Annex A - transnet.net...Oil Spills: Collision of an iron-ore carrier with a moored tanker Such a...
Transcript of Annex A - transnet.net...Oil Spills: Collision of an iron-ore carrier with a moored tanker Such a...
Annex A
Specialist Reports
Port of Saldanha expansion of iron-ore handling facilities: Phase 2 Environmental Screening Study
Marine Risks
Prepared by: Roy van Ballegooyen and Pedro Monteiro Natural Resources and the Environment
CSIR P.O Box 320
Stellenbosch 7599
and
Dr Robin Carter Lwandle Technologies (Pty) Ltd.
Prepared for: Environmental Resources Management (Pty) Ltd
August 2008
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CSIR Report No CSIR/NRE/ECO/ER/2008/0119/C
Prepared for:
Environmental Resources Management (Pty) Ltd
This report was compiled by: Roy van Ballegooyen NRE, CSIR
Dr Robin Carter Lwandle Technologies (Pty) Ltd.
Dr Pedro Monteiro NRE CSIR
Published by: CSIR
P O Box 395
0001 PRETORIA
Republic of South Africa
Issued and printed by, also obtainable from: CSIR
P O Box 320
STELLENBOSCH
7599
South Africa
Tel: + 27 21 888-2400
Fax: +27 21 888-2574
Email: [email protected]
The report to be cited as:
van Ballegooyen, R., R. Carter and P. Monteiro (2008) Port of Saldanha expansion of
iron-ore handling facilities: Phase 2 Environmental Screening Study - Marine Risks,
CSIR Report No CSIR/NRE/ECO/ER/2008/0119/C, 29pp.
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CCOONNDDIITTIIOONNSS OOFF UUSSEE OOFF TTHHIISS RREEPPOORRTT
1. This report is the property of the sponsor who may publish it provided that:
(a) the CSIR is acknowledged in the publication;
(b) the report is published in full or, where only extracts therefrom or a summary
or an abridgement thereof is published, prior written approval is obtained
from the CSIR for the use of the extracts, summary or an abridged report;
and
(c) the CSIR is indemnified against any claim for damages that may result from
the publication.
2. The CSIR will not publish this report or the detailed results without the sponsor's
prior consent. The CSIR is however entitled to use the technical information
obtained from the investigation but undertakes, in doing so, not to identify the
sponsor or the subject of this investigation.
3. The contents of this report may not be used for purposes of sale or publicity or in
advertising without the prior written approval of the CSIR.
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SCOPE OF WORK
The CSIR and Lwandle Technologies were approached by ERM to contribute to an
environmental screening of various development options for the Phase 2 expansion of
iron-ore handling facilities in Saldanha Bay.
This contribution comprised;
• the attendance of a one day workshop together with other marine specialists:
• preparation of a formalised specialist contribution (this report) to the overall
Phase 2 Environmental Screening Study undertaken by ERM.
This study assesses the comparative risks of four potential development options in the
marine environment related to:
• Potential changes in the long-term ecosystem functioning in the Saldanha Bay-
Langebaan Lagoon system associated with the proposed expansion of port
facilities;
• Dredging activities associated with the various options;
• Operational discharges to the marine environment (storm water, ballast water,
etc).
While the report includes a discussion of the transport and fate of potential oil spills,
more detailed analyses of incremental shipping risks and risks to shoreline stability have
been undertaken in companion studies (CSIR, 2008, WSP, 2008).
These assessments have been undertaken based on the details provided by ERM for the
various options under consideration. The robustness of the assessment is determined
by the accuracy of this information. The assessment has been undertaken based on all
information available to date. The detail of the information available is quite variable for
the various options considered.
R van Ballegooyen
Coastal Systems Research Group Stellenbosch, South Africa
Natural Resources and the Environment CSIR August 2008
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EXECUTIVE SUMMARY
This study comprises a comparative screening of four proposed development options for
the Phase 2 expansion of iron handling facilities in Saldanha Bay. This screening is
based on a one day workshop of marine specialist and subsequent focussed discussion
between the relevant marine specialists.
This study assesses the comparative risks of the four development options in the marine
environment related to:
• Potential changes in the long-term ecosystem functioning in the Saldanha Bay-
Langebaan Lagoon system associated with the proposed expansion of port
facilities;
• Dredging activities associated with the various options;
• Operational discharges to the marine environment (storm water, ballast water,
etc).
While the report includes a discussion of the transport and fate of potential oil spills,
more detailed analyses of incremental shipping risks and risks to shoreline stability have
been undertaken in companion studies (CSIR, 2008; WSP, 2008).
The conclusions of this study follow.
Long-term Ecological Consequences
Current understanding of the ecosystem functioning of the Saldanha Bay – Langebaan
Lagoon system is that Langebaan Lagoon is dependant on the physics and productivity
processes in Big Bay, particularly the flux of organic material into the latter system from
Big Bay. Being less directly linked, the ecosystem functioning of Small Bay is likely to
be of lesser importance to Langebaan Lagoon than that of Big Bay. Nevertheless there
are significant ecosystem services provided by Small Bay (e.g. mariculture, assimilation
of discharges, etc).
The quantitative aspects of the link between Big Bay and Langebaan Lagoon are not
fully understood. This requires that the precautionary principle be invoked when
assessing risks to Langebaan Lagoon. We have interpreted this as a requirement that
there be no change to the indices selected (i.e. phytoplankton production, dissolved
oxygen) at locations adjacent to and in the lagoon mouth. This implies that the
ecosystem thresholds in turn would not be threatened.
