Geohydrological Assessment and Borehole

Siting at Hazendal Wine Estate, Bottelary

Road, Stellenbosch.
REPORT: PREPARED BY:
GEOSS Report No: 2019/01-17 Charles Peek
GEOSS - Geohydrological and Spatial
PREPARED FOR: Solutions International (Pty) Ltd
Shlomi Azar Unit 12, Technostell Building,
Managing Director 9 Quantum Street,
Hazendal Wine Estate Technopark
021 903 5034 / 079 100 9035 Stellenbosch 7600
shlomi@hazendal.co.za Tel: (021) 880 1079
Email: info@geoss.co.za
(www.geoss.co.za)

28 January 2019
 Geohydrological Assessment and Borehole Siting at Hazendal Farm near Brackenfell, Western Cape

EXECUTIVE SUMMARY
GEOSS – Geohydrological and Spatial Solutions International (Pty) Ltd was appointed by
Shlomi Azar to complete a geohydrological assessment for groundwater development at
Hazendal Estate near Vredenburg on the West Coast. GEOSS has previously conducted two
groundwater exploration phases on the Estate. The aim of the study is to complete a full
conceptual geological model of the Estate and assess the feasibility for further groundwater
development.

In general, the Estate is underlain by the Kuilsrivier granite Pluton of the Cape Granite Suite
(N-Ck) on the northern and southern tips of the which intruded the greywackes of the
Malmesbury Group. The central portion of the Estate is underlain by the Tygerberg
Formation (Nt), and sands of the Springfontyn formation (Qs) underlay the northern-most
section. A north-west trending magnetic anomaly trends through the middle section of the
wine estate. The middle section, which is the area of priority for groundwater development,
forms the base of the granite hills and has varying depths of sandy soil and clay rich soils, a
weathering product of the granite and greywackes. The regional aquifer directly underlying the
south of the property is classified as an intergranular and fractured with an average yield
potential of 0.1 – 0.5 L /s. The northern section has been classified to be underlain by a
fractured aquifer with an average yield of 0.5 – 2.0 L/s. A fractured or secondary aquifer
describes an aquifer in which groundwater flows through fractures or fault structures. The
groundwater quality is classified as “marginal” with an associated electrical conductivity (EC)
of 70 - 300 mS/m.

Three additional drill targets have been delineated for drilling of a water supply borehole on
the Estate (HZ_Drill_1, 2 and 3). The drill targets are based on the previous knowledge
obtained and geophysical methods. A summary with expected drilling conditions is provided
in the Table below. The borehole design based on expected drilling conditions is included in
Appendix A.

Latitude Longitude
ID Drilling depth (m) Priority
(WGS84) (WGS84)
HZ_Drill_1 -33.905861 18.723093 1
HZ_Drill_2 -33.901474 18.718330 120 2
HZ_Drill_3 -33.905071 18.722145 3

GEOSS_DT (Drill Targets) selected in 2017 have also been included on Map 5, however, the
two drill targets on the southern portion of the boundary fall within a 32 m buffer of a
river/drainage channel. Should these boreholes be considered for drilling they would require
further environmental assessments.

It is recommended that a hydrogeologist be on site to help define the depth and design of the
boreholes. Once the borehole is drilled, it should be properly developed with compressed air
upon completion. If successful, abstraction from the borehole will also need to be carefully
tested, monitored, managed and authorised to ensure sustainable use.
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TABLE OF CONTENTS
1. INTRODUCTION ................................................................................................ 1
2. SITE GEOLOGY AND GEOHYDROLOGY ...................................................... 1
2.1 Geology ............................................................................................................................... 1
2.2 Geohydrology .................................................................................................................... 5
3. SITE VISIT AND DISCUSSION.......................................................................... 5
3.1 Geophysics ......................................................................................................................... 8
3.1.1 Resistivity Method ............................................................................................................ 8
3.1.2 Electromagnetic Method ................................................................................................. 11
4. BOREHOLE SITING ......................................................................................... 12
5. RECOMMENDATIONS .................................................................................... 15
6. REFERENCES.................................................................................................... 16
7. APPENDIX A: BOREHOLE DESIGN ............................................................. 17
8. APPENDIX B: MONITORING INFRASTRUCTURE .................................... 19
9. BOREHOLE LOG .............................................................................................. 24

