Hydrogeological Investigation Report for the Proposed Berenice Coal Mine … · 2018-01-20 · Proposed Berenice Coal Mine in Makhado, Limpopo Province Report Prepared by NALEDZI

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Hydrogeological Investigation Report for the

Proposed Berenice Coal Mine in Makhado,

Limpopo Province

Report Prepared by

NALEDZI WATERWORKS (PTY) LTD 12/8/2016

Prepared for:

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TABLE OF CONTENTS

CHAPTER PAGE

1 Introduction and Scope of work...................................................................................... 4

1.1 Background of the project ........................................................................................... 4

1.2 Applicable legislation and standards ......................................................................... 5

1.3 Objectives ...................................................................................................................... 5

1.4 Scope of work undertaken........................................................................................... 6

2 Site description ................................................................................................................. 6

2.1 Location .......................................................................................................................... 6

2.2 Land use......................................................................................................................... 6

2.3 Topography .................................................................................................................... 7

2.4 Climate ........................................................................................................................... 7

2.5 Drainage ......................................................................................................................... 8

2.6 Geology .......................................................................................................................... 8

2.7 Groundwater use ........................................................................................................ 17

2.8 Hydrogeology .............................................................................................................. 21

3 Hydraulic testing ............................................................................................................. 23

3.1 Slug test in the exploration coreholes ..................................................................... 23

3.2 Pumping testing of existing boreholes..................................................................... 26

4 Groundwater levels and flow ........................................................................................ 29

5 Water quality ................................................................................................................... 32

5.1 Baseline Water quality ............................................................................................... 32

5.2 Applicable guidelines ................................................................................................. 35

5.3 Chemical analysis ....................................................................................................... 35

6 Conceptual model .......................................................................................................... 38

7 Numerical model ............................................................................................................. 39

7.1 Model boundaries and discretisation ....................................................................... 40

7.2 Model Characteristics................................................................................................. 41

7.3 Model Calibration ........................................................................................................ 43

7.4 Simulated water balance ........................................................................................... 45

7.5 Model Predictions ....................................................................................................... 45

7.6 Mass Transport Simulation ....................................................................................... 61

8 Impact assessment and mitigation .............................................................................. 63

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8.1 Methodology ................................................................................................................ 63

8.2 Impact Assessment .................................................................................................... 66

9 Water management programme .................................................................................. 69

9.1 Purpose and scope..................................................................................................... 69

9.2 Monitoring programme ............................................................................................... 69

10 Groundwater supply potential ................................................................................... 72

11 Conclusions......................................................................................................... 72

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1 Introduction and Scope of work

1.1 Background of the project

Universal Coal is planning to establish an opencast operation, Berenice Coal Project, located in

the Limpopo Province of South Africa. The project is located approximately 120 kilometers (km)

north of Polokwane and east of the settlement of Alldays (Figure 1). Universal Coal appointed

Jomela Consulting (Pty) Ltd (Jomela) to undertake the Environmental Impact Assessment for

the Berenice Project.

Ms. Yvonne of Jomela has appointed Naledzi Group (Pty) Ltd (Naledzi) to conduct a

hydrogeological, which will form part of the Environmental Impact Assessment (EIA) that is

being undertaken for the proposed Berenice Coal Project. The process is conducted in an

integrated approach. It is conducted in line with the National Environmental Management Act,

1998 (Act 107 of 1998) in support of the Application for a Mining Right. This will also involve

compliance with other sets of legislation to obtain all the necessary permits to commission the

project.

Figure 1: Locality map

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1.2 Applicable legislation and standards

The mining and associated mining activities will be undertaken in compliance with

environmental standards accepted as good mining practices in South Africa. The main

legislations relevant to this groundwater study are:

Constitution of the Republic of South Africa No. 108 of 1996;

National Water Act 36 of 1998;

Regulation 704 of the National Water Act (NWA);

Mineral and Petroleum Resources Development Act No. 28 of 2002 (MPRDA).

1.3 Objectives

The purpose of this report is to present the baseline hydrogeological conditions of the project

prior to mining and establishment of mining related infrastructures. The baseline assessment of

the prevailing groundwater conditions is required for the environmental impact assessment of

the project.

This report also quantifies impacts that the proposed project will have on groundwater (levels,

quantity and quality) and recommends mitigation and management measures to minimize

environmental impacts throughout the mine life (construction, operation, closure and post

closure).

The objectives for the groundwater study are as follows:

To characterize the hydrogeological regime and establish baseline conditions for the

proposed development;

To develop a hydrogeological conceptual and numerical model to assist in the

assessment of the pit dewatering requirements as well as understanding the impacts of

the proposed mine development on the water resources;

To use the results of the numerical model to quantify impacts on groundwater levels,

yields and quality;

Recommend mitigation and management measures to minimize environmental impacts

throughout the mine life (operation, closure and post closure).

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1.4 Scope of work undertaken

The completed hydrogeological investigation scope of work for the current study consisted of

the following:

Review of existing relevant data and reports compiled for the project area and the

surrounding properties;

Site visit and hydrocensus;

Compilation of baseline hydrogeological conditions based on existing data and site

observation;

Development of the conceptual and numerical hydrogeological model;

Calibration of the numerical hydrogeological model;

Impact assessment;

Development of mitigation measures;

Reporting.

2 Site description

2.1 Location

The project is located in the Limpopo Province of South Africa, some 120°km to the North of

Polokwane and to the east-southeast of the settlement of Alldays. The project may be reached

via an all-weather gravel road which branches off from the tar road between Alldays and

Waterpoort. The project area is approximately 50 km by road from Alldays and about 30°km by

road from Waterpoort. The nearest sizeable town is Makhado (Louis Trichardt) some 80°km by

road to the south-east. The nearest accessible railway siding is at Waterpoort, approximately

30°km south-east.

2.2 Land use

The study area is used as commercial game hunting farms as well as commercial cattle grazing.

Some of the farms near the project area are being used for commercial crop farming.

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2.3 Topography

The topographical setting of the study area is closely related to its geology and structural

history. The area south of the project area is mainly underlain by Karoo lava which forms a

monotonous and featureless landscape. The project area is located in an area which is relatively

flat lying with the incision of the Brak River valley towards the north of the area, at a surface

elevation of 690-735 mamsl (Gemecs, 2016). The elevation in the area rises gently to 900

mamsl in the south (Golder, 2012).

Some distance to the south of the project area, the Soutpansberg forms high mountainous

terrain with an elevation of 2000 mamsl and this exceptionally high ground extends for more

than 60 km’s in an east-westerly trending direction.

2.4 Climate

The project area is located within a dry tropical climate zone characterised by dry winters and

hot humid summers. The area experiences one cycle of rainfall that extends from October of

the previous year and end in March of the following year (approximately 182 days). The rainfall

information is based on the data obtained from Meteoblue weather; station N0.949649 -

Vetfontein Farm (Figure 2). Most of the rainfall occurs as localized heavy thunderstorms.

The area normally receives about 209 mm of rain per year, peaking during January and

February, with most rainfall occurring during the summer. The area receives the lowest rainfall

(1 mm) in July and highest (47 mm) in December (Figure 2).

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Figure 2: Average monthly rainfall and temperature for Weather Station N0.949649

The monthly distribution of average daily maximum temperatures shows that the average

midday temperatures range from 22°C in July to 30°C in January (Figure 2). The region is coldest

during July when the mercury drops to 4°C on average during the night (Figure 2).

2.5 Drainage

The Berenice project is located mostly in the quaternary catchment A72B and to a much lesser

extent in the A71J. The drainage system in the area is defined by the non-perennial Brak River

in the quaternary catchment A72B and the perennial Sand River (A71J) in the north-easterly

direction. The Brak River flows in the north-easterly direction, north of the planned mine pits

and mine infrastructures.

2.6 Geology

Several historical geological assessments and studies have been carried out to characterise the

regional geology of the area and to quantify the coal reserve in the project area and

surrounding farms. These include:

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The geological mapping of the general extent of the Karoo by RSA Geological Survey

(published maps sheet 2228 ‘Alldays’, 1:250 000, 2002);

The drilling of five boreholes by Trans-Natal Coal Corporation, a subsidiary of General

Mining & Finance Corporation, on the farm Cygnus 549MS in 1974 as a part of the

evaluation of coal deposits in their so-called Langjan Proposition;

The drilling of two boreholes by Goldfields of South Africa in 1977 on the farm Celine

547MS;

Mapping and drilling of four boreholes by Rio Tinto Mining and Exploration in 2004/5

Cygnus 549MS, Berenice 548MS, Celine 547MS and Doorvaardt 355MS);

Resource assessment by Venmyn Rand Consulting for Pioneer Coal in 2008;

Gemecs produced a Competent Person Report (CPR) for the portions of the farms

Berenice 548MS, Celine 547MS and Doorvaardt 355MS, based on limited historical

borehole data projected from the farm Cygnus 549MS in 2010;

Golder compiled the geological and hydrogeological conditions of the Berenice Coal

project as part of the Preliminary Hydrogeological Study in 2012.

Gemecs produced a Competent Person Report (CPR) for the whole Berenice Coal project

in 2016.

The regional and local geological setting of the area is well documented in the reports by

Golder (2012) and Gemecs (2016).

