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HYDROGEOLOGICAL EVALUATION HYDROGEOLOGY

Project Number: WH16093

Tecoplan Environmental

Hydrogeological Evaluation, Venbeck Filling Station, Ba-

Phalaborwa Local Municipality, Limpopo Province

Date: 16 January 2017

Report Version: V1.0

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REPORT ON A HYDROGEOLOGICAL EVALUATION FOR THE VENBECK FILLING STATION, PHALABORWA, BA-PHALABORWA

LOCAL MUNICIPALITY, LIMPOPO PROVINCE

Client Name: Tecoplan Environmental

Contact Person: Mr. Anton von Well

E-mail Address: tecoplan@mweb.co.za

Contact Number: 015 291 4177

Document History

Rev. Date Revised Editor Details Note of Changes Conducted

V1.0 2017-01-16 CJ Haupt First edit Final Report

Document Approval and Quality Control

© WSM Leshika Consulting (Pty) Ltd. No part of this document or any of the information or data within may be disclosed, copied, distributed or used for any purposed without the written permission of WSM Leshika Consulting (Pty) Ltd.

Action Responsible Person Profession and Registration

Fieldwork SJ Koekemoer Hydrogeologist – Not Registered

Data capturing SJ Koekemoer Hydrogeologist – Not Registered

Data analysis SJ Koekemoer Hydrogeologist – Not Registered

Report writing SJ Koekemoer Hydrogeologist – Not Registered

Reviewed by CJ Haupt Hydrogeologist – Pr.Sci.Nat

Approved by CJ Haupt Hydrogeologist – Pr.Sci.Nat

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ABSTRACT Hydro part The Hydrogeological investigation was conducted to assess the impact of the proposed Venbeck filling station on the groundwater resource. A desk study and field visit was conducted to collect data. Water samples were also collected during the field visit and were submitted to an accredited laboratory to establish the water quality as well as the BTEX and TPH prior to development. Due to the relative deep water table and medium permeability of the cover soils the groundwater is at moderate risk to pollution from spills. It is recommended that mitigation measures are followed to ensure the protection of the groundwater resource and to limit the possibility of contamination. It is further recommended that a monitor borehole be drilled downstream of the storage tanks and site to monitor the potential impact in future.

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TABLE OF CONTENTS

1 INTRODUCTION ....................................................................................................................... 1 2 SCOPE OF WORK ..................................................................................................................... 1 3 REGIONAL GEOLOGY ............................................................................................................... 2 4 HYDROGEOLOGICAL EVALUATION ........................................................................................... 2

4.1 Existing Borehole Data ................................................................................................................ 4 4.2 Aquifers ....................................................................................................................................... 5 4.2 Aquifer Storage ........................................................................................................................... 5 4.4 Groundwater levels and flow direction ...................................................................................... 6 4.5 Recharge ..................................................................................................................................... 6 4.6 Sustainable yield ......................................................................................................................... 6 4.7 Water Quality ............................................................................................................................. 7

5 CURRENT AND PROPOSED WATER USE .................................................................................... 9 6 MONITOR BOREHOLE FOR THE FILLING STATION .................................................................... 10 7. IMPACT ASSESSMENT OF THE PROPOSED FILLING STATION DEVELOPMENT ON THE GROUNDWATER RESOURCE AND PROPOSED MITIGATION MEASURES ........................................ 10 7.1 Sewage Facilities ................................................................................................................... 10 7.2 Fuel storage and dispensing Facilities ..................................................................................... 10 8. WATER MANAGEMENT AND MONITORING ............................................................................ 11 9. CONCLUSION AND RECOMMENDATIONS ............................................................................... 12 10. REFERENCES .......................................................................................................................... 14

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LIST OF FIGURES (Appendix A)

FIGURE 1: Locality Map FIGURE 2: Layout Map FIGURE 3: Regional Geology FIGURE 4: Hydrocensus Map 1 FIGURE 5: Hydrocensus Map 2 FIGURE 6: 50ha Catchment Area Map LIST OF PHOTOS