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The indices used in this screening study have indicated that the morphological changes
(and linked changes in ecosystem function) associated with either of the Locations 1 and
2 development options do not pose any identified long-term risk to the Saldanha Bay –
Langebaan Lagoon system. Thus either of these development options (Options 1
and 2) could be acceptable, although each suggests a possible foreclosure of the
range of potential future development scenarios in both Small Bay (Option 1) and
Big Bay (Option 2) that need to be considered. These are addressed in more detail
in ERM (2008).
The overall consequences in terms of ecosystem function are likely to be significantly
greater for Options 3 and 4. The overall consequences of the changes for Option 3 are
likely to be insignificant in terms of the overall ecosystem functioning of the ecosystem of
Big Bay and the coupling of the Big Bay – Langebaan lagoon ecosystems. However, the
expansion of modified benthic habitat in Small Bay is appreciable and the loss of such
habitat under the reclaim in Big Bay is large relative to Option 1 and Option 2. The
consequences of these changes are uncertain. With regards to Option 4, when
compared to Option 1 and Option 2, habitat loss and/or modification is appreciable in
Small Bay and Big Bay. The latter specifically in the inter- and shallow subtidal area
which is known to be important as a fish nursery area. Option 4 is the least suitable of all
alternatives put forward because of this and uncertainties of affects on other functions in
the Saldanha Bay-Langebaan Lagoon ecosystem.
We are uncertain where the ecosystem thresholds lie for the linkages between Big Bay
and Langebaan Lagoon. It is possible that extended development within in Big Bay, be
this port development or other operations such as mariculture, etc, may ultimately
threaten ecosystem thresholds. The risk (in terms of linkages between Big Bay and
Langebaan Lagoon) of similar extended development in Small Bay is likely to be lower.
Thus, within the context of present available knowledge of the functioning of the
Saldanha Bay – Langebaan lagoon ecosystem and associated ecosystem thresholds,
the selection of option 2 on this occasion should not be considered to set a precedent for
further development in Big Bay by either the port or other industry. Assessment of the
acceptability of any further or extended development in Big Bay will need to be based on
an improved understanding of potential ecosystem thresholds to ensure that the risks
posed by such further development in Big Bay on the Saldanha Bay – Langebaan
Lagoon ecosystems remain acceptable.
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Shoreline Stability
The conclusion around shoreline stability are discussed in a companion study by WSP
Coastal Africa (Pty) Ltd (WSP, 2008).
Risk during construction
Dredging and reclaim Activities
The observations made for long-term ecological consequences are of equal relevance
here, i.e. the risks associated Options 1 and 2 are unlikely to be significantly different
however the risks associated with Options 3 and 4 overall are significantly higher.
Blasting
If a properly controlled blasting programme is undertaken, the risks will be so low that it
is not possible to differentiate between the various options in terms of the risks
associated with blasting activities.
Risks associated with Operational Activities
Ballast Water
The scales and characteristics of Saldanha Bay does not enable us to differentiate the
various proposed locations in terms of risk of establishment of alien species.
Discharges from Site
The only likely differentiating factor between the various locations would be the receiving
environment in terms of dispersion of pollutants. It is not possible to differentiate
between the various proposed locations in terms of the above.
Oil Spills: Collision of an iron-ore carrier with a moored tanker
Such a spill is only likely to occur for Options 1, 3 and 4. . A collision between a moored
tanker and an ore carrier is not possible for Option 2 as berths located in Big Bay will not
require that the iron-ore bulk carriers pass moored tankers. Small spills are likely to be
confined to Small Bay, particularly as mitigation measures can relatively easily be
deployed in Small Bay which is a relatively sheltered environment. However, under
development Option 1, large spills could enter Big Bay. Such an oil spill is likely to occur
at the end of the causeway where ebb flow tidal currents and/or north-westerly wind
conditions) could easily allow an oil spill to enter Big Bay and possibly ultimately
Langebaan Lagoon.
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Oil spill- Grounding of an iron-ore carrier or collision with a concrete structure
(jetty or quay).
The consequences of such an oil spill will be greatest for Option 2 as the oil will be
released into Big Bay where it will be more difficult to contain the oil spill and there is a
greater likelihood of the oil reaching Langebaan Lagoon. The consequences of an oil
spill at the berth locations for Option 1 is likely to be less than for Option 2, but perhaps
not as different as would be expected, due to the fact that the outer extremity of Small
Bay is strongly linked to Big Bay by tidal and wind-driven flows (particularly the clockwise
circulation that is considered to prevail in Small Bay under both southerly and north-
westerly wind conditions). The likelihood of containing oil spilt at berth locations for
Options 3 and 4 are significantly higher, particularly for Option 4. Consequently the
potential impacts associated with oil spills associated with the grounding of an iron-ore
carrier or collision with a concrete structure at these two locations is significantly less
than for Options 1 and 2.