LIST MAPS

Map 1: Locality of Hazendal Estate near Brakenfell. ........................................................................ 2

Map 2: Geological setting of the area (CGS, 3318DC – Bellville. Scale 1: 50 000). ..................... 4
Map 3: Regional aquifer yield (DWAF, 2000). ................................................................................... 6
Map 4: Regional groundwater quality (mS/m) from WRC (2012) .................................................. 7
Map 5: Site map showing, geophysical profile locations and drill targets. ................................... 14

LIST OF FIGURES AND TABLES

Table 1: Geological formations within the study area. ...................................................................... 1

Table 2: Drill targets location and expected drill conditions.......................................................... 13

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ABBREVIATIONS

CGS Council for Geoscience

DD decimal degrees
DWAF Department of Water Affairs and Forestry
WCEDO West Coast Education District Offices
EC electrical conductivity
EOH End of hole
L/s litres per second
m metres
mbgl meters below ground level
mS/m milliSiemens per metre
NGA National Groundwater Archive
SANS South African National Standard

GLOSSARY OF TERMS

Aquifer: a geological formation, which has structures or textures that hold water or permit
appreciable water movement through them [from National Water Act (Act No. 36 of
1998)].
Borehole: includes a well, excavation, or any other artificially constructed or improved
groundwater cavity which can be used for the purpose of intercepting, collecting or
storing water from an aquifer; observing or collecting data and information on water
in an aquifer; or recharging an aquifer [from National Water Act (Act No. 36 of
1998)].
Groundwater: water found in the subsurface in the saturated zone below the water table or
piezometric surface i.e. the water table marks the upper surface of groundwater
systems.

Suggested reference for this report:

GEOSS (2019). Geohydrological Assessment and Borehole Siting at Hazendal Wine
Estate, Bottelary Road, Stellenbosch. GEOSS Report Number: 2019/01-17. GEOSS -
Geohydrological & Spatial Solutions International (Pty) Ltd. Stellenbosch, South
Africa.
Cover photo:
Property boundary superimposed onto Google EarthTm
GEOSS project number:
2018_12-3298
Review:
Julian Conrad (28 January 2019).

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1. INTRODUCTION

GEOSS – Geohydrological and Spatial Solutions International (Pty) Ltd was appointed by
Shlomi Azar to complete a geohydrological assessment for groundwater development at
Hazendal Estate near Vredenburg on the West Coast (Map 1). GEOSS has previously
conducted two groundwater exploration phases on the Estate (GEOSS, 2017a & GEOSS,
2017b). The aim of this study is to complete a full conceptual geological model of the
Estate and assess the feasibility for further groundwater development.

The study included additional remote geological and topographical investigation of the area
and lineament mapping; this preceded the site visit. The site visit included an evaluation of
the site geology and geophysics. The geophysics was carried out using the resistivity and
electromagnetic methods. The resistivity method measures the resistivity of the subsurface
using direct current coupling; the resistivity of the subsurface is likely to be lower in areas
of increased porosity and water saturation, whereas the EM method measures ground
conductivity by means of electromagnetic induction. The ground conductivity will likely be
higher in areas of increased fracturing and water saturation. The site boundary is presented
in Map 1.

2. SITE GEOLOGY AND GEOHYDROLOGY

2.1 Geology

The Geological Survey of South Africa (now the Council for Geoscience (CGS)) has
mapped the area at 1:50 000 scale (3318DC - Bellville). The geological setting is shown in
and the main geology of the area is listed in Table 1.

Table 1: Geological formations within the study area.

Code Formation/Suite Group Description
Qs Springfontyn - Scree
Mainly coarse-grained porphyritic
N-Ck Cape Granite Suite n/a - intrusion
granite with some granodiorite
Greywacke, phyllite and quartzitic
Nt Tygerberg Malmesbury
sandstone.