PHOTO 1: Borehole BH1 PHOTO 2: Borehole BH2 PHOTO 3: Borehole BH3 PHOTO 4: Borehole BH4 PHOTO 5: Borehole H13-0344 PHOTO 6: Borehole H13-0394 LIST OF TABLES

TABLE 1: Field Census Borehole Information TABLE 2: Water chemistry TABLE 3: BTEX and TPH

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LIST OF ABBREVIATIONS Abbreviation or Acronym

Definition

a Annum DWS Department of Water and Sanitation

GRA II Groundwater Resource Assessment Phase II GRIP Groundwater Resource Information Project Ha Hectares km Kilometres

l Litres (1000ℓ or 1kℓ = 1m3 ) Lat Latitude Lon Longitude m Meters m3 Cubic meters, (1m3 = 1kℓ or 1000ℓ)

mamsl Meters above mean sea level mbgl Meters below ground level mm Millimetres MAE Mean Annual Evaporation MAP Mean Annual Precipitation NWA National Water Act

pH Power of Hydrogen (Acidity, Alkalinity measurement) s Seconds

SACNASP The South African Council for Natural Scientific Professions SANAS South African National Accreditation System S-Pan Symons’s Pan evaporation TDS Total Dissolved Solids SWL Static Water Level

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LIST OF DEFENITIONS The Groundwater Dictionary, 2nd Edition: Department of Water Affairs

Hydrogeology

Abstraction: The act of removing water from a groundwater resource, the removal of water from an aquifer by pumping

Aquiclude: A geologic formation, group of formations, or part of formation through which virtually no water moves

Aquifer: A geological formation which has structures or textures that hold water or permit appreciable water movement through them

Aquitard: A saturated low permeability unit that can restrict the movement of groundwater. It may be able to store groundwater

Basic Water Supply: The prescribed minimum standard of water supply services necessary for the reliable supply of sufficient quantity and quality of water to households, including informal households, to support life and personal hygiene and is currently set at 25litres/person/day

Blow Yield: The volume of water per unit of time blown from the borehole during drilling

Borehole: Includes a well, excavation, or any other artificially constructed or improved underground cavity which can be used for the purpose of intercepting, collecting or storing water in or removing water from an aquifer; observing and collecting data and information on water in an aquifer; or recharging an aquifer

Borehole yield: Borehole yield is the water that can be abstracted from a borehole and is expressed as l/s, m3/hr, m3/day or m3/a

Catchment: Catchment in relation to watercourse or watercourses or part of a watercourse, means the area from which any rainfall will drain into the watercourses or part of a watercourse through surface flow to a common point or points

Cone of Depression: The depression of hydraulic head around a pumping borehole caused by the withdrawal of water

Contamination: The introduction of any substance into groundwater systems by the action of man

Dip Meter: A device used to measure depth to groundwater

Drilling: The task of sinking a borehole into the subsurface using a drilling rig

Effluent: A liquid waste discharge, that discharges into the environment. Liquid waste or sewage discharge, usually discharged in rivers or the sea

Electrical Conductivity (EC): Electrical conductivity is a measure of how well a material accommodates the transport of electric charge. The more salts dissolved in the water, the higher the EC value. It is used to estimate the amount of total dissolved salts, or the total amount of dissolved ions in the water

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Evapotranspiration: The loss of water from a land area through transpiration of plants and evaporation from the soil and surface water bodies. The process by which water is discharged to the atmosphere as a result of evaporation from the soil and surface water, and transpiration by plants Transpiration is the process by which water passes through living organisms, primarily plants, into the atmosphere

Fractured Aquifer: An aquifer that owes its water-bearing properties to fracturing. A fractured aquifer is defined as a formation that contains sufficient fissures, fractures, cracks, joints and faults that yields economic quantities of water to boreholes and springs.