The project area fall within the 1:250 000 Geological Map series of South Africa – Sheet 2228 of

Alldays (2002). The description of the regional geological settings of the area is based on the

geological description by Günter Brandl (2002). The regional geology is depicted in Figure 3 with

major faults of relevance (Tshipise, Bosbokpoort and Verrulam) labelled.

2.6.1 Regional geology

Regionally, the Berenice project is located within the Soutpansberg Coalfield which is situated

north of the Soutpansberg Mountain Range along the north-eastern edge of the Kaapvaal

Craton. Coal-bearing strata in Soutpansberg Coalfield are inconsistently developed within this

area with the coal occurrences being typically bright coal/carbonaceous mudstone associations,

forming composite coal ‘zones’.

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The Soutpansberg Coalfield is characterised by intensive faulting. Dislocations both parallel to

strike and at a high angle thereto are common and subdivide the coalfield into numerous

irregular-sized blocks. The displacements vary between 20 m and 200 m. Syn-depositional

faulting has to some degree controlled the size of individual coal “blocks” and has affected coal

distribution significantly.

The thickest coal zone in this region is to be found some distance to the east of Waterpoort,

comprising up to nine composite seams separated by carbonaceous mudstone, over a

stratigraphic interval of about 40 m.

The coal zones in this area are developed within the Ecca Group in strata which may be broadly

correlated to the Mikambeni and Madzaringwe Formations. The Mikambeni and Madzaringwe

Formations are the local representatives of the Vryheid and Volksrust Formations of the Main

Karoo basin. These formations consist principally of fine-grained sediments such as siltstone,

mudstone and shale and a number of zones/seams of coal.

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Figure 3: Regional geological setting

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The Ecca Group strata are underlain by varying thicknesses of the Tshidzi Formation (Dwyka

Group) comprising a glacial sequence of tillites, diamictites, etc., representing the

encroachment of the Karoo Supergroup over the pre-Karoo basement.

The Karoo Sequence rocks in the Soutpansberg Coalfield overlie Limpopo Mobile Belt and

Soutpansberg-age rocks and dip at 2°-20° northwards, terminating against east-west trending

strike faults forming the northern margins of the coalfield (Gemecs, 2016).

2.6.2 Geology of the Berenice project

The Berenice project is reported to be located within the so-called “B”-block of the Mopane

sector of the Soutpansberg coalfield (Gemecs, 2016). The coal-bearing strata in the “B” block

are deposited in a half-graben within the basement (Limpopo Mobile Belt) bedrock, fault-

bounded toward the north-west and sub-outcropping towards the south-east. The locality of

the Berenice Coal Project, superimposed on the regional geological map is shown in Figure 4.

The full Karoo Sequence is present in the Berenice area is shown in Figure 5 and the coal-rich

Ecca Formation is underlain by tillites and diamictites of the Tshidzi Formation (Dwyka Group)

and overlain by the sandstone package of the Fripp Formations (Figure 5).

In the deeper parts of the basin the Fripp Formation is overlain by siltstones and red

mudstone/shales of the Beaufort Group.

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Figure 4: Berenice Coal Project location (published geological map extract)

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Figure 5: Generalised stratigraphic column for the Berenice Coal Project area

2.6.2.1 Description of the coal zones

The coal deposits of this locality consist typically of bright coal/carbonaceous mudstone

associations, forming a series of composite coal ‘zones’. Three coal zones (Figure 6) can be

identified and are named from top to bottom:

Upper Coal Zone - The Upper Coal Zone consist mostly of interlaminated to inter-

bedded mudstone, coal and shale. The zone appears to be more variable in terms of

thickness and is seemingly absent in some localities. In general this zone comprises

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between two and five sub-zones or “plies”. The upper portion of this zone generally

contains a slightly greater proportion of coal to the lower section and in some areas

“shaling-out” of plies. The zone consists of only one ply which is regarded as a

carbonaceous zone with minor coal content that includes greyish mudstone partings.

The ply is mostly absent in the south-western segment (Matsuri, Longford and

Doorvaardt) of the project area and is best developed on Celine, Berenice and the

north-eastern part of Doorvaardt; hence to the north (and east).

Main Coal Zone - The Main Coal zone is also consisted mostly of interlaminated to inter-

bedded mudstone, coal and shale. This zone where preserved from weathering and

erosion, is persistently well-developed and contains a number of sub-zones comprising

“plies” with a significant proportion of bright coal. This zone is divided into up to 15 plies

based mainly on lithological criteria but also taking into account mineability

considerations in terms of economic feasibility of extraction.

Lower Coal Zone – The zone, where well developed, tends to be formed of a number of

relatively thin coal beds or seams separated by non-carbonaceous or carbonaceous

partings. This zone appears to be only significantly developed towards the west of the

exploration area (farms Longford and Matsuri) and is seemingly absent in general in the

east (Berenice farm). The zone is not consistently developed and is absent over elevated

palæo-topographic (basement) “highs. The zone is overlain by mudstone that seems to

be devoid of carbonaceous and/or coaly content. Carbonaceous content gradually

increases towards the base to the point that carbonaceous shales are identified with

minor coal occurrences found in the vicinity of diamictite and sandstone beds (Gemecs,

2016).

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Figure 6 : Typical profile showing the Coal Zones in the Berenice Coal Project

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2.6.3 Structural geology

Regionally, the Karoo strata of the Tshipise basin are slightly tilted to the north-northwest at an

angle of 10° to 20°. Intense block faulting caused the developments of a series of stepped half-

grabens, seen as repeatedly occurring narrow strips of Karoo sediments.

Several brittle shear zones are developed in the area, which are generally normal faults with an

east-north-east or easterly trend. Most of them are down-thrown to the south. The more

prominent faults are the Tshipise and Bosbokpoort Faults with estimated vertical displacement

of about 500 m. The Tshipise fault is generally identifiable on aerial photos as a line of dense

vegetation, in particular where Karoo Basalt is displaced against lower Karoo sediments.

The envisaged local geological structure has been interpreted based on the available borehole

intersections, both historical and from Universal Coal’s 1st phase drilling programme, and with

reference to the published surface geological map. Based on the structural interpretation, the

following conclusions were made:

The coal measures are preserved within down-faulted (graben-type) structures.

The coal measures are dislocated by faulting both parallel to strike and at an angle

The western section of the coal-bearing area of the Berenice project appears to be

structurally more stable than further towards the north-east and east.

Regional dip appears to be towards the north with local deviations towards the north-

east or north-west presumably due to block rotation of strata between fault zones or

resulting from presently undetected cross-faulting.

The predominant west-east faulting pattern appears to be represented by faulted zones

and the widths of the fault zones is not known.

2.7 Groundwater use

The primary objective of the hydrocensus was to identify the baseline groundwater use and

users within the study area. A detailed hydrocensus in the area was conducted by Golder in

2012 as part of the Preliminary Hydrogeological Study for the Berenice Coal Water Resource

Options. The hydrocensus covered Berenice, Margate, Brenhilda, Celine, Cygnus, Doorvaardt,

Longford, Matsuri and Thurso farms.

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In the current programme, several water sources were visited to confirm their existence by

Naledzi hydrogeological team. The results of the current hydrocensus together with the

previous hydrocensus by Golder (2012) were used to determine the baseline water use in the

area. The groundwater in the project area is used for domestic and game watering purpose

with several boreholes pumping water into the drinking troughs located in the bushes (Figure

7). The details of the visited sites are presented in Appendix A and their positions are shown in

Figure 8.

Figure 7: Water trough in Berenice farm

2.7.1 Existing boreholes

Golder in 2012 visited of 39 boreholes located within the eight farms (Figure 8). Of these, four

boreholes are equipped with mono pump, 13 are equipped with submersible and 2 are

equipped with windmills. These boreholes are used for both domestic and game watering. A

total of 20 boreholes are not equipped and unused.

The borehole recorded borehole depths ranged between, 26 and 146 mbgl with average

borehole depths of 72 mbgl. Two collapsed boreholes BGA-23 and BGA-14 with depths of 8.7

And 10.2 mbgl, respectively, were excluded. The static water level in the visited boreholes

ranges between 8.6 and 60 mbgl, with average static water level of 27 mbgl.

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Figure 8: Hydrocensus results

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2.7.2 Coreholes

A total of 29 coreholes were visited and recorded by Golder in 2012 (Figure 8). Of these, 16

coreholes were drilled and completed as large diameter holes. These coreholes are not in use

and some of them are not capped (Figure 9). Most of these coreholes have collapsed. The

groundwater resting level in the coreholes ranges between 19 and 52 mbgl with an average of

52 mbgl.

Figure 9: Uncapped large diameter core hole

2.7.3 Monitoring boreholes

Two Department of Water and Sanitation regional groundwater monitoring boreholes, H18-

1521 and H18-1522, were visited and recorded (Figure 8). These boreholes are located in the

southern part of the project area. The static water level in the monitoring boreholes is reported

to be 52 and 56 mbgl.

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2.8 Hydrogeology

While several boreholes were drilled within and around the Berenice project area, several

comprehensive regional hydrogeological investigations of the groundwater potential in the

western parts of the project area were carried out by Department of Water and Sanitation

(DWS) between 1982 and 1989 (Golder, 2012). The studies were aimed at identifying additional

water resources for the Alldays area and the detailed report was compiled by Fayazi and Orpen

in 1989.

