Groundwater Baseline and Impact
Assessment for the Establishment of
Servitudes for the Inhlansi Project,
Richard Bay
Report Prepared for
Nozalela Mineral Sands Pty (Ltd)
366069/GW
January 2008
SRK Consulting
Nozalela, Groundwater
Page i
Groundwater Baseline and Impact
Assessment for the Establishment of
Servitudes for the Inhlansi Project,
Richard Bay
Nozalela Mineral Sands Pty (Ltd)
SRK Project Number 366069
SRK Consulting
265 Oxford Road
Illovo
2196
South Africa
P O Box 55291
Northlands
2116
South Africa
Tel: (011) 441-1111
Fax: (011) 880-8086
[email protected]
January 2008
Compiled by:
Reviewed by
I. Milenkovic
_______________________
Hydrogeologist
DM Duthe (Pr. Sci. Nat.)
_________________________
Partner
Ref no: 366069/GW
I. Milenkovic
366069GW_DUTH_DEBE_20080128.doc
November 2007
SRK Consulting
Nozalela, Groundwater
Page ii
Table of Contents
1 Introduction .................................................................................................................. 1
1.1 Background....................................................................................................................... 1
1.2 Objective ........................................................................................................................... 2
1.3 Scope of work ................................................................................................................... 2
1.4 Limitations and assumptions ............................................................................................. 3
1.5 Legal framework ............................................................................................................... 3
1.5.1
National Water Act (36 of 1998) .............................................................................................. 3
1.5.2
The Mineral and Petroleum Resources Development Act (28 of 2002) ................................. 5
1.5.3
Mhlathuze Water Service Bylaw ............................................................................................. 6
2 Methodology and Approach ........................................................................................ 7
2.1 Site work ........................................................................................................................... 7
2.2 Data collection .................................................................................................................. 7
2.3 Data processing ................................................................................................................ 7
3 Description of the Environment .................................................................................. 8
3.1 Locality ............................................................................................................................. 8
3.2 Topography and drainage ................................................................................................. 8
3.3 Climate ........................................................................................................................... 10
3.3.1
Regional climate .................................................................................................................... 10
3.3.2
Precipitation........................................................................................................................... 10
3.3.3
Evaporation ........................................................................................................................... 10
3.4 Geology .......................................................................................................................... 10
3.4.1
Regional geology................................................................................................................... 10
3.4.2
Site geology........................................................................................................................... 11
4 Hydrogeology ............................................................................................................. 13
4.1 Aquifer lithologies............................................................................................................ 13
4.2 Recharge ........................................................................................................................ 13
4.3 Flow directions and Groundwater levels .......................................................................... 13
4.3.1
Flow directions ...................................................................................................................... 13
4.3.2
Groundwater levels ............................................................................................................... 16
5 Baseline water quality assessment .......................................................................... 19
5.1 Groundwater monitoring results and discussion .............................................................. 19
5.1.1
I. Milenkovic
Samples collected ................................................................................................................. 19
366069GW_DUTH_DEBE_20080128.doc
November 2007
SRK Consulting
Nozalela, Groundwater
5.1.2
Page iii
Laboratory analysis of water samples ................................................................................... 19
5.2 Discussion ...................................................................................................................... 21
5.3 Existing sources of potential contamination..................................................................... 23
5.4 Groundwater usage ........................................................................................................ 24
6 Impact Assessment .................................................................................................... 26
6.1 Modifications of flow directions and groundwater levels .................................................. 26
6.2 Changes in groundwater quality ...................................................................................... 27
7 Monitoring ................................................................................................................... 29
8 Conclusions ................................................................................................................ 30
9 Recommendations ..................................................................................................... 31
10 References .................................................................................................................. 33
Appendices ...................................................................................................................... 34
Appendix I Groundwater Levels .............................................................................................. 35
Appendix II Laboratory Certificates ......................................................................................... 38
Appendix III Impact Assessment Methodology ........................................................................ 42
I. Milenkovic
366069GW_DUTH_DEBE_20080128.doc
November 2007
SRK Consulting
Nozalela, Groundwater
Page iv
List of Tables
Table 5-1 Sample Coordinates and Description........................................................................... 19
Table 5-2 Laboratory Results ...................................................................................................... 20
Table 5-3 Hydrochemical water type ........................................................................................... 21
Table 5-4 Sources of existing contamination ............................................................................... 23
Table 5-5 Selected surface and groundwater users ..................................................................... 24
Table 6-1: Sources of pollutants and potential impacts arising from transport activities ................ 28
List of Figures
Figure 3-1 Proposed servitudes and infrastructure in relation to surface water resources, sample
location and DWAF surface water surface water monitoring points ............................... 9
Figure 4-1 Map of groundwater flow direction ............................................................................... 15
Figure 4-2 Map of Water depth in mbgl ......................................................................................... 17
Figure 4-3 Map of Water depth groups ......................................................................................... 18
Figure 5-1 a) Piper and b) Schoeller diagrams of groundwater samples ....................................... 22
Figure 5-2 Map of water users and waste waters .......................................................................... 25
I. Milenkovic
366069GW_DUTH_DEBE_20080128.doc
November 2007
SRK House
265 Oxford Road, Illovo
2196 Johannesburg
PO Box 55291
Northlands
2116 South Africa
e-Mail: [email protected]
URL: http://www.srk.co.za
Tel: +27 (11) 441 1111
Fax: +27 (11) 880 8086
January 2008
366069GW
Groundwater Baseline and Impact Assessment for the Establishment of Servitudes for the
Inhlansi Project, Richard Bay
1
Introduction
1.1
Background
Nozalela Mineral Sands Pty (Ltd) (Nozalela) has Tisand (Pty) Ltd and the Dube and Mkhwanazi
Traditional Authorities as shareholders, and has a license to mine the Zulti South Mineral Lease
Area (ZSMLA). The ZSMLA is located along the KwaZulu Natal coastline and falls to the south of
Richards Bay and the Umhlathuze River and to the north of Port Durnford. This mining lease area
covers a length of approximately 20 km and varies in width from 0.5 to 2 km inland from the high
water mark.
Nozalela commenced small scale mining in 2002 and is planning to commence with full scale
mining of 20 million tonnes per annum (Mtpa) in 2011.
Partners
JCJ Boshoff, MJ Braune, JM Brown, JAC Cowan, CD Dalgliesh, JR Dixon, T Hart, PR Labrum, LGA Maclear, RRW McNeill, HAC Meintjes,
BJ Middleton, MJ Morris, GP Murray, GP Nel, VS Reddy, PN Rosewarne, PE Schmidt, PJ Shepherd, VM Simposya, AA Smithen,
PJ Terbrugge, KM Uderstadt, AJ van der Merwe, DJ Venter, HG Waldeck, A Wood
Directors
Associates
Consultants
AJ Barrett, S Mayekiso, BJ Middleton, MJ Morris, PE Schmidt, PJ Terbrugge, MB Zungu
AN Birtles, DM Duthe, R Gardiner, SA McDonald , WA Naismith, JP Odendaal, D Visser, AC White, ML Wertz, AC Woodford
AC Burger, BSc (Hons);
IS Cameron-Clarke, PrSci Nat, MSc;
JH de Beer, PrSci Nat, MSc; GA Jones, PrEng, PhD;
WD Ortlepp, PrEng, MEng; TR Stacey, PrEng, DSc; OKH Steffen, PrEng, PhD; RJ Stuart, PrTech Eng, GDE;
DW Warwick, PrSci Nat, BSc (Hons)
Corporate Shareholder: Kagiso Enterprises (Pty) Ltd
SRK Consulting (South Africa) (Pty) Ltd
Bellville
Cape Town
Durban
East London
Johannesburg
Kimberley
Pietermaritzburg
Port Elizabeth
Pretoria
Rustenburg
+27
+27
+27
+27
+27
+27
+27
+27
+27
+27
(0) 21 913 2960
(0) 21 659 3060
(0) 31 279 1200
(0) 43 748 6292
(0) 11 441 1111
(0) 53 861 5798
(0) 33 345 6311
(0) 41 581 1911
(0) 12 361 9821
(0) 14 594 1280
Dar-es-Salaam
Harare
+25 (5) 22 260 1881
+263 (4) 49 6182
Reg No 1995.012890.07
2
SRK Consulting
Nozalela Groundwater
Page
Nozalela is undertaking a feasibility study for the design, construction and operation of the proposed
new mine layout. SRK Consulting (SRK) has been appointed by Nozalela to undertake an
Environmental Impact Assessment (EIA) for the establishment of servitudes for the provision of
electricity, water, an access road and the transport of heavy mineral concentrate (HMC) to the
Smelter Complex north of Richards Bay.