Groundwater: Water found in the subsurface in the saturated zone below the water table. All water occurring in the saturated zone. The water table marks the upper surface of groundwater systems

Groundwater monitoring: The regular or routine sampling, analysis and evaluation of one or more elements of the groundwater resource for a specific objective(s)

Harvest Potential: The harvest potential is the maximum amount of groundwater that can be abstracted per square kilometre per annum in South Africa without depleting the aquifers

Hazard: Source of potential harm

Intergranular Aquifer: A term used in the South African map series referring to aquifers in which groundwater flows in openings and void space between grains or weathered rock

Monitoring Borehole: A borehole used to measure groundwater trends

Observation Hole: A borehole used to measure the response of the groundwater system to an aquifer test. A borehole drilled at a selected location for the purpose of observing parameters such as water levels, pressure changes and water quality during aquifer tests. They can later be used for groundwater monitoring

Permeability: The ease with which a fluid can pass through a porous medium and is defined as the volume of fluid discharged from a unit area of an aquifer under unit hydraulic gradient in unit time (expressed as m3/m2/d or m/d); it is an intrinsic property of the porous medium and is dependent of the properties of the saturating fluid

Quaternary Catchment: A fourth order catchment in a hierarchal classification system in which a primary catchment is the major unit. Quaternary catchments are the principal water management units in South Africa; and 1946 have been demarcated. Catchments are a basic hydrological unit. The quaternary catchment is the basic unit for water resource management in South Africa

Recharge: The addition of water to the saturated zone, either by the downward percolation of precipitation or surface water and/or the lateral migration of groundwater from adjacent aquifers

Reserve: Reserve means the quantity and quality of water required -

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a) to satisfy basic human needs by securing a basic water supply, as prescribed under the Water Services Act, 1997 (Act No 108 of 1997), for people who are now or who will, in the reasonably near future, be -

- relying upon;

- taking water from; or

- being supplied from,

The relevant water resource; and

b) To protect aquatic ecosystems in order to secure ecologically sustainable development and use the relevant water resource

Reservoir: A natural or artificial unit used for the storage and regulation of water. A receptacle or chamber for storing a fluid

Safe Yield/Sustainable yield: Safe yield is defined as the maximum rate of withdrawal that can be sustained by an aquifer without causing an unacceptable decline in the hydraulic head or deterioration in water quality in the aquifer

Storage Coefficient: The volume of water an aquifer releases from or takes into storage per unit surface area of the aquifer per unit change in head

Total Dissolved Solids (TDS): The quantity of dissolved materials in a sample of water. Total dissolved solids in water, expressed in mg/l. It is determined by chemical analyses and is a measure of the salinity of water. Electrical conductivity measurements can also be used to estimate TDS

Water Management Area: Water Management Area (WMA) is an area established as a management unit in the National Water Resource Strategy within which a Catchment Management Agency will conduct the protection, use, development, conservation, management and control of water resources in South Africa

Water Table: The upper surface of the saturated zone of an unconfined aquifer at which pore pressure is equal to that of the atmosphere. This is the interface between the unsaturated zone and groundwater and may rise and fall seasonally

Geology

Anatectic: The process of metamorphism of plutonic rock into magma in the lower levels of the crust

Biotite Gneiss: Mineralogically this gneiss consists mainly of feldspar and quartz with subsidiary biotite. It has a banded structure

Dolerite: A fine to medium-crystalline rock consisting of plagioclase and pyroxene. Diabase is a mafic, holocrystalline, igneous rock equivalent to volcanic basalt or plutonic gabbro. Diabase is also called Dolerite. Diabase dykes and sills are typically shallow intrusive bodies and often exhibit fine grained to aphanitic chilled margins which may contain tachylite (dark mafic glass)

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Dyke: A tabular or sheet-like body of igneous rock that cuts through and across the layering of adjacent rocks. They form when igneous molten rock rises into an existing fracture or zone of weakness. They usually comprise of dolerite or diabase. Dykes often have low permeability and thus form aquicludes or aquitards. Contact zones between the dykes and host rocks can be fractured and transmissive