The detailed hydrogeological investigation of the Berenice project was undertaken by Golder in

2012 as part of the preliminary hydrogeological investigation for Berenice Project. The study

was aimed at assessing the existing groundwater sources within the Berenice project area and

further identifies possible groundwater supply options in the areas surrounding the project

area. Several boreholes within the project area were tested to determine the sustainable yields

and for quality.

The information published on the 1:500 000 hydrogeological map – 2127 Messina (2002),

indicate that the regional geohydrological attributes of the area are clearly a function of the

geological host matrix distribution. The groundwater in the area primarily occurs within the

fractured and weathered zones or in joints and fractures of the competent arenaceous rocks,

related to tensional and compressional stresses and offloading. Groundwater also occurs along

the sedimentary contacts. The borehole yield potential of the Ecca Group (Pe) and differential

Ecca and Clarens Formation (Pe-Trc) is classified as b3 in the 1:500 000 hydrogeological map,

indicating that an average borehole yield in the group ranges between 0.5 and 2.0 l/s.

2.8.1 Aquifers

Golder (2012) analysed the pump testing data and geological settings of the area to determine

the occurrence of groundwater and to assess the types of aquifer systems that occur in the

area. This analysis revealed that there are two dominant aquifer types that occur in the area,

the secondary fractured aquifer system and secondary intergranular and fractured aquifer

systems associated with the geological formations. The analysis of core logs revealed that the

aquifer system in the area can be divided into three aquifer systems as follows.

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2.8.1.1 Shallow weathered aquifer system

This is the predominant aquifer system present within the project area and is laterally

extensive, occurring in the shallow weathered zone and weathering related fractured zone. This

aquifer extends across the entire extent of the project area and ranges between 5 and 26 mbgl.

This is a minor aquifer system and water drains through into the underlying aquifer systems. It

is unconfined to semi-confined in nature and highly susceptible to surface induced activities

and impacts.

2.8.1.2 Secondary intergranular and fractured aquifer system

This is the predominant and major aquifer system in the area. This aquifer system is laterally

extensive occurring between the shallow weathered aquifer system and the underlying

fractured aquifer system. The aquifer system is comprised of fractured zone overlain by varying

thicknesses of weathered saturated materials. The groundwater storage and flow is controlled

by the fractures that again act as conduits during abstraction and vertical recharge from

intergranular zone.

2.8.1.3 Secondary fractured aquifer system

The localized fractured aquifers systems are restricted to the contact zones between the fault

zone and contacts between the sedimentary sequences. Although these aquifer systems may

be high yielding, they have limited storage capacity and recharge. Most of groundwater in the

fractured aquifer system is drained laterally from the storage within the overlying shallow

weathered and intergranular and fractured aquifer systems.

2.8.2 Recharge

The mean annual recharge to the groundwater system in the study area is estimated to be

between 5.6 and 9.6 mm per annum (Golder 2012).

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3 Hydraulic testing

Hydraulic tests were undertaken to determine the in-situ hydraulic parameters of the

hydrostratigraphic units underlying the area. The hydraulic test was comprised of the test

pumping of existing boreholes and slug testing of the exploration coreholes. These tests were

undertaken by Golder in 2012. The tested boreholes and coreholes are shown in Figure 10 and

Figure 11.

3.1 Slug test in the exploration coreholes

The slug test involved positive displacement of water by injecting a known volume of water into

the identified exploration and using the rate at which the water levels returns to its

undisturbed state to determine the hydraulic conductivity. The hydraulic conductivity values

were determined using the Bouwer and Rice (1976) method.

Slug tests were performed on open exploration coreholes with a nominal inside diameter of

150 mm. A total 14 exploration coreholes and one monitoring borehole (H18-1522) were tested

and their details are presented in Table 1 together with the estimated hydraulic conductivity (k).

Table 1: Summary of the slug testing programme (Golder, 2012)

Site ID

GPS Coordinates WGS 84

Depth (mbgl)

Water level

(mbgl)

Est. hydraulic

Conductivity (m/d) Latitude Longitude

BGAC-6 -22.72335 29.51875 106 45.1 0.0353

BGAC-7 -22.73469 29.49068 71 45.9 0.0109

BGAC-8 -22.73755 29.46358 60 33.4 0.00781

BGAC-9 -22.73761 29.46354 69.1 33.5 0.1100

BGAC-10 -22.72035 29.48618 66 44 0.1400

BGAC-11 -22.72082 29.46679 - 26.3 0.0583

BGAC-12 -22.72716 29.47307 - 29.4 0.0353

BGAC-13 -22.68617 29.51700 - 32.7 0.019

BGAC-14 -22.69107 29.53883 - 32.7 0.0136

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Site ID


Depth (mbgl)

Water level

(mbgl)

Est. hydraulic

Conductivity (m/d) Latitude Longitude

BGAC-15 -22.67328 29.53076 - 18.8 0.0295

BGAC-16 -22.73403 29.45369 91.6 20.4 0.00478

BGAC-17 -22.72931 29.50428 - 24.1 0.0215

BGAC-19 -22.70953 29.54431 - 47.4 1.3800

BGAC-21 -22.71692 29.53894 - 39 0.00025

H18-1522 -22.72976 29.53827 - 55.9 0.0581

The hydraulic conductivity of the tested areas ranges between 0.00025 and 1.38 m/d indicating

a low to very high permeability (Table 1). Corehole BGAC-19 was drilled through a very high

permeability zone with an estimated hydraulic conductivity of 1.38 m/d. Coreholes, BGAC-9 and

BGAC-10, were drilled through a moderate permeable zone with estimated hydraulic

conductivities of 0.11 and 0.14 m/d, respectively. The moderate to high hydraulic conductivities

in coreholes, BGAC-19, BGAC-9 and BGAC-10, indicate the high permeability of the fractured

bedrock aquifer system and the less permeable weathered aquifer system. The low to very low

hydraulic conductivities reported in other tested coreholes suggest that the bedrock matrix is

absence or the fracturing is less or very tight.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 1 0 : L o c a t i o n o f t h e t e s t p u m p e d b o r e h o l e s

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3.2 Pumping testing of existing boreholes

The test pumping was undertaken to determine the bulk hydraulic parameters of the

underlying hydrostratigraphic units penetrated by the tested borehole. A total of 21 boreholes

were subjected to a full test pumping programme which included step drawdown and constant

discharge tests which were followed by recovery monitoring. The details of the tested

boreholes are presented in Table 2 and their positions in Figure 11. The tests were undertaken as

detailed below:

The Step Drawdown Test (SDT) comprised of up to 4 x 1 hour steps with the discharge

at the subsequent step increased immediately after the completion of the previous

step. Each step was undertaken for 60 minutes. Water level drawdown was recorded in

each pumping hole during the SDT. After the completion of the last step of the SDT,

water level recovery was recorded.

The Constant Discharge Test (CDT) comprised pumping at a constant yield for extended

periods of time. The duration of the CDTs run on the boreholes varied from 1 to 24

hours according to the borehole capacity. Water level drawdown was recorded in each

pumping hole during the entire duration of CDT pumping. Recovery was recorded

immediately after CDT pumping ceased.

A Recovery Test (RT) followed directly after pump shut down at the end of the SDT and

CDT in the tested borehole. The residual drawdown over time (water level recovery)

was measured in the tested borehole until 95% recovery was reached or up to the

equivalent of the pumping time.

The test pumping data were interpreted using FC-Method, an aquifer testing software

developed by the Institute for Groundwater Studies (IGS). The software includes various

methods and allows for aquifer boundary conditions. The methods used for parameter

estimations included basic Flow Characteristics Method (FC), Cooper-Jacob and Barker Bangoy.

Aquifer Transmissivity were determined for all boreholes subjected to SDT and CDT. A summary

of the pumping tests results are presented in Error! Not a valid bookmark self-reference..

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Table 2: Summary of the aquifer test pumping (adopted from Golder, 2012)

Site ID


Depth (mbgl)

Water level

(mbgl) T (m2/d) Latitude Longitude

BGA-1 -22.76449 29.43482 58.6 26 10.0

BGA-2 -22.74664 29.41682 68.3 12.7 3.2

BGA-3 -22.75104 29.42799 66.4 18.3 23.6

BGA-4 -22.74090 29.45683 78.6 26.5 8.0

BGA-5 -22.73571 29.46560 51.6 32.5 6.0

BGA-6 -22.73057 29.48132 117.6 37.3 2.0

BGA-7 -22.73050 29.48119 53 37.8 1

BGA-12 -22.67106 29.50627 53.8 20.3 23.2

BGA-13 -22.67240 29.50992 81 26.6 5.7

BGA-15 -22.75045 29.46630 60 31.9 1

BGA-18 -22.71540 29.46802 52.3 24.4 5.6

BGA-20 -22.71136 29.48423 146.1 41.2 2.0

BGA-21 -22.72729 29.46159 114.5 28.8 1

BGA-24 -22.72608 29.46018 41.2 26.9 1

BGA-27 -22.67398 29.54159 121.4 13.5 8.5

BGA-29 -22.66740 29.53858 29.7 23.8 24.0

BGA-31 -22.63533 29.53192 56.7 28.9 11.0

BGA-32 -22.67757 29.52559 45.6 18.3 <1

BGA-33 -22.73250 29.44803 33 13.6 26.1

BGA-37 -22.72108 29.53422 110.5 60.8 1.8

BGA-39 -22.72856 29.44822 50.6 8.6 13.1

The estimated transmissivities of the tested areas ranges between 1 and 26.1 m2/d, indicating

an anisotropic nature of the underlying weathered and fractured aquifer systems.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 1 1 : L o c a t i o n o f t h e t e s t p u m p e d b o r e h o l e s

__________________________________________________________________________________

4 Groundwater levels and flow

No consistent groundwater monitoring is being undertaken in the area and no water level data

was available for the area until Golder conducted a hydrogeological investigation in 2012. The

project baseline groundwater level is based on data obtained from:

Water levels as measured in the existing boreholes and coreholes by Golder 2012;

Water levels as measured in the existing boreholes and coreholes by Naledzi 2016.