The EIA process requires that the pre-construction surface water baseline conditions be established
as well as the potential impacts associated with construction, operation and closure phases for the
servitude areas to be disturbed.
These areas include the following:
•
A power line servitude (6 km);
•
A water supply and HMC pipeline route (43.5 km). The major portion of this length is along
existing servitudes and will be constructed a minimum of 1.2 m meter below ground level;
•
1.2
An access road (approximately 7.5 km to be upgraded).
Objective
The objective of the present assessment is to establish pre-construction groundwater baseline
conditions for the servitude areas, to determine potential impacts on groundwater quality and flow
and to recommend management measures to mitigate perceived impacts.
1.3
Scope of work
The scope of this study comprises the following:
•
Undertaking a borehole census in order to identify groundwater resources in the areas of the
services and the quality and yield of these
•
Determine flow directions groundwater levels and in the area so that the impacts can be
ascertained;
•
Identify potential sources of groundwater pollution in the area;
•
Identify potential receptors for groundwater impacts specifically relating to modifications to
groundwater availability;
•
MILI
Identify groundwater users in the area;
366069GW_DUTH_DEBE_20080128.doc
January 2008
3
SRK Consulting
Nozalela Groundwater
•
Page
Liaison with the surface water team to determine impacts on surface water as a result of
potential changes to groundwater flow;
•
Assess impacts in terms of groundwater resources as a result of the proposed development will
be assessed;
•
1.4
Provide management measures for the mitigation of the impacts on groundwater. This will need
to include a groundwater monitoring programme if required.
Limitations and assumptions
The limitations and assumptions of this study include the following:
•
Due to the limited timeframe of the project, only one sampling run could be performed early in
the rainy season. Ideally additional samples should be collected during the dry season in order to
perform an initial characterisation of the groundwater quality encountered across the site;
•
Historical and limited data were provided by the Department of Water Affairs & Forestry
(DWAF). No other water table level data was available and therefore the estimation of
groundwater is based on the assumption that the water table mimics the topography and is as
based on the 1:50 000 topographic maps.
•
There may be additional impact nodes not identified in this report due to the limited current
available information but it would be included in the detailed design phase once a detailed
survey along the proposed route has been carried out;
•
There are various design options for installing the pipeline (crossing existing rivers and existing
infrastructure) and this would need to be confirmed during the detailed design phase;
1.5
Legal framework
1.5.1 National Water Act (36 of 1998)
The surface water management for the servitudes and infrastructure units falls under legislation
contained in, amongst others, the National Water Act (No 36 of 1998).
Section 4 deals with prevention of contamination: The person who owns, controls, occupies or uses
the land in question is responsible for taking measures to prevent pollution of water resources. If
these measures are not taken, the catchment management agency concerned may itself do whatever
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
4
SRK Consulting
Nozalela Groundwater
Page
is necessary to prevent the pollution or to remedy its effects, and to recover all reasonable costs from
the persons responsible for the pollution
This can be broadly summarised as:
•
Separate “clean” and “dirty water”;
• Water contaminated by activities / infrastructure may not be discharged to surface water resources;
and
• Prevention of erosion.
Extracts from National Water Act No 36 of 1998, Section 4
(1) An owner of land, a person in control of land or a person who occupies or uses the land on which (a) any activity or process is or was performed or undertaken; or
(b) any other situation exists, which causes, has caused or is likely to cause pollution of a water
resource, must take all reasonable measures to prevent any such pollution from occurring, continuing or
recurring.
(2) The measures referred to (above) may include measures to (a) cease, modify or control any act or process causing the pollution;
(b) comply with any prescribed waste standard or management practice;
(c) contain or prevent the movement of pollutants;
(d) eliminate any source of the pollution;
(e) remedy the effects of the pollution; and
(f) remedy the effects of any disturbance to the bed and banks of a watercourse.
Regulations relating to capacity requirements of “clean” and “dirty” water systems
Every person in control of an activity musta)
confine any unpolluted water to a clean water system, away from any dirty area;
b)
collect the water arising within any dirty area, into a dirty water system;
c)
design, construct, maintain and operate any dirty water system so that it is not likely to spill into any clean
h
MILI
i 50
366069GW_DUTH_DEBE_20080128.doc
January 2008
5
SRK Consulting
Nozalela Groundwater
Page
The following water use activities will require authorisation and possibly licensing from the DWAF
prior to commencement of said activities:
Extract from the NWA, Section 21
For the purposes of this Act, water use includes (a)
taking water from a water resource;
(b)
storing water;
(c)
impeding or diverting the flow of water in a watercourse;
(d)
engaging in a stream flow reduction activity contemplated in section 36;
(e)
engaging in a controlled activity identified as such in section 37 (1) or declared under section 38 (1);
(f)
discharging waste or water containing waste into a water resource through a pipe, canal, sewer, sea outfall or
other conduit;
(g)
disposing of waste in a manner which may detrimentally impact on a water resource;
(h)
disposing in any manner of water which contains waste from, or which has been heated in, any industrial or
power generation process;
(i)
altering the bed, banks, course or characteristics of a watercourse;
(j)
removing, discharging or disposing of water found underground if it is necessary for the efficient continuation
of an activity or for the safety of people; and
(k)
using water for recreational purposes
1.5.2 The Mineral and Petroleum Resources Development Act (28 of 2002)
As the proposed transport activities are a part of a mining operation, the above mentioned act must
be adhered to. Section 37 of the act deals with integrated environmental management and the
responsibility to remedy impacts and states that the holder of a prospecting / mining right is
responsible for any environmental damage, pollution or ecological degradation as a result of his
mining operations and which may occur inside and outside the boundaries of the area to which such
right, permit or permission relates.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
6
SRK Consulting
Nozalela Groundwater
Page
(1) The holder of a reconnaissance permission, prospecting right, mining right, mining permit or retention permit (a) must at all times give effect to the general objectives of integrated environmental management laid
down in Chapter 5 of the National Environmental Management Act, 1998 (Act No 107 of 1998);
(b) must consider, investigate, assess and communicate the impact of his or her prospecting or mining on
the environment as contemplated in section 24(7) of the National Environmental Management Act,
1998 (Act No.107 of 1998);
(c) must manage all environmental impacts (i) in accordance with his or her environmental management plan or approved environmental
management programme, where appropriate; and
(ii) as an integral part of the reconnaissance, prospecting or mining operation, unless the
Minister directs otherwise;
(d) must as far as it is reasonably practicable, rehabilitate the environment affected by the prospecting or
mining operations to its natural or predetermined state or to a land use which conforms to the
generally accepted principle of sustainable development; and
(e) is responsible for any environmental damage, pollution or ecological degradation as a result of his or
her reconnaissance prospecting or mining operations and which may occur inside and outside the
boundaries of the area to which such right, permit or permission relates.
(2) Notwithstanding the Companies Act, 1973 (Act No. 61 of 1973), or the Close Corporations Act, 1984 (Act
No.69 of 1984), the directors of a company or members of a close corporation are jointly and severally liable
for any unacceptable negative impact on the environment, including damage, degradation or pollution
advertently or inadvertently caused by the company or close corporation which they represent or represented.
1.5.3 Mhlathuze Water Service Bylaw
The installation and operation of water supply infrastructure is subject to the Mhlathuze Water
Service Bylaw. Extract from Water Services Bylaw, Section 64
(1) A consumer shall provide and maintain approved measures to prevent the entry of a substance, which may be a
danger to health or adversely affect the potability of water or affect its fitness for use, into
(a) the water supply system; and
(b) any part of the water installation on the consumer’s premises.
(2) If any person contravenes subsection (1), the Municipality may:
(a) by written notice require the consumer to take remedial steps to prevent pollution of the water in the
water supply system or water installation on the consumer’s premises within a specified period; or
(b) if it is of the opinion that the situation is a matter of urgency, without prior notice undertake the work
required by subsection 2(a) and recover the costs from the consumer
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
7
SRK Consulting
Nozalela Groundwater
Page
2
Methodology and Approach
2.1
Site work
A site visit was undertaken by Mr A. Sibiya and Mr I. Milenkovic of SRK from the 17th to 19th of
October 2007 and comprised the following:
•
Familiarisation with the servitude routes and groundwater regime that may potentially be
impacted upon;
•
Collection of four groundwater samples from different areas to assist with water quality baseline
establishment; and
•
Performance of field measurements and determination of surface water crossings and sample
coordinates (coordinates were determined by hand held GPS).