Fault: A zone of displacement in rock formations resulting from forces of tension or compression in the earth’s crust. A fracture or zone of fractures along which there has been displacement of the sides relative to one another parallel to the fracture. Faults can form conduits for groundwater movement and groundwater contamination; as well as impermeable zones where metamorphism of the rocks have taken place

Fracture: Any break in a rock including cracks, joints and faults

Formation: A body of rock identified by lithic characteristics and stratigraphic position

Granite: A coarse crystalline rock consisting of quartz, potash feldspar, plagioclase, biotite and / or muscovite and hornblende. Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite has a medium to coarse texture, occasionally with some individual crystals larger than the ground mass forming a rock known as porphyry. Granites can be pink to dark gray or even black, depending on their chemistry and mineralogy. Outcrops of granite tend to form tors, and rounded massifs

Granite Gneiss: Mineralogically a gneiss consists mainly of feldspar and quartz with variable amounts of mica, amphibole and pyroxene. It has a banded texture. Gneisses are the metamorphic product of quartz- and feldspar-rich igneous rocks such as granite, as well as of sandy and gravelly sediments such as arkose

Migmatite: a Rock that is a mixture of metamorphic rock and igneous rock. It is formed when a metamorphic rock, usually gneiss partially melts, and then that melt recrystallizes into an igneous rock, creating a mixture of the unmelted metamorphic part with the recrystallized igneous part

Syenite: is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (<5%) therefore consisting primarily of potassic Feldspar, Plagioclase and amphibole. Some syenites contain larger proportions of mafic components and smaller amounts of felsic material than most granites

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REPORT ON A HYDROGEOLOGICAL EVALUATION FOR THE VENBECK FILLING STATION, BA-PHALABORWA LOCAL

MUNICIPALITY, LIMPOPO PROVINCE

1 INTRODUCTION

This report gives the results of a Hydrogeological evaluation conducted for the proposed

Venbeck Filling station on the R40 road between Phalaborwa and Mica, Ba-Phalaborwa Local

Municipality (Figure1). The site was used in the past as a filling station and is currently used as

a general shop (Figure 2).

The Hydrogeological study was conducted for Tecoplan Environmental and Mr. H Venter

Venbeck

Site centre coordinates:

• S23.985022°

• E31.070848°

The hydrogeological conditions pertaining to the area and potential ground water resources

available are based on a field census conducted by WSM Leshika (Pty) Ltd, existing borehole

information, water quality analyses and the experience of WSM Leshika (Pty) Ltd in the area.

2 SCOPE OF WORK

The purpose of the investigation was to assess the impact of the proposed project on the

groundwater.

WSM Leshika (Pty) Ltd was tasked with providing:

• A list of existing available borehole information

• Evaluation of the existing use, ground water potential and water quality

• Evaluation of the impact the proposed development is expected to have on the

groundwater resources

• Recommendations as to a potential monitoring borehole

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3 REGIONAL GEOLOGY

Based on the 1:250 000 scale 2330 Tzaneen Geological series the site is underlain by grey

biotite Gneiss and migmatite with anatectic mobilisates of the Makhutswi Gneiss (Zm). To the

north east of the project site lies Syenite of the Phalaborwa complex (Mps). North-east, South-

west striking dolerite dykes (di) also occur in the area. (Figure 3)

4 HYDROGEOLOGICAL EVALUATION

Table 1 below gives a summary of the information collated.

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Table 1: Field Census Borehole information

Latitude LongitudeWATER LEVEL

SWL (m)WATER SAMPLE

-25.98 -

None-45.47

10.62 - Mono Diesel pump

EQUIPMENTABSTRACTION

(m3/day)

17.28

17.28

0

WATER LEVEL DATE

1997/11/25

1998/01/25

1998/02/08

2016/10/13

- 2016/10/13

28 while pumping

ELEVATION (m)

Grip and Field Data Blocked at 23m

GRIP

NOTES

385

374

GRIP 369

QUALITY

CLASS 3

CLASS 2

CLASS 3

BOREHOLE DEPTH (mbgl)