The groundwater level data used to compile the groundwater surface piezometric map (Figure

12) is presented in Appendix A.

The groundwater elevation in the Berenice Coal Project area ranges between 667 and 700

mamsl with an average of 680 mamsl (Appendix A). The depth to the groundwater level is

generally increasing with an increase in distance from the Brak River, therefore, the

groundwater flow directions is towards the River, suggesting that Brak is a gaining stream.

To assess the groundwater flow systems in the area, the water elevations were plotted against

topography elevations. Two distinct sets of water elevations were identified from the collected

data, the shallow weathered aquifer system characterised by water levels shallower than 26

mbgl and a ‘deeper system’ with water level deeper than 26 mbgl.

Figure 13 shows the correlation between groundwater and topography elevations in the shallow

weathered system. There is a good correlation between topography and groundwater

elevations in the shallow aquifer system (Figure 13), suggesting unconfined aquifer conditions

and the groundwater mimics the topography.

Due to low yields in the shallow aquifer system, most of the drilled boreholes penetrated the

deep aquifer systems. The main and lower coal zones are deeper than 26 mbgl and all

exploration coreholes penetrated the deeper aquifer system. The correlation between

topography and groundwater elevation in boreholes and coreholes penetrating the deeper

aquifer system is shown in Figure 14. The figure (Figure 14) shows poor topography-groundwater

elevation correlation compared to the correlation in the shallow aquifer system. It is postulated

that poor correlation in deeper aquifer system indicates compartmentalization of the

groundwater flow system by structural features in the area. Groundwater flow in the deeper

aquifer system is controlled by geological structures in the area.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 1 2 : P i e z o m e t r i c s u r f a c e m a p o f t h e p r o j e c t a r e a

__________________________________________________________________________________

Figure 13: Correlation between topography and groundwater elevation (shallow aquifer system)

Figure 14: Correlation between topography and groundwater elevation (deeper aquifer system)

y = 1.0278x R² = 0.9113

670

680

690

700

710

720

730

740

650.00 660.00 670.00 680.00 690.00 700.00 710.00 720.00

Series1

Linear(Series1)

y = 1.0558x R² = 0.0352

680

690

700

710

720

730

740

750

650.00 660.00 670.00 680.00 690.00 700.00 710.00

Series1

Linear(Series1)

__________________________________________________________________________________

5 Water quality

5.1 Baseline Water quality

The baseline description for surface and groundwater quality in the Berenice Coal Project area

is required to characterize the water quality condition in the area before infrastructure

construction and mining at Berenice begins.

5.1.1 Surface water

The rivers and streams in the area are non-perennial and only flow after floods. No surface

water samples were collected to determine the surface water baseline quality.

5.1.2 Groundwater

No consistent groundwater monitoring is being undertaken in the area, currently. No samples

were collected and analysed in the area prior to the hydrogeological investigations by Golder in

2012. Therefore, the baseline groundwater quality is based on data obtained from water

samples collected from the existing groundwater supply boreholes by Golder (2012) and

Naledzi (2016). A total of 21 boreholes were sampled by Golder in 2012. Naledzi only sampled

eight boreholes which were in use and pumping during the site visit. The samples were

submitted to UIS Laboratories in Pretoria and Capricorn Veterinary Laboratories for analysis.

The analytical results for the samples collected by Naledzi were still pending during the

compilation of this report, therefore, only Golder water quality data was used to define the

baseline groundwater quality in the area.

The details of the sampled boreholes are presented in Table 3 and their locations are shown in

Figure 15.

The groundwater quality information for the Berenice Coal Project was compiled to

characterise the groundwater condition in the area before mining begins. The water quality

gathered in this study will form part of the baseline water quality condition to be used as

reference in assessing possible groundwater contamination emanating from mining activities in

the future. Note the water quality presented here is a ‘snap shot’ and variability of the water

quality should be established prior to mining. The details of the recommended monitoring

network to establish a baseline groundwater level and quality data is presented in Section 9.2.

__________________________________________________________________________________

Table 3: Details of the sampled boreholes

Site ID


Sampling events Sampled by Comments Latitude Longitude

BGA-1 -22.76449 29.43482 October 2012; June 2016 Golder; Naledzi June 2016 results still outstanding




BGA-5 -22.73571 29.46560 October 2012 Golder Not sampled in 2016



BGA-8 -22.73288 29.50891 June 2016 Naledzi June 2016 results still outstanding















_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 1 5 : L o c a t i o n o f t h e s a m p l e d b o r e h o l e s

__________________________________________________________________________________

5.2 Applicable guidelines

The land use within the Berenice Coal Project area is mainly associated with agricultural

practices, game farming, and a few residential areas. The people and wild animals in the area

rely on groundwater from boreholes for daily domestic and stock watering purposes. On the

basis of the current water use in the area, the baseline water quality is assessed against:

South African National Standard for drinking water (SANS241:2011); and

Department of Water Affairs Irrigation and Livestock Watering Guidelines (DWAF, 1996).

A summary of groundwater analytical results together with the stipulated SANS 241:2015 and

Irrigation and Livestock Watering Guidelines are presented in Table 4. Parameters with

concentrations above the stipulated standards and guidelines are highlighted in yellow.

5.3 Chemical analysis

The groundwater from the sampled boreholes is neutral to slightly alkaline with pH ranging

between 6.9 and 7.8 (Table 4). The groundwater is brackish to saline with Electric Conductivity

(EC) ranging between 92 to 752 S/m and 668 to 7 430 S/m, respectively (Table 4). The

concentration of EC in the groundwater is above the stipulated Drinking Water Standard (SANS

241) of 170 mg/l. The total dissolved solids of several groundwater samples are above the

stipulated Drinking Water Standard (SANS 241) and Livestock Watering Guidelines (DWAF,

1996), of 1 200 and 2000 mg/l (Table 4), respectively.

5.3.1 Major ions

A Piper diagram was used to graphically depict the overall composition of the groundwater in

the project area based on its major cation and anion composition. To present information on a

Piper plot, concentrations in milligrams per litre for major anions and cations are converted to

milli-equivalents per litre and then plotted in the lower ternary diagrams to show the

percentage contribution of each major ion; one for anions and one for cations. The locations of

each sample in the anion and cation ternary fields are then projected into the “diamond” plot.

Waters that lie in similar locations in the “diamond” plot are interpreted to be of the same

origin and general composition.

__________________________________________________________________________________

Table 4: Summary of groundwater quality analytical results and compliance limits

Variables Units

Livestock

Watering

SANS 241

(2015) BGA-1 BGA-2 BGA-3 BG-4

BGA-

5

BGA-

6

BGA-

7

BGA-

12

BGA-

13

BGA-

15

BGA-

18

BGA-

20

BGA-

21 BGA-24 BGA-27 BGA-29 BGA-31 BGA-32 BGA-33 BGA-37 BGA-39

pH

<5.0

>9.7

7.63 7.82 7.71 7.12 6.95 7.07 7.17 7.75 7.31 7.45 7.53 6.94 7.60 7.35 7.54 7.51 7.45 7.13 7.69 7.39 7.74

E. Conductivity mS/m 170 98.2 114 92.1 369 509 752 544 130 300 96.3 369 917 432 240 580 348 143 273 120 302 135

TDS mg/l 0 - 2000 1 200 72.2 774 684 2 830 4 040 6 010 4 030 944 2 430 668 2 570 7 430 2 940 1 630 4 500 2 690 950 1 790 816 2 180 912

Suspended Solids mg/l <20 <20 <20 <20 <20 109 133 <20 <20 209 <20 31.6 339 65.6 20.2 <20 <20 298 <20 <20 <20

Chloride mg/l 300 61.2 100 75.7 1040 1370 2300 1460 125 714 31.3 712 2860 1130 364 1560 919 141 426 129 589 160

Sulphates mg/l 468 500 13.5 1.55 13.1 128 317 417 22.5 75.8 214 1.02 397 869 201 127 660 291 27.3 241 23.5 351 82.8

Fluoride mg/l 1.5 0.567 <0.1 0.454 0.626 1.39 0.132 0.226 0.413 0.319 0.453 0.455 0.565 0.572 0.572 0.533 0.364 0.533 0.407 0.617 0.342 0.606

Nitrate as N mg/l < 11 11.00 20.3 <0.3 13 <0.3 <0.3 <0.3 <0.3 30.5 <0.3 <0.3 0.94 <0.3 <0.3 7.87 <0.3 1.56 8.55 <0.3 12.3 1.04 6.94

Sodium mg/l 0 – 2000 200 86.1 163 69.1 314 498 573 415 115 235 178 604 1 070 626 329 727 354 206 438 165 344 190

Potassium mg/l 100 11.9 4.49 7.51 20.5 35.9 42.9 42.4 42.4 12.4 14.9 6.22 21.1 52.1 20.7 20.3 31.2 11.1 15.4 12 8.62 27.6

Calcium mg/l 300 45.1 22.3 41.1 116 182 328 78 75.4 201 28.8 48.1 265 105 66.8 179 136 56.8 80 34.3 140 35.7

Magnesium mg/l 100 74.3 49.1 72.2 262 350 538 360 85.6 191 25.5 167 594 188 143 349 235 73 117 68.8 185 52

Iron mg/l 0 - 10 2 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 0.2 <0.05 <0.05 0.14 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Manganese mg/l 0.4 <0.01 <0.01 <0.01 0.016 <0.01 0.11 0.118 <0.01 0.061 0.172 0.016 0.302 0.285 0.123 0.142 0.021 <0.01 0.175 0.016 0.049 <0.01

__________________________________________________________________________________

The groundwater composition of the area is presented on a piper diagram (Figure 16). The

piper diagram indicates that the water in the area is dominated by recently recharged

magnesium carbonate water with a chloride dominance mixing line. The mixing is due to

Figure 16: Piper diagram

5.3.2 Metals

The analytical results indicate very low concentrations of several metals in the groundwater.