In general, the Estate is underlain by the Kuilsrivier granite Pluton of the Gape Granite
Suite (N-Ck) on the northern and southern tips of the which intruded the greywackes of
the Malmesbury Group. The central portion of the Estate is underlain by the Tygerberg
Formation (Nt) and sands of the Springfontyn formation (Qs) underlay the northern-most
section. A north-west trending magnetic anomaly runs through the middle section of the
wine estate. The middle section, which is the area of priority for groundwater development,
forms the base of the granite hills and has varying depths of sandy soil and clay rich soils, a
weathering product of the granite and greywackes.

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Map 1: Locality of Hazendal Estate near Brakenfell.

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The national aeromagnetic survey for South Africa dataset was used to determine if the
magnetic anomaly occurred within the confines of the Estate boundary and determine its
spatial extent and orientations. Figure 1 shows the estate boundary overlain onto the
national aeromagnetic dataset. The dataset shows a magnetic high anomaly which has been
delineated with magnetic anomaly lineaments. The Lineaments correlated with the mapped
structure. The large magnetic anomaly may be associated with either an intrusive dyke
structure or different magmatic phase within the granite pluton.

Figure 1: The national aeromagnetic survey (SAMAG).

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Map 2: Geological setting of the area (CGS, 3318DC – Bellville. Scale 1: 50 000).

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2.2 Geohydrology

The regional aquifer directly underlying the south of the property is classified by the
Department of Water Affairs and Forestry (DWAF, 2001) as an intergranular and fractured
with an average yield potential of 0.1 – 0.5 L/s. However, underlining the intergranular
aquifer is a fractured aquifer with an unknown yield potential. The northern section has
been classified to be underlain by a fractured aquifer with an average yield of 0.5 – 2.0 L/s
(Map 3). A fractured or secondary aquifer describes an aquifer in which groundwater flows
through fractures or fault structures.

The groundwater quality is classified as “marginal” with an associated electrical

conductivity (EC) of 70 - 300 mS/m (Map 4) (DWAF, 2001). Both of these classifications
are based on regional datasets, and therefore only provide an indication of conditions to be
expected. Both these classifications are marginally favourable for groundwater
development.

3. SITE VISIT AND DISCUSSION

A site visit was carried out on 14 and 15 January 2019 to assess the geology and conduct a
geophysical survey. GEOSS has previously conducted a hydrocensus for the area, report
(2017/03-20), no new data was located with the exception of the newly drilled hole on the
premises.

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Map 3: Regional aquifer yield (DWAF, 2000).

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Map 4: Regional groundwater quality (mS/m) from WRC (2012)

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3.1 Geophysics

In addition to the field mapping, a geophysical survey was undertaken using the
electromagnetic and resistivity methods. The electromagnetic and resistivity method was
used to locate lateral changes in electrical properties that may be related to changes in the
formation properties.

3.1.1 Resistivity Method

The Lund imaging system is a completely automated resistivity tomography data acquisition
system. The resistivity tomography method provides a pseudo-section of change in
electrical properties in the subsurface along a specified profile line. Four multi-core cables
with 16 electrode take-outs every 10 m were used. These cables were laid out on the
ground end to end in a straight line (where possible). An electrode (metal stake) is inserted
into the ground next to every electrode take-out on the cable, using a hammer. The
electrode take-out is then connected to the electrode with a short cable jumper. The multi-
core cables are connected to the ABEM electrode selector ES464 that controls the
measurement sequence. The electrode selector is connected to the ABEM Terrameter
SAS1000 that takes the apparent resistivity measurements. The data were collected using a
standard protocol with the Wenner array. All data were acquired for n = 1 to 8 and 10, 12,
14 and 16 where “n” is the electrode separation multiplication factor.

The apparent resistivity data acquired in the field were inverted using the RES2DINV
software (Loke and Barker, 1996) to provide a true-depth resistivity section. The only pre-
processing done was to erase obviously erratic data points (minimal). The resulting true
resistivity pseudo-sections are used for the interpretation.