H13-0344

H13-0345

-23.994870

-23.992320

COORDINATESBH No

31.067190

31.058376 59.83

54.69

H13-0322 -23.983740 31.047170 56

BH4

BH2 -23.985018 31.067612 -

BH3 -23.993036 31.059131 55

378H13-0346 -23.988820 31.067470 37.5 29 - 0.72 CLASS 31998/01/10 - GRIP

- None GRIP 387

- - GRIP 354

0

0 CLASS 3

365M13-0494 -23.972360 31.059720 78.6 11.26 138.24 CLASS 3

- None GRIP and Field data 383H13-0394 -23.984473 31.064530 51.07 1 0 CLASS 2

- Recorder GRIP Monitoring

2016/10/13

2005/03/01

2016/10/13

H13-0380 -23.997370 31.081410 101.12 14.08

H13-0373 -23.994290 31.055920 0 0 0

1998/01/10

- 2.5Electric

SubmersiblePrivate 389-

- -Electric

SubmersibleBorehole collapsed on equipment 376-

From tank 2016/10/13

5Electric

SubmersibleHlolwa Lodge Mr T T Thete

0722118326; thete-at@nix.co.za361CLASS 3-23.985163 31.076117 -

25 while pumping

2016/10/13

- -Electric

SubmersibleBorehole on site

Borehole collapsed on equipment370-BH1 -23.985446 31.070726 - Dry

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4.1 Existing Borehole Data

Within the site no existing boreholes were registered on the DWS GRIP data base. However, 1

borehole (BH1) was found on site and 3 other boreholes BH2, BH3 and BH4 around the site

during the field visit conducted on the 13th of October 2016. The GRIP database did reveal 3

boreholes in a 1.5km radius around the site and a further 4 boreholes just outside the 1.5km

radius (see table 1). Water samples of borehole BH4, which is situated 440m downstream

from the site to the east, was collected and analysed by a SANAS certified laboratory to test

the water chemistry, BTEX and TPH (par. 4.7) (Figure 4 and 5).

Photo 1: BH1 Photo 2: BH2

Photo 3: BH3 Photo 4: BH4

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Photo 5: H13-0344 Photo 6: H13-0394

4.2 Aquifers

According to the 1:500 000 scale 2330 Phalaborwa Hydrogeological Map series the site is

underlain by intergranular and fractured aquifers (d3) consisting of predominantly meta-

arenaceous rocks (Quartzite, Gneiss and Migmatite) as stated in section 3 Regional Geology,

The expected borehole yields are given as 0.5 to 2.0 l/s.

4.2 Aquifer Storage

The aquifer storage is difficult to determine. As the predominant aquifer type is known to be

a, intergranular and fractured aquifer, the storage is estimated from the Groundwater

Resources Assessment Study (GRA II) as about 0.0018, further the aquifer thickness is

conservatively estimated to be only about 16.14m.

The project area only constitutes 2.2ha therefore an uninfluenced upstream catchment area

of 50 ha (Figure 6) was used for the groundwater storage and is estimated to be:

AREA x THICKNESS x STORATIVITY

= 500 000m2 X 16.14m X 0.001754

= 14 154.78m3

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4.4 Groundwater levels and flow direction

The highest elevation of 374mamsl occurs on the west of the property and slopes towards the

east, where the elevation is 368mamsl.

The project site is located in the B 72 K quaternary catchment. A small drainage feature occurs

on the development site in the north eastern corner and flows from west to east towards the

Ga-Selati River which drains in a south eastern direction (Figure 4).

The static water level was measure at boreholes H13-0394, H13-0344, BH3 and BH4 at

1.0mbgl (Perched water table), >23.0mbgl, 28.0mbgl (while pumping) and 25mbgl (while

pumping) respectively. It is expected that the groundwater flow direction will mimic a

subdued form of the surface topography. Flow direction is thus thought to be in an eastern to

south eastern direction along the drainage feature towards the Ga-Selati River in the east.