__________________________________________________________________________________

6 Conceptual model

Based on the interpretation of the available and gathered geological and hydrogeological

information of the area, a conceptual hydrogeological model was developed as an adequate

description of the groundwater system of the Berenice Coal Project. Due to limited information,

the hydrogeological conceptual model of Berenice Coal Project comprise of an assemblage of

justifiable, simplifying assumptions which summarises the principal characteristics of the real

system so that its behaviour may be clearly understood. The hydrogeological conceptual model

represents the current consensus on system behaviour based on the existing information and

data gathered during the site visit and intrusive investigation.

The basic components of a conceptual hydrogeological model are the primary hydrogeological

units derived from the geological settings of the area and the groundwater flow in the area. The

conceptual hydrogeological model serves as an input and basis of the numerical

hydrogeological model. For the purpose of the current study, the subsurface was envisaged to

consist of the following hydrogeological units:

Layer 1- The upper weathered zone few meters below surface consist of completely

weathered material. This layer is anticipated to have a reasonable low to medium

hydraulic conductivity. The depth of this zone (as determined by the contact between

weathered and the fractured zone) ranges between 5 and 26 mbgl. The thickness of the

aquifer system ranges between 2 and 20 m. The weathered aquifer system is less

permeable and low yielding than the underlying fractured zone. This aquifer system

stores and transports the bulk of the groundwater resource in the area. This aquifer is

unconfined to semi-confined in places and it is highly susceptible to surface induced

activities and impacts. The flow in this aquifer system is expected to follow topography.

Layer 2 – This zone underlines the weathered zone. This zone is slightly weathered,

highly fractured with a medium to high hydraulic conductivity. The thickness of the

fractured rock aquifer system ranges between 20 and 200 m and its depth is between

26 and 300 mbgl. The groundwater flow direction in this unit is influenced by regional

topography and locally by the geological structures and in the project area the flow

would be in general from high lying areas towards the Brak River.

__________________________________________________________________________________

7 Numerical model

The numerical groundwater was set up using the conceptual model as basis. The numerical

model is intended to reflect the site specific conditions as accurately as possible to achieve the

highest level of confidence in the simulated impacts.

Groundwater flow at the Berenice was simulated with a finite difference model called

MODFLOW that was developed by the United States Geological Survey.

For the current model, the Block Centre Flow (BCF) flow package and the Preconditioned

Conjugate Gradient 2 (PCG2) solver were used to solve the flow matrix (Hill, 1990). The BCF

package involves assigning hydraulic properties to individual cells based on their location within

a particular layer of the model domain. The critical assumption of this approach is that every

cell within a particular section of a layer is assigned the same set of hydraulic properties and

that any localized heterogeneity is subsumed into the bulk permeability of a zone. There is

however no limit to how finely a layer can be discretized horizontally into rectangular cells, but

each layer of a finite difference grid is necessarily one cell thick.

This numerical flow model is a mathematical representation of the conceptual model presented

and enables a quantitative analysis of local groundwater flow and contaminant plume

migration. The conceptual model was represented numerically based on the following

assumptions:

The aquifer system at the Berenice can be subdivided into hydrostratigraphic units;

Each hydrostratigraphic unit can be represented as a single model layer with

representative hydraulic properties (i.e. hydraulic conductivity, anisotropy, storage) and

recharge can be estimated as a proportion of incident rainfall;

Groundwater movement in the hydrostratigraphic units follows Darcy’s law and hence

can be modelled using the ‘equivalent porous medium’ approach. i.e. the use of

effective (or bulk) hydraulic properties to approximate conditions in the aquifer;

The available information on the geology and field tests was considered as correct; and

It is important to note that a numerical groundwater model is a representation of the

real system. It is therefore at most an approximation and the level of accuracy depends

__________________________________________________________________________________

on the quality of the data that is available. This implies that there are always errors

associated with groundwater models due to uncertainty in the data and the capability of

numerical methods to describe natural physical processes.

7.1 Model boundaries and discretisation

The model domain and boundaries are given in Figure 17.

Boundaries of the numerical model domain were setup, in consideration with the proposed

mine plan and natural groundwater flow boundaries such as topographical highs and rivers. The

model is intended to reflect the site specific conditions as accurately as possible in order to

achieve the highest level of confidence. However, it still has to be taken into consideration that

this is regional model spanning an area of 75.2 km (east-west) by 66 km (north-south). The

model is bounded by A71J and A72B quaternary catchments.

The numerical model domain was spatially discretized into a 3-dimensional grid with a uniform

grid spacing of 50 m within the mine site, and up to 400 m by 400 m in areas beyond the mine

site. The model domain was discretized as a 2-layer model to represent conceptual

hydrostratigraphic units per the Golder (2012) conceptual model. Layer thicknesses and

description are summarized as follows:

Layer 1: 0 to 26 m to represent the weathered aquifer;

Layer 2: 26 to >300 m to represent the fractured aquifer.

SRTM elevation data was used to contour the surface elevation (top of Layer 1). The top of

Layer 2 was offset by the thicknesses listed above. The bottom of Layer 2 was assigned a constant

elevation of 400 mamsl.

__________________________________________________________________________________

Figure 17: Model mesh (rivers in cyan and drains in yellow)

7.2 Model Characteristics

7.2.1 Initial groundwater levels

The initial groundwater levels for the steady state calibration model were interpolated and

assigned based on the 2012 hydrocensus data. Once the model was calibrated, the calibrated

groundwater levels for each aquifer as was assigned as starting conditions for the transient

state calibration simulations.

7.2.2 Surface water bodies

A number of rivers and streams occur in the area. The rivers were simulated using the river

package where the river stage, river depth and hydraulic conductivity of the river bed material

__________________________________________________________________________________

were specified. The hydraulic conductivity of the river bed material was estimated from the

surrounding geology. All seasonal streams were simulated with drain package by assigning

drain elevation and conductance based on topography and geology.

7.2.3 Abstraction

Existing abstraction boreholes were assigned (Figure 18) based on yields described in Golder

2012.

Figure 18: Model mesh with abstraction boreholes (red points)

7.2.4 Recharge

The study area generally experiences low rainfall and is characterised by deep groundwater

levels. This indicates regional low recharge rates. The low recharge rates are supported by very

high chloride concentrations in groundwater. An initial recharge of 1% MAP was assigned for

model calibration.

__________________________________________________________________________________

7.2.5 Hydraulic Conductivity

Analysis of hydraulic conductivities from Golder 2012 indicated a geometric mean of 0.03 m/d.

This value was assigned as starting value for model calibration.

7.3 Model Calibration

The numerical model was calibrated in steady state by keeping the model complexity to

minimum. Calibration was achieved by varying recharge, hydraulic conductivity, riverbed

conductance and abstraction rates from existing abstraction boreholes within their acceptable

range in order to fit the simulated groundwater levels to observed groundwater levels.

The quality of the fit between simulated and observed water levels was visually evaluated

based on the geodetic elevation of the simulated water level and by means of a statistical

analysis.

From an initial assigned value of 1 %, model calibration 0.1 % can be effectively used to

simulate recharge to the model domain. The weathered aquifer can be represented with a

hydraulic conductivity of 0.08 m/d and the thicker fractured aquifer, with a hydraulic

conductivity of 0.008 m/d. Groundwater levels in boreholes the vicinity of the Brak River are

very deeper than 13 m which signifies that the Rivers although perennial, are not continuous

with the groundwater table. The disconnection between the rivers and groundwater table was

achieved by assigning a low river bed conductance of 1.4 m2/d. The final stage of calibration

was done by modifying abstraction rates in existing pumping boreholes.

The modelled versus measured groundwater levels are shown in Figure 19, depict a good

correlation (91 %) between calculated and observed hydraulic heads. The mean residual value

is calculated to be 1.1 m, meaning that on average the calculated groundwater levels are 1.1 m

above the levels measured in the field. This slight difference will have an insignificant impact on

the calculated groundwater inflow volumes into the pits. The simulated steady state flow field

are shown in Figure 20.