2.2
Data collection
The following databases were queried, data collected and considered as part of this study:
•
Available groundwater quality information for relevant water bodies were obtained from
(DWAF);
•
The DWAF’s Water Resource Management Strategy (WRMS) database was queried for water
use information pertaining to Section 21 a, d, e, f, g, h and k of the National Water Act (NWA,
Act 36 of 1998);
•
Analytical results of four water quality samples as taken during the site visit;
•
Proposed route and Digital images supplied by Nozalela Mineral Sands Pty (Ltd);
•
Rainfall, evaporation, flow were obtained from the Report to RBM on the groundwater
modelling of Zulti South (2006) by the Hydrological Research & Training Specialists.
2.3
Data processing
All groundwater quality data were processed and imported into Aquachem v4. AquaChem is a
software package developed specifically for graphical and numerical analysis and modeling of water
quality data. It features a fully customizable database of physical and chemical parameters and it
provides a comprehensive selection of analytical tools, calculations and graphs for interpreting water
quality data.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
8
SRK Consulting
Nozalela Groundwater
Page
3
Description of the Environment
3.1
Locality
The ZSMLA is located along the KwaZulu Natal coastline and falls to the south of Richards Bay and
the Umhlathuze River and to the north of Port Durnford. The land is owned by the Ingonyama Trust
and occurs mainly along the boundary of the old forestry area. Lake Qhubu, the town of Esikhawini
and the N2 highway are to the north-west of the mining area. The proposed mining area covers a
length of approximately 20 km and varies in width from 0.5 to 2 km inland from the high water
mark.
The locality of the ZSMLA is shown on Figure 3-1. The proposed routes for the services associated
with the mining of the ZSMLA are also shown on Figure 3-1. These alignments are still under
consideration as part of the environmental studies and remain subject to change.
3.2
Topography and drainage
The ZSMLA occupies part of a coastal dune cordon extending parallel to the coast between the
Umhlathuze Lagoon in the north and the Mlalazi River in the south. This dune cordon is 25 km long
and varies in width from 0.5 km to a maximum of 2 km at about the centre of the lease area.
Over most of the dune length there is a fairly steep rise from sea level to an elevation of 40 to 50
meters above mean sea level (mamsl). West of the dune cordon, the topography is fairly flat-lying
and is accentuated by lakes (Lake Qhubu, Lake Nsezi), the Umhlathuze lagoon, wetlands and flat
bottomed drainage features (Mhlathuze River, Nseleni River, Nyokaneni River). The interaction
between surface water and groundwater is therefore fundamental to the interpretation of the baseline
hydrogeological conditions.
Roads in the area generally require to be raised well above potential flood plain conditions.
A number of valley areas drain inland and away from the coastal dunes. The hinterland, on the other
hand, drains down towards the dunes and this water meets with the seepage from the dune aquifer,
resulting in wetland areas along the fringe adjoining the dune. These wetlands are substantially
degraded due to agricultural usage by the local population.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
9
SRK Consulting
Nozalela Groundwater
Figure 3-1
MILI
Page
Proposed servitudes and infrastructure in relation to surface water resources, sample location and DWAF surface water surface water monitoring points
366069GW_DUTH_DEBE_20080128.doc
January 2008
10
SRK Consulting
Nozalela Groundwater
3.3
Page
Climate
3.3.1 Regional climate
The Richards Bay area is described by Schutte (1965) as having a warm to hot and humid
subtropical climate. It is one of the highest rainfall areas of South Africa, with an annual mean
ranging from 1100 mm to 1400 mm along the Indian Ocean coast.
3.3.2 Precipitation
Rainfall occurs throughout the year, with a peak in summer between February and March.
The rainfall patterns over the northern part of the ZSMLA will be similar to those that prevail at the
Richards Bay weather station. See Table 3-1.
Table 3-1: Comparison of Climatic Data between Stations at Richards Bay and Port
Durnford
Richards Bay
(17 mamsl)
RAINFALL
Mean annual total (mm)
Port Durnford
(30 mamsl)
1 102
1 479
253
353
8
*
Average number of days with thunder/year
19.5
*
Average number rain days/year
225.4
*
Maximum in 24 hours (mm)
Maximum number of months/year without rainfall
3.3.3 Evaporation
The evaporation rate is directly linked to land use. The evaporation is equivalent to the potential
evapotranspiration (atmospheric demand). The greater proportion of the evapotranspiration rate is
assumed to be from the unsaturated zone of the soil profile under average rainfall conditions. This
implies an evapotranspiration rate of about 6 mm/day for grassland conditions, which has been
attributed to the 25-30 % loss from rainfall leading to the gross recharge Hydrological Research &
Training Specialists (2006).
3.4
Geology
3.4.1 Regional geology
The coastal strip south of Richards Bay is characterised by high recent dunes, overlying sediments of
the Port Dunford Formation. The sediments are made up of old dune, beach and swamp deposits laid
down during the Pleistocene Period.
They consist mostly of fine grained sands and silts with lenses of lignite and carbonaceous clays.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
11
SRK Consulting
Nozalela Groundwater
Page
Recent drilling in the area has proved that the Port Durnford Formation overlies a Miocene coquina
(Pecten Bed) and recent calcarenites over a wide area. The calcarenites are well lithified calcareous
sandstone, fine, medium and coarse grained and are lithologically the same as the free running
mineralized cover sands. They extend from the present coastline to as much as 2 km inland. Along
the coast they outcrop forming the local features known as Dawson’s Rock and Cape St Lucia. See
Figure 3-2.
3.4.2 Site geology
Three geological formations are observed in the area. From the basal sequence upwards they are the
Port Durnford Formation, the Sibayi Formation and the recent Holocene alluvium and sands.
The Port Durnford Formation in the lease areas is represented by a variable succession of mudstones,
shales, clay, clay-rich sands and lignite. The lowest unit of formation intersected in drilling was an
intermittent and variable lignite band which overlies a dark red coloured sandy unit. Resting on the
lignite bed are variously coloured sands of the upper arenaceous unit. Colours range from red, to
orange, to grey to green.
The lime content of these sands alternates from a low of 10 percent to a high of 50 percent. The
upper 2 to 4 meters of dark red, medium grained sand had local concentrations of valuable heavy
minerals (VHM, 2.5% FeTIO2). Below the horizon of poorly mineralized sand, the clay content
increases rapidly to over 10 percent and has been used as the effective clay floor of the ore body. A
discontinuous but distinct white to grey clay unit can be identified at this horizon.
Fine to coarse grained, recent Holocene sands covers the Sibayi Formation. These sands are white,
or light brown, quartz-rich and are slightly calcareous in places.
The pipeline will be constructed at a maximum depth of 2 m, so the subsurface geology shown on
Figure 3-2 indicates only three formations will be impacted: Qs, Qb, and Qp, respectively yellowish
redistributed sand formation, Port Durnford and Bluff (Sibayi) Formation.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
12
SRK Consulting
Nozalela Groundwater
Page
Figure 3-2 Geological map
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
13
SRK Consulting
Nozalela Groundwater
4
Hydrogeology
4.1
Aquifer lithologies
Page
From the groundwater modelling report of Zulti South of the Hydrological Research & Training
Specialist (2006), it is evident that the servitude is underlain by formations with a high hydraulic
conductivity due to their lithologies mainly consisting of unconsolidated porous sands:
•
The yellowish redistributed sand formation (Qs) has a high permeability of 1 m/day
approximately.
•
The Bluff (Sibayi) Formation (Qb) has an high permeability with a range of 10-50 m/day.
No physical tests such pumping tests have been undertaken and so these values are based only on
lithologies.
In the absence of impermeable soil (i.e. clays cover) it is important to highlight the link between
surface water and groundwater, and the groundwater is therefore very vulnerable to contamination.
The high conductivity of these formations guarantees a good pathway for contamination of surface
water to groundwater and visa versa.
4.2
Recharge
The recharge rate is high due to percolation through the highly permeable sand cover. However in
areas which are saturated or close to saturation, the response to high intensity rainfall could be a
rapid runoff. According to Hydrological Research & Training Specialist (2006), the infiltration is
estimated to be 75 % of the incidental rainfall which may be reduced by 25 % due to evaporative
losses. The recharge is therefore estimated as 50 % of the mean annual rainfall or 500-600 mm per
annum.
4.3
Flow directions and Groundwater levels
4.3.1 Flow directions
The highly permeable and homogeneous lithologies are present ubiquitously along the servitudes
routes and the natural flow of the groundwater is towards the estuaries and ultimately the Indian
Ocean.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
14
SRK Consulting
Nozalela Groundwater
Page
The groundwater levels mimic topographic levels. Rivers, lakes and all drainage figures are
considered as part of the groundwater system with the Indian Ocean and estuaries considered as
groundwater flow boundaries. The main drainage features along the servitude route from North to
South respectively includes:
•
Nseleni river and wetland
•
Umhlathuze River
•
Mhlathuze Lagoon
•
Lake Cubhu
Where the pipeline servitude crosses hydraulic divides between two drainage systems, the hydraulic
gradient of the groundwater table is very flat and the flow direction cannot be clearly defined. Three
no-groundwater flow areas have been identified along the servitudes route as shown in Figure 4-1
and include the following areas:
•
Top north part of the servitude route.
