climate

Wolvekrans Colliery North section is located in the Highveld climatic region, where the climate is characterised by warm summers, with an average daily maximum temperature of approximately 24˚C. Winters are cold with incidences of sharp frost. Average minimum temperatures are approximately 7˚C, with the average number of days per year when the minimum temperature drops below 0 ˚C is 66 at Middelburg. Table 6.1(a) provides the long-term monthly minimum, mean and maximum temperature for eMalahleni for the period 2008-2010 (Synergistics, 2012).

Table 6.1(a) Long-term minimum, maximum and mean temperature for eMalahleni for the period 2008 – 2010 (Synergistics, 2012).

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Minimum 16.1 15.1 13.9 10.9 8.32 5.75 4.47 6.79 10.2 13.4 14.3 15.4

Mean 19.6 19.6 18.3 15.7 13.5 11 10.2 13.3 17.3 19.0 18.5 19.8

Maximum 23.7 24.5 23.6 21.4 19.9 17.5 17 20.8 24.7 25.3 23.5 24.8

The majority of precipitation is experienced during the summer months, occurring from November to March, predominantly as showers and thunderstorms. Mean annual precipitation (MAP) is approximately around 600 – 700mm, with 85% of the annual rainfall occurring between October and March. Mean annual evaporation (MAE) in the region is approximately 1600 mm.

6.2 Catchment description

6.2.1 General description

The Wolvekrans Colliery North section is located on portions of farms Hartbeesfontein 339JS, Bankfontein 340 JS, Sterkwater 317 JS and Goedehoop 315 IS.

Wolvekrans Colliery North section is situated within the catchment area of the Klein-Olifants and Olifants Rivers. These catchments make up part of the Loskop Dam catchment. The mine is situated predominantly within quaternary sub-catchment B11H of the Niekerkspruit and Spookspruit. A small portion of the Goedehoop section falls within quaternary sub-catchment B12D of the Vaalbankspruit, with the western portion of the Hartbeesfontein section falling within quaternary sub-catchment B11G of the Olifants River. These quaternary sub-catchments, namely B11H, B11G and B12D of the Limpopo-Olifants primary drainage region, are indicted in Figure 6.2.1(a) taken from “Surface Water Resources of South Africa – 2005” (Midgley, Pitman & Middleton, 2005) (WR05)).

The runoff from these sections of the colliery eventually flows into the Loskop Dam. Both the Niekerkspruit and the Spookspruit flow through the mine’s property and have been diverted around the mine workings.

47



Figure 6.2.1(a): Location of site in relation to its catchment

48



From the Loskop Dam, the Olifants River flows through the central parts of the Mpumalanga Province and the Kruger National Park, into Mozambique. It joins the Limpopo River and discharges to the Indian Ocean on the east African coastline.

6.2.2 Receiving water body

In terms of the catchment description, the receiving water body is an important concept. The receiving water body is the point below which the mine’s impact on the catchment is considered to be negligible. This implies that aspects such as surface water users need only be defined down to the receiving water body.

The receiving water body for the assessment of potential surface water quality impacts of the mine is taken as the Loskop Dam.

The use of this dam is motivated on the basis that:

� The proposed additional mining areas lie across drainage boundaries of the Klein-Olifants and Olifants River catchment and therefore the Loskop Dam has been selected as it is located downstream of both the Olifants and Klein-Olifants River catchment areas.

� Beyond Loskop Dam, the potential impact of the mine becomes extremely small due to the water volumes in the catchment and dilution effects.

� Further, by the time the water reaches Loskop Dam, it is required to be suitable for use for all of the expected uses (drinking water, agricultural, industrial and aquatic ecosystems). Thus, by achieving compliance in terms of these, no additional impacts are expected downstream of Loskop Dam. The receiving water body is relevant only in so far as it defines the aerial extent of the catchment to be considered in the impact assessment, and described in the baseline study.

� The use of Loskop Dam is based on the relatively small size of the Middelburg North Extension operations compared to the entire catchment for Loskop Dam.

� The catchment area for Loskop Dam totals some 12 285 km². The proposed extension area covers approximately 12.4 km2. The mine area thus totals approximately 0.10% of the Loskop Dam catchment.

� The mean annual runoff (MAR) for Loskop Dam is some 384 x 106 m3, while the MAR for the proposed mining area is estimated at 0.39 x 106 m3.

6.3 Rainfall and evaporation

6.3.1 Rainfall data

The Daily Rainfall Extraction Utility, developed by the Institute for Commercial Forestry Research (ICFR) in conjunction with the School of Bio-resources Engineering and Environmental Hydrology (BEEH) at the University of KwaZulu-Natal, Pietermaritzburg, was used to obtain summary data for all rainfall stations within the vicinity of the site. This data was assessed in terms of length of record, completeness of the data set, mean annual precipitation (MAP) and location of the rainfall station with respect to the site and the catchment. Key data extracted from the database for the five most reliable stations is shown in Table 6.3.1(a). The ICFR database contains daily patched rainfall data for all official South African Weather Service (SAWS) stations, and includes data up to August 2000.

After an assessment of the length of the record, MAP and the reliability of the data for the five rainfall stations, the Witbank, EDE and Blinkpan rainfall stations were disregarded. This was due to the limited length of the records and low reliability of the

49



data sets. To further assess the two remaining rainfall stations, and select choose an appropriate and representative station for the site, each of the records was assessed to determine whether the records contained events exceeding the 1:50 year event.

Table 6.3.1(a): Key data for selected rainfall stations (ICFR database)

Station number Station name Reliable (%) MAP

(mm)

Length of record

(years)

0515826_W Middelburg (TNK) 51.9 643 96 (1903 – 1999)

0516201_W EDE 42.2 643 90 (1903 – 1993)

0515412_W Witbank (MUN) 37.1 641 44 (1956 – 2000)

0478546_W Vandyksdrift 59.8 686 82 (1928 – 2010)

0478786 Blinkpan 25 643 13 (1987 – 2000)

The top 100 ranked peaks from the two rainfall records were plotted along with the rainfall depths relating to various recurrence intervals, extracted from the SAWS design rainfall depths manual. For both rainfall stations it was found that only one event exceeded the 1:50 year event. Therefore, the Vandyksdrift rainfall station was selected as being the representative rainfall data set for the site. The Vandyksdrift rainfall station was found to have the most reliable data set with a high MAP.

It was found that, although data was available for the Vandyksdrift station after 1998, this data was not completely intact, with data missing and inconsistencies. Therefore, only data up until 1998 was considered for the station. A mass plot was produced for the record and is shown in Figure 6.3.1(a). A mass plot is a graph showing the cumulative rainfall depth with time for the full rainfall record. It is good indication of the reliability of the data set. A good mass plot will produce a straight line, with slight oscillations for seasonality. Any changes in the slope indicate a potential problem in the data set.

50



Figure 6.3.1(a): Rainfall mass plot for the rainfall record

The mass plot for the rainfall record is considered to be acceptable. The record has therefore been selected as being a representative rainfall data set for the site for the hydrological assessment. A different rainfall station, (i.e. Langsloot/Secunda), has been used in the water balance modelling (please refer to Section 5 above), which is more representative of rainfall extremes.

The average monthly rainfall depths are presented in Table 6.3.1(b). The rainfall record is presented graphically in Figure 6.3.2(a). The entire rainfall record is presented graphically in Figure 6.3.1(b). Mean monthly rainfall is shown graphically, together with mean monthly evaporation, in Figure 6.3.2(b).

6.3.2 Evaporation data

Evaporation data was taken from the evaporation station for Witbank Dam (B1E001). Monthly data for this station was only available for the period 1964 to 2009. Over the periods for which there was no monthly evaporation data, average evaporation depth, taken directly from the WR90 report for the Evaporation Zone into which the site falls. The Evaporation Zone is 4A. The Mean Annual Evaporation for this zone is 1600 mm. The average monthly evaporation depths are presented in Table 6.3.1(b) and Figure 6.3.2(b).

51



Table 6.3.1(b): Average monthly rainfall depth for the Vandyksdrift rainfall record (0478546_W) and evaporation depths (from WR90)

Month Average rainfall (mm) Average evaporation (mm)

October 70 176

November 108 147

December 109 145

January 109 111

February 94 94

March 72 76

April 42 83

May 17 110

June 8 143

July 7 172

August 7 163

September 24 179

Annual Total 669 1600

Figure 6.3.1(b): Rainfall record for Vandyksdrift

52



Figure 6.3.2(b): Mean monthly rainfall and evaporation for Vandyksdrift

6.3.3 Maximum rainfall intensities

6.3.3.1. Rainfall extremes

Apart from the normal criteria of being statistically consistent, normally measured by considering the mass plot and ensuring that it is linear, it is also important that the rain gauge have a long record, and within that record that it contain rainfall events that correspond to at least the 1:50 year event, since the legal requirement is that a mine should not spill dirty water to the environment more than once in 50 years (a 2% risk of spilling in any one year). The duration of the event can vary, and in most of the larger mines, the critical event is not the 24 hour event, but rather above average rainfall over a period of several months, typically with several extreme rainfall events occurring during a wetter than average period.

Statistical rainfall extremes corresponding to various recurrence intervals where extracted from the Design Rainfall Depths of SAWS Rainfall Stations (Smithers and Schulze, WRC Project No K5/1060). These are shown in Table 6.3.3(a).

Table 6.3.3(a): Statistical rainfall extremes for Vandyksdrift rainfall station (from WRC K5/1060)

Event Rainfall depth (mm)

1:2 1:5 1:10 120 1:50 1:100 1:200

1 day 54 72 85 99 117 132 148

53



Figure 6.3.3(a) illustrates the top 100 one day ranked rainfall peaks, along with the statistical rainfall extremes for Vandyksdrift, from the WRC. It is evident that, for the Vandyksdrift station, there are no events that has been recorded at the station, which are in excess of the 1:50 year event, making this record unsuitable for the water balance assessment. However, the rainfall record is still suitable for the hydrological assessment. Therefore for the water balance modelling Langsloot/Secunda gauge was used and further detail is given in Section 5 above.

Figure 6.3.3(a): Top 100 one day ranked rainfall peaks

6.4 Surface water quantity

The quantity of water under average and extreme rainfall conditions (wet and dry) is given below.

6.4.1 Mean Annual Runoff (MAR)

The Mean Annual Runoff (MAR) below was extracted from the 2002 EMPR.

Table 6.4.1(a) details the MAR for the catchment areas that were defined as part of the MAR study, as taken from the 2002 EMPR. Figure 6.4.1(a) illustrates these catchments and nodes.

54



Table 6.4.1(a): Mean Annual Runoff (MAR) for catchment areas at Wolvekrans Colliery North section

Node Location

Description MAR

(x106m3)

A Sub catchment immediately upstream

of the mine. 3.1

BN Sub catchment upstream of the

receiving water body and immediately downstream of the mine.

7.1

6.4.2 Normal Dry Weather Flow

The dry weather flow (DWF) was extracted from the 2002 EMPR using the total of the monthly average rainfall figures of the four dry months of the year, namely May, June, July and August. This was found to equate to 46.4mm.

The expected DWF for the various catchments is presented in Table 6.4.2(a) and the catchments considered can be seen in Figure 6.4.1(a).

Table 6.4.2(a): Computed dry weather flows of the affected rivers at MMS North

Location Description Dry Weather Flow

(x106m3 per month)

A Sub catchment immediately upstream

of the mine. 0.19

BN Sub catchment upstream of the

receiving water body and immediately downstream of the mine.

0.45

6.4.3 Flood peaks and volumes

Flood peaks were calculated for the 2002 EMPR using the Rational Method and unit Hydrograph techniques as shown in Table 6.4.3(a).

For the 2002 EMPR, flood peaks and volumes for different recurrence interval floods were determined at various points on the mine, as indicated in Figure 6.4.1(a). Flood peaks for various recurrence intervals were computed using the Rational Method and the Unit Hydrograph Method.

For the floodline determination, flood peaks were computed along the Spookspruit diversion, as well as along an unnamed tributary of the Vaalbankspruit and are indicated in Figure 6.4.1(a). Catchment areas and slopes were determined from the contour plan provided by the client, as well as the 1:50 000 series topographical maps.

There are a multitude of methods available for the determination of peak flows, with the applicability of each method depending largely on catchment area, but also the region in which the peak flow is being determined.

The peak flows calculated using each method were evaluated for each node and a representative value adopted. The 1:50, 1:100, 1:200 year and Regional Maximum Flood (RMF) for each node, together with catchment areas, are presented in Table 6.4.3(b).

55



Figure 6.4.1(a): Catchment boundaries and nodes

56



Table 6.4.3(a): Peak flows (m3/s) for various recurrence intervals ( from 2002 EMPR)

Catchment Recurrence interval Flood Peaks (m3/s)

A

20 year 122

50 year 192

100 year 270

RMF 511

BN

20 year 195

50 year 307

100 year 432

RMF 767

Table 6.4.3(b): Peak flows (m3/s) for various recurrence intervals

Catchment Area (km2) Recurrence interval Flood Peaks (m3/s)

A2 94.10

10 300

20 409

50 596

100 799

RMF 562

A8 5.40

10 27

20 41

50 60

100 77

RMF 190

6.4.4 Floodlines

Floodlines were determined based on the calculated flood peaks at each node, as indicated in Figure 6.4.3(a). The floodline model was developed using the River and Flood Analysis Module of AutoCAD Civil 3D Ultimate, in which a steady flow, backwater analysis was performed. The River and Flood Analysis Module is a module in the AutoCAD Civil 3D Ultimate software package that provides a CAD interface to the HEC-RAS River Modelling System. HEC-RAS was developed by the Unites States Army Corps of Engineers, and is considered industry standard software for floodline analysis in many countries, including the United States, the United Kingdom, Europe, Australia and South Africa.

An electronic digital terrain model (DTM), in the form of a LiDAR survey with contours at 0.5 mm intervals was provided by South32 and utilised in the model.

When determining floodlines, the streams were defined by inputting a number of cross sections along the length of the watercourse. The cross sections are determined from the contour data. Cross sections were measured at approximately 20 m intervals on average, as well as at significant features which may act as controls, such as bridges or culverts.

57



The 1:50 and 1:100 year floodlines were determined for the Spookspruit diversion and an unnamed tributary of the Vaalbankspruit as part of this study. These floodlines are indicated in Figure 6.4.4(a). This figure also includes Floodlines carried out during previous studies.