__________________________________________________________________________________

Figure 19: Correlation between modelled and measured heads

Figure 20: Steady state groundwater flow fields

__________________________________________________________________________________

7.4 Simulated water balance

Simulated inflow and outflow to the proposed open cast areas and the model domain are

summarised on Table 5. Positive numbers denote an inflow to the groundwater system, such as

recharge. Negative numbers represent an outflow from the groundwater system (i.e.

groundwater discharge). Key aspects of the water balance are summarised as follows:

Recharge to the entire model domain constitutes 59% of the total inflow. The remaining

41 % is sourced from rivers;

45 % of the total inflow is abstracted through pumping boreholes, 36 % contributes to

flow in the rivers and the remaining 19 % contributes to flow in seasonal streams;

In the proposed OC1 footprint, groundwater comes in a rate of 475 m3/d, with recharge

contributing only 16 m3/d. 70 % of the total influx is abstracted through pumping

boreholes with the footprint and the remaining 30 % flows downgradient;

Groundwater passage through OC2 footprint is relatively small, with surrounding

aquifers taking entirely what flows from up gradient; and

The portion of the Brak River that flows through OC3 contributes up 59 m3/d (24 %) of

the total inflow to OC3 footprint. 49 % of the total influx is abstracted through pumping

boreholes with the footprint and the remaining 51 % flows downgradient.

Table 5: Water balance

Component (all in m3/d) OC1 OC2 OC3 Model Domain

Recharge 16 1 6 2177

Abstraction -342 0 -120 -1623

Inflow from surrounding aquifers 475 34 178

Outflow to Surrounding aquifers -149 -35 -123

Infiltration from rivers 59 1489

Exfiltration to rivers -1331

Exfiltration to streams -711

Balance 0 0 0 0

7.5 Model Predictions

The predictive model was setup according to the mine plan to estimate the inflow rates, predict

the cone of dewatering and contamination plume originating from potential sources. Aspects of

the predictive model are discussed below.

__________________________________________________________________________________

7.5.1 Mine Dewatering

The level of detail provided in the mine plan was modelled as accurately as possible by dividing

the model into 26 stress periods, representing each mining strip per the mine plan.

Drain cells were used to model inflows due to mining. The modelled drain elevation were set to

the final pit floors and progressed through yearly increments for the first 25 years. Year 26 to

33 was modelled as a single stress period.

All abstraction boreholes were left as is until such time when the mine plan approaches an

abstraction borehole. Abstraction from boreholes affected by the mine plan was shut down to

simulate destruction of the borehole. The following abstraction borehole will be affected by

mining:

BGA 6, BGA7, BGA 21, and BGA 24 in OC1;

BGA27 and BGA 32 in OC3.

It is important to mention that the portion of the Brak River that traverses OC3 was diverted in

FY23 ahead of mining in FY25. The predicted inflows are given in Table 6. Key aspects of the

simulated dewatering are as follows:

Inflows into OC1 are predicted to oscillate between 2000 and 2400 m3/d during the first

twelve years of mining;

Inflow are predicted to fall below 2000 m3/d from Y13 onwards, below 1000 m3/d from

Y18 and finally to 530 m3/d as mining ceases in OC1 ceases in Y20;

Inflows into OC3 are predicted to peak at 1150 m3/d as mining commences in Y20. OC3

inflows are not predicted to fall below 800 m3/d year on year till Y25;

The average inflow into OC3 during the final 8 years of mining a predicted at 1190 m3/d.

Similarly OC2 inflows during the final 8 years of mining are predicted at 1270 m3/d.

Table 6: Predicted inflows

FY OC1 (m

3/d)

OC1 (m

3/d)

OC3 (m

3/d)

Total Inflow to Active Mining (m

3/d)

Y1 2440 2440

Y2 2290 2290

Y3 2090 2090

Y4 2270 2270

Y5 2300 2300

__________________________________________________________________________________

FY OC1 (m

3/d)

OC1 (m

3/d)

OC3 (m

3/d)

Total Inflow to Active Mining (m

3/d)

Y6 2330 2330

Y7 2130 2130

Y8 2090 2090

Y9 1940 1940

Y10 2070 2070

Y11 2460 2460

Y12 2400 2400

Y13 1890 1890

Y14 1810 1810

Y15 1670 1670

Y16 1430 1430

Y17 1320 1320

Y18 1070 1070

Y19 924 924

Y20 530 1150 1680

Y21 1190 1190

Y22 1040 1040

Y23 818 818

Y24 852 852

Y25 930 930

Y26-33 1270 1190 2460

The predicted drawdown cones created by mining are depicted from Figure 21 to Figure 25.

Associated predicted monitoring borehole hydrographs are given in Figure 26. The simulated

hydraulic heads at end of mining are given in Figure 27. Hydrographs after closure are given in

Figure 28. Figure 29 shows the final hydraulic heads 100 years after closure. Pit decant points

and decant analyses are given from Figure 30 to Figure 33. Key aspects of the groundwater flow

regime during and after mining are as follows:

Impacts on groundwater levels are indicated by a 5 m drawdown. The steady state

groundwater levels are used as initial conditions to delineate further drawdown due to

mining;

The severity of groundwater drawdown on groundwater users will depend on the

distance between the groundwater user and the pits. Higher drawdowns will be

experienced by groundwater users closer to the pit. In the pits, the deeper the coal floor

to the pre-mining groundwater level, the higher the drawdown;

__________________________________________________________________________________

A maximum drawdown of 65 m is predicted in during mining Year 1. It should be

mentioned that boreholes labelled BGAC are exploration boreholes and are not

considered to represent groundwater users;

Therefore only boreholes BGA-06, BGA-07 and BGA-09 are predicted to fall within the

cone of dewatering during mining Y1. A drawdown of 8 m is predicted in BGA-06 and

BGA-07. A 6 m drawdown is predicted in BGA-09;

Mining will progress with concurrent rehabilitation. This was taken into consideration in

the model. According to the mine plan, Year 19 marks the last year for mining at OC1

only. OC1 and OC3 will be mined in Year 20, which marks the final mining year in OC1;

In Year 19, a maximum drawdown of 95 m is predicted in OC1. The predicted drawdown

cone extends about 5 km south, 2.6 km west and 4 km north of the pit outline. In

addition to the boreholes that will be destroyed as part of the mining process, the

following boreholes will fall with the drawdown cone;

o BGA-20 (55 m drawdown);

o BGA-18 ( 50 m drawdown);






o BGA-37 (15 m drawdown);

o H18-1522 (13 m drawdown)

o H18-1521 (12 m drawdown); and

o BGA-10 (9 m drawdown).

With the introduction of OC3 in Year 20, the boreholes BGA-32 and BGA-27 are

predicted to fall within the new drawdown cone. A drawdown of 5 m is predicted for

BGA 32 and 9 m for BGA-27. A maximum drawdown of 48 m is predicted in OC 3 during

this year;

In Year 25, groundwater levels in OC1 would have recovered for 5 years. The levels in

OC1 are predicted to be at a minimum of 35 m below pre-mining levels (a maximum

__________________________________________________________________________________

recovery of 50 m from Year 20 drawdowns). The maximum drawdown in OC3 during

Year 25 is predicted to be 55 m. Boreholes BGA-12, BGA-13 and BGA-17 are predicted to

add to the list of impacted boreholes. A 7 m drawdown is predicted in these boreholes;

The drawdown cone in the final 8 years of mining will be deepest in OC2 (105 m), with a

corresponding hydraulic head of 570 mamsl;

Groundwater levels in impacted boreholes are predicted to recover to pre-mining levels

with 100 years after closure;

Pre-mining groundwater levels are in the proposed pit areas are below the pits decant

elevation. The decant elevation for OC1 is 709 mamsl, 697 mamsl for OC2 and 681 for

OC3. Heads in OC1 are predicted to stabilise around 700 and 680 mamsl (or at least 9 m

below the decant elevation) at 100 years after closure. OC2 and OC 3 will be connected

after closure and heads are predicted to be just below 680 mamsl 100 years after

closure. Water from OC2 will flow to OC3 due to their interconnection. Decant at OC3 is

highly likely and decant at OC1 is probable. The decant rates will be the effective

recharge rates to the pit areas;

In consideration of the pit surface areas and 20% of MAP as recharge rate to the

backfilled pits, OC1 is predicted to decant at a rate of 1920 m3/d. OC2 is predicted to

decant at a rate of 138 m3/d, and OC3 at a rate of 1 278 m3/d; and

Assuming the average sulphate generation rates at coal mines (7 kg/ha/d),

approximately 1 130 mg/L of sulphate is predicted to be associated with the decanting

pits.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 2 1 : Y e a r 1 d r a w d o w n

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 2 2 : Y e a r 1 9 d r a w d o w n

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_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _


_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 2 5 : Y e a r 2 6 - 3 3 d r a w d o w n

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F i g u r e 2 6 : P r e d i c t e d h y d r o g r a p h s d u r i n g t h e l i f e o f m i n e

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 2 7 : H e a d s a t e n d o f m i n i n g

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F i g u r e 2 8 : H y d r o g r a p h s a f t e r c l o s u r e

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F i g u r e 2 9 : H e a d s a t 1 0 0 y e a r s a f t e r c l o s u r e

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

F i g u r e 3 0 : D e c a n t p o s i t i o n s w i t h d e c a n t e l e v a t i o n s a n d h y d r a u l i c h e a d s 1 0 0 y e a r s a f t e r c l o s u r e

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Figure 31: OC1 predicted decant rate and sulphate concentration


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7.6 Mass Transport Simulation

Solute transport in groundwater is controlled by physical and geochemical mass transport

processes. All solutes are influenced by the same physical transport processes, namely

advection and dispersion. In contrast, geochemical transport parameters depend on the solute

of interest, as well as geochemical conditions in the aquifer. Solutes which are not influenced

by geochemical transport processes are defined as non-reactive or conservative solutes and can

be simulated using a conservative solute transport model. Solutes which are influenced by

chemical transport processes are defined as reactive solutes and require the use of a reactive

solute transport model.