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TABLE OF CONTENTS
SCOPE OF WORK I
EXECUTIVE SUMMARY III
TABLE OF CONTENTS VII
LIST OF FIGURES IX
LIST OF TABLES IX
GLOSSARY OF TERMS AND LIST OF ABBREVIATIONS XI
1. COMPARATIVE ASSESSMENT OF MARINE RISKS
1.1 INTRODUCTION 1
1.2 ECOLOGICAL CONSEQUENCE (LONG TERM) 2
1.3 SHORELINE STABILITY (GS, KS) 10
1.4 CONSTRUCTION (SHORT-TERM) (RC, RVB, PM) 10
1.4.1 Dredging 10
1.4.2 Blasting 15
1.5 OPERATIONAL 16
1.5.1 Routine 16
1.5.2 Oil SPills 16
1.6 CONCLUSION 25
1.6.1 Long-term Ecological Consequences 25
1.6.2 Shoreline Stability 26
1.6.3 Construction 26
1.6.4 Operational 27
2 REFERENCES 28
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LIST OF FIGURES
Figure 1: Alternative berth locations considered in this study. 1
Figure 2: Wind roses of the winds measured at Port Control in Saldanha Bay (see
inset). 18
Figure 3a: Flood tide surface and bottom currents in Saldanha Bay during spring
tide and under relatively calm conditions. 20
Figure 3b: Ebb tide surface and bottom currents in Saldanha Bay during spring tide
and under relatively calm conditions. 20
Figure 4a: Schematic of the wind driven and tidal currents in Saldanha Bay under S
wind conditions. 21
Figure 4b: Schematic of the wind driven and tidal currents in Saldanha Bay under
NW wind conditions. 21
LIST OF TABLES
Table 1: Key descriptors of the project 1
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GLOSSARY OF TERMS AND LIST OF ABBREVIATIONS
Biogeochemical processes those physical, chemical and geological processes
determining the inter-relationship between the
geochemistry of an region and the animal and plant life
in that region
Flocs a flocculent mass formed in a fluid through precipitation
or aggregation of suspended particles
Gracilaria (gracilis) a red agar-producing seaweed that grow in Saldanha
Bay and is harvested via the collection of wash-ups on
the beaches. Agar is a product in demand by the
microbiological, medical and food industries
Elutriation analyses: Procedure for estimating the concentration of
contaminants that could be released from sediments
during dredging activities or sea dumping
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1. COMPARATIVE ASSESSMENT OF MARINE RISKS
1.1 INTRODUCTION
The project description assumed for this assessment is that provided by Transnet Projects in their document “H500107-MP-ZJ1-10019 Rev 1 18 06 08.pdf” supplied to the CSIR on the 19 June 2008 and August 21 2008 (Figure 1). The key descriptors of the project are as tabulated below.
Figure 1: Alternative berth locations considered in this study. Table 1: Key descriptors of the project
Option 1 Option 2 Option 3 Option 4 Area of Reclaim 392 000 m2 560 000 m2 890 000 m2 1 540 000 m2
Volume to be accommodated in Reclaim area
4.90 million m3 7.20 million m3 9.24 million m3 15.24 million m3
Extent of area to be dredged
832 000 m2 650 000 m2 980 000 m2 1 200 000 m2
Volume of material to be dredged
4.10 million m3 6.25 million m3 7.70 million m3 12.7 million m3
Duration of dredging activities
24 weeks 40 weeks 46 weeks 75 weeks
Volume of rock to be blasted
51 250 m3 90 000 m3 136 000 m3 205 000 m3
Cost R 9.111 bn R 8.859 bn R 13.671 bn R 11.888 bn
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1.2 ECOLOGICAL CONSEQUENCE (LONG TERM)
The assessment criterion used is to minimise the changes to the biogeochemical
processes that support the key ecosystem services from the Saldanha Bay – Langebaan
Lagoon System.
The key biogeochemical process underpinning ecosystem services in the system is
biological productivity (distribution in space and time) and its utilization in the system
reflected through changes in oxygen in bottom waters (e.g. increased phytoplankton
ultimately results in greater loads of detrital carbon that can accumulate in the more
quiescent regions of the bay and result in a reduction in the oxygen concentration of the
bottom and near bottom waters of the bay). Also of concern is habitat destruction (direct
or indirectly).
The three metrics of change utilised are:
• The extent of change in water column phytoplankton productivity;
• The extent of change in dissolved oxygen in the bottom waters of the system
(low dissolved oxygen concentrations may lead to ecological effects such as
reductions in benthic biomass, species abundance and diversity, as well the
elimination of crustacean at very low concentrations);;
• The extent of physical habitat change (i.e. shipping channel) and habitat loss
(i.e. reclamation area).
The degree of change considered to be significant is an anomaly of 10% in the
phytoplankton productivity and dissolved oxygen in the water column that has a
persistence of 7 days or greater. The basis for this criterion is that changes smaller than
10% are unlikely to be reliably measured/resolved. Furthermore, the reason for selecting
a 7 day or greater persistence of the > 10% anomalies is that, for changes to be
ecologically meaningful, such changes need to persist for at least one upwelling cycle
(that here is considered to be of an approximate 7 day duration). Non-exceedence of
these metric thresholds is considered to represent a “no change” scenario for the
ecological status of the Saldanha Bay-Langebaan Lagoon ecosystem.
In terms of habitat, the comparative magnitude of habitat change (either volume or
spatial extent) is considered. In this it has been assumed that the project description
provided is correct in stating that no other beneficial uses or alternatives exist other than
to use the dredge material for reclaim in Big Bay.
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The anticipated changes in the Saldanha Bay-Langebaan ecosystem associated with the
various options are described below. This is followed by an assessment of each of the
metrics.
Option 1:
The dredge channel will result in a deepened channel (832 000 m2 in extent) extending
as far as the MPT berth in Small Bay and a reclaim area (392 000 m2 in extent) in Big
Bay.
Compared to the existing layout, there will be increased penetration of cold bottom water
(< 10ºC water containing high silicates and nitrates) into the eastern side of Small Bay.