•
Wetland of Nsezi, northern central part of the servitude route.
•
Between the Lake Cubhu’s tributary’s (Minzengwenya River) and the future mined dunes, in
the southern part of the mine lease area
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
15
SRK Consulting
Nozalela Groundwater
Figure 4-1
MILI
Page
Map of groundwater flow direction
366069GW_DUTH_DEBE_20080128.doc
January 2008
16
SRK Consulting
Nozalela Groundwater
Page
4.3.2 Groundwater levels
Water level information was obtained from three data sources, namely (Appendix I):
•
SRK data collected during the site visit in 2007
•
DWAF, from 1959 to 2004
•
Groundwater Consulting Specialists (2005) report on groundwater levels between November
2002 and May 2003.
The results shown on Figure 4-2 confirm that the water depth correlates with surface topographical
elevations and the groundwater levels along the pipeline route have been estimated on this
assumption, in the absence of field data.
In spite of the data available on boreholes in the area, the spatial distribution of the borehole is not
equidistant and the distance between boreholes is too great in the Richard Bay area to allow for the
construction of a piezometric map of the area. At best the depth to groundwater has been estimated
on a localised scale along the servitude route.
The servitudes route was divided into three zones categorised by the depth to the water table in
meters below ground level (mbgl):
•
Less than 2 m
•
Between 2 and 4 m
•
More than 4 m
The HMC pipeline will not be placed more than 2m below ground level, and therefore the zones
where the water table is less than 2 mbgl (as shown in red in Figure 4-3) are the most critical in
terms of evaluating impacts on the groundwater regime.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
17
SRK Consulting
Nozalela Groundwater
Figure 4-2
MILI
Page
Map of Water depth in mbgl
366069GW_DUTH_DEBE_20080128.doc
January 2008
18
SRK Consulting
Nozalela Groundwater
Figure 4-3
MILI
Page
Map of Water depth groups
366069GW_DUTH_DEBE_20080128.doc
January 2008
19
SRK Consulting
Nozalela Groundwater
Page
5
Baseline water quality assessment
5.1
Groundwater monitoring results and discussion
5.1.1 Samples collected
Four groundwater samples were collected during the site visit undertaken during the site visit in
October 2007. Sample coordinates are presented in Table 5-1 and positions in relation to surface
water resources and proposed servitudes are indicated in Figure 3-1.
Table 5-1 Sample Coordinates and Description
Stations
BH25011
Projected
Coordinates¹
Y
X
-3196096 94577
Elevation
(mamsl)
34
WLD01
-3191613
96315
7
WLD02
-3191085
95613
6
DURA01
-3184648
93368
8
Description
Community borehole
Hand auger hole from the wetland separating Lake Cubhu
from the Richards Bay
Hand auger hole from the wetland separating Lake Cubhu
from the Richards Bay
Excavated hole for road building along the N2
¹ Transerve Mercator, Central Merdian 31 & WGS84 Datum
5.1.2 Laboratory analysis of water samples
Water samples were analysed by M&L Laboratory Services (a SANAS accredited laboratory based
in Johannesburg) for inorganic constituents. The results are presented in Table 5-2. Refer to
Appendix A for copies of original laboratory certificates.
The analytical results are compared to the DWAF’ Water Quality Guidelines for human
consumption and the aquatic ecosystems as well as to the SANS 241 (2005) guidelines and are
presented in Table 5-2. Exceedances of the guideline values for human consumption are indicated by
grey shading while exceedances of the aquatic ecosystem guideline values are indicated by bold text.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
20
SRK Consulting
Nozalela Groundwater
Table 5-2
Page
Laboratory Results
Parameters
Units
DWAF
Human
Consumption
Total Alkalinity as CaCO3
mg/l
na
Bicarbonate, HCO3
mg/l
Aluminum, Al
mg/l
0.15
Free and Saline Ammonia as
NH3
mg/l
1.2
Antimony, Sb
mg/l
Arsenic, As
mg/l
Barium, Ba
mg/l
Beryllium, Be
mg/l
Bismuth, Bi
mg/l
Boron, B
mg/l
na
NS
na
0.006
0.14
0.14
0.19
0.32
Cadmium, Cd
mg/l
0.005
0.005
0.00015
0.001
<0.001
<0.001
<0.001
<0.001
Calcium, Ca
mg/l
32
150
na
1
6.1
7
50
7.7
Carbonate, CO3
mg/l
2
Nil
Nil
Nil
Nil
Chloride, Cl
mg/l
100
200
na
5
35
43
383
99
Total Chromium, Cr
mg/l
0.003
<0.003
<0.003
<0.003
<0.003
Cobalt, Co
mg/l
Copper, Cu
mg/l
1
mS/m
150
mg/l
1
Conductivity mS/m @ 25°C
Fluoride, F
SANS 241:2005
Drinking Water Standard
DWAF
Aquatic
Ecosystems
NS
na
NS
0.3
0.005
0.008
0.01
0.5
DURA01
WLD02
14
2
24
36
112
2
29
44
137
17
0.009
<0.009
0.27
<0.009
0.08
<0.1
<0.1
<0.1
<0.1
<0.01
<0.01
<0.01
<0.01
0.01
0.02
<0.02
<0.02
<0.02
<0.02
0.01
0.12
0.14
0.34
0.46
na
0.002
<0.002
<0.002
<0.002
<0.002
0.005
<0.005
<0.005
0.03
0.008
0.1
na
WLD01
0.1
NS
na
BH25011
0.01
0.01
0.01
Detection
Limit
na
0.0003
0.001
0.003
0.001
0.009
0.003
3
<0.002
<0.002
<0.002
<0.002
1
17.9
20
153
40.6
0.1
<0.1
<0.1
0.1
<0.1
0.706
% Error
%
3.43
-4.316
-2.591
Iron, Fe
mg/l
0.1
0.2
na
0.001
0.006
0.11
0.35
1.1
Lead, Pb
mg/l
0.001
0.02
0.0002
0.01
<0.01
<0.01
<0.01
<0.01
Magnesium, Mg
mg/l
30
70
na
1
7.1
2.4
47
12.5
Manganese, Mn
mg/l
0.05
0.1
0.18
0.003
0.03
0.09
6.4
0.09
Mercury, Hg
mg/l
0.000001
0.001
0.00004
0.001
<0.001
<0.001
<0.001
<0.001
Molybdenum, Mo
mg/l
na
NS
na
0.001
0.005
0.005
<0.001
0.005
Nickel, Ni
mg/l
na
0.15
na
0.003
<0.003
<0.003
<0.003
<0.003
Nitrate as N
mg/l
6
10
0.5
0.1
0.3
<0.1
0.2
0.2
Nitrate, NO3
mg/l
NS
0.1
1.5
0.4
1
1
pH Value @ 22°C
unit
6.0-9.0
5.0-9.5
0.01
6.3
4.6
6.6
5.1
Phosphorus, P
mg/l
na
0.04
0.28
0.1
0.26
0.11
Potassium, K
mg/l
50
50
na
0.1
0.2
8
0.9
<0.1
Selenium, Se
mg/l
0.02
0.02
0.002
0.03
<0.03
<0.03
<0.03
<0.03
Silicon, Si
mg/l
na
Silver, Ag
mg/l
Sodium, Na
mg/l
Strontium, Sr
mg/l
Sulfate, SO4
mg/l
100
200
0.015
na
200
400
na
na
?
3.6
8.6
7.1
10
0.004
<0.004
<0.004
<0.004
<0.004
1
19.6
29
140
47
?
0.05
0.07
0.57
0.13
5
6.7
12.3
3.7
15.4
3.408
Sum of Anions
meq/ℓ
1.63
2.194
13.137
Sum of Cations
meq/ℓ
1.746
2.013
12.473
3.457
5
<1
12690
17
60470
Total Suspended Solids
mg/l
Thallium, Tl
mg/l
0.009
<0.009
0.01
<0.009
0.02
Thorium, Th
mg/l
0.002
0.004
0.003
<0.002
<0.002
Tin, Sn
mg/l
0.02
<0.02
<0.02
<0.02
<0.02
Titanium, Ti
mg/l
0.001
0.001
0.001
<0.001
0.001
Total Dissolved Solids
mg/l
450
1000
15% var.