Data was acquired along two profiles (Map 5) Res_line1 was conducted on the southern
portion of the property. The second profile (Res_Line2) was conducted on the northern
portion of the Estate. The profiles were located as such to attempt to characterise the
subsurface in the area and to delineate the deeper weathered zones and the delineated
magnetic anomaly. The profiles have been normalized for direct comparison.

The inverted resistivity data for this profile line Res_Line1 is shown in Figure 2. This
resistivity profile in general shows:
 Low resistivity, dark blue to green contours (5.98 – 60 ohm.m), is likely indicative
of dry sand and clayey material to a depth of 31 m.
 An intermediate resistivity zone, green to red contours (60 - 226 ohm.m), is likely
indicative of highly weathered bedrock which is argillaceous in nature. The
excepted depth to bedrock is 50 – 60 m.

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 Higher resistivity, red to purple contours (>226 ohm.m) is likely indicative of

bedrock. Bedrock is expected to be a “soft brittle” shale grading into a more
competent formation.

One drill target was delineated on Res_Line1, the drill target is located at 110 m along the
profile.

The inverted resistivity data for this profile line Res_Line2 is shown in Figure 3. This
resistivity profile was limited in spatial extent (length), the reduction in length limits the
skin depth. In general shows:

 Low resistivity, dark blue to green contours (5.98 – 55 ohm.m), is likely indicative
of dry sand and clayey material to a depth of 30 m.
 An intermediate resistivity zone, green to red contours (55 - 200 ohm.m), is likely
indicative of highly weathered bedrock which is argillaceous in nature.
 Higher resistivity, red to purple contours (>200 ohm.m) from surface to shallow
depth (0 – 20 m), is likely indicative is likely indicative of bedrock. Bedrock
underlaying the area is expected to be granite. a weathered granite zone is expected
to be intersected between 35 – 65 meters below the ground level (mbgl).
Competent granite is expected to be located below 65 m.

One drill target was delineated on Res_Line2, the drill target is located at 125 m along the
profile. The drill sited is located on a potential weathered zone/ contact. Based on the
previous drilling mission (Appendix C) fractures are likely to be intersected between 51 –
68 mbgl in the weathered granite formation. the lithology log provided by the drilling
company correlates with the Res_line2 interpretation.

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Southwest HZ_Drill_3 Northeast

Figure 2: Inverted resistivity profile - ResLine1, showing drill target HZ_Drill3

HZ_Drill2
North
South

Figure 3: Inverted resistivity profile – ResLine2, showing drill target HZ_Drill2

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3.1.2 Electromagnetic Method

The electromagnetic survey was carried out using a CMD-DUO electromagnetic

conductivity meter which measures the ground conductivity of the subsurface. It is a rapid
data acquisition instrument that can be successfully applied to groundwater exploration.
The CMD-DUO induces a changing electromagnetic (EM) field with a known frequency
into the subsurface using a sender coil. This changing EM field induces current flow in
conductive subsurface areas (for example fractured sandstone saturated with groundwater),
which is measured by the receiver coil. This is then automatically converted to ground
conductivity. In general, the ground conductivity measured has a direct correlation with
formation porosity and groundwater salinity; i.e. if porosity of the formation or
groundwater salinity increases, this will be reflected as a higher ground conductivity
measurement (Telford et al, 1990).

Data were acquired along three profiles on the property (Map 5), using a 40 m coil
separation with a horizontal co-planar coil orientation. This enables the measurement of
the ground conductivity at an approximate depth of 60 m. Two of the three profiles
showed substantial anomalies and will be discussed below.

Southwest Northeast

HZ_Drill_1

Figure 4: Electromagnetic data plot: EM_2, showing drill target HZ_Drill_1.