Phytoplankton Productivity
Associated with this is the possibility of an increase in phytoplankton production over a
small area of the new dredge channel, however these changes are unlikely to be
significant. An opposing effect is also possible in the sense that a larger volume of cold
water could result in a stronger thermocline, reduced nutrient fluxes into the surface
layers and consequently decreased phytoplankton production. It will be similarly spatially
very limited and not significant in that it will not affect significantly existing ecosystem
services (e.g. mariculture activities) and the overall productivity of the bay.
.
Dissolved Oxygen
Such increased production may result in a possible increase in deposition of detrital
material in the immediate vicinity of the dredge channel in Small Bay. However,
depending on the exact nature of the circulation, this material may “drain out” of Small
Bay as flocs. There may be a possible increase in the deposition of detrital material in
the western side of Small Bay. In the absence of detailed modelling as has been
undertaken for Option 2, the extent to which the deposition of detrial material will indeed
occur in Small Bay and the likely consequences thereof are not clear. However, any
increase in deposition of detrital material and/or sediments in the newly dredged area is
expected to be limited due to the fact that much of the proposed dredge channel area
(-21m CD) already exists as a shipping channel deepened to approximately -15m CD.
Should the increase in phytoplankton production be limited or not occur, there is likely to
be no impact on the anoxic sediments in Small Bay, however due to seabed morphology
there may be increased deposition in the dredge channel that with a limited localised
effect on dissolved oxygen concentrations near the seabed.
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Benthic habitats
While the increase in the spatial extent of the existing dredge area is fairly limited, the
total area of the dredge area in Option 1 (832 000 m2) is nevertheless greater than for
Option 2 (650 000 m2).
The loss of benthic habitat due to the establishment of the reclaim area in Big Bay is
approximately 392 000 m2. This is less than that occurring for Option 2 (560 000 m2).
This loss of benthic habitat is relatively modest in terms of the spatial extent of available
benthic habitat in Big Bay (> 30 000 000 m2 ), The consequences in terms of water
column “habitat” in Big Bay is insignificant.
Conclusion
The overall consequences of the changes associated with Option 1 are likely to be
insignificant in terms of the overall ecosystem functioning of the ecosystem of Big Bay
and the coupling of the Big Bay – Langebaan lagoon ecosystems.
Option 2:
The dredge channel will result in a deepened channel (650 000 m2 in extent) extending
into the shallower waters alongside the causeway in Big Bay and a reclaim area (560
000 m2 in extent) in Big Bay.
Compared to the existing layout, there will be increased penetration of cold bottom water
(< 10ºC water containing high silicates and nitrates) into the proposed dredge area
alongside the causeway in Big Bay.
Phytoplankton Productivity
Associated with this is the possibility of an increase in phytoplankton production over
mostly the area of the new dredge channel. The likelihood of such an increase in
phytoplankton production is greater than for option 1 because of a larger mixing energy
in Big Bay, however existing detailed modelling results indicate that these changes
remain insignificant.
Dissolved Oxygen
The modelling results indicate that the increased production that does occur, results in
deposition of detrital material in the area alongside the causeway and the area between
the northern extremity of the proposed shipping channel and the reclaim area. There are
also indications of deposition of detrital material resulting in a lowering of dissolved
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oxygen in the offshore area between the causeway and Lynch Point, however this is
evident for a total duration of approximately 24 hours in summer and autumn. The model
results indicate that the deposition of detrital carbon in the proposed dredge area and
any associated effects on dissolved oxygen are limited.
Benthic habitats
Modification of benthic habitats will occur throughout he proposed new shipping channel,
however the spatial extent of benthic modification remains limited. It should be noted
that in overall terms, the spatial extent of the proposed dredge area for Option 2 (650
000 m2) is less than that for Option 1 (832 000 m2).
Conversely, the habitat destruction due to the establishment of the reclamation area is
greater for Option 2 (560 000 m2) than for Option 1 (392 000 m2), i.e. an approximate
40% increase. This loss of habitat is relatively modest in terms of the aerial extent of
available benthic habitat in Big Bay (> 30 000 000 m2), The consequences in terms of
water column “habitat” in Big Bay is insignificant.
Conclusion
The overall consequences of the changes associated with Option 2 are likely to be
insignificant in terms of the overall ecosystem functioning of the ecosystem of Big Bay
and the coupling of the Big Bay – Langebaan lagoon ecosystems.
Option 3
The dredge channel will result in a deepened channel (980 000 m2 in extent) extending
into the shallower waters alongside the causeway in Big Bay and a reclaim area (890
000 m2 in extent) in Big Bay. Compared to the existing layout, there will be increased
penetration of cold bottom water (< 10ºC water containing high silicates and nitrates) into
the proposed dredge area, extending into the shallower waters of Small Bay.
While much of the proposed shipping channel has been dredged to -15 m CD, the
dredging of the shipping channel to an increased depth of -21 m CD will result in cold
nutrient –rich water extending into Small Bay in areas where exposure to these waters is
normally more limited. Furthermore the deepened shipping channel will result in
increased exposure of Small Bay to smaller upwelling events as the cold waters
associated with the weaker upwelling events will more easily enter Small Bay in the
deeper shipping channel.
Phytoplankton Productivity
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Despite the increased occurrence of cold nutrient-rich waters in the bottom waters of
Small Bay, the mixing of these nutrient-rich waters into the surface waters may be quite
limited due to the low wave energy in the affected areas in Small Bay and possibly the
limited exposure to winds that mix these nutrient-rich bottom waters into the surface
waters. The impact of shipping stirring these deeper nutrient-rich waters into the surface
layers is unknown. It is likely that there will be increased phytoplankton growth, however
the extent of the increase is uncertain. Despite the higher frequency of upwelling events
penetrating further into Small Bay, the change in phytoplankton production (although
likely to be greater that Options 1 and possibly Option 2) is likely to be insignificant.