In most cases, contaminant transport is driven by advection i.e. groundwater flow is the main

mechanism controlling the movement of solutes in groundwater. Advection implies that

contaminants migrate at a rate similar to the groundwater flow velocity and in the same

direction as the hydraulic gradient. Therefore, knowledge of groundwater flow patterns and

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hydraulic parameters can be used to predict solute transport under advection. Other

parameters to consider include dispersion, diffusion, effective porosity and the specific yield.

Dispersion of contaminants in groundwater is also important in terms of contaminant

transport. Dispersive transport is caused by the tortuous nature of pores or fracture openings

that result in variable flow velocity distributions within an aquifer and movement of

contaminants due to the difference in concentration gradient.

Dispersion has two components; longitudinal and transversal dispersivity. The longitudinal

dispersivity is scale dependent and is approximately 10% of the travel distance of the plume

(Fetter, 1993). The transversal dispersivity is approximately 10% of the longitudinal dispersivity.

The higher the dispersivity, the smaller the maximum concentration of the contaminant, as

dispersion causes a spreading of the plume over a larger area. Considering the distance of

centre of the tailings dam to the pit centres, a longitudinal dispersivity of 400 m is estimated.

The percentage of void volume that contributes to groundwater flow is expressed by the term

porosity. Not all pores are interconnected and therefore cannot contribute equally to

groundwater flow, leading to the derivation of the term effective porosity, used to express the

interconnected void volume that effectively contributes to groundwater flow and therefore

contaminant transport. No site specific field measurement of effective porosity is available. An

average 10% effective porosity is assumed for the aquifer systems.

To simulate the constant availability of contaminants at the potential contaminant sources, a

constant source term pollution simulation was done. In the absence of a geochemical

characterisation, a unit source concentration of 100% was applied. The predicted plume

indicates a limited movement of potential contaminants away from the project area. The

dominant direction of migration of contaminants from the surface facilities will be towards the

pits as they flood. Apart from boreholes with the pit areas which will be destroyed, boreholes

BGA-18, BGA-20, and BGA-13 are predicted to be impacted by the mine wide plume.

__________________________________________________________________________________

8 Impact assessment and mitigation

8.1 Methodology

The first stage of risk/impact assessment is the identification of environmental activities,

aspects and impacts. This is supported by the identification of receptors and resources, which

allows for an understanding of the impact pathway and an assessment of the sensitivity to

change. The definitions used in the impact assessment are given below:

An activity is a distinct process or task undertaken by an organization for which a

responsibility can be assigned. Activities also include facilities or pieces of infrastructure

that are possessed by an organization;

An environmental aspect is an ‘element of an organizations activities, products and

services which can interact with the environment’1. The interaction of an aspect with

the environment may result in an impact;

Environmental risks/impacts are the consequences of these aspects on environmental

resources or receptors of particular value or sensitivity, for example, disturbance due to

noise and health effects due to poorer air quality. Receptors can comprise, but are not

limited to, people or human-made systems, such as local residents, communities and

social infrastructure, as well as components of the biophysical environment such as

aquifers, flora and palaeontology. In the case where the impact is on human health or

well-being, this should be stated. Similarly, where the receptor is not anthropogenic,

then it should, where possible, be stipulated what the receptor is;

Receptors comprise, but are not limited to people or man-made structures;

Resources include components of the biophysical environment;

Frequency of activity refers to how often the proposed activity will take place;

Frequency of impact refers to the frequency with which a stressor (aspect) will impact

on the receptor;

Severity refers to the degree of change to the receptor status in terms of the

reversibility of the impact; sensitivity of receptor to stressor; duration of impact

1 The definition has been aligned with that used in the ISO 14001 Standard.

__________________________________________________________________________________

(increasing or decreasing with time); controversy potential and precedent setting; threat

to environmental and health standards;

Spatial scope refers to the geographical scale of the impact;

Duration refers to the length of time over which the stressor will cause a change in the

resource or receptor.

The significance of the impact is then assessed by rating each variable numerically according to

defined criteria as outlined in Figure 35. The purpose of the rating is to develop a clear

understanding of influences and processes associated with each impact. The severity, spatial

scope and duration of the impact together comprise the consequence of the impact and when

summed can obtain a maximum value of 15.

The frequency of the activity and the frequency of the impact together comprise the likelihood

of the impact occurring and can obtain a maximum value of 10. The values for likelihood and

consequence of the impact are then read off a significance rating matrix (Figure 36), and are

used to determine whether mitigation is necessary.

The assessment of significance should be undertaken twice. Initial significance is based only

natural and existing mitigation measures (including built-in engineering designs). The

subsequent assessment takes into account the recommended management measures required

to mitigate the impacts. Measures such as demolishing infrastructure, and reinstatement and

rehabilitation of land, are considered post-mitigation.

The model outcome of the impacts is then assessed in terms of impact certainty and

consideration of available information. The Precautionary Principle is applied in line with South

Africa’s National Environmental Management Act (No. 107 of 1998) in instances of uncertainty

or lack of information by increasing assigned ratings or adjusting final model outcomes. In

certain instances where a variable or outcome requires rational adjustment due to model

limitations, the model outcomes are adjusted.

__________________________________________________________________________________

Figure 34: Criteria for assessing significance of impacts

Severity of impact RATING

Insignificant / non-harmful 1

Small / potentially harmful 2

Significant / slightly harmful 3

Great / harmful 4

Disastrous / extremely harmful 5

Spatial scope of impact RATING

Activity specific 1

Mine specific (within the mine boundary) 2

Local area (within 5 km of the mine boundary) 3

Regional 4

National 5

Duration of impact RATING

One day to one month 1

One month to one year 2

One year to ten years 3

Life of operation 4

Post closure / permanent 5

Frequency of activity/ duration of aspect RATING Annually or less / low 1

6 monthly / temporary 2

Monthly / infrequent 3

Weekly / life of operation / regularly / likely 4

Daily / permanent / high 5

Frequency of impact RATING

Almost never / almost impossible 1

Very seldom / highly unlikely 2

Infrequent / unlikely / seldom 3

Often / regularly / likely / possible 4

Daily / highly likely / definitely 5

CONSEQUENCE

LIKELIHOOD

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Figure 35: Significance Rating Matrix

Figure 36: Positive/Negative Mitigation Ratings

8.2 Impact Assessment

8.2.1 Introduction

This section presents the environmental assessment for the effects of the proposed Berenice

Coal project on groundwater resources. The information presented in this section meets the

requirements of the terms of reference as well as the legislative requirements for the project

and included details on:

Components within each phase (construction, operation and closure) of the project that

may influence or affect groundwater resources and/or groundwater quality;

Impact assessment for the potential impact of the project on the groundwater system;

Concerns that might be identified by stakeholders and regulators regarding

groundwater impacts;

Colour Code

Significance Rating

Value Negative Impact Management Recommendation

Positive Impact Management Recommendation

Very high 126-150 Improve current management Maintain current management

High 101-125 Improve current management Maintain current management

Medium-high 76-100 Improve current management Maintain current management

Low-medium 51-75 Maintain current management Improve current management

Low 26-50 Maintain current management Improve current management

Very low 1-25 Maintain current management Improve current management

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Sustainability assessment for groundwater issues;

Proposed mitigation measures to be considered during the construction, operation and

closure phases of the project to minimize groundwater-related effects; and

The monitoring program that will be used to identify and monitor project impacts on

groundwater levels and quality.

This section also considers potential positive environmental impacts or opportunities that the

proposed project will bring in the area. Given the location of the project, specific emphasis was

placed on the relevant environmental, social and economic impacts that might be raised by the

stakeholders. The identification of the significant potential impacts was guided by the

professional judgement of the hydrogeological and EAP team.

The objectives of the specialist studies and further investigation by Naledzi of each of the

potential environmental impacts identified was to determine their significance and to promote

mitigation measures to reduce the impacts to an acceptable level where required.

Each of the identified impacts was assessed in a separate section. Considering the general

nature of the proposed project each section will take cognisance of the construction,

operational and closure phases as well as the different alternatives, where possible. This is

intended to:

Allow the comparison of the various alternatives of the proposed project, facilitate the

comparison of the alternatives and to identify the preferred alternative during the

decision making process of the Limpopo Department of Economic Development,

Environment and Tourism (LDEDET) and Department of Environmental Affairs (DEA);

Enable stakeholders to understand the potential impact of the project in their specific

area. All potential environmental impacts have been addressed in this section, according

to the adopted methodology for assessing impacts as described in Section 8 and the

impacts presented in Table 7.

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Table 7: Impact assessment and mitigation measures

POTENTIAL ENVIRONMENTAL IMPACT

ENVIRONMENTAL SIGNIFICANCE BEFORE MITIGATION RECOMMENDED MITIGATION MEASURES/

REMARKS

ENVIRONMENTAL SIGNIFICANCE AFTER MITIGATION

Se Sp Du Fa Fi TOTAL SP Se

Sp

Du

Fa

Fi TOTAL SP

Construction and Operation Phase Impacts

Site construction and grading could cause changes in runoff and infiltration that could reduce groundwater recharge

2 1 4 1 3 28 Low (-) Construction stage will be planned to minimise the removal of vegetation and opportunities for revegetation will be maximised.