The data for EM profile EM_2 were acquired from southwest to northeast. The profile
data were acquired sub-parallel to the resistivity profile (Res_Line1). The data is shown in
Figure 4. The conductivity scale on the EM profiles have been normalised to allow for
direct comparison across EM profiles. In general, the ground conductivity measured with
the 40 m horizontal coil (HC) orientation (60 m depth of investigation) is relatively
moderate (>60 mS/m). The ground conductivity in the southwest section of the profile is
low and gradual increase towards the northeast. This is likely indicative of a change in
lithology, granite to shale. One substantial anomaly was observed between stations 15 – 35,

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the anomaly corelates with the SAMAG regional anomaly. One drill target was delineated
on the profile (HZ_Drill1).

South
North

HZ_Drill_2

Figure 5: Electromagnetic data plot: EM_3, showing drill target HZ_Drill_2.

The data for EM profile EM_3 were acquired from north to south. The profile data were
again acquired parallel to the resistivity profile (Res_Line2) and. The data is shown in
Figure 5 5. In general, the ground conductivity measured is relatively moderate than (>40
mS/m).
One substantial anomaly was observed between stations 25 – 45, the broad anomaly
correlates with a weathered zone identified on the Res_Line2. One drill target has been
delineated on the profile (HZ_Drill_2).

4. BOREHOLE SITING

Three additional drill targets have been delineated for drilling of a water supply borehole
on the Estate (HZ_Drill_1, 2 and 3). The drill targets have been indicated on Map 5. The
drill targets are based on geophysical methods. A summary with expected drilling
conditions is provided in Table 2. The borehole design based on expected drilling
conditions is included in Appendix A.

GEOSS previously sited boreholes which were sited in 2017 have also been included on
Map 5, however, the two drill targets (GEOSS_2 and 3) on the southern portion of the
boundary fall within a 32 m buffer of a river/drainage channel. Should these boreholes be
considered for drilling they would require further environmental assessments. The third
borehole sited (GEOSS_1) in the north-east corner is located near neighbouring boreholes
existing (Myburg_BH1, Map3). Should the borehole be considered for drilling is likely that
it may influence or be influenced by the existing boreholes in close proximity.

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Table 2: Drill targets location and expected drill conditions.

Drilling
Latitude Longitude
ID depth Priority Target
(WGS84) (WGS84)
(m)
0 – 30 m of clayey material
grading into hornfels or soft
HZ_Drill_1 -33.905861 18.723093 1
shales.

Sandy /clayey material and

120 weathered granite (clay)
HZ_Drill_2 -33.901474 18.718330 2
followed by hard bedrock
(granite).
0 – 30 m of clayey material
HZ_Drill_3 -33.905071 18.722145 3 grading into hornfels or soft
shales.

It must be noted that targets Drill_site1, 2 and 3 have been sited on a fractured aquifer with
a classified yield potential of 0.5 – 2 L/s. This, however, does not mean that any borehole
drilled in the area will obtain a borehole yield in this range. As it is a fractured aquifer the
groundwater only occurs in narrow fractures within the bedrock and if fractures are not
intersected the borehole may be dry.

It is recommended that a hydrogeologist be on site to help define the depth and design of
the boreholes. The recommended drill depths are in Table 2. Once the borehole is drilled,
it should be properly developed with compressed air upon completion. If successful,
abstraction from the borehole will also need to be carefully managed to ensure sustainable
use.

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Map 5: Site map showing, geophysical profile locations and drill targets.

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5. RECOMMENDATIONS

The following recommendations are made for the drilling and development of the
boreholes for groundwater utilisation:
 The boreholes can be drilled up to a maximum depth of about 180 m. Should
sufficient water be intersected before then, the drilling should continue for 10 m
beyond the main water strike. Should the formation be favourable, the drilling can
continue beyond this depth.
 A well experienced driller (with good references) and local knowledge should be
used for the work.
 During the borehole drilling, geological samples must be collected for every 1 m
drilled and the depth of fractures and associated yields noted. A hydrogeologist
should be on site to help with borehole construction and design and log the
borehole details. When drilling a borehole, the main issue is “when is the borehole
deep enough” and this issue is best addressed by a hydrogeologist.
 The borehole should be developed with compressed air for at least two hours upon
completion of the borehole (if successful).
 The borehole, once drilled, should be tested to determine the groundwater yield
available. This is to be done according to scientifically acceptable standards (as
outlined by the SABS) and will form part of the groundwater use license application
process. Please note that non-SABS yield tests (Farmer method or constant-
head) are not accepted by Department of Water and Sanitation (DWS)
during a license application.
 Samples of the groundwater should be submitted to an accredited laboratory for
analysis to determine if the quality is suitable for its intended use.
 Licensing of the water use should be addressed upon successful completion of the
borehole drilling.