Such increased production may result in a possible increase in deposition of detrital
material in the immediate vicinity of this more extensive and deepened dredge channel in
Small Bay. However, depending on the exact nature of the circulation, this material may
“drain out” of Small Bay as flocs. There may be a possible increase in the deposition of
detrital material in the western side of Small Bay. In the absence of detailed modelling
as has been undertaken for Option 2, it is not clear the extent to which the deposition of
detrial material will indeed occur in Small Bay and the likely consequences thereof.
Dissolved Oxygen
There will be increased deposition of detrital carbon in the deeper, more extensive
shipping channel that could lead to local oxygen depletion. Should the increase in
phytoplankton production be limited, there is likely to be no impact on the anoxic
sediments in Small Bay. There is however likely to be increased deposition of detrital
material in the dredge channel that may have a limited localised effect on dissolved
oxygen concentrations near the seabed.
Benthic habitats
The proposed shipping channel for option 3 (980 000 m2 in extent) is significantly greater
than for Options 1 (650 000 m2) or 2 (832 000 m2), however a large proportion of the
proposed shipping channel under Option 3 is already a shipping channel, albeit only at –
15 m CD rather than 21 m CD. Therefore the increase in modified benthic habitats in
Small Bay under development Option 3 is likely to be insignificant However, the overall
extent of the modified habitat (980 000 m2) under development Option 3 approaches an
area approximately 10% of the total benthic habitat in Small Bay (~ 14 000 000 m2) and
therefore comprise a significant portion of the available benthic habitat in Small Bay.
The loss of benthic habitat due to the establishment of the reclaim area in Big Bay is
approximately 890 000 m2. This is significantly greater than that proposed for Option 1
(392 000 980 000 m2) or for Option 2 (560 000 m2). While this loss of habitat remains
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relatively modest in terms of the aerial extent of available benthic habitat in Big Bay
(> 30 000 000 m2), the consequences in terms of available benthic habitat remains
uncertain. The consequences in terms of water column “habitat” in Big Bay is likely to
remain insignificant.
Conclusion
The overall consequences of the changes are likely to be insignificant in terms of the
overall ecosystem functioning of the ecosystem of Big Bay and the coupling of the Big
Bay – Langebaan lagoon ecosystems. However, the expansion of modified benthic
habitat in Small Bay is appreciable and the loss of such habitat under the reclaim in Big
Bay is large relative to Options #1 and #2. The consequences of these changes are
uncertain.
Option 4
The dredge channel will result in a deepened channel (1 180 000 m2 in extent) extending
deep into Small Bay. The deep channel will cut into the shallow oligotrophic (nutrient
poor) waters of Small Bay, resulting in the injection of nutrient rich water into the shallow
northern euphotic zone of Small Bay directly. Furthermore the extended shipping
channel will result in increased exposure of Small Bay, particularly the shallow waters
along the northern shore, to smaller upwelling events as the cold waters associated with
the weaker upwelling events will more easily enter Small Bay in the deeper shipping
channel extending all of the way into the shallow waters.
Phytoplankton Productivity
The result of this is likely to be a significant increase in the phytoplankton productivity
and biomass in the northern region of the bay which is usually clear and nutrient poor.
The aesthetics of these waters will change with a likely reduction in the water clarity
(required by macrophytes). There is a strong possibility that this will result in a > 10%
change in water clarity compared to present conditions. Consequently these changes
are likely to be of moderate/medium significance.
Dissolved Oxygen
Such increased production will result in an increase in deposition of detrital material in
the immediate vicinity of this more extensive and deepened dredge channel in Small Bay
that could lead to local oxygen depletion. Furthermore an increase in the deposition of
detrital material in the western side of Small Bay in likely resulting in a small but
measurable impact on the dissolved oxygen conditions in this region. In the absence of
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detailed modelling as has been undertaken for Option 2, it is not clear the extent to which
the deposition of detrital material will indeed occur in Small Bay and the likely
consequences thereof.
Benthic habitats
Modification of benthic habitats will occur throughout the proposed new shipping channel
(1 180 000 m2 in extent) extending to the area north of the MPT. The proposed shipping
channel for option 4 (1 180 000 m2 in extent) is significantly greater than all of the other
options. The extent of the modified habitat (1 180 000 m2) approaches an area
approximately 10% of the total benthic habitat in Small Bay (~ 14 000 000 m2) and
therefore starts to become significant.
The loss of benthic habitat due to the establishment of the reclaim area in Big Bay is
approximately 1 540 000 m2. This is approximately 3 to 4 times more extensive than that
proposed for Options 1 and 2 and double that of Option 3. There is also a loss of
intertidal and shallow subtidal area (important for fish spawning and recruitment) that will
not occur for the other options. The loss of habitat due to the proposed reclaim area
(whilst still < 10% of the available benthic habitat in Big Bay) is likely to constitute a
moderate to severe loss of habitat in Big Bay. The consequences in terms of the loss of
water column “habitat” in Big Bay is likely to remain small.
The likely changes in circulation and associated consequences for the ecosystems in Big
Bay and the coupling of the Big Bay – Langebaan lagoon ecosystems are not known.
However, given the significant greater loss of water area in Big Bay it can be safely
assumed that the potential impacts will be greatest for the option.
Conclusion
Habitat loss and/or modification is appreciable in Small Bay and may be so in Big Bay.