It should be noted that the accuracy of the floodlines produced in this study is commensurate with the accuracy of the digital terrain model (DTM) data provided. With a contour interval of 0.5 m, the accuracy of the floodlines can be considered to be within 0.5 m vertically. The floodlines given here are considered suitable for planning purposes only and are not certified. Where infrastructure is to be located adjacent to the streams, the floodlines should be determined more accurately using a DTM developed from a field survey at the area of concern.

The LiDAR survey that was provided by South32 is of good resolution. However, there were portions along the Spookspruit diversion where detail was poor, particularly with respect to defining the shape (depth and width) of the diversion canal. It is recommended that a field strip survey be undertaken in these areas and the floodline re-evaluated. However, bearing this in mind, the floodlines represented here are the best estimate given the accuracy of the survey available.

6.4.5 Watercourse Alterations

Watercouse alterations have been described in Section 4.6.

58



Figure 6.4.4(a): 1:50 and 1:100 year Floodlines

59



6.5 Surface water quality

This section details sampling locations and water quality objectives, with respect to surface water and provides an assessment of the surface water quality and the impact of mining on the surrounding watercourses and catchments.

6.5.1 Class and Resource Quality Objectives

The Minister of Water and Sanitation published the classes and Resource Quality Objective (RQO) of water resources for the Olifants River catchment in GN R466 on 22 April 2016. These RQOs were published in terms of S13(4) of the NWA. The purpose is to ensure ecological sustainability by taking into consideration the social and economic needs of competing interests of all who rely on the water resources.

Water resources are classified in terms of their permissible utilisation and protection. The proposed classification of the Upper Olifants River catchment is Class III, requiring sustainable minimal protection and indicating high utilisation.

In terms of the Government Notice, quaternary drainage region B11H is to be maintained at Ecological Category C, and quaternary drainage regions B11G and B12D are to be maintained at Ecological Category D.

6.5.2 Surface water quality monitoring locations

Wolvekrans Colliery North section has an extensive water quality monitoring programme in place. Water quality data, for several locations around the site, extending from August 2012 to May 2015 was received from South32 CSA.

The surface water monitoring locations are illustrated in Figure 6.5.1(a) and the coordinates of these points are given in Table 6.5.1(a).

Table 6.5.1(a) List of surface water monitoring locations

Sampling Location Coordinates

E6 Decant

S25°55.243'

E29°25.675'

E6 Sump

S25°55.289'

E29°25.709'

D6 Dam 6

S25°54.048'

E29°26.443'

D7 Dam 7

S25°53.633'

E29°26.973'

D8 Dam 8

S25°52.323'

E29°26.436'

D9 Dam 9 S25°52.066'

E29°26.611'

D10 Dam 10

S25°51.855'

E29°26.439'

D20 Tings eye in Game Camp

S25°55.379'

E29°23.226'

60




D20B Small Dam in Game Camp

S25°55.731'

E29°23.507'

Spk 2 (along the Spookspruit)

S25°55'44.81'

E29°26'48.14

Spk2 (along the Spookspruit)

S25°55'38.9

E29°26'40.2


S25°55'20.8

E29°26'10.8


S25°55'11.

E29°25'40.8

S55 Spookspruit entrance

S25°56.638'

E29°27.972'

Spookspruit @ R35

S25°57'43.0

E29°28'37.4

Spk 1(along the Spookspruit)

S25°56'39.0

E29°27'58.9

Goedehoop Dam

S25°52.415'

E29°25.891'

DC5 Farm Dam

S25°52.988'

E29°25.478'

M1 Mavela Colliery Decant

S25°52.717'

E29°26.281'

S53 Spookspruit Exit

S25°55.185'

E29°25.679'

S54 Spookspruit Exit

S25°55.330'

E29°26.200'

S55 Spookspruit entrance

S25°56.638'

E29°27.972'

S63 Spookspruit MMS road

S25°51.436'

E29°23.777'

Spookspruit Muhanga Bridge

S25°53'28.24'

E29°25'20.64

Spookspruit Joins Olifants

S25°48'749

E29°19'348

Olifants Before Spookspruit

S25°48'749

E29°19'557

Presidenstrus before waterworks

S25°45.709'

E029°19.026'

S-55

S25°45.709'

E029°19.026'

Spookspruit before Bankfontein Dam S25°45.709'

E029°19.026'

61




Spk5 – Muhanga (along the Spookspruit)

S25°53'28.1

E29°25'21.2


S25°51'32.0

E29°23'49.8

DC5

S25°52'59.2

E29°25'28.9

Niekerspruit

S25°55'003

E29°25'009

6.5.3 Surface water quality objectives

There are various standards and objectives in terms of surface water quality, depending on what the end use is to be. Some of these include the Department of Water Sanitation (DWS) Domestic Use Guidelines and the SANS 241 Drinking Water specifications. In some cases, however, there are more specific standards in terms of the catchment itself, as determined by the Catchment Management Agency (CMA).

The Directorate National Water Resource Planning (DNWRP) of the (then) Department of Water Affairs and Forestry (DWAF) developed a water quality management strategy for the Upper and Middle Olifants River catchment, which was published in 2009 (DNWRP, 2009). One of the key elements of this strategy is Resource Water Quality Objectives (RWQO). The catchment was delineated into catchment management units (CMUs) and RWQO were developed for each CMU.

The Wolvekrans Colliery North section is located within the Olifants River water management area, and within Catchment Management Unit (CMU) 26. Figure 6.5.2(a) shows the site in relation to its CMU and the RWQO for this CMU, against which the water quality monitoring data have been compared, are presented in Table 6.5.2(a).

Table 6.5.2(b) Interim Resource Water Quality Objectives for the Loskop Dam incremental catchment

Constituent Unit CMU 26 Loskop Dam

Physical

Electrical conductivity (EC)

mS/m 90 40

Dissolved oxygen (DO) % Sat 70 70

pH - 6.5-8.4 6.5-8.4

Suspended solids mg/ℓ - -

Turbidity NTU - -

Chemical, Inorganic

Alkalinity mg CaCO3/ℓ 120 85

Boron (B) mg/ℓ 0.5 0.5

Calcium (Ca) mg/ℓ 150 32

Chloride (Cl) mg/ℓ 20 25

62



Constituent Unit CMU 26 Loskop Dam

Fluoride (F) mg/ℓ 0.75 0.75

Magnesium (Mg) mg/ℓ 100 20

Potassium (K) mg/ℓ 20 10

Sodium (Na) mg/ℓ 70 25

Sodium Absorption Ration (SAR)

Meql0.5 2 1.5

Sulphate (SO4) mg/ℓ 400 120

Total Dissolved Solids (TDS)

mg/ℓ 650 260

Chemical, Organic

Dissolved Organic Carbon (DOC)

mg/ℓ 10 10

Metals, Dissolved

Iron (Fe) mg/ℓ 1 1

Manganese (Mn) mg/ℓ 0.4 0.18

Aluminium (Al) mg/ℓ 0.02 0.02

Chromium VI (Cr VI) mg/ℓ 0.05 0.05

Plant Nutrients

Ammonia (NH3)* mg/ℓ as N 0.007 0.007

Nitrate (NO3) mg/ℓ as N 6 6

Phosphate (PO4) mg/ℓ as P 0.05 0.02

Total phosphorus mg/ℓ as P 0.25 0.05

Total Inorganic Nitrogen

mg/ℓ as N 2.5 0.2

Microbiological

E. coli # per 100 mℓ 130 130

Chlorophyll a mg/ℓ 0.02 0.02

* Free unionised NH3

63



Figure 6.5.1(a): Surface water monitoring locations

64



Figure 6.5.2(a): Location of site in relation to the Catchment Management Units

65



6.5.4 Baseline water quality analysis

The summarised baseline water quality results, for the data provided by South32 CSA, can be seen in Table 6.5.3(a), where the average, maximum and minimum concentrations are presented, together with the coefficient of variation. Values in red indicate where the interim RWQO for CMU26 are exceeded.

Figures 6.5.3(a) to (c) indicate the average and maximum concentrations measured at each monitoring location, in terms of compliance with the RWQO, pH, sulphate (SO4) and electrical conductivity (EC) respectively.

6.5.5 Baseline water quality interpretation

The values for various constituents measured around the project area were compared to the interim RWQO for CMU26; pH, SO4, EC, Iron (Fe), Aluminium (Al) and Manganese (Mn) are discussed below:

6.5.5.1. pH

The pH of natural waters is a measurement of the acidity/alkalinity and is the result of complex acid-base equilibrium of various dissolved compounds. The pH of most raw water sources is within the range of 6.5 to 8.5 (DWAF, 1996). A decrease in the pH of water in a mining area will be an indication of acid mine drainage (AMD).

The results in Table 6.5.3(a) to (c) indicate that the monitoring locations along the Spookspruit (locations within the mining area, as well as upstream and downstream of the mining area) are below the pH limits of the interim RWQO.

At several dams namely (D6 Dam 6, D9 Dam 9, D10 Dam 10 and DC5 Farm Dam) low pH limits were observed when compared to the interim RWQO. All the above areas are within the mining area. Low pH levels in the above areas are therefore an indication of acid mine drainage.

Elevated pH levels were noted within the mining area at D7 Dam 7, D8 Dam 8 and downstream of the mining area at Goedehoop Dam. These elevated pH levels may be due to agricultural activities within the surrounding area.

pH levels are indicated in Figure 6.5.3(a).

Time series graphs for pH are given below in Figures 6.5.4(a) to (h).

66



Figure 6.5.4(a) Time Series graph 1 of pH

Figure 6.5.4(b) Time Series graph 2 of pH

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

1-Apr-12 18-Oct-12 6-May-13 22-Nov-13 10-Jun-14 27-Dec-14 15-Jul-15

pH

Date

pH

Goedehoop Dam

E6 Decant

E6 Sump

D6 Dam 6

Limit (6.5 - 8.4)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00


pH

Date

pH

D7 Dam 7

D8 Dam 8

D9 Dam9

D10 Dam10

Limit (6.5 -

8.4)

67



Figure 6.5.4(c) Time Series graph 3 of pH

Figure 6.5.4(d) Time Series graph 4 of pH

0.00

2.00

4.00

6.00

8.00

10.00

12.00


pH

Date

pH

D20 Tings Eye

D20B Small Dam

DC5 Farm Dam

M1 Mavela Collierg

Limit (6.5 - 8.4)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00


pH

Date

pH

S53 Spkspr Exit

S54 Spkspr

bankfontein Exit

S55 Spkspr

Entrance

S63 Spkspr Mms

Road

Limit (6.5 - 8.4)

68



Figure 6.5.4(e) Time Series graph 5 of pH

Figure 6.5.4(f) Time Series graph 6 of pH

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

6-Aug-12 3-Jan-13 10-May-13 5-Sep-13 6-Feb-14 3-Jul-14 4-Dec-14

pH

Date

pH

Spk Spruit Joins

Olifants

Olifants Before

Spk Spruit

Presidentsrus

S-55

Limit (6.5 - 8.4)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00


pH

Date

pH

Spk before

bankfontein Dam

Spookspruit

@R35

Spk 1

Spk2

Limit (6.5 - 8.4)

69



Figure 6.5.4(g) Time Series graph 7 of pH

Figure 6.5.4(h) Time Series graph 8 of pH

6.5.5.2. Sulphate (SO4)

The concentration of sulphates in surface water is typically low (~5mg/ℓ), although concentrations of several hundred mg/ℓ may occur where dissolution of sulphate minerals or discharge of sulphate-rich effluents takes place (DWAF, 1996). AMD decanting or seeping from mining areas can increase the sulphate in surface water significantly. Chemical fall-out during rain events in areas where coal burning takes place can also increase the sulphate content of surface water bodies.

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00


pH

Date

pH

Spk3

Spk4

Spk5 - Muhanga

Spk 6

Limit (6.5 - 8.4)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00


pH

Date

pH

DC5

Niekerkspruit

Exit

70



Sulphate is a key indicator of water affected by coal mining.

On average, the sulphate concentration at all locations within and outside the mining area, except monitoring location D10 Dam 10, D20 Tings eye in Game Camp and D20B Small Dam in Game Camp, are highly elevated when compared to the interim RWQO of 400mg/ℓ, particularly at all the dirty water dams, which can be attributed to mining activities in the area.

On average, locations within the mining area where the sulphate concentration is within the interim RWQO limits are at D10 Dam 10, D20 Tings eye in Game Camp and D20B Small Dam in Game Camp.

Other locations upstream and downstream of the mining area where on average, the sulphate concentration is within the interim RWQO limits but the maximum concentration of sulphate was well above the interim RWQO (i.e. > 900mg/l recorded) are along the Spookspruit at R35, D10 Dam 10 and along the Spookspruit before Bankfontein Dam.

SO4 concentrations are indicated in Figure 6.5.3(b).

Time series graphs for SO4 are given below in Figures 6.5.4(i) to (p).

Figure 6.5.4(i) Time Series graph 1 of SO4

0

1000

2000

3000

4000

5000

6000

7000

8000


SO

4m

g/l

Date

SO4

Goedehoop Dam

E6 Decant

E6 Sump

D6 Dam 6

Limit (400)

71



Figure 6.5.4(j) Time Series graph 2 of SO4

Figure 6.5.4(k) Time Series graph 3 of SO4

0

1000

2000

3000

4000

5000

6000

7000

8000


So

4m

g/l

Date

SO4

D7 Dam 7

D8 Dam 8

D9 Dam9

D10 Dam10

Limit (400)

0

500

1000

1500

2000

2500

3000

3500

4000

4500


SO

4m

g/l

Date

SO4

D20 Tings Eye

D20B Small Dam

DC5 Farm Dam

M1 Mavela Collierg

Limit (400)

72



Figure 6.5.4(l) Time Series graph 4 of SO4

Figure 6.5.4(m) Time Series graph 5 of SO4

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000


SO

4 m

g/l

Date

SO4

S53 Spkspr Exit

S54 Spkspr

bankfontein Exit

S55 Spkspr

Entrance

S63 Spkspr Mms

Road

Limit (400)

0

500

1000

1500

2000

2500

3000

3500


SO

4m

g/l

Date

SO4

Spk Spruit Joins

Olifants

Olifants Before

Spk Spruit

Presidentsrus

S-55

Limit (400)

73



Figure 6.5.4(n) Time Series graph 6 of SO4

Figure 6.5.4(o) Time Series graph 7 of SO4

0.0

200.0

400.0

600.0

800.0

1000.0

1200.0

1400.0

1600.0

1800.0


So

4 m

g/l

Date

SO4

Spk before

bankfontein Dam

Spookspruit

@R35

Spk 1

Spk2

Limit (400)

0.0

500.0

1000.0

1500.0

2000.0

2500.0

3000.0

3500.0

4000.0

4500.0

5000.0


SO

4m

g/l

Date

SO4

Spk3

Spk4

Spk5 - Muhanga

Spk 6

Limit (400)

74



Figure 6.5.4(p) Time Series graph 8 of SO4

6.5.5.3. Electrical conductivity

Electrical conductivity (EC) is a measure of the ability of water to conduct an electrical current, which is as a result of the presence of charged ions such as carbonate, bicarbonate, chloride, sulphate, nitrate, potassium, calcium and magnesium (DWAF, 1996). It is therefore an indicator of the salinity, or total salt content, of water. Accumulation of salts can influence the potential to use the water downstream by water users, such as irrigation for agriculture, as well as livestock watering.