4.5 Recharge

Recharge can be described as the replenishment from rainfall to the aquifers. Information

from the Groundwater Resources Assessment Study (GRA II) gives the annual average aquifer

recharge as 8.95mm/a from a rainfall of 495mm/a.

For the catchment area of 50ha this evaluates to:

500 000m2 X 0.00895m/a

= 4475m3/annum or 12m3/day

4.6 Sustainable yield

During drought or low rainfall periods, recharge could be significantly reduced and any

abstraction would need to draw water from storage. Evaluation of drought indices (F. P.

Cornelius and E. A. Nel) indicates that drought periods in the study area could last for 7-8

years. If we assume that for these 7 – 8 year periods recharge would only be 70% of the

average annual i.e. 0.70 x 4475 =3132.5m3/a and that for a 2 year period within this drought

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period there would only be 20% recharge i.e. (0.20 x 4475) = 895m3/a. If storage is utilised

over this 2 year period the available yield would then be 895 + (14 154.78/2) = 7972.39m3/a.

The sustainable yield would therefore be evaluated as the lesser of the 3132.5m3/a or

7972.4m3/a, thus the sustainable yield for the 50ha catchment area is calculated as

3132.5m3/a or 8.5m3/day.

4.7 Water Quality

Water samples were taken from the tank stand that is supplied by borehole BH4 and

submitted to a SANAS accredited laboratory to analyse for the main physio-chemical

properties, BTEX and TPH. Borehole BH4 is located approximately 440m to the east and

downstream of the site. (Figure 5)

The water samples were taken on 13th October 2016 and submitted to the lab the following

day; the results are listed in table 2 and 3.

The water from BH4 has an overall Class III classification, according to DWA Standards. The

quality of the water is considered Poor, with highly elevated concentrations of Sodium,

Chloride and Sulphate; and elevated concentrations of Calcium, Magnesium and Manganese;

which leads to highly elevated Conductivity, Total Dissolved Solids (TDS) and Total hardness

(Table1). The water is not suitable for human consumption unless treated.

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Table 2: Water Chemistry

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Table 3: BTEX and TPH

The BTEX and TPH tests were done to give an indication of the background quality of the

water with regard to petroleum products in the groundwater prior to the fuel station

development and will be used in the future to identify whether fuel leaks occur on site. The

BTEX and TPH test results are as expected for the area and shows no sign of spillage or

contamination at present.

It should be noted that borehole BH4 is 440m downstream from the development in a

neighbour’s property. A Monitor borehole should be drilled on the development site directly

downstream of the fuel storage tanks. Water quality should be analysed twice annually.

5 CURRENT AND PROPOSED WATER USE

Presently the water use on site consists of a general goods store/shop and liquor shop as well

as 2 houses through a municipal water connection.

The average daily demand of the Filling Station can be estimated at 3.5 kl/day with a peak

demand of 5.3kl/day using previous filling station reports.

The Filling Station Development will only rely on a municipal water connection as the main

water supply. A monitor borehole should still be drilled downstream of the development.

Sustainable yield calculations indicate that 8.5m3/day are available for the development

should groundwater be considered. This is a Borehole being pumped at 1.18l/s for

2hours/day.

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6 MONITOR BOREHOLE FOR THE FILLING STATION

It is advised that a monitor borehole be drilled on site downstream of the fuel storage tanks

and that the borehole is regularly monitored. The most suitable site for the monitor borehole

is in the south-eastern corner of the property (Figure 5). The borehole should be monitored at

least twice annually which includes water levels and sampling to test the water chemistry,

BTEX and TPH. See section 8.

7. IMPACT ASSESSMENT OF THE PROPOSED FILLING STATION DEVELOPMENT ON THE GROUNDWATER RESOURCE AND PROPOSED MITIGATION MEASURES

7.1 Sewage Facilities

An approved sewage treatment facility will be required to treat the sewage from the filling

station according to DWS standards. The property already has sewage treatment facilities for

the 2 houses and store/shop.