The latter specifically in the inter- and shallow subtidal area which is known to be
important as a fish nursery area. This option (4) is the least suitable of all alternatives put
forward because of this and uncertainties of affects on other functions in the Saldanha
Bay-Langebaan Lagoon ecosystem.
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Summary
Option 1 Option2 Option 3 Option 4
Phytoplankton Productivity
Significance Insignificant Insignificant Very low Medium Risk of impact on Small Bay Confidence Medium Medium/High Low/Medium Low/Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Big Bay Confidence Medium Medium/High Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence Medium Medium/High Medium Medium
Dissolved Oxygen
Significance Very low Insignificant Very low Low Risk of impact on Small Bay Confidence Medium Medium/High Low/Medium Low/Medium
Significance Insignificant Very low Insignificant Insignificant Risk of impact on Big Bay Confidence Medium Medium/High Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence Medium Medium/High Medium Medium
Habitat Modification (Shipping Channel/Dredge Area)
Significance Very low Insignificant Very low Low/Medium Risk of impact on Small Bay Confidence Medium Medium/High Low/Medium Low/Medium
Significance Insignificant Very low Insignificant Insignificant Risk of impact on Big Bay Confidence Medium Medium/High Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence High High High High
Habitat Destruction (Reclaim Area)
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Small Bay Confidence High High High High
Significance Insignificant Insignificant Very low/Low Low/Medium Risk of impact on Big Bay Confidence Medium Medium/High Medium Low/Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence Medium Medium/High Medium Medium
Significant changes in phytoplankton are only expected for Option 4. Changes in phytoplankton productivity are not considered to be a differentiating factor between Options 1, 2 and 3. Loss of benthic habitat should be greatest for options 3 and 4 with the latter extending into the inter- and shallow subtidal areas of the northern shores of Big Bay.
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1.3 SHORELINE STABILITY
The issues around shoreline stability are discussed in a companion study by WSP
Coastal Africa (Pty) Ltd (WSP, 2008).
1.4 CONSTRUCTION (SHORT-TERM)
1.4.1 Dredging
Dredging activities will increase water column turbidity and have the potential to change
particle size distribution in the sediments. Increased turbidity in the water column, in
turn, may impact phytoplankton production and larval and juvenile fish survival. There
may be feeding efficiency effects on filter feeders such as mussels and very high
suspended sediment concentrations can affect mussel recruitment.
There are two sources of turbidity:
• Sediment suspension at the dredge head;
• Suspended sediments in the return flows from the proposed reclaim areas.
The quantity of suspended sediments entering the marine environment (and the resultant
column turbidity observed) is proportional to the quantity of material that is dredged.
Consequently the sediment suspension at the dredge head is variable (in both
magnitude and location) between the proposed options, while return from the reclaim
areas will vary over small spatial scales in Big Bay. Turbidity due to suspension at the
dredge head is expected to be significantly less than that due to return flows from the
reclaims area(s).
1.4.1.1 Dredge Head suspension
Water Column Turbidity
Option 1 will result in the generation of plumes (dredge head suspension) at the outer
extremity of Small Bay that may have direct effects (feeding efficiency, mussel
recruitment) on the adjacent mariculture areas. Most likely to be affected is the
mariculture area adjacent to the Marcus Island breakwater. The effects are likely to
remain low for a properly controlled dredge operation.
Option 2 will result in the generation of plumes in Big Bay and is likely to have a limited
effect on existing mariculture areas in Small Bay and/or in Big Bay.
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In the early stages of dredging the impacts for Option 3 will be the same as for Option 1.
During the latter stages, it may also affect the mariculture activities in the centre of Small
Bay.
Option 4 will have the same effects as for Option 3 but with increased duration. There
may be some effects on the Gracileria in Small Bay
The scale of potential impacts is likely to be roughly proportional to the quantity of
material to be dredged.
Effects on Benthic Habitats
The likely impacts here are:
• inundation, the effects of which are not likely to be significant for any of the
options due to the burrowing abilities of benthic organisms, and;
• the longer term effects of modified particle size distributions in the host sediments
affecting the benthos community structure.
The effects of modified particle size-distribution have been shown to persist for up to 4
years for dredging activities in Small Bay. Due to the more dispersive environment in Big
Bay, it is likely that the effects will be less persistent in Big Bay. In terms of these effects
options 1 and 2 are unlikely to be significantly different, however potential impacts due to
modified particle size-distribution are likely to increase for options 3 and 4, with option 4
being the greatest.
The ecological implications of these changes on overall system productivity are uncertain
but an effect on biodiversity will occur.
Re-mobilisation of contaminants during dredging at the dredge head
The anthropogenic contaminants are known to exist in Small Bay, particularly adjacent to
the MPT. Recent surveys have shown there to be petroleum hydrocarbon
contamination in the existing dredge channel to the south of the MPT. In Big Bay there is
no evidence of any such contamination.
It is possible that trace metals (e.g. lead, zinc and copper) may be remobilised during
dredging but elutriation tests carried out in sediments from the Port of Cape Town
indicate that, in the presence of absorption species such as iron and manganese, the
amount of toxicants entering the water column are limited. Being a similar West Coast
environment, it is highly likely that a similar conclusion could be reached for sediments in
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Saldanha Bay. Elutriation tests of the release of contaminants associated with the TPH
in the sediments in the vicinity of Caisson 3 and 4 of the causeway in Saldanha Bay,
indicate that the toxicants entering the water column are also likely to be limited.