On average, the EC levels at all locations within and outside the mining area, except monitoring location D10 Dam 10, D20 Tings eye in Game Camp and D20B Small Dam in Game Camp, are highly elevated when compared to the interim RWQO limits, which can be attributed to mining activities in the area.

On average, locations within the mining area where the sulphate concentration is within the interim RWQO limits are at D10 Dam 10, D20 Tings eye in Game Camp and D20B Small Dam in Game Camp.

Other locations upstream and downstream of the mining area where on average, the EC level is within the interim RWQO limits but the maximum levels recorded was well above the interim RWQO (i.e. > 200 recorded) are along the Spookspruit at R35, D10 Dam 10 and along the Spookspruit before Bankfontein Dam.

EC levels are indicated in Figure 6.5.3(c).

Time series graphs for EC are given below in Figures 6.5.4(q) to (x).

0.0

500.0

1000.0

1500.0

2000.0

2500.0

3000.0

3500.0

4000.0

4500.0

5000.0


SO

4 m

g/l

Date

SO4

DC5

Niekerkspruit Exit

Limit (400)

75



Figure 6.5.4(q) Time Series graph 1 of EC

Figure 6.5.4(r) Time Series graph 2 of EC

0

100

200

300

400

500

600

700

800


EC

Date

EC

Goedehoop Dam

E6 Decant

E6 Sump

D6 Dam 6

Limit (90)

0

100

200

300

400

500

600

700

800

900


EC

Date

EC

D7 Dam 7

D8 Dam 8

D9 Dam9

D10 Dam10

Limit (90)

76



Figure 6.5.4(s) Time Series graph 3 of EC

Figure 6.5.4(t) Time Series graph 4 of EC

0

100

200

300

400

500

600


EC

Date

EC

D20 Tings Eye

D20B Small Dam

DC5 Farm Dam

M1 Mavela Collierg

Limit (90)

0

100

200

300

400

500

600


EC

Date

EC

S53 Spkspr Exit

S54 Spkspr

bankfontein Exit

S55 Spkspr

Entrance

S63 Spkspr Mms

Road

Limit (90)

77



Figure 6.5.4(u) Time Series graph 5 of EC

Figure 6.5.4(v) Time Series graph 6 of EC

0

50

100

150

200

250

300

350

400

450


EC

Date

EC

Spk Spruit Joins

Olifants

Olifants Before

Spk Spruit

Presidentsrus

S-55

Limit (90)

0

50

100

150

200

250


EC

Date

EC

Spk before

bankfontein Dam

Spookspruit

@R35

Spk 1

Spk2

Limit (90)

78



Figure 6.5.4(w) Time Series graph 7 of EC

Figure 6.5.4(x) Time Series graph 8 of EC

6.5.5.4. Iron (Fe)

Iron (Fe) is the fourth most abundant element, constitutes 5% of the earth's crust and is found in many minerals. An important mineral in the context of this investigation is pyrite (FeS), which is often associated with coal formations. Iron can be present in water as dissolved ferric iron (Fe III), as ferrous iron (Fe II) or as suspended iron hydroxides. The concentration of dissolved iron in unpolluted surface water is typically in the range of 0.001 - 0.5 mg/ℓ (DWAF, 1996). The interim RWQO for iron was set as 1 mg/ℓ for CMU26.

0

100

200

300

400

500

600


EC

Date

EC

Spk3

Spk4

Spk5 - Muhanga

Spk 6

Limit (90)

0

100

200

300

400

500

600


EC

Date

EC

DC5

Niekerkspruit

Exit

79



On average, highly elevated iron concentrations were noted at D6 Dam 6, D9 Dam 9 and M1 Mavela Colliery Decant. All of these locations are located within the mining area and therefore may be attributed to mining activities.

6.5.5.5. Aluminium

Aluminium occurs in water either as suspended aluminium minerals or as dissolved aluminium species. The concentration of dissolved aluminium in unpolluted water at neutral pH is typically 0.005 mg/ℓ or less. In water with a low pH, or where soluble aluminium complexes are present, the dissolved aluminium concentration can rise to high values (DWAF, 1996).

On average, all locations display highly elevated aluminium concentrations.

Elevated aluminium concentrations may be due to agricultural activities and mining activities in the surrounding area.

6.5.5.6. Manganese

Manganese (Mn) is a relatively abundant element which constitutes 0.1% of the earth’s crust. The median concentration in fresh water is 8 µg/ℓ, with a range of 0.02 to 130 µg/ℓ (DWAF, 1996).

On average, highly elevated manganese concentrations were noted at majority of sampling locations, with the exception of D8 Dam 8 within the mining area and Goedehoop dam, downstream of the mining area.

Elevated manganese concentrations may be due to agricultural activities and mining activities in the surrounding area.

80



Table 6.5.3(a) Surface water quality data (August 2012 to May 2015) within the mining area

Interim RWQO

limits for MU26120 90 6.5-8.4 650 - 150 20 100 6 20 70 400 0.02 1 0.4

E6 Decant S25°55.243' Average 71 478 7.0 5571 92 436 9 724 1 24 44 3917 0.57 1 10.9

E29°25.675' Maximum 172 674 8.0 9618 1141 771 18 1382 5 38 64 6883 9.00 12 28.1

Minimum 17 120 6.5 1054 2 84 5 85 0 6 4 653 0.02 0 0.0

Coeff of Variation% 1 0 0.1 0 2 0 0 0 2 0 0 0 3.07 2 0.8

E6 Sump S25°55.289' Average 152 536 7.2 6525 49 506 111 825 0 32 33 4476 0.06 0 16.6

E29°25.709' Maximum 176 544 7.7 7052 62 562 737 910 0 35 37 4895 0.11 1 18.2

Minimum 142 528 6.9 5988 34 422 6 752 0 27 27 4194 0.01 0 13.6


D6 Dam 6 S25°54.048' Average 111 367 5.6 3707 33 347 12 378 1 23 85 2674 8.33 16 20.4

E29°26.443' Maximum 263 536 8.1 7012 99 709 22 805 4 42 587 4809 32.60 80 92.2

Minimum 5 60 2.7 458 1 1 5 44 0 8 9 292 0.03 0 0.6


D7 Dam 7 S25°53.633' Average 62 482 7.9 5424 53 528 19 603 0 39 106 3732 0.26 0 22.7

E29°26.973' Maximum 127 781 8.9 9658 106 845 36 1187 0 66 206 6733 2.11 1 196.0

Minimum 25 164 6.7 1508 10 219 2 88 0 11 16 945 0.03 0 0.0


D8 Dam 8 S25°52.323' Average 71 257 8.1 2666 33 313 6 268 0 16 21 1742 0.59 0 0.3

E29°26.436' Maximum 110 280 8.6 3014 320 400 9 328 1 20 28 2010 14.42 2 2.6

Minimum 25 159 6.8 1522 0 172 4 140 0 12 3 892 0.02 0 0.0


D9 Dam 9 S25°52.066' Average 17 100 4.9 814 33 90 11 62 0 14 18 536 2.12 7 7.2

E29°26.611' Maximum 43 332 7.5 3236 194 328 38 210 1 45 51 2269 35.50 69 31.9

Minimum 5 2 3.0 24 4 2 2 1 0 1 3 10 0.02 0 0.0


D10 Dam 10 S25°51.855' Average 18 26 6.6 226 120 25 7 16 0 6 6 133 0.50 0 0.1

E29°26.439' Maximum 103 262 7.7 2562 1166 286 22 228 1 17 23 1661 5.39 3 0.7

Minimum 5 4 3.3 36 1 2 3 1 0 1 3 14 0.02 0 0.0

Coeff of Variation% 1.40 2 0.1 3 2 2 1 3 1 1 0.88 2.79 2.47 1.70 2.1

D20 Tings eye in Game Camp S25°55.379' Average 34.45 20 7.5 132 10 8 24 5 0 5 24 29 0.09 0 0.0

E29°23.226' Maximum 49 28 9.9 196 71 13 35 10 1 23 36 49 0.40 1 0.3

Minimum 19 15 0.4 96 1 5 16 0 0 3 5 16 0.01 0 0.0


D20B Small Dam in Game Camp S25°55.731' Average 19 19 6.9 137 15 12 19 6 0 8 16 54 0.18 1 0.9

E29°23.507' Maximum 32 64 9.0 420 47 48 28 13 0 19 26 249 1.45 4 10.0

Minimum 6 12 4.0 88 3 8 11 2 0 0 10 24 0.02 0 0.0

Coeff of Variation % 0 1 0.2 1 1 1 0 0 0 0 0 1 1.96 1 2.9

Spk 2 S25°55'44.81' Average 138.5 89 8.0 680 4 66 30 52 1 13 55 301 0.07 0 0.2

E29°26'48.14 Maximum 139 92 8.0 698 6 70 31 55 1 14 56 316 0.08 0 0.2

Minimum 138 85 8.0 662 3 61 29 48 1 11 53 286 0.06 0 0.1

Coeff of Variation% 0.01 0 0.0 0 1 0 0 0 0 0.04 0.07 0.20 0.28 0.3

Spk2 S25°55'38.9 Average 47.84 110 6.8 927 13 98 22 67 0 10 60 563 0.23 0 3.8

E29°26'40.2 Maximum 169 232 8.1 2204 66 238 34 148 1 30 139 1433 1.18 1 26.6

Minimum 6 60 4.2 440 1 33 15 25 0 4 18 259 0.02 0 0.0


Spk3 S25°55'20.8 Average 134.07 215 7.3 2074 26 270 12 186 0 11 43 1335 0.51 0 2.3

E29°26'10.8 Maximum 239 379 8.0 4672 116 603 28 478 1 23 73 2972 17.60 2 9.3

Minimum 10 69 3.4 249 2 54 6 40 0 6 12 308 0.01 0 0.0


Spk4 S25°55'11. Average 59 294 7.0 3083 24 268 12 364 0 15 44 2101 0.19 0 3.6

E29°25'40.8 Maximum 112 526 7.9 6564 68 493 27 1004 1 30 89 4671 4.06 2 17.4

Minimum 8 101 5.4 832 3 95 3 80 0 7 22 533 0.01 0 0.2


Sample Location

TALK

(Total

Alkalinity)

EC

(Electrical

Conductivity)

pHFe

(Iron)

Mn

(Manganese)

Ca

(Calcium)

Cl

(Chloride)

Mg

(Magnesium)

N_NO3

(Nitrate)

K

(Potassium)

Na

(Sodium)

SUSP_SOLID

(Suspended Solids)

Number of

Data Points

TDS

(Total

Dissolved

Solids)

Within Mining Area

28

7

24

14

32

Mine

SO4

(Sulphate)

Al

(Aluminium)

26

19

33

18

2

45

47

47

81



Table 6.5.3(b) Surface water quality data (August 2012 to May 2015) upstream of the mining area

Interim RWQO

limits for MU26120 90 6.5-8.4 650 - 150 20 100 6 20 70 400 0.02 1 0.4

S55 Spookspruit entrance S25°56.638' Average 43 131 5.3 1211 18 134 20 90 0 10 38 766 9.72 1 7.6

E29°27.972' Maximum 77 424 7.4 4666 34 422 69 631 1 31 100 3244 37.90 3 54.0

Minimum 7 17 3.4 124 6 11 9 8 0 4 10 44 0.02 0 0.1


Spookspruit @ R35 S25°57'43.0 Average 38 43 6.8 335 9 38 23 18 1 8 26 164 0.14 0 2.1

E29°28'37.4 Maximum 103 216 7.6 2106 59 238 53 179 4 37 64 1413 1.95 2 33.0

Minimum 6 19 4.3 132 1 10 9 5 0 2 15 26 0.01 0 0.0


Spk 1 S25°56'39.0 Average 35 133 5.4 1163 26 135 21 81 1 9 42 741 9.84 1 6.0

E29°27'58.9 Maximum 79 227 7.6 2278 328 295 52 158 2 23 93 1567 39.50 2 17.6

Minimum 7 28 3.4 196 2 21 10 15 0 3 4 65 0.02 0 0.1


Upstream of Mining Area

33

Mine

Sample LocationNumber of

Data Points

TALK

(Total

Alkalinity)

EC

(Electrical

Conductivity)

pH

TDS

(Total

Dissolved

Solids)

SUSP_SOLID

(Suspended Solids)

Ca

(Calcium)

Cl

(Chloride)

Mg

(Magnesium)

N_NO3

(Nitrate)

K

(Potassium)

Na

(Sodium)

SO4

(Sulphate)

Al

(Aluminium)

Fe

(Iron)

Mn

(Manganese)

40

45

82



Table 6.5.3(a) Surface water quality data (August 2012 to May 2015) downstream of the mining area

Interim RWQO

limits for MU26120 90 6.5-8.4 650 - 150 20 100 6 20 70 400 0.02 1 0.4

Goedehoop Dam S25°52.415' Average 70 190 8.2 1784 14 200 10 187 1 14 26 1158 0.08 0 0.0

E29°25.891' Maximum 92 207 9.0 2040 40 231 12 212 12 19 37 1399 0.46 0 0.1

Minimum 45 174 7.5 1274 2 178 8 153 0 12 20 913 0.01 0 0.0


DC5 Farm Dam S25°52.988' Average 23 302 6.8 3230 20 299 11 369 0 15 52 2211 0.11 0 2.0

E29°25.478' Maximum 65 494 7.5 6134 92 464 29 822 1 36 376 4143 0.36 1 9.6

Minimum 5 92 5.9 742 0 104 2 52 0 5 17 453 0.01 0 0.1


M1 Mavela Colliery Decant S25°52.717' Average 287 3.0 2654 88 273 5 174 0 12 46 1788 28.68 58 63.2

E29°26.281' Maximum 371 4.1 3856 1550 358 10 261 1 18 70 2772 59.90 377 168.0

Minimum 26 2.6 172 8 18 2 12 0 4 6 100 0.66 0 3.2

Coeff of Variation% 0 0.1 0 3 0 0 0 1 0 0 0 0.40 1 0.5

S53 spookspruit Exit S25°55.185' Average 62 304 6.9 3064 27 290 11 372 0 15 44 2165 0.10 1 5.3