10
230
210
1000
332
Uranium, U
mg/l
na
NS
na
0.004
<0.004
<0.004
<0.004
<0.004
Vanadium, V
mg/l
0.1
0.2
na
0.002
0.1
0.1
0.1
0.11
Zinc, Zn
mg/l
3
5
0.002
0.005
0.06
0.05
0.007
0.52
MILI
na
NS
na
366069GW_DUTH_DEBE_20080128.doc
January 2008
21
SRK Consulting
Nozalela Groundwater
Turbidity, N.T.U.
Page
N.T.U.
1
na
0.9
19
7.5
5.5
Exceedance of DWAF target human health and SANS 241:2005
Drinking Water Standard criteria
bold
Exceedance of DWAF aquatic ecology criteria
The parameters (anions and dissolved metals) listed in Table 5-3 were not detected in any of the
samples analysed. It can be seen that the detection limit for ammonia, lead, arsenic, mercury and
selenium exceed either or both recommended guideline values for these parameters.
5.2
Discussion
Piper and Sheller plots were realised to assist in the interpretation of water quality Figures 5-1 a)
and b). These plots help in showing the complex interactions between the different parameters in
the water and the trends and groupings of those parameters. Some of the types of tools used in
this report are briefly described below:
•
Schoeller plot: demonstrates different hydrochemical water types on the same plot by
showing the major ion concentrations for a number of sample sets.
•
Piper plot: shows major ion distribution for a range of sample points to indicate
clustering of samples e.g. due to geochemical similarities.
Table 5-3 Hydrochemical water type
Sample ID
Water Type
BH25011
DURA01
WLD01
WLD02
Na-Mg-Cl-HCO3
Na-Mg-Cl
Na-Cl-HCO3
Na-Mg-Cl
Based on limited available information, the following comments on the groundwater quality in the
study area are listed:
•
Slightly elevated concentrations of chloride, magnesium and sodium confirmed by the
higher total dissolved solids were determined for the water sample DURA01. This sample
was taken from an excavation for a bridge foundation and intercepted the shallow
groundwater table. The high salinity is an indication of the intermixing with the marine
environment.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
22
SRK Consulting
Nozalela Groundwater
Page
Figure 5-1 a) Piper and b) Schoeller diagrams of groundwater samples
a)
MILI
b)
366069GW_DUTH_DEBE_20080128.doc
January 2008
23
SRK Consulting
Nozalela Groundwater
•
Page
The samples from the wetlands (WLD01 and WLD02), have a lower pH low (4.6 – 5.1) due
to the organic acids (such as humic and tannic acid) released by decaying organic matter.
These samples also have higher total suspended solids, also due to the organic matter and
increased turbidity.
•
Sodium is the dominant cation, followed by magnesium with chloride and bicarbonate as the
dominant anions.
•
The Piper diagram in Figure 5-1 a) shows that these four groundwater samples have a fairly
similar ionic composition, plotting towards the right hand side of the diamond shaped field
which is indicative of mixing with brines due to the higher concentration of sodium and
chloride. This is an indication of the influence of marine water environment on the shallow
groundwater table, resulting in brackish water quality.
•
The DWAF human health guidelines limits are exceeded for several parameters for the
sample taken from the excavation (DURA01). However, as this shallow groundwater is not
utilised for domestic consumption, it is merely flagged at this stage of the feasibility study.
•
The DWAF aquatic guidelines limits are exceeded for zinc, iron and aluminium in the
samples from the wetland. These higher concentrations are caused by the acidic conditions
which result in the dissolution of metals from the heavy minerals in the unconsolidated
sands.
5.3
Existing sources of potential contamination
The shallow groundwater and surface water are hydraulically connected due to the the shallow water
table and the absence of impermeable clays. The potential contamination that could impact surface
water will also impact on the groundwater. These sources are defined in detail in the Surface Water
Specialist report and only listed below in Table 5-4.
Table 5-4 Sources of existing contamination
Register
No.
Latitude
Longitude
21045361
-28.828120
31.890080
21066962
-28.773028
31.897167
MILI
Wastewater
Composition
10-100%
INDUSTRIAL
WASTE
WATER
DOMESTIC
WASTE
WATER
Industrial
Percentage
Annual
Discharge
Volume
m3/a
Water
Resource
Resource
Type
Position
79
680000
MHLATUZE
RIVER
RIVER /
STREAM
Up
gradient
-
4092000
UMHLATUZE
RIVER
RIVER /
STREAM
Adjacent
366069GW_DUTH_DEBE_20080128.doc
January 2008
24
SRK Consulting
Nozalela Groundwater
Page
Effluent from Register No 21045361 is considered to be too far up gradient from the proposed
servitudes (in excess of 8km) to have any impact on the groundwater regime, and the volume too
low to significantly influence the water quality within close proximity to the proposed servitudes.
Effluent associated the domestic waste water from Register No 21066962 is expected to be easily
distinguished from parameters likely to be associated with the proposed project (refer to Section
6.2). Common parameters, however, include turbidity and suspended solid concentrations
(potentially associated with construction activities and pipeline spillage) as well as oils, soaps and
greases (potentially associated with the road). These parameters are also likely to occur in domestic
wastewater.
No water use is registered by the Exxaro mining activities situated approximately 1.5 km to the east
of Lake Cubhu. These mining activities may potentially impact on the Mhlathuze River which
borders the Exxaro mining area on the north but no impact is anticipated on the groundwater regime
due to the distance from this potential source of contamination.
5.4
Groundwater usage
The DWAF WARMS database was also queried for the following water uses:
•
Taking water from a water resource;
Refer to Figure 3-2 for a locality map indicating water usage per sector within the study area where
“DW760 taking water and DW764 flow reduction” relates to uses as listed above. The water use is
dedicated for water supply (from Lakes Cubhu and Mzingani) and irrigation in sugar canes fields in
down gradient flow (alluvial plain of Nseleni and Umhlathuze alluvial plains) by pumping boreholes
or directly in river (see Table 5-5).
Table 5-5 Selected surface and groundwater users
DWAF ID
21132686
Lat
-28.803020
Long
32.092100
21148937
-28.800000
31.957778
21070822
-28.674167
32.046944
MILI
WU Sector
SCHEDULE 1
AGRICULTURE:
IRRIGATION
SCHEDULE 1
Resource Type
Resource Name
BOREHOLE
TRIBUTARY OF MHLATUZE
RIVER CATCHMENT
SCHEME
BOREHOLE
366069GW_DUTH_DEBE_20080128.doc
Position
Down gradient
Adjacent
NSELENI RIVER CATCHMENT
Up gradient
January 2008
25
SRK Consulting
Nozalela Groundwater
Page
Figure 5-2 Map of water users and waste waters
-
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
26
SRK Consulting
Nozalela Groundwater
6
Page
Impact Assessment
Servitudes and associated infrastructure related to the Inhlansi Project are described in detail by the
Scoping Report (SRK report 366069/2). This impact assessment has been undertaken based on this
project description and through the use of the methodology as provided in Appendix III
The following potential impacts on have been identified and are discussed in more detail in the
following sub-sections:
•
Modifications of groundwater flow directions and levels
•
Changes on groundwater quality
Following a discussion of the identified impacts there is a summary impact assessment table. For the
purposes of this report the initial impact assessment (without mitigation) takes into consideration
natural mitigating factors (such as surface water quality background conditions) but makes no
allowance for any designed control measures. High level mitigation objectives are then given in the
summary table on how the identified impacts could be reduced or prevented. The second impact
assessment at the end of the summary table is then based on the assumption that these additional
mitigation measures are put in place.
6.1
Modifications of flow directions and groundwater levels
It is our understanding that the pipeline would be buried at a minimum depth of 1.2 m (i.e. top of the
pipe at 1.2 mbgl) for most of the track but will daylight at some of the river/road crossings. During
construction of the trench for the pipeline, dewatering will be required in sections where the
groundwater table is very shallow (<2 mbgl). Control of the groundwater will be necessary to:
•
Intercept seepage that would otherwise emerge in the excavated trench;
•
Increase the stability of the excavated trenches;
These activities could therefore have a localised impact on the groundwater flow and water table,
although it will be temporary during the construction of sections of the pipeline. If no mitigation is
put in place, working conditions in the trench, if below the groundwater table, could be unsafe due to
collapse of the side walls. Inflows into the trench from the shallow groundwater will make it
difficult to secure the pipeline and buckling of the pipeline could occur.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
27
SRK Consulting
Nozalela Groundwater
Page
Mitigations measures for controlling groundwater may include:
•
Pumping from the trenches;
•
Interception and removal of groundwater from the site by pumping from wells, or drains;
•
Reduction of artesian pressure beneath the bottom of the trench to eliminate heave;
•
Isolation of the excavation from the inflow of groundwater by a sheet-pile cut-off, grout
curtain, or slurry cut off wall.