In terms trace metal contaminants the risks are highest for options 3 and 4. For TPH the
risks are equally high for options 1, 3 and 4. Option 2 does not present any risk in this
regard.
Phytoplankton Productivity
Elevated turbidity will affect the light distribution within the water column. For an effect
on phytoplankton production to be expressed, the turbidity needs to penetrate into the
upper layers of the water column. For an effect on benthic algal production
(macrophytes in Small Bay and/or benthic diatoms, seagrasses, etc in Langebaan
Lagoon), any elevation in water column turbidity may generate an effect.
The risks posed on production are likely to be roughly proportional to the duration of the
dredging activities as the main process affecting the distribution of turbidity is mixing by
high energy wave events. Accordingly the potential impacts are greatest for options 4,
followed by option 3. Option 2 may have slightly higher risks associated with elevated
water column turbidity than option 1 due to Big Bay being a more exposed location.
1.4.1.2 Suspended sediments in return flows from the Reclaim Areas
Whilst the concentration or load of sediments in the return flows from the proposed
reclaim areas can be controlled, the higher the degree of control required, the higher the
costs of the operation and possibly the greater the duration of reclaim activities.
Turbidity from the reclaim return flows.
Return flows will occur into Big Bay. Given that these discharges will occur in more or
less the same location, the magnitude of any effects are likely to be dependant on only
the quantity of material dredged and the duration of dredging.
Based on this the impacts are likely to be greatest for Option 4, followed by Option 3,
Option 1 and Option 2. Whether these differences are significant will depend on the
extent to which the reclaim area is managed to minimise sediment concentrations in the
outflow. Should the control of sediment concentrations in the return flows from the
reclamation be effective, there is a strong likelihood that the potential effects on water
column turbidity will be mitigated to such an extent that it will not be possible to
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differentiate between the various options in terms of the generation of water column
turbidity and associated impacts.
Effects on Benthic Habitats
The effects on benthic habitats is likely to be proportional to the quantities being dredged
and dredge durations. Based on this the impacts are likely to be greatest for Option 4,
followed by Option 3, Option 1 and Option 2.
Phytoplankton Productivity
The effects on phytoplankton productivity in Big Bay is likely to be proportional to the
quantities being dredged and dredge durations. Based on this the impacts are likely to
be greatest for Option 4, followed by Option 3, Option 1 and Option 2.
1.4.1.3 Summary
The potential Impacts from re-suspension of material at the dredge head are
summarised in the table below.
Option 1 Option2 Option 3 Option 4
Water Column Turbidity
Significance Very low Insignificant Very low Low Risk of impact on Small Bay Confidence Medium Medium Low/Medium Low/Medium
Significance Insignificant Very low Insignificant Insignificant Risk of impact on Big Bay Confidence Medium Medium Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence Medium Low/Medium Medium Medium
Effects on Benthic Habitat
Significance Very low Very Low Low Low/Medium Risk of impact on Small Bay Confidence Medium Medium/High Low/Medium Low/Medium
Significance Insignificant Very low Insignificant Insignificant Risk of impact on Big Bay Confidence Medium Medium/High Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence Medium Low/Medium Medium Medium
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Re-mobilisation of contaminants in the sediments (trace metals)
Significance Very low Insignificant Low Low Risk of impact on Small Bay Confidence Medium High Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Big Bay Confidence Medium High Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence High High High High
Re-mobilisation of contaminants in the sediments (TPH)
Significance Low Very low Low Low Risk of impact on Small Bay Confidence Low Low Low Low
Significance Very low Very low Very low Very low Risk of impact on Big Bay Confidence Medium Medium Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence Medium Medium Medium Medium
Effects on Phytoplankton Productivity
Significance Very Low Insignificant Insignificant Insignificant Risk of impact on Small Bay
(water column) Confidence Medium Medium Medium Medium
Very low Insignificant Very low Very low Risk of impact on Small Bay (Gracileria) Confidence Medium Medium Medium Medium
Significance Insignificant Very low Insignificant Insignificant Risk of impact on Big Bay Confidence Medium Medium Medium Low/Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence Medium Medium Medium Medium
The impacts due to return flows from the reclaim area are expected to be significantly larger than those associated with the suspension of sediments at the dredge head. Option 1 Option2 Option 3 Option 4
Water Column Turbidity
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Small Bay Confidence Medium Medium Medium Medium
Significance Low Low Low/Medium Low/Medium Risk of impact on Big Bay Confidence Medium Medium Low/Medium Low/Medium
Significance Insignificant Insignificant Very low Low Risk of impact on Langebaan Lagoon Confidence Medium Low/Medium Low Low
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Effects on Benthic Habitat
Significance Very low Very Low Low Low/Medium Risk of impact on Small Bay Confidence Medium Medium/High Low/Medium Low/Medium
Significance Low Low Low/Medium Low/Medium Risk of impact on Big Bay Confidence Medium Medium/High Medium Medium
Significance Insignificant Insignificant Insignificant Insignificant Risk of impact on Langebaan Lagoon Confidence High High High High
Effects on Phytoplankton Productivity
Significance Insignificant Insignificant Very low Very low Risk of impact on Small Bay Confidence Medium Medium Medium Medium
Significance Very low Very Low Low Low/Medium Risk of impact on Big Bay Confidence Low/Medium Low/Medium Low/Medium Low/Medium
Significance Insignificant Insignificant Very Low Low Risk of impact on Langebaan Lagoon Confidence Medium Medium Medium Low/Medium
It has been assumed above that the concentration of sediments in the return flows from
the reclaim areas will be strongly controlled so as to minimise any impacts in Big Bay
and to avoid impacts on Langebaan Lagoon. However for long dredge duration it may
be difficult to limit the long-term sediment loads entering Big Bay thus the impacts for
Options 3 and 4 being indicated as being very low and low, respectively (i.e. not
insignificant). It is assumed that the dredging activities will be managed to avoid impacts
on Langebaan Lagoon, however the longer-term sediment loading into Big Bay for
Options 3 and 4 will require a much greater diligence and/or reduction of sediments in
the return flows from the reclaim.