E29°25.679' Maximum 216 522 7.7 6298 63 566 25 888 1 32 83 4353 0.29 10 16.2

Minimum 8 122 4.3 456 7 103 2 77 0 8 26 612 0.01 0 0.4


S54 Spookspruit Exit S25°55.330' Average 140 229 7.1 2307 26 280 12 212 0 12 45 1470 1.73 0 3.6

E29°26.200' Maximum 318 398 8.1 4578 78 604 39 483 1 25 84 3041 32.40 2 16.7

Minimum 8 48 3.5 380 1 45 2 33 0 6 10 212 0.02 0 0.3


S55 Spookspruit entrance S25°56.638' Average 43 131 5.3 1211 18 134 20 90 0 10 38 766 9.72 1 7.6

E29°27.972' Maximum 77 424 7.4 4666 34 422 69 631 1 31 100 3244 37.90 3 54.0

Minimum 7 17 3.4 124 6 11 9 8 0 4 10 44 0.02 0 0.1


S63 Spookspruit Mms road S25°51.436' Average 40 236 5.8 2397 20 243 11 240 0 14 42 1613 3.99 1 16.7

E29°23.777' Maximum 491 413 7.1 4516 141 403 26 535 0 28 61 3187 28.30 9 67.0

Minimum 5 67 4.4 532 3 50 7 50 0 1 20 321 0.03 0 0.1


Spookspruit Muhnga Bridge S25°53'28.24' Average 14.5 131 6.2 1144 11 119 7 116 0 9 17 755 0.11 0 8.8

E29°25'20.64 Maximum 22 161 6.3 1398 13 150 10 145 0 12 22 912 0.11 0 17.3

Minimum 7 101 6.2 890 9 88 5 86 0 5 13 598 0.11 0 0.2


Spookspruit Joins Olifants S25°48'749 Average 88 119 7.3 1068 49 113 28 99 2 11 46 631 0.22 0 1.2

E29°19'348 Maximum 257 358 8.0 3638 518 432 57 408 8 23 83 2394 4.46 2 16.9

Minimum 8 14 6.5 220 1 16 9 16 0 5 18 79 0.02 0 0.0


Olifants Before Spookspruit S25°48'749 Average 66 144 7.3 1328 23 138 24 126 2 11 45 811 0.12 0 2.5

E29°19'557 Maximum 135 406 8.1 4392 180 466 54 421 10 31 164 2869 0.49 1 29.5

Minimum 6 30 6.0 218 1 21 7 14 0 4 18 75 0.02 0 0.0


Presidenstrus before waterworks S25°45.709' Average 91 82 7.9 647 15 68 30 51 1 9 43 328 0.11 0 0.1

E029°19.026' Maximum 157 226 9.2 2078 187 204 58 208 5 26 73 1348 0.47 3 3.0

Minimum 40 32 6.8 224 1 23 9 14 0 1 18 80 0.01 0 0.0


S-55 S25°45.709' Average 13 219 5.6 2166 20 224 14 206 0 16 43 1460 5.92 0 17.4

E029°19.026' Maximum 68 410 8.0 4898 135 409 39 536 2 146 68 3272 27.10 2 77.5

Minimum 1 36 3.4 242 1 25 7 12 0 0 22 136 0.02 0 0.2


Spookspruit before bankfontein Dam S25°45.709' Average 58 53 7.1 393 90 40 28 26 1 8 32 185 1.17 1 1.2

E029°19.026' Maximum 113 158 8.4 1420 2858 174 55 82 3 17 71 911 24.00 2 10.3

Minimum 17 18 3.4 118 1 14 10 7 0 4 10 26 0.01 0 0.0


Spk5 - Muhanga S25°53'28.1 Average 20 281 6.4 2936 35 275 11 331 0 15 42 2032 0.33 0 4.1

E29°25'21.2 Maximum 54 514 7.3 6040 364 471 20 908 1 31 76 4418 1.73 1 17.4

Minimum 5 77 4.5 626 1 60 3 62 0 4 11 409 0.03 0 0.0


Spk6 S25°51'32.0 Average 15 226 5.6 2309 29 231 12 220 0 14 44 1530 5.12 0 17.8

E29°23'49.8 Maximum 97 413 7.9 4710 295 402 23 537 3 38 69 3296 27.30 1 74.2

Minimum 5 96 4.4 798 4 72 6 73 0 7 20 489 0.03 0 0.2


DC5 S25°52'59.2 Average 21 280 6.6 2914 18 273 11 326 0 17 43 2000 0.17 0 1.8

E29°25'28.9 Maximum 50 525 7.2 6342 41 485 21 796 1 102 77 4345 1.31 1 8.2

Minimum 5 77 5.0 630 3 63 2 63 0 5 11 411 0.03 0 0.0


Niekerspruit S25°55'003 Average 41 275 6.4 2894 39 248 8 350 1 13 23 1994 1.14 1 11.2

E29°25'009 Maximum 85 456 7.2 5586 160 487 17 742 3 72 41 3788 12.90 17 152.0

Minimum 5 3 3.0 32 2 2 3 1 0 2 5 10 0.02 0 0.0


2

33

32

33

32

33

33

33

46

46

46

45

63

65

65

45

51

Downstream of Mining Area

Mine

Sample LocationNumber of

Data Points

TALK

(Total

Alkalinity)

EC

(Electrical

Conductivity)

pH

TDS

(Total

Dissolved

Solids)

SUSP_SOLID

(Suspended Solids)

Ca

(Calcium)

Cl

(Chloride)

Mg

(Magnesium)

N_NO3

(Nitrate)

K

(Potassium)

Na

(Sodium)

SO4

(Sulphate)

Al

(Aluminium)

Fe

(Iron)

Mn

(Manganese)

83



Figure 6.5.3(a) Surface water quality – pH

84



Figure 6.5.3(b) Surface water quality – SO4

85



Figure 6.5.3(c) Surface water quality – EC

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6.5.5.7. Other constituents

Analysis of the other constituents in Table 6.5.3(c) indicates the following for catchment MU26:

� On average the TDS levels at majority of locations was highly elevated when compared to the interim RWQO, which can be attributed to mining in the area.

� Highly elevated Calcium (Ca) and Magnesium (Mg) were observed at majority of locations when compared to the interim RWQO. These elevated concentrations may be due to farming activities in the area.

� Chloride (Cl) concentrations were within the interim RWQO limits with the exception of monitoring locations E6 Sump, D20 Tings eye in Game Camp, Spk 2 Spk 1, Spookspruit at R35, Spookspruit joining Olifants, Olifants before the Spookspruit, Presidenstrus before the waterworks and along the Spookspruit before Bankfontein Dam. These elevated concentrations may be due to farming activities in the area.

� On average, potassium (K) concentrations were within the interimRWQO limits with the exception of marginally E6 Decant, E6 Sump, D6 Dam6 and D7 Dam which are located within the mining area.

� Highly elevated sodium (Na) concentrations were observed at D6 Dam6 and D7 Dam7 which are located within the mining area.

Therefore in terms of surface water quality within the study area there are visible impacts associated with mining activities.

6.5.6 Biomonitoring

Biomonitoring is addressed in a separate specialist report as part of this EMPR amendment.

6.5.7 Water authority

The water authority is the Department of Water and Sanitation, Mpumalanga Region.

6.5.8 Wetlands

The delineation of sensitive areas such as wetlands is addressed in a separate specialist report as part of this EMPR amendment.

6.6 Surface water users

The area north of Hartbeesfontein and west of Goedehoop is drained by the Spookspruit. On exiting the mine’s boundary, the Spookspruit flows for a further 17 km before joining the Olifants River. The main use of water along this stretch is for agricultural purposes, ranging from large-scale arable farming to casual grazing around plots.

The main users include Loskop Dam and various farmers. The main farming activities include dairy farms and grazing, as well as crops for market garden produce (AGES, 2013). A portion of Goedehoop could potentially drain to the Pienaars Dam, this being used as the main source of water for the town of Middelburg.

Surface water users in the vicinity of the mine include the following:

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• Farmers in the area using water for agricultural purposes. The main farming activities include dairy farms and grazing, as well as crops for market produce.

• The eMalahleni Local Municipality, as the major surface water user from the Witbank Dam. The foremost use of the water will therefore be drinking water and industrial supply.

• Recreational water users at the Witbank Dam.

• Eskom (i.e. Duvha Power Station) also abstracts water from the Witbank Dam for industrial purposes.

• Other coal mines such as Shanduka Coal, BlackWattle, Optimum Eikeboom section, the Pienaarsdam resort, as well as the Steve Tshwete Local Municipality (AGES, 2016).

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7. CONSIDERATION OF ALTERNATIVES

In accordance with Section 50(d) of the Mineral and Petroleum Resources Development Regulations, GN R527, under the Mineral and Petroleum Resources Development Act (2002) (MPRDA), as well as the Environmental Impact Assessment (EIR) Regulations Government Notice (GN) R982 to 985 of 2014: Listed activities in terms of NEMA., the alternatives considered in terms of minimising the impacts on surface water and the overall water balance are discussed in this section.

Various alternatives were evaluated in terms of the overall water management, including the following issues:

7.1 Clean water management

In so far as is practically possible all clean catchment draining towards the dirty areas at Wolvekrans Colliery North section will be diverted around the dirty areas, in order to minimise the generation of contaminated water, as well as maximise the clean runoff draining to the natural system, thereby minimising the impact on catchment yield.

7.2 Minimising the generation of dirty water make

All storm water generated on the site is considered dirty and will be contained in the opencast pits or underground workings before being directed to the various PCDs across the site for temporary storage prior to treatment in the MWRP. The mixing of clean and dirty water will be avoided, and the footprint of the dirty water areas have been minimised as far as is practically possible.

7.3 Maximising the reuse of dirty water

Dirty water will be collected and stored at either Goedehoop Dam or Dam 5 Pollution Control Dam. Surplus water will be pumped from either Goedehoop Dam or Dam 5 Pollution Control Dam to the MWRP for treatment and discharged to the Spookspruit.

7.4 Implementing treatment where required

Surplus water will be pumped from Goedehoop Dam or Dam 5 Pollution Control Dam to the MWRP for treatment and discharged to the Spookspruit.

7.5 Alternatives in terms of process development

These are detailed in the main EMP document.

7.6 Infrastructure alternatives at Dispatch Rider

Two coal transport corridors have been identified for the transport of coal from the Dispatch Rider area to the South Eskom Plant using road haulers or conveyor. Transporting coal to the Middlings Plant in the North was considered. However, additional existing infrastructure is in place towards the south. The first coal transport option considered is coal transport infrastructure on a newly proposed road that will run from the Dispatch Rider stockpile area to the existing haul road, and then along the existing haul road which goes to the South Eskom Plant. This first option will also require a crossing of the existing conveyor. The second option under consideration is the development of coal transport infrastructure on a new road travelling to the south west of the Dispatch Rider infrastructure area (to an area that has been used for the disposal of slurry in the past) that will join an existing haul road which goes to the South Eskom Plant.

89



For either option, coal will be transported via road or conveyor, using existing infrastructure as far as possible and constructing new roads where necessary. The two coal transport corridors have been outlined along the proposed road areas (solid lines) and along the existing haul roads areas (dotted lines).

Dirty water will be pumped to the existing voids for storage before it is re-used, or conveyed via the existing dirty water management systems to the Middelburg Water Reclamation Plant for treatment. Other options that were considered but ruled out on the basis that they do not address the surplus dirty water make as effectively as treatment, include:

� The use of forced evaporators.

� Pumping of surplus water to in-pit water storage/evaporation areas.

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8. ENVIRONMENTAL IMPACT ASSESSMENT AND MITIGATION MEASURES

8.1 Introduction

In order to quantify the potential impacts, the general format of the assessment is to first assess the impact assuming no mitigation measures are applied. In some instances these impacts could not result without extreme or unlawful practices, such as discharging all of the affected water from Wolvekrans Colliery North Extension project into the river system. However, this provides a basis for the “worst case” scenario, from which mitigation measures can be evaluated (such as containment or treatment for example). The residual impact after implementation of the mitigation measures is then assessed and indicated.

As required by the NEMA, cumulative impacts are also assessed as and where this is relevant and possible.

The format of the impact assessment is as follows:

� Section 8.2: The impact assessment methodology and rating system is described.

� Section 8.3: The nature of the various activities is described in terms of the phases of the project, from construction through to post-closure.

� Section 8.4: The activities are assessed, detailing the potential impacts, proposed mitigation measures and the residual impact over the full life-cycle of the project.

� Section 8.5: A qualitative note on cumulative impacts.

A summarised water management plan is provided in Section 10.

8.2 Impact assessment methodology and rating system

The rating of impacts was undertaken according to the impact rating and assessment process outlined in Appendix C.

8.3 Activities to be undertaken at Wolvekrans Colliery North that could potentially affect surface water

There are five main phases within the proposed project, namely:

� Planning / Definition Phase.

� Construction Phase.

� Operational and Maintenance Phase.

� Rehabilitation Phase.

� Decommissioning / Closure Phase.

Each of these phases is outlined below.

8.3.1 Planning /Definition Phase

During the planning phase, the proposed project is conceptualised. This includes undertaking preliminary designs of the proposed mining expansion. Section 7 evaluates the potential alternatives. Negotiations between the applicant and landowners will also conclude during this phase.

8.3.2 Construction phase

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Once the authorisation is received the proposed project will commence. This phase will commence when the construction contractors establish on site and will end with the commissioning of the operation, when the first coal is mined.

Activities to be undertaken that will potentially impact on surface water include the following:

� General construction activities:

� Civil works.

� Movement of materials and equipment.

� Servicing of construction vehicles and equipment.

� Construction of mine surface infrastructure:

� Construction of the mine surface infrastructure terrace and access roads.

� Construction of the change house, wash bays, boot washing, offices, laundry and workshops.

� Construction of the mine adit:

� Earthworks and access roads.

� Excavation and stockpile waste material.

� Concrete and steel work.

� Construction of water management infrastructure:

� Clean and dirty water canals.

� Sediment traps.

� Pollution control dams.

� Pump stations and pipelines.

� Construction of roads:

� Access and internal roads.

8.3.3 Operational Phase

This phase commences at the end of the construction period, and will end when Wolvekrans Colliery North extension mining reaches the end of its LOM, and mining activities cease.