7.2 Fuel storage and dispensing Facilities

Hazardous liquids spilled on surface will either run off the sealed areas into surface water

drainage channels or enter the soil profile and percolate vertically down to the groundwater

level, which is expected to be relatively deep, between 10-25mbgl on the site. Thereafter the

light non aqueous phase liquids (LNAPL’s) will be transported on the groundwater in a

presumably easterly to south eastern direction along the drainage feature towards the

drainage Ga-Selati River. The dense non aqueous phase liquids (DNAPL’s) such as motor oil will

move down until solid bedrock is encountered where it will move along the on top of the

bedrock and through fractures.

Due to the relatively pervious nature of the soils near surface (gravelly silty sands) and the

moderately deep water table (Shallow perched water table in places), it may be assumed that

the pollutants will travel through the upper soils and weathered bedrock at a medium to high

rate down to the less weathered bedrock. As the boreholes in the granites and gneisses have

low to moderate yields it is assumed that the bedrock is only fractured and slightly weathered

in places. These permeable fracture zones could provide preferential flow paths. As the area

has a relatively deep water table, the site should be considered only moderately sensitive to

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pollution.

It can therefore be assumed that the aquifers will be at a moderate to high risk to pollution

from surface spills.

The following precautionary measures are therefore recommended:

• Sealing of the forecourt area and other areas where fuel products are handled to

prevent infiltration of petroleum products into the soil underlying the site.

• Storm water draining from the surfaced areas should be collected in a sealed sump to

be treated or removed.

• Preventative measures should be installed to prevent the storm water or other liquids

draining into the natural soil.

• The site will need some good planning to cope with surface runoff and runoff volumes

must be calculated and proper separation facilities installed.

• The free product and polluted water must be removed from site by a licensed

contractor.

Prevention of pollutants reaching the groundwater and soil will be good practice and may

include the following:

• Fuel tanks should be placed in a water tight encasement (UPVC or concrete) with a

sump system to prevent spilled fuel from entering the soil and weathered rock.

• Fuel lines and dispensers should be rendered leak-proof. This may include the boxing of

these services.

Further detailed accounting of the fuel delivered and supplied will be required to determine if losses occur.

8. WATER MANAGEMENT AND MONITORING

As no long-term water levels and abstraction rates are available the above evaluation is based

on the best knowledge and experience available. However it is strongly advised that a proper

management and monitoring programme for a future borehole be implemented to ensure

that the groundwater resources react as predicted. This should include:

- Recording of pumping times and abstraction rates (if the borehole is used as production

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borehole as well)

- Measure water level in proposed monitor borehole (before and after pumping)

- Take water samples from the proposed monitor borehole and analyse for, macro

elements, BTEX and TPH at least twice annually

- Implement management and monitoring programme together with neighbours to

obtain a greater regional perspective

9. CONCLUSION AND RECOMMENDATIONS

From the evaluation, the following conclusions are made:

• No existing groundwater use occurs on the development site;

• Groundwater occurs mainly in weathered and fractured aquifers, d3 with 0.5– 2.0 l/s

yields;

• Regional groundwater flow is expected to mimic a subdued form of the surface

topography and the flow direction is thought to be in an east to south eastern direction;

• From the GRA II Storage is estimated at 0.0018 and the aquifer thickness at 16.14m thus

14 154.78m3 for a 50ha catchment area;

• Average annual recharge is estimated to be 8.95mm/a from rainfall off 495mm/a thus

4475m3/a or 12m3/day for a 50ha catchment area;

• The sustainable yield for the 50ha catchment area was calculated as 3132.5m3/a or

8.5m3/day;

• Water samples of borehole BH4, that is situated 440m downstream of the site, were

taken and submitted to a SANAS accredited laboratory to test the water chemistry,

BTEX and TPH;

• Borehole BH4 resulted in water quality of Class III (Poor quality) with highly elevated

Sodium, Chloride and Sulphate and marginally elevated Calcium, Magnesium and

Manganese, which results in very high Conductivity, TDS and Hardness;

• The groundwater is thus not suitable for human consumption unless treated;

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• BTEX and TPH tests indicated no pollution thereof in the area and will serve as

background data for future studies and monitoring for petroleum spillages;

• Water supply will rely on a municipal water connection;

• A proposed borehole position downstream of the site is recommended to serve as a

monitor borehole;

• Recommended abstraction for the monitor borehole if used as production hole is as

follows, 1.18l/s for 2hours a day for a total abstraction of 8.5kl/day.