The modification of the flow direction and groundwater levels will therefore be localised and
temporary during the construction phase but flow conditions should return to normal once the
pipeline is emplaced and vegetation has re-established back to current conditions.
Mitigation
status
Without
mitigation
Spatial
extent
Intensity
Duration
Consequence
Probability
Significance
Status
Confidence
Local
Medium
Shortterm
Very Low
Probable
Very Low
-'ve
Medium
1
2
1
4
•
Dewatering measures, where required for installation of the pipeline along the servitude should be
well designed by qualified personnel to minimise the long term impact on the groundwater regime.
Best practice methodologies should be applied.
•
During construction and closure embankments and temporary slopes must be battered back at an
angle no steeper than 1:1.5 (v:h) and re-vegetated to reduce overland flow velocity, erosion damage
and possible slope failure;
•
Temporary erosion control measures such as the use of sand bags, hessian sheets and silt traps
can be implemented at discharge points, edges of slopes etc.
Mitigation
Measures:
With
mitigation
6.2
Local
Low
short term
Very Low
1
1
1
3
Possible
Very Low
-'ve
Medium
Changes in groundwater quality
Various activities associated with construction, operation and closure of the Inhlansi Project’s
servitudes have the potential to generate/release contaminants which may impact on groundwater
quality. Contaminants could be released during the construction phase (e.g. diesel or oil spills when
excavating the trench) and during the operational phase if there is a rupture or corrosion of the
pipeline. Where the pipeline crosses an area with shallow groundwater table, unless it is well
secured, buckling of the pipeline could result in rupturing and failure of the pipeline during the
construction and operation). Corrosion of the pipeline could occur due to the humidity in the coastal
environment and the low pH associated with the wetlands. The highly permeable sands covering the
pipeline route make the shallow groundwater aquifer vulnerable to any contamination. Mitigation
measures would include that the design of the pipeline material is non-corrosive and that pressure
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
28
SRK Consulting
Nozalela Groundwater
Page
valves are in place to detect rupture of the pipeline particularly where the pipeline is below ground
level. Where the pipeline traverses shallow groundwater, it must be concreted in blocks to ensure
that it will not buckle.
Possible contaminants and their impacts on the groundwater environment - which could arise if not
appropriately managed, are described in Table 6-1. The table also indicates the specific sources that
may give rise to such pollutants and outlines the circumstances under which such pollution could
occur.
Table 6-1: Sources of pollutants and potential impacts arising from transport
activities
Possible contaminant and resulting impacts
Possible sources
There may be a slight increase of ions in
solution (calcium, magnesium, sodium,
carbonate, chloride and sulphate). These are
relatively non-toxic though they may have
adverse health effects and nuisance effects
(such as taste, scaling and corrosion) through
their contribution to the salinity of the water.
A slight increase in salinity may occur during the
construction and closure phases, as well as in the event of
pipeline failure. To this end good industry management
practices (as indicated in the mitigation measures) have
been recommended for management during construction
and closure as well as for spillage cleanup. It is expected
that this should minimise any impacts.
Metals can be mobilised from disturbed areas
or during pipeline failures events. Toxicity is
dependent on the species present, however,
heavy metals tend to be more toxic than salts
even at low (ug/l) concentrations.
The naturally occurring dissolved and total metal
concentrations in the various water courses likely to be
impacted on within the project area vary significantly but
concentrations are generally low. Aluminium and iron are
however generally naturally elevated in most of the
receiving water bodies. It is expected that low
concentrations of metals may be mobilised during
construction and closure phases as well as during pipeline
failure events. The solution of metals is not generally
considered a significant risk although the pH in auger holes
from the wetland areas is low due to the humic acids and
could result in dissolution of metals.
Ilmenite (FeTiO3), rutile (TiO2) and zircon (ZrSiO4) will
constitute the main ore minerals to be transported via the
pipeline. Those minerals are inert and will not lead to any
dissolution.
Hydrocarbons (such as oil, petrol, diesel and
grease) can have toxic effects and can
block/smother the respiratory organs of aquatic
life.
A potential source of hydrocarbon contamination includes
an accident involving a tanker truck transporting diesel to
the mining area along the access road. Depending on the
position of such an event, soil and groundwater resources
may be affected.
In summary, the potential for salts and metals to be mobilised in significant quantities is considered
to be low. These parameters are therefore not considered a major risk associated with the servitudes.
There is also the potential that catastrophic incidents associated with pipeline failure and spillage /
diesel tanker accidents could impact on the groundwater resources. Therefore, the impact assessment
that follows below focuses in particular on the potential impacts associated with a pipeline rupture
releasing HMC to the sub-surface and hydrocarbon spillages. Suggested mitigation measures,
however, target all potential contamination sources.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
29
SRK Consulting
Nozalela Groundwater
Mitigation
status
Without
mitigation
Mitigation
Measures
Page
Spatial
extent
Intensity
Duration
Consequence
Regional
Medium
Long-term
High
2
2
3
7
Probability
Significance
Status
Confidence
Probable
High
-'ve
Medium
General
•
Good housekeeping practices are to be implemented across the site. Any sources of secondary pollution
must immediately be contained and remediated by the developer upon occurrence;
Pipeline
•
Trenches for the installation of the pipeline must be opened in short sections and dewatered. Pipes /
cables are to be installed and encased and/or backfilled before the next section of trench is opened.
Trench water must be settled and discharged. It is understood that excavated material (as opposed to
foreign material) will be used as trench backfill;
•
The pipeline is to be constructed of high quality (steel) and fitted with pressure valves to minimize the risk
of below ground ruptures or leakage, which would result in deterioration in groundwater quality. It will
have significant corrosion protection measures;
•
Where the pipeline crosses shallow groundwater, it must be secured with concrete blocks to ensure that
it cannot “float” on the groundwater (particularly if empty) which could result in buckling and rupture of the
pipe;
•
The entire pipeline route is to be monitored visually on a weekly basis, while the system should be
monitored online through the use of instrumentation that must be installed to detect leaks and identify
leak positions. Automatic shut down systems must be put in place to stop pumping immediately if a drop
in the pumping pressure is detected;
•
Sound waste management practices (including hazard classification, separation, storage, handling,
transport, recycling, reduction, cleanup and disposal) must be implemented during construction and
decommissioning so as not to cause any groundwater pollution or a health hazard. Waste must be
disposed of to a licensed landfill site;
Roads
With
mitigation
7
•
An emergency preparedness plan must be developed and adequate spill containment and cleanup
equipment must be kept on hand a well as the required knowledge, training and support to stop, contain,
remove, assess and remediate all spillages. Significant spillages (i.e. during pipeline failure / tanker
accidents) must be documented and reported to the DWAF and other relevant authorities;
•
Speed limits on the access road should be enforced so as to minimise the potential of accidents which
may lead to hydrocarbon spillage along the access road;
•
Maintenance / service procedures should be implemented / proof provided so as to ensure that all
transport hydrocarbon transport vehicles are road worthy. Poorly maintained vehicles will increase the
risk of accidents and therefore spillage;
•
Vehicles transporting fuel must be equipped with emergency containment / remediation equipment.
Personnel must be adequately trained to use this equipment where appropriate.
Local
Low
Shortterm
Very Low
1
1
1
3
Possible
Insignificant
-'ve
Medium
Monitoring
No groundwater users were identified in the immediate vicinity of the proposed pipeline route. It is
therefore not necessary to drill monitoring boreholes at any specific sensitive area along the route
unless a spillage or rupture occurs, in which case a borehole will be required to monitor the fate and
transport of any contamination released during such an event. If other groundwater users are
identified in the future which could be impacted on during the operation of the pipeline, monitoring
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
30
SRK Consulting
Nozalela Groundwater
Page
boreholes should be drilled as an early warning system between the groundwater users and the
nearest location to the pipeline.
8
Conclusions
The conclusions drawn from the preliminary baseline assessment of the groundwater regime along
the proposed pipeline servitude are as follows:
•
The geology of the length of the route traverses highly permeable sands of Quaternary age.
•
The area has a high rainfall and infiltration is therefore high, estimated at 50% of the
mean annual rainfall.
•
The groundwater table mimics the topography and is very shallow varying from < 2mbgl
to 4 mbgl.
•
Groundwater flow is generally either towards the Indian Ocean, or the wetlands which are
abundant in the area.