The mining of coal will commence during this phase. The first box cut will be made using the truck and shovel method and the required infrastructure for the operation of a dragline will be completed, after which mining will progress using a dragline. Coal will be transported with trucks to the crusher/screener, from where it will be placed on a conveyor, transporting it to storage silos. From the storage silos, the coal will then be conveyed to the North Plant for processing

The activities that can impact on surface water include the following:

� Opencast mining operation.

� Destruction of water courses as mining progresses.

� Transport of coal to the existing crushing and screening plant

� Loading and unloading of coal.

92



� Operation and maintenance of the water management system around the opencast operations.

� Cleaning, repair and maintenance activities along roads.

� Dust and fire suppression water management.

� Offices, change house, laundry and ablution facilities.

� Workshop.

� Wash bays and boot washing.

� Underground shaft area.

� Operation of the water management system, including sediment management and management of the water levels in the PCDs and the pumping systems, which will include water make from the underground, and the circulation of this water to the underground.

8.3.4 Rehabilitation Phase

Rehabilitation of the mine pits will take place concurrently with mining, with final rehabilitation taking place after the operational phase has come to an end.

8.3.5 Decommissioning Phase

The decommissioning and closure of the Wolvekrans Colliery North Section will occur with the decommissioning of the mine in accordance with the EMPR and any other closure plans pertaining to mine infrastructure and facilities.

This phase starts at the end of the operational phase, and involves the closure of the Wolvekrans Colliery North Extension operation. This phase ends when the site obtains a Closure Certificate from the regulatory authorities, but may include a period where there is no activity on the site other than monitoring prior to Closure being obtained. Closure refers to the point at which the State assumes responsibility for the liabilities associated with the site. This acceptance is in turn based on the proponent providing an acceptable financial provision to meet any future costs related to the attainment of various closure objectives set for the site.

Activities expected for this period include:

� Civil works and materials movement.

� Closure of the mine operations, dismantling and removal of machinery and mine surface infrastructure.

� Rehabilitation of the footprints of the mine’s surface infrastructure.

8.3.6 Post closure

This phase will commence when the site has obtained Closure. The post-closure phase has no defined end, with the State managing the post closure impacts related to the site. However, should the authorities deem at the time that the proponent has not correctly defined the residual impacts, the proponent could also be required to address future impacts even after a Closure certificate has been issued.

The primary activity expected for this period is the monitoring of aspects such as surface and ground water quality.

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8.4 Surface water impact assessment and mitigation measures

The impacts are described in terms of the nature of the activity that could potentially impact on surface water, the nature of the impact if not mitigated, possible mitigation measures and the long-term impact.

Cumulative impacts are not addressed in the tables in Sections 8.4, but are noted in Section 8.5.

8.4.1 Construction Phase

8.4.1.1. Impact on surface water quality

The construction phase impacts on surface water quality are detailed in Impact Tables C1 to C4.

8.4.1.2. Impact on surface water quantity – catchment yield and flow rates

The construction phase impacts on surface water quantity are detailed in Impact Tables C5.

8.4.2 Operational Phase


The operational phase impacts on surface water quality are detailed in Impact Tables O1 to O5.

8.4.2.2. Impact on surface water quantity – catchment yield

The operational phase impacts on surface water quantity are detailed in Impact Tables O6 and O7.

8.4.3 Decommissioning and Closure Phases


The decommissioning and closure phase impacts on surface water quality are detailed in Impact Tables D1, D2 and PC1.


During decommissioning and closure the affected areas will be rehabilitated to generate clean runoff and will be restored to free draining conditions. Until the water management infrastructure is decommissioned the impact on catchment yield will remain as per the Operational Phase.

8.4.4 Post Closure Residual Impacts


Post closure the site will be rehabilitated, grassed and made free draining. All of the contaminated materials will have been removed from the site.

The impact on water quality is detailed in Impact Assessment Impact Table PC1

94




Post closure all areas, including the shaft area, will be rehabilitated and made free draining. There will therefore be no long-term impact on catchment yield.

8.5 Cumulative impacts

The Wolvekrans Colliery North and South form a large portion of surface disturbance in relation to the other activities in the area that could potentially impact on surface water. The Wolvekrans Colliery North extension area is small in relation to the existing Wolvekrans Colliery North and South mining area, however adds to the surface disturbance of Wolvekrans Colliery as a whole with a moderate to high impact on Pans in the area.

There are other existing coal mining operations in the region, namely Black Wattle Colliery to the north, as well as Mavela Colliery and Muhanga Mine on the banks of the Spookspruit downstream of the MWRP but are small in relation to Wolwekrans Colliery.

Therefore, there are numerous coal mines in the Olifants River catchment, both upstream and downstream of the mine, as well as surrounding agricultural activities, power stations and industrial areas that also potentially impact on the water quality and quantity in the catchment. Wolvekrans Colliery does form a large portion of this area.

The cumulative impact of the Wolvekrans Colliery North mining operation extension, with the mitigation measures described in the impact assessment, is considered to be medium to high in relation to the current and anticipated future activities in the area, as the catchment is already impacted by mining activities The cumulative impact of all of the coal mines in the area has resulted in a regional crisis in terms of water quality and quantity. Every new mine contributes to the further reduction and / or deterioration of the water resources in the Mpumalanga region and it is essential that good water management be implemented at Wolvekrans Colliery North to prevent further contributions to the existing impacts in the catchment.

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Impact C1 Construction Phase – General mine development – Impact on surface water quality

PHASE CONSTRUCTION PHASE

ACTIVITY

LOM: General mine development

Construction camps, construction works, movement of materials and construction equipment

ASPECT Water Quality – discharge of contaminated water

IMPACT DEFINITION Pollution of surface water resources

IMPACT DESCRIPTION AND EVALUATION

During the construction phase topsoil will be stripped and civil works, in the form of earthworks and terracing will be undertaken as part of the preparation of the area for the mine development.

Impacts may arise from:

• Erosion of soils during rainfall events, with elevated suspended solids in the runoff water.

• Resultant elevated suspended solids in the watercourses, as well as sedimentation in the watercourses.

• Hydrocarbon spillages from fuel storage, servicing areas or construction equipment itself, with resultant elevated hydrocarbon concentrations in runoff water and watercourses.

The surrounding and downstream surface water resources, namely the Spookspruit, Vaalbankspruit and Olifants Rivers, are considered stressed water resources in terms of both the quantity of water in the system and the quality of the water. The Olifants River also forms part of the water supply for irrigation water further downstream (from the Loskop Dam). Any impact on the quantity or quality of water in the system has the potential to affect the quality and assurance of supply to the community and agriculture.

IMPACT BEFORE MANAGEMENT

Significance Extent Duration Probability RATING Impact Class Confidence

Low Local Short-term

Very Likely LOW 2 Probable

2 3 2 4 1.87

MANAGEMENT MEASURES

The following mitigation measures will be implemented:

• The footprint of disturbed areas will be minimised.

• “No-go” zones will be delineated for construction plant and personnel.

• Diversion of clean upslope runoff away from the new proposed pits to be constructed first before establishment of box-cuts.

• Appropriate storm water management measures will be implemented, including the temporary diversion of upstream runoff around the construction and laydown areas.

• Surface water management infrastructure, such as storm water canals, sediment traps and sumps are to be constructed first at Dispatch Rider infrastructure area to ensure that runoff and dirty water spills are contained.

• Servicing of construction vehicles will take place only in dedicated areas that are equipped with drip trays.

• Bunded containment and settlement facilities will be provided for hazardous materials, such as fuel and oil.

• Spill-sorb or a similar product will be kept on site, and used to clean up hydrocarbon spills in the event that they should occur.

• Erosion protection measures will be implemented at steep areas.

• A waste management plan will be developed for the construction phase.

• Appropriate sewage management will be implemented during the construction phase that would tie into the existing sewage management strategy at Wolvekrans Colliery which will entail portable chemical toilets.

• Water quality monitoring will be undertaken downstream of the construction areas, before and during construction where practical, in order to detect any increase in suspended solids or turbidity.

• If erosion is evident, or the water quality monitoring indicates an increase in suspended solids, water management around the construction areas will be reviewed.

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ACTIVITY

LOM: General mine development




IMPACT AFTER MANAGEMENT


Very Low Study Area

Short-term Could happen VERY LOW 1 Probable

1 2 2 3 1.0

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Impact C2 Construction Phase – Linear infrastructure – Impact on surface water quality


ACTIVITY

Linear infrastructure





For Wolvekrans Colliery North Extension Project for majority of the pits existing haul roads and conveyors will be used, however there will be new haul roads or extensions to existing hauls roads required which were not available at the time of writing and are therefore not assessed.

The potential impacts and mitigations are given below:

During the construction phase for any linear infrastructure, topsoil will be stripped and civil works, in the form of earthworks and terracing will be undertaken as part of the preparation of the area for the relocation and construction of infrastructure.


• Disturbance of the watercourses at watercourse crossings (both on the existing infrastructure routes and the relocation alignments) resulting in erosion of soils during flow or rainfall events, with elevated suspended solids in the runoff water.


• Hydrocarbon spillages from fuel storage, servicing areas or construction equipment itself, with resultant elevated hydrocarbon concentrations in runoff water and watercourses.

MANAGEMENT MEASURES

The following mitigation measures should be implemented at new haul roads or haul road extensions:

• Mitigation measures as proposed in Table C1 above will apply.

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Impact C3 Construction Phase – Removal of material from the initial boxcuts– Impact on surface water quality


ACTIVITY Initial boxcut

Removal of material from the boxcut




The construction phase is considered to end once carbonaceous material, in the form of the coal seam, is exposed within the boxcut. However, much of the overburden removed prior to the exposing of coal has the potential to contain some carbonaceous material.

The hard rock removed from the initial boxcuts will be placed in the existing pits and used for rehabilitation, with the possible exception of the GP Pit in the north.

The excavated hard material that is clean will be stockpiled adjacent to the and later used to backfill the mine at mine closure. This material will remain in the stockpiles for the duration of mining until closure.


• Erosion during rainfall events, resulting in increased turbidity and suspended solids in the runoff water, reporting to the local watercourses.

• Deposition of sediments in the local watercourses, impacting on the aquatic ecology.

• Overburden stockpiles will potentially contain carbonaceous material, with the potential to affect downstream watercourses by increasing sulphate and TDS concentrations.

• Increase in turbidity and suspended solids.



Moderate Local Medium

term Very Likely MODERATE

3 Definite

3 3 3 4 2.4

MANAGEMENT MEASURES


• Overburden material from the boxcuts will be handled in-pit, therefore runoff and seepage from this material will be contained in the opencast pit, with the exception of GP pit where an overburden stockpile may be required. All runoff and seepage from this stockpile will be directed to Goedehoop Dam.

• Monitoring of the water qualities in the streams downstream of the boxcuts and overburden stockpile will be undertaken, in order to identify the potential impacts on water quality.



Very Low Local Medium

term Unlikely VERY LOW

2 Definite

1 3 3 2 0.93

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Impact C4 Construction Phase – Dewatering of water ingress to boxcut – Impact on surface water quality


ACTIVITY Initial boxcut

Dewatering of water ingress to boxcut




Water that enters the boxcut, both from groundwater seepage and direct rainfall, is expected to be largely clean. However, there is a possibility that this water will make contact with carbonaceous and pyritic materials. The water quality from the boxcut is therefore likely to be slightly to moderately impacted in terms of sulphate, TDS and suspended solids.


• Deposition of sediments in the local watercourses, impacting on the aquatic ecology.

• Discharge of the potentially impacted water to the environment, with a resultant increase in sulphate and TDS concentrations in the natural watercourses.





3 Definite

3 3 3 4 2.4

MANAGEMENT MEASURES


• The water will be contained at the site, at in-pit sumps and pumped from here to either Goedehoop Dam or Dam 5 for reuse in the existing mining operations or pumping to the MWRP for treatment.

• Surface water management measures, such as clean upslope diversion canals and berms to divert clean catchment away from mine workings.

• A Water Use Licence for the dewatering of groundwater encountered during mining will be applied for, including the reuse of this water for dust suppression.



Low Local Short term Unlikely VERY LOW 2 Definite

2 3 2 2 0.93

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Impact C5 Construction Phase – mine surface infrastructure, and boxcut area - Impact on surface water quantity


ACTIVITY

Mine surface infrastructure, and boxcut areas

Construction camps, construction works, movement of materials and construction equipment, excavation of boxcut and incline shaft

ASPECT Water Quantity – containment of runoff from the site

IMPACT DEFINITION Reduction in catchment yield


During construction, surface runoff will be released to the catchment once sediment has settled out.

All runoff and rainfall in the boxcut pits will be contained in the dirty water system and will therefore be lost to the catchment.

The loss in yield during the construction phase will be significantly lower than during the operational phase, which is quantified in Table O6 below, and is therefore not quantified individually here, given that the construction of the boxcuts will take place while the rest of the mine is operational.


• Containment of contaminated runoff water emanating from the site, with no release to the catchment.

Although runoff from dirty areas will be contained (see management measures below) and the probability of impact is definite, its significance has still been assessed as VERY LOW on the basis of the very small volumes of water that will be contained.



Very Low Study Area

Medium term

It’s going to happen

LOW 1 Definite

1 2 3 5 2

MANAGEMENT MEASURES


• The aerial extent of the disturbed and potentially contaminated areas will be kept to a minimum.

• Areas where dirty construction activities are carried out (e.g. servicing areas and workshops, fuel storage areas, waste storage areas) will be minimised and surrounded by bunds.

• Upslope runoff will be diverted around construction activities to minimise the volume of dirty water generated and contained.

• Surplus dirty water will be treated at the MWRP and released to the catchment.



Very Low Study Area

Short-term It’s going to

happen LOW

1 Definite

1 2 2 5 1.67

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Impact O1 Operational Phase – Mine water discharge – Impact on surface water quality

PHASE OPERATIONAL PHASE

ACTIVITY Mine water discharge

Discharge of mine water to the natural watercourses




It is important to note that the mine water balance assessment undertaken in Section 5 is aimed at ensuring that the mine does not spill water during the operational phase, except for extreme events related to rainfall with a risk of recurrence of 2% or less in any one year. The water management measures detailed in Sections 4 and 5 are mitigation measures, focusing primarily on the storage, reuse and treatment of water.

However, to merely indicate that the mine will not spill dirty water does not allow an assessment of the potential impact of non-compliance with the mitigation measures proposed. In order to assess the impact without mitigation, this impact assessment assumes that all dirty water is discharged to the catchment, where after detail is provided on how this will be prevented, and the impact after management is then assessed.

Impacts are as a result of runoff entering the mine affected areas and coming into contact with carbonaceous material, with resultant high salinity, particularly sulphate content.