Once the borehole has been drilled and is in use, it is recommended the owner implements
certain groundwater “best management practices”. Also note, in January 2018 the
Department of Water and Sanitation released a Government Gazette stating that: “All
water use sector groups and individuals taking water from any water resource (surface or
groundwater) regardless of the authorization type, in the Berg, Olifants and Breede Gouritz
Water Management Area, shall install electronic water recording, monitoring or measuring
devices to enable monitoring of abstractions, storage and use of water by existing lawful
users and establish links with any monitoring or management system as well as keep
records of the water used.” It is important to note that these best management practises are
merely a recommendation to aid in complying with the DWS requirements.

These include (See Appendix B):

 Installation of a 32 mm (inner diameter, class 10) observation pipe from the pump
depth to the surface, closed at the bottom and slotted for the bottom 5 – 10 m.

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This allows for a ‘window’ of access down the borehole which enables manual
water level monitoring and can house an electronic water level logger.
 Installation of an electronic water level logger (for automated water level
monitoring)
 Installation of a sampling tap (to monitor water quality).
 Installation of a flow volume meter (to monitor abstraction rates and volumes).
 The appropriate borehole pump must be installed, i.e. not an over-sized pump that
is choked with a gate valve.
 The borehole and pump should be serviced annually. A water sample should also
be collected annually and the flow rate and volume of water abstracted recorded
monthly (along with the measured water level).

The importance of monitoring a production borehole cannot be overstated. It is critical for

sustainable management of groundwater and promoting longevity of boreholes. Collapse
of fractures due to over abstraction is permanent. Examples of suitable monitoring
infrastructure is provided in Appendix B.

6. REFERENCES

Council for Geoscience, (1972). 1:125 000 Geological series. 3217D & 3218C St. Helena
Bay and 3317B & 3318A Saldanha Bay.
DWAF (2000). The hydrogeological map series of the republic of South Africa. Cape
Town, 3318. Scale: 1:500 000.
GEOSS (2017a). Geohydrological Assessment and Borehole Siting at Hazendal Farm near
Brackenfell, Western Cape. GEOSS Report Number: 2017/03-20. GEOSS -
Geohydrological & Spatial Solutions International (Pty) Ltd. Stellenbosch, South
Africa.
GEOSS (2017b). Geohydrological Assessment and Borehole Siting at Hazendal Manor
House, Brackenfell, Western Cape. GEOSS Report Number: 2017/10-02. GEOSS
- Geohydrological & Spatial Solutions International (Pty) Ltd. Stellenbosch, South
Africa.
Loke M. H. and Barker R. D., (1996). Rapid least-squares inversion of apparent resistivity
pseudosections by a quasi-Newton method. Geophysical Prospecting, Volume 44,
Issue 1, pp 131-152.
National Water Act (1998). The National Water Act, No 36. Department of Water Affair
and Forestry. Pretoria.
Telford W. M., Geldart L. P. and Sheriff R. E., (1990). Applied Geophysics: Second
Edition. Cambridge University Press.
WRC (2012). A Groundwater Planning Toolkit for the Main Karoo Basin: Identifying and
quantifying groundwater development options incorporating the concept of
wellfield yields and aquifer firm yields. WRC Report No. 1763/1/11, Pretoria,
South Africa.

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7. APPENDIX A: BOREHOLE DESIGN

(These recommendations are a guideline only for quoting purposes – each driller will use
different techniques and casing diameters appropriate to their equipment). Make sure a
well-established driller with a good Western Cape track record is appointed.