•
The shallow aquifer is very vulnerable to any contamination due to the highly permeable
overlying sands of Quaternary age.
•
Groundwater surface water interactions are therefore very significant, and any impacts
should be considered as interconnected between these two resources.
•
The groundwater quality is marginally brackish confirming the marine influence which is
between 0.2 -2 km distant from the pipeline.
•
The low pH associated with the wetlands (and therefore shallow groundwater) has resulted
in slightly elevated metal concentrations due to mobilisation from the heavy mineral sands
in Quaternary sand.
•
No groundwater users were identified in the immediate vicinity of the pipeline route,
although a few boreholes used for irrigation of sugar cane fields were identified in the
region.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
31
SRK Consulting
Nozalela Groundwater
•
Page
The main impact identified are that the pipeline trench will have to excavated through
areas with a shallow water table which will require sections to be dewatered during the
construction phase. This could result in localised disturbance of the ground flow directions
and water table, but the impacts will be temporary.
•
Mitigation measures proposed to reduce the impacts are that the dewatering designs for
each section are designed by qualified specialists in this field and that the impacts are kept
to a minimum using Best Practice techniques.
•
Damage to the pipeline due to corrosion or rupture could result in localised deterioration
in the groundwater quality due to leakage of the HMC. Elevated metals could occur
especially in areas where the pH is low due to humic acids in the wetland areas.
•
Mitigation measures include the securing of the pipeline in concrete blocks especially in
areas with a shallow groundwater. The pipeline is to be constructed with high quality noncorrosive steel and pressure valves will be installed to monitor for leakage.
•
During construction, diesel or fuel spills could also impact on the shallow groundwater
quality, as the overlying sands are very permeable and vulnerable to contamination.
•
Mitigation measures during the construction phase include good housekeeping, bunding of
storage areas and proactive response to any spills.
9
Recommendations
As no groundwater users were identified in close proximity to the pipeline route during the prefeasibility study, no monitoring boreholes are required at this stage. However, if there are any
spillages or ruptures during the construction or operation phases, boreholes would be required to
monitor the fate and transport of any contaminants identified in the groundwater.
If in future any groundwater users are identified in close proximity to the pipeline, a monitoring
borehole should be installed as an early warning detection system.
I. Milenkovic
D. Duthe (Pr. Sci. Nat.)
Hydrogeologist
MILI
Partner
366069GW_DUTH_DEBE_20080128.doc
January 2008
32
SRK Consulting
Nozalela Groundwater
Page
SRK Consulting
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
33
SRK Consulting
Nozalela Groundwater
Page
10 References
Groundwater Consulting Services, 2005. Zultu South groundwater investigation. Report to RBM by
Groundwater Consulting Services.
Groundwater Modelling of Zulti South 2006. Hydrological Research & Training Specialists .
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
34
SRK Consulting
Nozalela Groundwater
Page
Appendices
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
35
SRK Consulting
Nozalela Groundwater
Page
Appendix I Groundwater Levels
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
36
SRK Consulting
Nozalela Groundwater
Page
ID
DWAF
SRK 2007
GCS 2005
MILI
Geographic coordinates
WGS84 Datum
Projected coordinates
Transverse Mercator,
Central Merdian 31,
WGS84 Datum
Y
X
Altitude
(masml)
Date
Water
depth
(mbgl)
Water level
(masml)
Lat
Long
NSONGENI
-28.708500
31.988890
-3177362
96628
160
Nov-1959
21.34
138.66
MAHALATUZI - LOWER UMFOLOZI
-28.858330
31.905560
-3193904
88359
100
Apr-2004
6.78
93.22
UMHLATUZI RIVER BRIDGE
-28.819450
31.965280
-3189641
94221
160
Oct-2004
6.52
153.48
ESIKHAWINI RIOOLWERKE
-28.915150
31.901930
-3200200
87957
40
Mar-1990
3.76
36.24
UVS SUGAR ESTATE 14749
-28.807450
31.953220
-3188301
93055
20
Apr-1990
2.85
17.15
UMHLATUZE VALLEY PTN. ICUBHU
EMPEMBENI PTN. EMPEMBENI HIGH
SCHOOL
-28.826300
31.958620
-3190395
93565
20
May-1990
3.25
16.75
-28.861000
31.982660
-3194260
95880
20
Feb-1990
11.61
8.39
UVS SUGAR ESTATE 14138
-28.818450
31.946560
-3189515
92395
30
Mar-1990
11.81
18.19
STURROCK ESTATE 14084
-28.892550
31.917800
-3197707
89524
50
Mar-1990
1.26
48.74
MTUNZINI FOREST
-28.890560
31.974710
-3197530
95077
50
Apr-1990
0.91
49.09
LOT K 35
-28.695830
32.058330
-3176016
103426
40
Apr-1990
19.79
20.21
LOT K 31
-28.708330
32.011110
-3177361
98800
40
May-1990
18.42
21.58
SOLITUDE
-28.720840
32.013070
-3178750
98979
40
Apr-1990
4.93
35.07
LOT K 33
-28.716670
32.008890
-3178284
98575
40
Apr-1990
4.99
35.01
MZINGAZI
-28.684130
32.114620
-3174769
108940
40
Apr-2004
11.26
28.74
BH25011
-28.877656
31.969461
-3196096
94577
34
Oct-2007
13
21
BH2509
-28.883328
31.959074
-3196716
93558
37
Oct-2007
13.86
23.14
WLD01
-28.837090
31.986898
-3191613
96315
7
Oct-2007
0.2
6.8
DURA01
-28.774467
31.956129
-3184648
93368
8
Oct-2007
1.3
6.7
Hand auger hole (DRY)
-28.760826
31.984635
-3183158
96164
28
Oct-2007
<2
<26
WLD02
-28.832375
31.979656
-3191085
95613
6
Oct-2007
0.2
5.8
ZS1
-28.921971
31.837973
-3200910
81714
41
Nov-2002
5.6
35.4
ZS6
-28.911027
31.873526
-3199722
85190
36
Nov-2002
2.7
33.3
ZS9
-28.870028
31.966585
-3195248
94303
21
Nov-2002
11.1
9.9
ZS10
-28.855782
31.975472
-3193676
95183
20
Nov-2002
0
20
ZS12
-28.882805
31.940811
-3196644
91777
32
Nov-2002
13.7
18.3
ZS13
-28.915667
31.825946
-3200203
80546
22
Nov-2002
12.5
9.5
ZS15
-28.855137
31.997027
-3193622
97287
16
Nov-2002
2.7
13.3
ZS16
-28.869975
31.987524
-3195259
96346
40
Nov-2002
1
39
ZS17
-28.862246
31.982255
-3194398
95839
23
Nov-2002
3.1
19.9
GCS1
-28.911717
31.921641
-3199834
89882
34.8
May-2003
23.4
11.4
GCS2
-28.911771
31.921652
-3199840
89883
39.8
May-2003
7.6
32.2
GCS3
-28.903136
31.916542
-3198879
89392
51.7
May-2003
31.3
20.4
GCS4A
-28.881797
31.973480
-3196558
94965
34.6
May-2003
10.6
24
GCS4S
-28.881770
31.973459
-3196555
94963
34.5
May-2003
10.9
23.7
GCS5
-28.877429
31.971174
-3196072
94744
29
May-2003
5.7
23.3
GCS6A
-28.868273
31.994570
-3195076
97035
22.4
May-2003
3.2
19.2
GCS6S
-28.868219
31.994569
-3195070
97035
22.6
May-2003
3.2
19.5
GCS7A
-28.927009
31.863169
-3201486
84167
26.9
May-2003
14.1
15.1
GCS7S
-28.927036
31.863149
-3201489
84165
26.6
May-2003
11.5
7.5
RBM1
-28.891511
31.975108
-3197636
95115
28.3
May-2003
20.7
14
RBM2
-28.889394
31.974597
-3197401
95067
49.2
May-2003
35.2
16
RBM3
-28.899029
31.949466
-3198449
92607
27.5
May-2003
11.5
16
RBM4
-28.912759
31.922286
-3199950
89944
36.2
May-2003
12
24.2
RBM5
-28.916029
31.899100
-3200295
87680
34.8
May-2003
23.3
11.5
RBM6
-28.927096
31.866411
-3201498
84483
40.5
May-2003
26.1
14.4
RBM7
-28.934938
31.841882
-3202350
82085
20.6
Nov-2002
8.9
10.4
366069GW_DUTH_DEBE_20080128.doc
January 2008
37
SRK Consulting
Nozalela Groundwater
MILI
Page
RMB9
-28.836360
31.982545
-3191529
95891
3.9
Nov-2002
11.1
RBM10
-28.835968
31.983156
-3191486
RBM12
-28.918103
31.881409
-3200512
RBM13
-28.918311
31.881421
RBM14
-28.925559
31.864111
RBM15
-28.927054
RBM16
-28.928696
RBM17
95951
3.9
Nov-2002
7.3
-3.4
85953
27.8
Nov-2002
2.2
24.4
-3200535
85954
31.7
Nov-2002
10.6
24.2
-3201326
84260
19
Nov-2002
2.7
15.5
31.863149
-3201491
84165
26.7
Nov-2002
9.6
14.9
31.939922
-3201730
91650
30.1
May-2003
7.9
22.2
-28.927691
31.842378
-3201547
82139
46.1
May-2003
21.5
24.6
RBM18
-28.917125
31.892906
-3200412
87075
14.8
May-2003
3.9
10.9
RBM19
-28.900745
31.913845
-3198612
89131
37.1
May-2003
5.6
31.5
RBM20
-28.901017
31.913693
-3198642
89116
36.1
May-2003
42
31.9
RBM21
-28.899909
31.929339
-3198531
90643
41.4
May-2003
3.6
37.8
RBM23
-28.894118
31.956177
-3197910
93266
38.6
May-2003
12.3
26.3
RBM24
-28.884018
31.954394
-3196789
93101
34
May-2003
8.3
25.7
RBM25
-28.884097
31.954661
-3196798
93127
34.7
May-2003
10.1
24.6
RBM29
-28.863429
32.010245
-3194552
98569
11.9
May-2003
4.2
7.7
RBM30
-28.854575
32.015519
-3193575
99092
4.3
May-2003
3
1.2
366069GW_DUTH_DEBE_20080128.doc
-7.2
January 2008
38
SRK Consulting
Nozalela Groundwater
Page
Appendix II Laboratory Certificates
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
39
SRK Consulting
Nozalela Groundwater
MILI
Page
366069GW_DUTH_DEBE_20080128.doc
January 2008
40
SRK Consulting
Nozalela Groundwater
MILI
Page
366069GW_DUTH_DEBE_20080128.doc
January 2008
41
SRK Consulting
Nozalela Groundwater
MILI
Page
366069GW_DUTH_DEBE_20080128.doc
January 2008
42
SRK Consulting
Nozalela Groundwater
Page
Appendix III Impact Assessment Methodology
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008
43
SRK Consulting
Nozalela Groundwater
Page
Impact Assessment Methodology
The significance of all potential impacts that would result from the proposed project is determined in order to
assist decision-makers. The significance rating of impacts is considered by decision-makers, as shown
below.