• The aquifers in the area will be at a moderate to high risk of pollution from spills at the

proposed filling station

• Mitigation measures as described in paragraph 7 will need to be implemented to reduce

the risk.

The following recommendations are also made:

• That a Monitor borehole be drilled downstream of the storage tanks to monitor the

groundwater in the future.

• That the mitigation measures as specified in section 7 be implemented

• That a management and monitoring programme be implemented (see section 8);

____________________ SJ Koekemoer BSc (Hons) Qualified Junior Hydrogeologist

____________________ CJ Haupt BSc (Hons) Pr.Sci.Nat. Registered Hydrogeologist SACNASP registration no. 40003194

© WSM Leshika Consulting (Pty) Ltd.

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10. REFERENCES

DWA [Department of Water Affairs], 2011. 2nded. The Groundwater Dictionary, A comprehensive reference of groundwater related terminology. Department of Water and Sanitation, Pretoria.

National Environmental Act. (1998). Government Gazette. Act 107, 1998. Pretoria, South Africa.

National Water Act. (1998). Government Gazette, 19182. Act 36, 26 August 1998. Pretoria, South Africa.

© WSM Leshika Consulting (Pty) Ltd.

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APPENDIX A: List of Figures

Project Description: Venbeck Filling Station Phalaborwa Investigation Type: Hydrogeological Assessments Figure 1: Locality Map Project no: WH16093

© 2016 GoogleEarth

Centre site coordinates (WGS84): Latitude: -23.985055° Longitude: 31.070836°

Palabora Mine

Ga-Selati River

Kruger National Park

Project Description: Venbeck Filling Station Phalaborwa Investigation Type: Hydrogeological Assessments Figure 2: Layout Map Project no: WH16093

© 2016 GoogleEarth

Centre site coordinates (WGS84): Latitude: -23.985055° Longitude: 31.070836°

Drainage Feature

General goods shop

Project Description: Venbeck Filling Station Phalaborwa Investigation Type: Hydrogeological Assessments Figure 3: Regional Geological Sheet – 1:250 000-scale 2330 Tzaneen Project no: WH16093

© 2016 Google Earth © The Government Printer

Centre site coordinates (WGS84): Latitude: -23.985055° Longitude: 31.070836°

Geology: Namibian Dolerite/Diabase Phalaborwa Complex Makhutswi Gneiss

Project Description: Venbeck Filling Station Phalaborwa Investigation Type: Hydrogeological Assessments Figure 4: Hydrocensus Map 1 Project no: WH16093

© 2016 GoogleEarth

Centre site coordinates (WGS84): Latitude: -23.985055° Longitude: 31.070836°

1.5km Hydrocensus Radius

Ga-Selati River

Phalabora Mine

Development Site

GRIP Boreholes

Project Description: Venbeck Filling Station Phalaborwa Investigation Type: Hydrogeological Assessments Figure 5: Hydrocensus Map 2 Project no: WH16093

© 2016 GoogleEarth

Centre site coordinates (WGS84): Latitude: -23.985055° Longitude: 31.070836°

Ga-Selati River

Shallow Water Table / Perched

Water table

1m SWL Dry to depth where blocked

Sampled

Dry to depth where blocked

Project Description: Venbeck Filling Station Phalaborwa Investigation Type: Hydrogeological Assessments Figure 6: 50ha Catchment Area Map Project no: WH16093

© 2016 GoogleEarth

Centre site coordinates (WGS84): Latitude: -23.985055° Longitude: 31.070836°

Ga-Selati River

Shallow Water Table / Perched

Water Table

1m SWL

50ha Catchment Area

Sampled

Dry to depth where blocked