The potential impact on aquatic life or downstream users of water within the rivers is highly dependent on the pH of the water discharged. This is because acidic conditions will result in mobilisation of metals, and this would be a major contributing factor to the potential toxicity of the water.



High Regional Medium to Long term

Very Likely HIGH 4 Definite

4 4 4 4 3.2

MANAGEMENT MEASURES

The mine water balance will be managed as detailed in Sections 4 and 5. These measures will include the following:

• Pumping of all dirty water generated at the Wolvekrans Colliery North Extension workings to either Goedehoop Dam, Dam 5 or directly to the MWRP.

• Reuse of dirty water in the operations at Middelburg North.

• Treatment of excess dirty water (water pumped from Goedehoop Dam or Dam 5 to the MWRP).

• Provision of water management facilities with a risk of spill that is lower than 2% in any one year.

• A surface water quality monitoring programme will be implemented, as detailed in Section 11, to detect any impacts.

• A water balance monitoring programme will be implemented, as detailed in Section 11, to enable calibration of the water balance.



Moderate Regional Medium to Long term

Unlikely LOW 3 Probable

3 4 3 2 1.33

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Impact O2 Operational Phase – Utilisation and management of linear infrastructure – Impact on surface water quality


ACTIVITY Utilisation and management of linear infrastructure

Operation and maintenance of roads

ASPECT Water Quality – poor quality runoff of the surfaces



The majority of existing haul roads for the Wolwekrans Colliery North extension project will be located within the dedicated dirty footprint area and all runoff from these haul roads will be contained by draining into the opencast pits or one of the other PCDs, to be managed along with the existing mine water make.

Positions of new haul roads or haul road extensions were not available at the time of writing and are not assessed. However, the potential impacts and mitigation are given below:


Storm water may be contaminated by hydrocarbon drips/spills from vehicles trafficking the road.

MANAGEMENT MEASURES

Mitigation measures will include the following:

• Water quality monitoring should be undertaken at each crossing in order to detect any deterioration in water quality. Refer to Section 11 of the surface water specialist report for details regarding proposed surface water quality monitoring locations.

• If erosion is evident or the water quality monitoring indicates a deterioration in water quality, water management around the linear infrastructure should be reviewed.

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Impact O3 Operational Phase – Mine development area (opencast pits, area and related infrastructure) – Impact on surface water quality


ACTIVITY Mine development area

Opencast pit, shaft area and related infrastructure




The required surface infrastructure at each pit and at the underground area (i.e. Dispatch Rider) will be constructed at the start of mining and will remain in place for the duration of mining.

The overburden material has the potential to generate poor quality runoff due to contact of the water with carbonaceous material. No overburden stockpiles are currently proposed, with the possible exception of the proposed Pit GP in the north of the Goedehoop area.

The overburden material has the potential to contain carbonaceous material and therefore potential to generate poor quality runoff due to contact of the water with carbonaceous material.

Impacts associated with the opencast pit are as a result of runoff entering the pits and coming into contact with carbonaceous material. At Dispatch Rider impacts are associated with runoff generated at dirty areas such as washbays, coal stockpiles, refuelling areas and machine loading and storage areas etc. entering the clean system.


• Contaminated storm water runoff, that discharges from the site, with resultant deterioration in water quality within the Spookspruit, Vaalbankspruit and Olifants River, associated with increased suspended solids, hydrocarbons (oils and greases), siltation of carbonaceous materials, and an increase in salinity and potential decrease in pH in the watercourses.

• Contaminated seepage from the overburden stockpile, with potentially elevated sulphate and TDS.

• Leakage of contaminated water from pipelines, poorly maintained storm water channels, sumps, sediment traps and oil skimmers, etc.

• Erosion at the clean canal discharge points could result in the formation of erosion gullies on surface, with elevated suspended solids in the runoff water, potentially impacting on the water quality in the watercourses in terms of suspended solids and deposition of silt.

• Increase in sulphate, turbidity, suspended solids and TDS due to runoff entering the pits and becoming contaminated.



Very High Regional Medium

term Very Likely HIGH

4 Probable

5 4 3 4 3.2

MANAGEMENT MEASURES


• All dirty runoff generated at Dispatch Rider adit area will drain by gravity towards the sumps at adit level (i.e. below natural ground level) and therefore will not be able to report to the clean system.

• All proposed facilities at Dispatch Rider with the potential to generate dirty storm water runoff, washdown water will be located within the designated dirty water areas.

• Clean runoff will be diverted around the designated dirty areas by means of cut-off canals, sized to accommodate at least the 1:50 year peak flow event.

• Adequate erosion protection will be provided at the clean canal discharge locations.

• All spills will be contained within dedicated bunded areas at Dispatch Rider (at wash bays, refuelling areas, coal stockpiles, etc.).

• Both general and hazardous wastes will be stored in skips until removal from the site. The skips in turn will be located under cover, in bunded areas, to prevent ingress of direct rainfall.

• Waste oil will be stored in drums in a bunded storage area.


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ACTIVITY Mine development area

Opencast pit, shaft area and related infrastructure



• All contaminated runoff and spills that escape bunded areas will be collected and contained in the Dispatch Rider Sump.

• All pipeline routes will be inspected regularly to enable early detection of leaks.

• All contaminated storm water generated at the proposed activities will be collected and pumped to either Goedehoop Dam or Dam 5. For Dispatch Rider dirty runoff will be directed to two sumps.

• Runoff from clean catchments draining towards the overburden stockpiles and new coal stockpile areas at GP Pit and Dispatch Rider respectively will be diverted around the stockpiles.

• An inspection and maintenance plan will be implemented on the storm water system to ensure that all sediment handling facilities are maintained and that storm water canals and pipelines remain unblocked and free flowing – monthly inspections will be carried out.

• Spill-sorb or a similar type product must be kept on site and used to clean up hydrocarbon spills in the event that they should occur.

� A surface water quality monitoring programme will be implemented to detect any impacts.



Moderate Regional Medium

term Unlikely LOW

2 Probable

3 4 3 2 1.33

105



Impact O4 Operational Phase – Dust Suppression with contaminated water – Impact on surface water quality


ACTIVITY Dust Suppression

Dust suppression on haul roads

ASPECT Water Quality – spillage of contaminated water and coal particulates



Dust suppression will be provided on surface along haul roads. This water will become contaminated once it comes into contact with the dirty surface.


Spillage of dust suppression water to the watercourses or associated watercourses, with resultant deterioration in water quality, in terms of elevated salinity, particularly sulphate.





3 Probable

3 3 3 4 2.4

MANAGEMENT MEASURES


• A formal procedure for dust suppression will be developed and implemented. This will ensure that dust suppression application rates are carefully controlled to prevent the application of excessive water and to prevent ponding and runoff of dust suppression water into the watercourses.

• No dust suppression should be carried out on surfaces that are already moist.

• Dust suppression with contaminated water should be confined to isolated dirty water management areas.



Low Site Medium

term Unlikely VERY LOW

1 Probable

2 1 3 2 0.8

106



Impact O5 Operational Phase – Transportation of Coal – Impact on surface water quality


ACTIVITY Transportation of coal

Transport of coal via haul roads for processing

ASPECT Water Quality – spillage of contaminated water and coal particulates



Transport of coal by road has the potential to impact on watercourses and general runoff quality, primarily due to spillage of coal from overloaded trucks, as well as contaminated water from the load boxes of the trucks on inclines.

Transport of coal by conveyor has the potential to impact on watercourses and general runoff quality, primarily due to spillage of coal, as well as contaminated water from the belt itself and at transfer stations.

At new opencast LOM areas:

Existing haul roads will be used to transport coal from the active pits to the coal processing area at the North Plant. From here an existing conveyor will convey coal to the loadout silo.

New haul roads or extension of existing haul roads are required but the positions of these were not available at the time of writing and therefore are not assessed. However potential impacts and mitigations are given below:


• Coal spillage, or spillage of water transported from the pit with the coal from the haul trucks onto the haul roads, with resultant contamination of storm water, particularly with elevated salinity and sulphate.

• Dripping of water from the conveyor belt at low points, as well as spillage at transfer stations.

• Spillage of coal at transfer, on-loading and offloading stations.

• Wind-blown dust at transfer stations settling on the adjacent surface and in watercourses.

• Storm water runoff coming into contact with these emissions would suffer a deterioration in water quality, with increased salinity, particularly sulphate.

MANAGEMENT MEASURES


• Majority of l haul roads and haulage of coal will take place within the dedicated dirty water area, with runoff draining either to the opencast pit or to Dam 5 or Goedehoop Dam, where it will be contained.

• New proposed haul roads were not available at the time of writing.

• From the Dispatch Rider, existing infrastructure (i.e. conveyors and haul roads) will be used for transportation of coal.

• All dirty water containment facilities should be designed, operated and maintained to have a risk of spill of 2% or less (1:50 year recurrence interval) in any one year.

• As far as is practical, ROM coal should be allowed to drain within the pit before being loaded onto the haul trucks, to prevent spillage of water from the haul truck load boxes onto the haul roads.

• Loading of trucks will be carefully controlled to ensure that overloading will not take place.

• Monitoring will be implemented downstream of all watercourse crossings along the conveyor route.

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Impact O6 Operational Phase – Wolvekrans Colliery North mining operation – Impact on surface water quantity


ACTIVITY Wolwekrans Colliery North mining operation

Isolation of dirty catchment




The impact assessment undertaken previously for the Wolwekrans Colliery North section will still be relevant except where mining has progressed.

The loss in yield associated with mining at the Wolvekrans Colliery North Extension operation will be primarily due to the pit areas, which will be isolated from the catchment. Although it is planned to undertake concurrent rehabilitation, so that the dirty water make, as well as the loss of yield to the catchment will be minimised, the assessment below assumes the worst case, being no concurrent rehabilitation, so that all opencast pits, as well as all overburden stockpiles would be isolated from the clean catchment.

Loss in yield is assessed for Loskop Dam, Pienaars Dam and Pans in the area. The reason for assessment of the Pienaars Dam catchment is because some of the pits fall within the Vaalbankspruit catchment.

The bord and pillar mining proposed at Dispatch Rider undermines five pans. Therefore the risk of subsidence (with resultant increased recharge from surface into the underground workings) will need to be minimised, particularly beneath the pans at the Dispatch rider area.

Opencast areas namely GN Pit near the north are in close proximity to a pan. A portion of the GWAB and GW Pis fall within the catchment to a pan. All pans are assessed in Table below:

The loss of yield is quantified in the following table:

Location Catchment area

(km2)

MAR Pre-Construction

(x106 m3)

MAR during operations

(x106 m3)

Percentage reduction

(%)

Old workings Partially rehabilitated

39 1.3 0 100

LoA mining extension area

12.4 0.4 0 100

A (Sub catchment immediately upstream of the mine.)

73 3.1 3.1 0

BN (Sub catchment upstream of the receiving water body and immediately downstream of the mine.)

172.3 7.1 5.1 28

Loskop Dam 12185 384 382.3 0.44*

Pienaars Dam 105.5 3.3 3.2 3

Affected Pans at Dispatch Rider

6.15 0.2 0 100**

Affected Pan at GN Pit 0.92 0.03 0.02 33

Affected Pan between GW and GWAB Pit

2.1 0.07 0.02 71

* Note: The runoff calculations are not accurate to three decimal places. However, the values remain indicative of the magnitude of the impact.

** Assuming all water from pans recharge UG

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ACTIVITY Wolwekrans Colliery North mining operation

Isolation of dirty catchment



It is evident from the table above that the impact in surface water yield to the most downstream watercourse as well as the affected pans, is VERY HIGH, with the impact on yield at Loskop Dam being VERY LOW.

IMPACT ON WATERCOURSES

LOCAL SCALE: Immediately downstream of site

Impact before management


Very High Local Medium term It’s going to

happen HIGH

3 Definite

5 3 3 5 3.67

Management measures


• Concurrent rehabilitation will take place, and the rehabilitation will be shaped to be free draining. Where rehabilitated areas are sloped towards the active opencast pit, berms and canals will be constructed to maximise the area that is free draining.

• The site layout has been designed to minimise the dirty footprint, and therefore to minimise the impact on the catchment yield. No further mitigation is considered necessary

• The risk of subsidence (with resultant increased recharge from surface into the underground workings) will be minimised, particularly beneath the pans at the Dispatch rider area, by employing suitable pillar safety factors.

• Options for the mitigation of the impacts on the pans need to be considered by a suitably qualified wetland and aquatic ecology specialist. These may include augmentation of water supply to the pans or off-set strategies.

Impact after management


High Local Medium term It’s going to

happen HIGH

3 Probable

4 3 3 5 3.33

REGIONAL SCALE: Loskop Dam

Impact before management


Very Low Regional Medium term It’s going to

happen MODERATE

1 Probable

1 4 3 5 2.67

Impact after management


Very Low Regional Medium term It’s going to

happen MODERATE

1 Probable

1 4 3 5 2.67

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Impact O7 Operational Phase – Consequence of extreme floods – Impact on surface water quality and quantity


ACTIVITY Wolvekrans Colliery North Extension

All activities

ASPECT Flooding of mine or mine infrastructure during extreme flood events

IMPACT DEFINITION Impact on mining operation


GN R704 stipulates that no mine workings may be placed within the 1:50 year floodline and no mine residue deposits or dumps may be placed within the 1:100 year floodline, or a distance of 100 m from any watercourse, whichever is the greater.

With no mitigation measures, under extreme flooding conditions in the watercourses (Niekerkspruit, Vaalbankspruit and the Spookspruit) the workings could be flooded, with consequent contamination of the flood waters, as well as loss of production or even life if the flooding in the pit is severe.

Preliminary floodlines have been determined, however better survey is required along portions of the river diversion as indicated in Section 5 in order to properly assess these areas. The proposed GZ and GO pits encroach on the 1:100 year floodline of the tributary of the Vaalbankspruit. Similarly, HN Pit extension encroaches on the 1:100 year floodline of the Spookspruit diversion. Therefore, relevant authorisations will be required.



High Regional Medium

term It’s going to

happen HIGH

4 Probable

4 4 3 5 3.67

MANAGEMENT MEASURES


• No mining within these restricted areas will take place without the relevant authorisations, in terms of GN R704 exemptions and Section 21(c) and (i) water use licenses (in terms of the NWA).

• A river diversion for the Spookspruit exists. Flood protection berms will be provided at the Spookspruit and Vaalbankspruit tributary where mining encroaches on the floodline.