•
INSIGNIFICANT: the potential impact is negligible and will not have an influence on the decision
regarding the proposed activity.
•
VERY LOW: the potential impact is very small and should not have any meaningful influence on
the decision regarding the proposed activity.
•
LOW: the potential impact may not have any meaningful influence on the decision regarding the
proposed activity.
•
•
MEDIUM: the potential impact should influence the decision regarding the proposed activity.
HIGH: the potential impact will affect a decision regarding the proposed activity.
•
VERY HIGH: The proposed activity should only be approved under special circumstances.
The significance of an impact is defined as a combination of the consequence of the impact occurring and
the probability that the impact will occur. The significance of each identified impact1 must be rated
according to the methodology set out below:
Step 1 – Determine the consequence rating for the impact by adding the score for each of the three criteria
(A-C) listed below:
Rating
Definition of Rating
Score
A. Extent– the area in which the impact will be experienced
None
0
Local
Confined to project area or part thereof
1
Regional
Exceeds project area
2
(Inter)
national
National / international
3
B. Intensity– the magnitude of the impact in relation to the sensitivity of the receiving environment
None
0
Low
Site-specific and wider natural and/or social functions and processes are negligibly
altered
1
Medium
Site-specific and wider natural and/or social functions and processes continue albeit
in a modified way
2
High
Site-specific and wider natural and/or social functions or processes are severely
altered
3
C. Duration– the time frame for which the impact will be experienced
None
1
MILI
0
Short-term
Up to 2 years
1
Medium-term
2 to 15years
2
Long-term
More than 15 years
3
This does not apply to minor impacts which can be logically grouped into a single assessment.
366069GW_DUTH_DEBE_20080128.doc
January 2008
44
SRK Consulting
Nozalela Groundwater
Page
The combined score of these three criteria corresponds to a Consequence Rating, as follows:
Combined Score (A+B+C)
Consequence Rating
0–2
3–4
5
6
7
8–9
Not significant
Very low
Low
Medium
High
Very high
Example 1:
Extent
Intensity
Duration
Consequence
Regional
Medium
Long-term
High
2
2
3
7
Step 2 – Assess the probability of the impact occurring according to the following definitions:
Probability– the likelihood of the impact occurring
Improbable
< 40% chance of occurring
Possible
40% - 70% chance of occurring
Probable
> 70% - 90% chance of occurring
Definite
> 90% chance of occurring
Example 2:
Extent
Intensity
Duration
Consequence
Regional
Medium
Long-term
High
2
2
3
7
Probability
Probable
Step 3 – Determine the overall significance of the impact as a combination of the consequence and
probability ratings, as set out below:
Significance Rating
Consequence
Insignificant
Very Low
&
Improbable
Very Low
&
Possible
Very Low
&
Probable
Very Low
&
Definite
Low
&
Improbable
Low
&
Possible
Low
&
Probable
Very Low
Low
Medium
High
Very High
MILI
Probability
Low
&
Definite
Medium
&
Improbable
Medium
&
Possible
Medium
&
Probable
Medium
&
Definite
High
&
Improbable
High
&
Possible
High
&
Probable
High
&
Definite
Very High
&
Improbable
Very High
&
Possible
Very High
&
Probable
Very High
&
Definite
366069GW_DUTH_DEBE_20080128.doc
January 2008
45
SRK Consulting
Nozalela Groundwater
Page
Example 3:
Extent
Intensity
Duration
Consequence
Regional
Medium
Long-term
High
2
2
3
7
Probability
Significance
Probable
HIGH
Step 4 – Note the status of the impact (i.e. will the effect of the impact be negative or positive?)
Example 4:
Extent
Intensity
Duration
Consequence
Regional
Medium
Long-term
High
2
2
3
7
Probability
Significance
Status
Probable
HIGH
– ve
Step 5 – State your level of confidence in the assessment of the impact (high, medium or low).
Depending on the data available, you may feel more confident in the assessment of some impact than others.
For example, if you are basing your assessment on extrapolated data, you may reduce the confidence level to
low, noting that further groundtruthing is required to improve this.
Example 5:
Extent
Intensity
Duration
Consequence
Regional
Medium
Long-term
High
2
2
3
7
Probability
Significance
Status
Confidence
Probable
HIGH
– ve
High
Step 6 – Identify and describe practical mitigation measures that can be implemented effectively to
reduce the significance of the impact. The impact should be re-assessed following mitigation,
by following Steps 1-5 again to demonstrate how the spatial extent, intensity, duration and/or
probability change after implementation of the proposed mitigation measures.
Example 6: A completed impact assessment table
Extent
Without Regional
mitigation
2
With
mitigation
Intensity
Duration
Consequence
Probability
Significance
Medium
Long-term
High
Probable
HIGH
– ve
High
Improbable
VERY LOW
– ve
High
2
3
7
Local
Low
Long-term
Low
1
1
3
5
Status Confidence
In the report, mitigation measures must be described as either:
•
MILI
Essential: must be implemented and are non negotiable; and
366069GW_DUTH_DEBE_20080128.doc
January 2008
46
SRK Consulting
Nozalela Groundwater
•
Page
Optional: must be shown to have been considered and sound reasons provided by the MJV if
not implemented.
Step 7 – Summarise all impact significance ratings as follows in your executive summary:
MILI
Impact
Consequence
Probability
Significance
Impact 1: XXXX
Medium
Improbable
LOW
With Mitigation
Low
Improbable
VERY LOW
Impact 2: XXXX
Very Low
Definite
VERY LOW
With Mitigation:
Not applicable
366069GW_DUTH_DEBE_20080128.doc
Status
–ve
Confidence
High
High
–ve
Medium
January 2008
47
SRK Consulting
Nozalela Groundwater
Page
SRK Report Distribution Record
Complete this form and include it as the final page for each copy of the report produced.
Report No.
366069
Copy No.
Name/Title
Company
Copy
Date
Authorised by
Approval Signature:
This report is protected by copyright vested in SRK Consulting. It may not be reproduced or transmitted in
any form or by any means whatsoever to any person without the written permission of the copyright holder,
SRK.
MILI
366069GW_DUTH_DEBE_20080128.doc
January 2008