1 1 4 1 2 18 Very Low (-)

Fuel & hydrocarbons leakages and spillages from the storage and transporting vehicles may cause groundwater contamination

2 1 4 1 3 28 Low (-)

All storage areas containing hazardous materials will have secondary containments capable of containing the volume of the largest tank or container plus 10%. Resort to immediate clean-up after accidental spillages.

Divert run-off from haul roads that may contain hydrocarbons into lined pollution control dams

1 1 4 1 2 18 Very Low (-)

Open cast mining below the water table will result in pit inflows

2 2 4 4 4 64 Low Medium (-)

Pit inflows cannot be mitigated (required to enable a safe work environment). Provision needs to be made within the mine water balance for the reuse or treatment of pit inflows. In case the water should be discharged, treatment will be required before discharge.

2 2 4 4 4 64 Low Medium (-)

Baseflow reduction caused by mining

1 1 1 1 1 6 Very low (-) Brak River and other streams in the project area are non-perennial and there are no baseflow into them. The baseflow into the streams and Brak River won’t be affected by mining activities.

1 1 1 1 1 6 Very Low (-)

Mine dewatering and groundwater abstraction for water supply purposes could reduce groundwater levels in the area

3 3 4 4 4 80 Med High (-)

Pit dewatering will cause a cone of drawdown which will affect the neighbouring farms in the north, east and south of the Berenice Coal Project area. The extent of the zone of influence will not extend beyond 1 000m and the maximum drawdown in the affected areas will range between 1 and 5 m, thereby not expected to impact on the yields of any supply boreholes around the mining area. Possible mitigation against such an impact is temporary water supply by the mine.

2 2 3 4 4 56 Low Medium (-)

Increased potential for groundwater contamination due to seepages from the overburden stockpiles

1 1 2 2 2 16 Very Low (-)

Compact footprint area of the overburden stockpiles to minimize groundwater infiltration.

Stormwater run-off from the overburden stockpiles will be diverted into dirty water dams.

A groundwater resources monitoring program will be implemented during to detect the groundwater contamination.

1 1 2 2 2 16 Very Low (-)

Water contained in dirty water dams may impact on groundwater quality

2 1 4 4 4 56 Low Med (-)

Pollution control dams need to be lined and designed to comply with NEMA and NWA requirements (Act 36 of 1998).

Manage any leakages and spills to prevent groundwater contamination.

Implement groundwater monitoring to detect groundwater contamination

1 1 1 1 2 6 Very Low (-)

Post Closure Impacts

Salt Load contribution towards Brak River or other streams

1 1 2 2 2 16 Very Low (-) The dominant direction of migration of contaminants from the surface facilities will be towards the pits and Brak River or any nearby streams won’t be affected.

1 1 1 1 2 6 Very Low (-)

Aquifer contamination caused by backfill

4 3 5 5 4 108 High (-)

Pollution plume migration will be towards the mine pits and around the stockpiles areas and the plume won’t affect the nearby farms.

The final backfilled opencast topography should be engineered in such that runoff is diverted away from the opencast area.

3 3 5 5 4 99 Med High (-)

Rebound water levels within backfill material may cause decant

1 2 1 1 2 12 Very Low (-)

The water level will rebound but unlikely that it will decant, however, two of the three potential decant positions are located within the mining area. In case there is decant, an impermeable layer can be applied below the topsoil cover, which will need to be compacted to prevent the ingress of water.

Install water monitoring boreholes closer to the decant points to monitor the water level and water quality.

1 1 1 1 2 6 Very Low (-)

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9 Water management programme

9.1 Purpose and scope

The operation and decommissioning of the project will result in generation of waste from

several mine facilities that will have the potential to impact on groundwater quality. Also in

cases where the depth to water table is shallower than the depth of mining, associated mine

activities and dewatering could result in groundwater quality impacts and lowering of regional

water levels within the radius of influence of the dewatering activity. This section describes the

action plan that has been designed to implement the measures required to mitigate, monitor

and manage impacts on groundwater resources (quality and quantity) that might be posed by

the proposed project.

Berenice Coal mine will put in place specific actions to appropriately reduce, mitigate, manage

and monitor the impacts of the proposed project on the groundwater resources from

development to post closure (Table 7). In this report, mitigation is taken to represent all facets

of actions taken to avoid or reduce negative effects and enhance positive effects, including the

following hierarchy:

avoidance.

minimization.

rehabilitation.

compensation.

NOTE: Closure mitigation requirements are addressed in Berenice Coal Mine Closure Plan.

9.2 Monitoring programme

The groundwater monitoring program is designed to detect changes in groundwater levels and

quality associated with the mine operations, and to provide early detection of undesirable

impacts arising from the construction, operation and closure activities of the project. The

program will also be used to establish a robust, pre-disturbance baseline. Such information is

used to demonstrate compliance with regulatory requirements and to amend the action plan,

as and when necessary, in order to ensure safe operation and optimal environmental

protection. The observed data will be compared to those predicted in the environmental

impact assessment and to provide information to refine and improve the calibration and

predictions of the groundwater flow model. The gathered data will also provide information

that can be used to guide continuous improvement in groundwater management approach and

actions.

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The groundwater monitoring will include the following components, water quality, water level

and groundwater abstraction monitoring in the abstracting boreholes. The main objectives in

positioning the initial monitoring boreholes are to:

Monitor the lowering of the water table and the radius of influence;

Monitor the movement of polluted groundwater migrating away from the mine area;

and

Monitor post closure groundwater recovery rates and possibility of decanting.

The details of the groundwater monitoring network are presented in Table 8. The monitoring

network is comprised of 16 existing boreholes and 6 proposed additional boreholes to be

installed in the identified areas. Each new borehole is recommended to be drilled to a

maximum depth of 120 m to monitor the water level and quality in the weathered and

fractured aquifer that are expected to contribute to inflows in the pits.

Table 8: Details of groundwater monitoring locations

Site name X Y Status

BGA-01 44656 -2518522 Existing borehole
















BBH1 51585 -2513444 Proposed monitoring borehole




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Site name X Y Status



The baseline groundwater monitoring period will be for a year. The baseline groundwater

monitoring programme will include sampling of the listed boreholes for a minimum of four

times in a year.

The abstraction monitoring will be done in the water supply boreholes and the monthly

abstraction volumes will be recorded. The groundwater levels will be recorded on monthly

basis.

Following two years of operational monitoring, the number of sites and frequency of sampling

will be revised to determine the optimal monitoring strategy.

__________________________________________________________________________________

10 Groundwater supply potential

Universal Coal appointed Golder to undertake a preliminary hydrogeological investigation

aimed at assessing the groundwater supply potential from the existing boreholes within the

project area. Apart from the groundwater supply option, Universal coal also requested Golder

to assess the surface water supply options. The indicated water demand for the planned mining

operation was estimated at 3 to 5 Ml/day.

The groundwater potential, to supply the mine with its process water and domestic use, was

evaluated from the pumping tests completed by Golder in 2012. The study concluded that the

groundwater resources within the Brak River – Berenice Groundwater Management Unit should

be considered as a viable water supply option for the planned mine operations. The study also

indicated that an estimated volume of 1.1 Ml/day should be developed within the Berenice

project area.

To meet the estimated water demand for the mine operations, additional groundwater sources

should be developed along the Waterpoort – Alldays road (referred as T2 by Golder).

11 Conclusions

This report is an interim document detailing the summary of the hydrogeological investigations

to date by Naledzi as part of the groundwater specialist study for the proposed mining activities

at the Berenice Coal Project. Golder conducted a detailed hydrogeological investigation in the

area and several boreholes were tested to determine the hydraulic parameters and sustainable

yields. Due to the amount of work covered by Golder (2012) and the distribution of the tested

coreholes and boreholes throughout the project area, the groundwater specialist study by

Naledzi included most of the data collected by Golder.

Naledzi collected several water samples from the boreholes which were pumping during the

site visits and the samples were submitted to the analytical laboratory in Polokwane for

analysis. During the compilation of this report, the analytical results of the submitted water

samples were still outstanding.

The drilling and testing of three boreholes for hydrogeological and geochemical investigations is

in progress and the findings from this programme will be used to update the report.

__________________________________________________________________________________

The initial model predictions show that the dewatering cone of drawdown will extend into the

neighbouring farms in the north, east and south of the project area and might affect some of

the groundwater sources in those farms, if there are any. To date Naledzi is not aware of any

groundwater sources that will be affected by the cone of drawdown in these farms.

The extent, at which the groundwater sources in the neighbouring farms will be affected by the

cone of drawdown, will be determined after identifying the existence of groundwater sources

and use in the nearby farms. A detailed hydrocensus in the nearby farms is required. The

hydrocensus will record the positions of the groundwater sources as well as the water level and

depth of these sources.

Prepared by

MUNYAI F.D. (PrSciNat) Senior Geohydrologist

NALEDZI WATERWORKS (Pty) Ltd

Documents

Hydrogeological Investigation Report for the Proposed Berenice Coal Mine … · 2018-01-20 · Proposed Berenice Coal Mine in Makhado, Limpopo Province Report Prepared by NALEDZI