Moderate Local Incidental Unlikely VERY LOW 1 Probable

3 3 1 2 0.93

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Impact D1 Decommissioning and Closure Phase – General decommissioning and rehabilitation – Impact on surface water quality

PHASE DECOMMISSIONING AND CLOSURE PHASE

ACTIVITY

General decommissioning and rehabilitation including water management infrastructure

Construction camps, construction (demolition) works, movement of materials and construction equipment




Impacts resulting from general rehabilitation and decommissioning works will be similar to those during the construction phase, with earthworks related to rehabilitation and the movement of construction equipment on the site.

The water management berms and canals isolate active areas from the catchment by diverting upslope clean runoff around the active areas and containing runoff generated on the active areas. These can only be removed once the area has been rehabilitated, but may result in increased erosion if not properly planned.


• Erosion of soils during rainfall events, with elevated suspended solids in the runoff water.


• Hydrocarbon spillages from fuel storage, servicing areas or construction equipment itself, with resultant elevated hydrocarbon concentrations in runoff water, watercourses and the adjacent pans.

These impacts are expected to be relatively small, with the resultant impact post decommissioning being positive in comparison with the operational phase.



Low Local Short-term Very Likely LOW 2 Definite

2 3 2 4 1.87

MANAGEMENT MEASURES


• The footprint of disturbed areas will be minimised.

• “No-go” zones will be delineated for construction plant and personnel.

• The storm water management infrastructure will be decommissioned last, if at all, to ensure adequate storm water management during the rehabilitation phase.

• Servicing of construction vehicles will take place only in dedicated areas that are equipped with drip trays.


• Spill-sorb or a similar type product will be kept on site and used to clean up hydrocarbon spills in the event that they should occur.

• Erosion protection measures will be implemented at steep areas.

• A waste management plan will be developed for the construction phase, which will include the handling of contaminated materials / soils found on site.

• All traces of hydrocarbons and residual waste will be removed before infrastructure is demolished.

• Contaminated soils will be excavated and placed on the discard facilities prior to their rehabilitation, or removed from site by an appropriately licensed waste contractor.

• An appropriate sewage management strategy will be implemented during the decommissioning phase.

• Water quality monitoring will be undertaken downstream of the construction areas, before and during construction where practical, in order to detect any increase in suspended solids or turbidity.

111




ACTIVITY

General decommissioning and rehabilitation including water management infrastructure

Construction camps, construction (demolition) works, movement of materials and construction equipment



• If erosion is evident, or the water quality monitoring indicates an increase in suspended solids, water management around the decommissioning areas will be reviewed.



Very Low Study Area

Short-term Unlikely VERY LOW 1 Definite

1 2 2 2 0.67

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Impact D2 Decommissioning and Closure Phase – Mine water balance – Impact on surface water quality


ACTIVITY Mine water balance

Recovery of water levels and possible decant




Once the pits have been backfilled and re-shaped dewatering will cease and water levels will begin to recover in the workings.

The predicted time to decant at each of the pits is detailed in Table below.

Pit/Mining Area Last year of

mining

Decant volume 75 years after

mining has ceased

(m3/day)

Time to decant

(Years)

Decant elevation

(mamsl)

GD 2030 827 28 1553

GN 2022 1470 8 1548

GO 2039 185 40 1575

GP 2039 110 13 1572

GW 2039 1780 9 1551

GWAB 2027 555 31 1565

GZ 2039 420 38 1576

HN 2035 11960 +/-6 1526

Goedehoop North and South

Partially rehabilitated

5639 Decanting

already 1542

Dispatch Rider UG 2030

From the table above it can be seen that the time to decant at GN and HN pits will take place during and just after mining respectively and other pits during or after the decommissioning phase. Note that the partially rehabilitated pits are already at decant level. This decant is collected in Goedehoop Dam.



High Regional Long term

It’s going to happen

HIGH 4 Definite

4 4 4 5 4.0

MANAGEMENT MEASURES


• All pits will be backfilled without a final void, rehabilitated and made free-draining.

• Monitoring of water levels in the mine and the associated water quality is committed to. This will allow both calibration of the post mining water quality and water volumes.

• The water level in the workings will be actively managed to ensure it remains below the decant elevation.

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ACTIVITY Mine water balance

Recovery of water levels and possible decant



• The post closure mine water make will be pumped from the mine workings to the Dam 5 or Goedehoop Dam and from here to the MWRP for treatment.

• The treated water will be discharged to the environment.



Low Local Short term

Very Likely LOW 2 Definite

2 3 2 4 1.86

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Impact PC1 Post Closure – Potential for acid mine drainage (AMD) and poor quality leachate – Impact on surface water quality

PHASE POST CLOSURE PHASE

ACTIVITY Potential for decant of AMD

Decant of mine water make




Post closure, the infrastructure areas will have been rehabilitated and made free draining. Similarly, the entire opencast will also have been rehabilitated and made free draining.

Two aspects have been considered here, namely the volume of decant that could be generated, and the potential quality of the decant.

If the water levels in the rehabilitated opencast are not controlled, the potential time to decant is estimated as follows:

Post closure decant assessment under Average rainfall conditions

Pit/Mining Area Last year of

mining

Decant volume 75 years after

mining has ceased

(m3/day)

Time to decant

(Years)

Decant elevation

(mamsl)

GD 2030 827 28 1553

GN 2022 1470 8 1548

GO 2039 185 40 1575

GP 2039 110 13 1572

GW 2039 1780 9 1551

GWAB 2027 555 31 1565

GZ 2039 420 38 1576

HN 2035 11960 +/-6 1526

Goedehoop North and South

Partially rehabilitated

5639 Decanting

already 1542

Dispatch Rider UG 2030

Note: Decant elevations and decant times are provisional, and will be confirmed as models are calibrated with actual inflows.

From the table above it can be seen that the time to decant at GN and HN pits will take place during and just after mining respectively and other pits during or after the decommissioning phase, this impact is taken into account in Impact Table D3 above. Note that the partially rehabilitated pits are already at decant level.

If the decant is not managed (as detailed below), there could be an impact on both the downstream catchment and the downstream dams.

The expected post closure mine water quality for key parameters, is as follows:

• The mean TDS levels are expected to be around 2343 mg/l

• The mean Sulphate levels are expected to be around 1486 mg/l

It is considered valuable to assess the potential sulphate loading of the mine on the catchment. This assessment is based on the assumption that the entire water make were to be discharged to the catchment.

115



PHASE POST CLOSURE PHASE

ACTIVITY Potential for decant of AMD

Decant of mine water make



The water balance at closure indicates that an average post closure water make in the order of 29 300 m3/day can be expected. Based on a sulphate concentration of around 1486 mg/l, this equates to around 9.5tons SO4 per day, or around 3486 tons SO4 per year.

The estimates given above are proposed to be refined over the life of mine as follows:

• On-going sampling and monitoring of parameters important to the final water quality and water volumes

• Quantification and verification of the groundwater model, the water balance model, and the geochemical model

• Evaluation and reassessment of alternative options for the final water use and required associated water quality, together with the technologies required to achieve the required quality.



High Regional Long term It’s going to

happen HIGH

4 Probable

4 4 4 5 4

MANAGEMENT MEASURES


� All pits will be backfilled without a final void, rehabilitated and made free-draining in order to minimise the post closure water make.

� Monitoring of water levels in the mine and the associated water quality is committed to. This will allow both calibration of the post mining water quality and water volumes.

� The water level in the workings will be actively managed to ensure it remains below the decant elevation.

� The post closure mine water make will be pumped from the mine workings and ultimately to the MWRP, which will remain operational post closure.

� Discharge of clean water to the river system.



Low Regional Long term Unlikely LOW 2 Probable

4 4 4 2 1.6

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E812_REP-01_rev0_mvmp2CEW_MMS_North_20161005_snopsis.docx

Jones & Wagener (Pty) Ltd

Engineering & Environmental Consultants

9. FINANCIAL PROVISION

For the operational phase, the water management costs are included in the infrastructure costs in most respects, including the associated storm water diversion canals and berms.

The financial provision related to water management during the construction, operational and closure phases includes the following:

� Construction of the storm water diversion canals around the mine surface infrastructure including Dispatch Rider and opencast areas.

� Construction of storm water management canals and pipelines for the collection of dirty runoff and seepage, with conveyance to the relevant sumps and pumping to the existing PCDs and to the MWRP.

� Construction of sediment handling facilities.

At closure these facilities will be demolished and removed, and the area will be rehabilitated. The cost related with this will also be included in the overall closure costing.

Post closure the infrastructure area will be rehabilitated and will not generate dirty surface runoff. The mine water make will need to be managed. The financial provision required for this will be dependent on the pumping / treatment strategy adopted.

.

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10. SUMMARISED WATER MANAGEMENT PLAN

In Section 8, mitigation measures have been indicated to manage the impacts assessed. These measures need to be incorporated into an Integrated Water and Waste Management Plan (IWWMP) that can be used to implement, audit and measure the performance of the water management measures detailed in the EMP.

This section is intended to only provide inputs on key aspects of the water management plan.

10.1 Construction Phase

10.1.1 Key issues and objectives

� To prevent the contamination of surface water runoff from the cleared construction site areas.

� To minimise erosion in the construction site areas and to minimise siltation in the adjacent watercourses.

� To prevent contamination of surface water runoff from the Dispatch Rider area of construction.

� To ensure that the required water management infrastructure is constructed timeously.

10.1.2 Key strategies

Areas where impacts in terms of construction activities could occur are listed below:

Construction of water management infrastructure.

� The upstream diversion of clean catchments should be constructed first in order to minimise the flow of water across the construction site

� The construction of the dirty water management measures should be completed prior to commencement of mining.

� Sumps will be constructed prior to the Dispatch Rider adit construction commencing.

� Construction of the materials handling area.

� Overburden material will be handled in-pit.

� Construction of infrastructure.

� The mine infrastructure will be constructed after the water management infrastructure, most notably the clean water diversion and sumps at Dispatch Rider.

� Control of suspended solids. Should wet conditions occur during construction, suspended solids in the watercourses must be monitored and silt traps must be provided on construction areas, should suspended solids be detected.

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10.1.3 Monitoring

Monitoring of water quality is undertaken under the mine’s current water quality monitoring programme. An assessment of the current status of surface water quality has been included in the baseline surface water assessment. Monitoring will continue throughout the construction and operational phases. A monitoring programme for the proposed activities is detailed in Section 11.

10.1.4 Knowledge gaps

Final design of the infrastructure and water management measures has still to be completed. The adequacy of the measures detailed in this document will be reviewed in the final designs and updated in the Water Use License application.

10.2 Operational Phase


� To minimise the impact of the proposed mining activity on the catchment yield.

� To identify and control surface runoff that may be affected by the planned activities.

� To ensure that the risk of spilling this water into the clean catchment is:

� In line with licensing requirements

� In line with legislative requirements

� Commensurate with the risks to downstream users associated with any spillage. This is taken currently at a 2% or lower risk in any one year.

� To prevent clean runoff from upstream / upslope areas from spilling into the dirty water systems for flood events up to at least the 1:50 year recurrence interval.

� To ensure adequate monitoring so that the objectives of the water management system can be met.


The key management strategy is to keep clean water clean and to minimise the generation of dirty water. This is to be achieved by diverting runoff from clean catchments around the dirty areas and minimising the extent of dirty areas as far as is practicable. Clean and dirty water systems should be designed and managed to have a risk of spill of 2% or less in any one year (1:50 year recurrence interval event). The key strategies include:

Minimising loss of catchment yield:

� The loss in yield is dependent on the on-site management and planning activities, including the following:

� Placement of upstream diversion berms/ canals so that the maximum volume of upstream runoff can be diverted around the dirty areas, back to the receiving environment.

� Minimising the dirty water footprint of the surface infrastructure areas associated with the proposed mining operations.

� Investigating and implementing water conservation and demand management, together with maximising recycling and reuse strategies on the site.

119





� Implementation of a water flow, pumping and dam water level monitoring programme to enable calibration of the water balance model and efficient management of the site water balance.

� Managing the generation of dirty water.

� The dirty water footprint will be minimised by diverting clean runoff around the dirty areas. Clean water cut-off canals, with capacity to accommodate at least the 1:50 year peak flow event, will be provided. Adequate erosion protection will be provided at the canal discharge points.

� The risk of subsidence (with resultant increased recharge from surface into the underground workings) will be minimised, particularly beneath the pans at the Dispatch rider area, by employing suitable pillar safety factors.

� Provision has been made to collect, store and reuse dirty water generated. The proponent has committed to having a 2% or lower risk of spilling in any one year.

� The risk of spilling is a function of adequate storage capacity, balanced against the reuse of water in the mining operations, as well as treatment at the MWRP.

� In line with best practice, the PCDs will be operated as empty as possible at all times to ensure that sufficient storm water retention capacity is available at all times.

� Ongoing calibration of the water balance is required to ensure that the estimates in terms of water make-up, water shortages and storage requirements are evaluated during the life of the mine. Key strategies to address these issues involve:

� Monitoring of water volumes pumped and stored.

� Documentation of any problems in reusing dirty water, such as operational difficulties.

� Ongoing rainfall monitoring.

� Management of water pumped / draining into the pollution control dams, including documentation of water volumes abstracted for use in the mine.

� Adjustment for any changes in process or infrastructure layout, where these could affect the water balance.

� Ongoing monitoring of water levels within the pollution control dams, as well as any spillages.

� Ongoing monitoring of water volumes supplied from the voids, including recycled water.

� These points indicate that the water management will be a dynamic and ongoing process, aimed at ensuring compliance with legal requirements and good environmental practice over the life of mine.

10.2.3 Monitoring

The objective of the surface water monitoring system is to ensure that the water management system performs in accordance with specifications, to act as an early warning system of contaminated surface water, to verify compliance with license requirements, and for reporting purposes. The objective of these systems will be achieved if there is an acceptable impact (attributable to the proposed opencast and underground mining operations) on the receiving environment.

120





Monitoring requirements are detailed in Section 11.


The water balance is at this stage based largely on theoretical modelling of the hydrological aspects and theoretical production values / parameters obtained from the mine. Monitoring of inflows, water use volumes and dam water levels will therefore be important inputs for the calibration of the water balance model, to ensure that the risks associated with the water management system are adequately defined. Key variables to be monitored (in terms of the water balance) are detailed in Section 10.2.2 above.

10.3 Decommissioning


� To limit the risk of increased erosion on site and downstream, relating to areas being rehabilitated and consequently impacting on water quality.

� To ensure that the area is decommissioned and rehabilitated “from the inside out”, thereby preventing spillage of any dirty water or waste in the process.

� To remove all carbonaceous and mining related material on surface at the pits and infrastructure areas.

� To make the rehabilitated areas free draining.