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Diagram
Borehole Specifications Re-Drill design for Varkies Kloof
0
Bhole ID DD5 (DD_B3_2017) re-drill 203mm ID Solid Steel
Casing (0 - 30 m)
Borehole Type (production/monitoring/windpump) Production
Sand / Rock Borehole? Rock 10

DRILLING DIAMETERS
20
Diameter 1 (mm); depth m 203 mm (0 - 35 m)
Diameter 2 (mm); depth m 177mm (30 - 80 m)
Diameter 3 (mm); depth m 155 mm ( 80 - 120 m) 30

40 ODEX Ring Bit

BOREHOLE CONSTRUCTION
177 mm Solid Steel
End of hole diameter (mm) / (inches) 168 mm Casing (0 - 80m)
Casing 1 diameter (OD - mm) / (inches) 8 " (216 mm) 50
Casing 1 diameter (ID - mm) / (inches) 203 mm
Casing depth m 0 - 35 m 60
Casing 2 diameter (OD - mm) / (inches) 177 mm
Casing 2 diameter (ID - mm) / (inches) 168 mm
Casing 2 depth m 0 - 80 m 70
Open hole depth m 80 - 120 m
80
Length of development time (hours) 2 hrs
Drilling mud required? Odex and air percussion
90
Geological description: Granite, Hornfels and shale
ODEX / Normal drilling? ODEX and Air Percussion 100 155 mm Open Hole
Borehole depth (m) (subject to change) 120 m (80 - 120 m)

110
Estimated depths of water strikes m

In situ perforation at water strikes: YES 120

EOH

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8. APPENDIX B: MONITORING INFRASTRUCTURE

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 Geohydrological Assessment and Borehole Siting at Hazendal Farm near Brackenfell, Western Cape

Schematic drawing of simplified setup of monitoring equipment in the borehole

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GEOSS Report No. 2019/01-17 28 January 2019
 Geohydrological Assessment and Borehole Siting at Hazendal Farm near Brackenfell, Western Cape

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GEOSS Report No. 2019/01-17 28 January 2019
 Geohydrological Assessment and Borehole Siting at Hazendal Farm near Brackenfell, Western Cape

An example of borehole with a monitoring system, note the observation pipe and flow metre.

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GEOSS Report No. 2019/01-17 28 January 2019
 Geohydrological Assessment and Borehole Siting at Hazendal Farm near Brackenfell, Western Cape

An example of a poorly managed borehole with water levels An example of a well-managed borehole. Abstraction leads to a
fluctuating substantially. This is coupled with rise in temperature, slight drop in water level and the borehole is rested, allowing the
indicating possible pump burnout. This over abstraction can water level to recover. The temperature fluctuates slightly with
collapse water bearing fractures – resulting in the borehole inflow of fresh water into the borehole. This is sustainable use
drying up. of the aquifer.

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GEOSS Report No. 2019/01-17 28 January 2019
 Geohydrological Assessment and Borehole Siting at Hazendal Farm near Brackenfell, Western Cape

9. BOREHOLE LOG

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GEOSS Report No. 2019/01-17 28 January 2019
 Geohydrological Assessment and Borehole Siting at Hazendal Farm near Brackenfell, Western Cape

Log of Borehole No.: BH_1

Location: Hazendal Wine Estate Latitude: -33.89896

Date: 19/05/2017 Longitude: 18.71803
Client: Hazendal Wine Estate Ground Elevation: 90

Description &
Lithological Description Lithology Symbol & Depth (m) Borehole Construction
water strike

0
Sand and Clay
8" Steel casing

10

20 6.5" Steel casing

30

Weathered Granite

40

Fractures:
50
51 and 53 m

60

62 m

68 m
70 6" Open hole

Granite

Drilled By: RPM Drilling Remarks:

Drill Method: Odex and Air percussion Blow yield = 12.5 L/s
Logged By: GEOSS

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GEOSS Report No. 2019/01-17 28 January 2019