� Dismantling and removal of the entire mine’s surface infrastructure, unless required to remain in place as a result of the post closure land use.

� Removal of all carbonaceous material and other contaminants / waste materials from the site.

� Pits backfilled to ground level by placing the overburden material back into the void. The backfilled pits will be shaped to ensure that they are made free draining, making allowance for future settlement of the backfill.

� Shaping and grassing of the pits and mine surface infrastructure area

� Erosion protection: The general area is susceptible to erosion. During rehabilitation, the areas where grass has not yet been established will be monitored to ensure that there is not excessive erosion prior to the grass establishing, and where necessary additional erosion protection such as the use of dump rock (non-carbonaceous, from commercial sources) or repair of gullies will be undertaken until such time that the rehabilitated surfaces can be shown to be sustainable.

10.3.3 Monitoring

Monitoring during decommissioning will be based on the operational phase monitoring, adapted to suit the final works to be implemented during this phase. However, in terms of surface water this will be primarily downstream of the area, as for the operational phase.

121






The final land use for the site is not certain at this stage. This may influence the rehabilitation strategy.

10.4 Post Closure


To manage the post closure water make.

To manage the rehabilitated area post closure.


Water management to avoid decant:

� If left to fill with no intervention, it is expected that the water level within the new mine workings will recover over a period of approximately 1 to 28 years from the date mining ceases, depending on pit floor elevations, topography and adjacent geological material,

� Water levels in the workings will need to be kept below decant level to prevent decant to the natural watercourses.

� Wolvekrans Colliery is committed to responsible environmental management, which includes containment and treatment of decant water to ensure that there is no downstream impact on water quality associated with future decant from the mine.

� Management of rehabilitated area.

� The key strategy is to ensure that the rehabilitation in terms of shaped land form and vegetation cover is maintained in the long term to ensure long term sustainability of the rehabilitated area.

10.4.3 Monitoring

Monitoring post closure will be undertaken only where required to prove the sustainability of the site. In terms of surface water, this relates primarily to managing the surface topography (monitoring for erosion), and water quality downstream of the site.


The water balance model and final water qualities are conceptual at this stage. These will need to be verified over the life of mine. The final land use for the site is not certain at this stage. The required post closure water management measures and monitoring may be influenced by the final land use.

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11. MONITORING AND AUDITING

The objective of the surface water monitoring system is to ensure that the water management system performs in accordance with specifications, to act as a pollution early warning system, to check compliance with license requirements and for reporting purposes. The objectives of these systems will be achieved if there is no impact (attributable to the LoA expansion and Dispatch Ruder project) on the in-stream and downstream fitness for use criteria.

11.1 Water quality monitoring

11.1.1 Monitoring locations

In order to detect impacts attributable to an activity, water quality monitoring would usually be carried out upstream and downstream of the site.

The proposed monitoring locations for the Middelburg LoA expansion and Dispatch Rider project are shown in Figure 11.1.1(a). The locations are described in Table 11.1.1(a). These locations are to be added to the existing monitoring programme, detailed in Section 6.

Table 11.1.1(a): Details of surface water quality monitoring locations

Monitoring location

Description Co-ordinate

Latitude Longitude

SW 1 GP Pit 25o51’15.78’’ 29o25’59.03’’

SW 2 Pan between GW and GWAB pit 25o54’49.99’’ 29o28’13.53’’

SW 3a Dispatch Rider clean diversions 25o58’59.00’’ 29o23’36.53’’

SW 3b Dispatch Rider clean diversions 25o59’11.03’’ 29o23’54.56’’

SW4 At Dispatch Rider 25o59’19.45’’ 29o24’30.68’’

11.1.2 Water quality sampling and analysis

During the Construction and Operational Phases of the Wolvekrans Colliery North Extension project, rivers, pans and dams should be sampled on a monthly basis.

Monitoring during the Decommissioning Phase will be based on the Operational Phase monitoring, adapted to suit the final works to be implemented during this phase. However, in terms of surface water this will be primarily downstream of the area, as for the Operational Phase.

Monitoring during the Post Closure Phase will be undertaken only where required to prove the sustainability of the site. In terms of surface water, this relates primarily to managing the surface topography (monitoring for settlements), and water quality and levels within the mined out area.

Any infrastructure (PCDs) that will remain on site, post closure, will continue to be included in the surface water monitoring programme and should be monitored in terms of water quality and water levels on a monthly basis. The water quality parameters that are currently being monitored at Wolvekrans North as per 2010 WULA are indicated in Table 11.1.2(a).

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Table 11.1.2(a) Water Quality monitoring parameters as per 2010 WULA

Location Constituent

Existing sampling points as detailed in Section 6

pH

Electrical Conductivity (EC)

Total Dissolved Solids (TDS)

Suspended Solids

Dissolved Oxygen

Ammonia as N

Nitrate as N

Ortho-Phosphate as P

Chloride as Cl

Sulphate as SO4

Sodium as Na

Magnesium as Mg

Aluminum as Al (total and dissolved)

Iron as Fe (total and dissolved)

Manganese as Mn (total and dissolved)

Fluoride as F

The recommended frequency of sampling and additional variables to be analysed are detailed in Table 11.1.2(b).

Samples will be grab samples, which will include:

� Filtered and unfiltered samples.

� Acid preservation of samples for metals analysis.

� All samples will be analysed by an accredited laboratory.

Table 11.1.2(b): Proposed Surface water quality sampling and analysis

Location Constituent Frequency

SW 1 to SW 4

Alkalinity as CaCO3

Potassium as K

Calcium as Ca

Zinc as Zn (total and dissolved)

Boron as B (total)

Antimony as Sb (total)

Molybdenum as Mo (total)

Lead as Pb (total)

Mercury as Hg (total)

Selenium (total)

Monthly

Bacterial analysis

Full elemental ICP scan (Al, Sb, As, Ba, Be, B, Br, Cd, Cs, Cr, Co, Cu, Fe, Pb, Li, La, Mn, Hg, Mo, Ni, Se, Ag, Sr, Te, Sn, Ti, Tl, W, U, V, Zn)

Every six months

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11.2 Water quantity monitoring (water balance monitoring)

For efficient management of water on the site, a good understanding of the site water balance will be required. To achieve this, the following monitoring will be needed:

� Rainfall – to be measured daily on the site.

� Evaporation – this is not essential but would be useful for calibration of the water balance model.

� Dam water levels – to be measured weekly.

� Flows – including the following, to be measured weekly:

� Mine water make pumped from the underground and opencast workings.

� Supply from the pits.

� Inflows to the Pollution Control Dams.

� Water pumped from the Pollution Control Dams for reuse in the operations.

� Water recycled at the Middelburg Water Reclamation Plant.

� Sewage volumes.

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Figure 11.1.1(a): Water quality monitoring locations

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11.3 Data management and reporting

11.3.1 Monthly

The monthly report is an internal environmental compliance report which is used to keep records of changing water qualities at the site. The report will include:

� Sites that are sampled.

� Water qualities for the relevant constituents.

� Dam levels and flow rates on site.

� Highlight significant issues that require immediate corrective / preventative action.

11.3.2 Quarterly

The quarterly report may be submitted to DMR / DWS and consists of the following components:

� Brief compliance assessment description.

� Brief description of monitoring actions performed.

� Dam water level status report.

� Highlight significant issues that require immediate corrective/ preventative action.

� Historical and present source chemistry report.

� Time dependent graphs for the relevant water quality variables.

11.3.3 Annually

The annual report consists of all the active environmental components, and for the chapter on surface water, the following components should be included:

� System audit

� Statutory/ regulatory requirements.

� Monitoring infrastructure.

� Data captured.

� Information generation.

� Management of system liquids.

� Data audit

� Verification of data.

� Compliance interpretation using SANS 241 Drinking Water Standard and management unit objectives.

� Setting of new objectives or recommendation of corrective measures.

� Historical and present source chemistry report.

� Dam level status report.

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11.4 Performance assessment/ audit

Annual audits should be carried out to determine the effectiveness of the water management systems that are in place. These should include a GN R704 audit.

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12. EMERGENCY AND REMEDIATION PROCEDURE

This section is detailed in the main EIR.

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13. CONCLUSION

The following conclusions can be drawn from the surface water study:

� All dirty water generated on the site will be directed to the relevant PCDs and reused in the mining operations, with surplus water that cannot be reused being pumped to the MWRP for treatment.

� Surface water impacts from the site can be effectively mitigated by applying best practice water management principles.

� The success of surface water impact management will be judged on the basis of successful prevention of spills from the site.

� The water balance modelling indicates the following:

� The Goedehoop Dam will cater for both surface runoff reporting to the dam as well as pit water, with surplus water being pumped to MWRP for treatment, with a risk of spill less than 2%, for average rainfall.

� Under extreme rainfall, water pumped to Goedehoop Dam will need to be re-directed to an alternative storage area of 3 million m3 to ensure a 2% or lower risk of spill in any one year at Goedehoop Dam.

� Dam 5 PCD will require an increased pumping of 25.5Ml/day to the MWRP under average rainfall and under extreme rainfall water will need to be re-directed to an alternate buffer storage area of 18 Million m3 coupled with a water use of 3 000m3/day for extreme rainfall in order to ensure a 2% or lower risk of spill in any one year at Dam 5 PCD.

� Increased pumping from Goedehoop Dam and Dam 5 PCD to the MWRP would require an increased treatment rate and therefore capacity at the MWRP.

� It is recommended that the old workings adjacent to the new pits be dewatered prior to the mining of the new pits in order to provide buffer capacity for the summer months and extreme events, as well as reduce the expected steady state seep volume reporting to the new pits from the old pits. In addition to this, further potential optimization of the buffer storage can be achieved if the potential water storage capacities of all the pits are known, thereby potentially allowing for the temporary storage of water in these pits during wet periods, with subsequent reduced pumping to Dam 5 PCD. The potential storage capacities of the pits, at a safe level below decant, will need to be determined and the water balance reassessed based on the storage capabilities of the pits.

� During the decommissioning phase, all pits will be backfilled without a final void, rehabilitated and made free-draining. The water level in the workings should be actively managed to ensure they remain below the decant elevation.

� The post closure mine water make will be pumped from the mine workings to the Goedehoop Dam and Dam 5 PCD and from there to the MWRP for treatment. The expected time to decant for each pit is given in Table 5.5 (a) above. From the table GN and HN pits will start decanting within or immediately after mining. The partially rehabilitated pits have already reached decant elevation.

� The assumptions upon which this water balance is based require careful verification, particularly with regard to the groundwater make on site.

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� The water balance will need to be refined as the mine design develops and the results presented here should be viewed as preliminary, for input to the mine design process.

Mike Palmer Pr Eng Malini Veeragaloo Pr Eng Technical Director Project Engineer for Jones & Wagener 5 October 2016 Document source: C:\Alljobs\E812_MiddelburgNorth\REP\ClientComments\E812_REP-01_rev0_mvmpCEW_MMS_North_20161005.docx Document template: repGen_14r1_TT.dotx

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14. REFERENCES

� Adamson, P.T. (1981) “TR102 Southern African Storm Rainfall” Department of Environment Affairs, Directorate of Water Affairs.

� Ages EMPR Consolidation Report for Middelburg Mine Complex, Jan 2013

� Alexander, W.J.R. (2002) “SDF2: The Standard Design Flood – theory and practice” University of Pretoria, Dept Civil Engineering.

� Alexander, W.J.R. (2002) “SDF3: User’s manual – The Standard Design Flood – a new design philosophy” University of Pretoria, Dept Civil Engineering.

� Daily Rainfall Extraction Utility, ICFR, BEEH University of Kwa-Zulu Natal, Pietermaritzburg.

� Department of Water Affairs (DWA) (accessed April 2011), hydrology website www.dwaf.gov.za/Hydrology, Gauging Station Data.

� Department of Water Affairs and Forestry (1998) “Minimum Requirements for Waste Disposal by Landfill” Department of Water affairs and Forestry, Pretoria.

� Department of Water Affairs and Forestry (1998) “Minimum Requirements for Handling, Classification and Disposal of Hazardous Waste” Department of Water affairs and Forestry, Pretoria.

� DWAF (1996) “South African Water Quality Guidelines – Volume 8 Field Guide” Department of Water Affairs and Forestry, Pretoria.

� Exigo, Ground Water Study, June 2016

� Gordon, G. (2012) “Anglo American Thermal Coal – Kriel Colliery Lifex Project – Block F Conveyor Route Selection” Received by email 20 July 2012.

� Government Notice No. 704, 1999: Regulations on use of water for mining and related activities aimed at the protection of water resources, dated June 1999, under the National Water Act, 1998, (Act 36 of 1998).

� Government Notice R385, April 2006: National Environmental Management Act, 1998 (Act 107 of 1998). Environmental Impact Assessment Regulations.

� Government Notice R386, April 2006: National Environmental Management Act, 1998 (Act 107 of 1998). Environmental Impact Assessment Regulations. National Water Act, 1998 (Act 36 of 1998)

� Government Notice R387, April 2006: National Environmental Management Act, 1998 (Act 107 of 1998), Environmental Impact Assessment Regulations.

� Government Notice R.527, April 2004: Minerals and Petroleum Resources Development Act, 2002 (Act 28 of 2002). Minerals and Petroleum Resources Development Regulations. Municipal Demarcation Board, 2006, Pretoria, South Africa

� Jones & Wagener, SWS Report for MWRP Project, Report JW92/11/B478-Rev2, July 2011

� Jones & Wagener, Amendment to EMP, Report JW84/06/A591, May 2006

� Kovács, Z. (1988) “TR137 Regional Maximum Flood peaks in Southern Africa” Department of Water Affairs.

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� Midgley, D.C., Pitman, W.V. and Middleton, B.J. (1995) “Surface Water Resources of South Africa 1990 – Volume I” WRC Report No. 298/1.1/94, Water Research Commission

� National Environmental Management Act, 1998 (Act 107 of 1998)

� South African Committee on Large Dams (SANCOLD) (1990) Safety evaluation of dams. Interim Guidelines on Freeboard for Dams. Report No 3.

� South African Committee on Large Dams (SANCOLD) (1991) Safety evaluation of dams. Guidelines on Safety in Relation to Floods. Report No 4.






SPECIALIST SURFACE WATER REPORT FOR SOUTH32 CSA

WOLVEKRANS COLLIERY NORTH: LIFE OF ASSET EXPANSION

AND DISPATCH RIDER PROJECT

Report: JW119/15/E812 - Rev 0

APPENDIX A

WATER QUALITY RESULTS









APPENDIX B

IMPACT ASSESSMENT RATING CRITERIA









APPENDIX C










APPENDIX D

CV’S

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