1.4.2 Blasting
The quantity of rock and required blasting is indicated to be roughly proportional to the
dredge area. This then suggests that the risk of upset conditions during blasting would
appear to be greatest for option 4, followed by Location 3, location 1 and location 2.
A properly controlled blasting program in whichever of the berth locations should pose
minimal risk to the environment. This would imply that the options could not be
differentiated from one another in terms of the risks associated with blasting. It is
however likely that there will be some residual risk associated with blasting. Thus Option
1 or 2 are preferred to either Option 3 or 4.
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1.5 OPERATIONAL
1.5.1 Routine
Ballast Water
The risks of the release of alien species and/or pathogenic organisms is roughly
proportional to the frequencies of ballast water releases and the volumes released; given
that trading patterns do not change.
The scales and characteristics of Saldanha Bay does not enable us to differentiate
the various proposed locations in terms of risk of establishment of alien species.
Discharges from site
The potential risks in terms of discharge from the site include:
• storm water run-off from the site
• possible spillages of iron-ore during ship loading;
• wind-blown dust.
The only likely differentiating factor between the various locations would be the receiving
environment in terms of the dispersion of pollutants. It is not possible to differentiate
between the various proposed location in terms of the above.
1.5.2 Oil Spills
The probability of oil spills occurring has been discussed in a companion environmental
screening report focussing on shipping risks (CSIR, 2008 – Hans Moes report).
The likely spill scenarios include:
• Collision of an iron-ore carrier with a moored tanker: A collision between a
tanker and an ore carrier could occur if the bulk carrier, in ballast or partially
laden, would be on its way to or from a berth of locations 1, 3 or 4 or to
anchorage in Small Bay. During this process, the bulk carrier could become out
of control and collide with a moored tanker. This is most likely to occur during a
north-westerly or westerly storm when the bulk carrier could drift against the
tanker (or against an ore carrier moored at the Saldanha side of the ore berth at
the jetty or against the concrete caisson structure or against the fenders). This oil
spill scenario is only relevant for Options 1, 3 and 4 where iron-ore bulk carriers
may pass moored tankers.
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• Grounding of an iron-ore carrier or collision with a concrete structure (jetty
or quay): The probability and consequences of grounding or collisions prior to
the iron-ore bulk carrier reaching the outer turning circle are similar for all options.
However should the grounding or collision occur in close proximity to the berthing
facilities, the likely fate of any oil spill may be significantly different for the various
Options.
Transport and fate of an oil spill
The transport and fate of any oil spill is largely determined by winds and currents, while
adverse wave conditions may significantly hamper any mitigation measures of
subsequent oil spill clean-up. The direct influence of winds on the transport and fate of
oil is likely to be greatest for heavy crude oils, while lighter fuel oil are more likely to enter
the water column and be influenced to a greater extent by currents, particularly tidal
flows.
There is a strong seasonality in the winds over Saldanha Bay, reflecting the changes in
the synoptic weather patterns prevailing at different times during the year. Southerly
winds pre-dominate in this region for most of the year, modulated by short periods of
calm conditions or north-westerly winds which are associated with the propagation of
coastal lows southwards along the west coast of southern Africa. Only in the mid-winter
months do north to north-westerly winds predominate.
Wind data from Port Control in Saldanha Bay (Figure 2) indicate that in summer the
winds are predominantly southerly with significant south-westerly and to a lesser extent
south-easterly wind components. In autumn the winds are predominantly southerly with
the development of a north-westerly wind component as the season progresses. The
regular passage of cold fronts in winter results in predominantly north-westerly winds
with the occurrence of significant south-westerly and south-easterly wind components.
The spring wind regime is similar to the summer wind regime but with increased south-
easterly wind components.
The winds along the West Coast also have a significant diurnal component (Jury and
Guastella, 1987) that is clearly observable in the wind records for Saldanha Bay. The
wind speed typically reaches a maximum in the late afternoon when the sea breeze cycle
is at its maximum.
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Figure 2: Wind roses of the winds measured at Port Control in Saldanha Bay (see inset).
Port Control
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The currents in the bay are predominantly forced by the wind and the tide, the relative
importance of the two processes changing with depth and location in the bay. In general,
wind is the dominant physical forcing mechanism determining the surface layer current
speed and direction in both Small and Big Bay (van Ballegooyen et al., 2002). Tidal
forcing (Figure 3a and b) is stronger at depth, in the vicinity of the mouth of Saldanha
Bay (Shannon and Stander, 1977) and with increasing proximity to Langebaan Lagoon
(Weeks et al., 1991a). In the surf-zone, wave-driven currents are expected to dominate.
Although residual flows associated with the tides occur in the bay, the greatest exchange
between Saldanha Bay and the shelf is a consequence of synoptic weather events
occurring on time scales of 3 to 10 days. South-south-easterly wind events are reported
to result in a general surface outflow and a subsurface inflow of cold bottom water
(Spolander, 1996; Monteiro and Largier, 1999), while indications are that north-westerly
wind events lead to the inflow of surface waters in the northern region of the mouth of
Saldanha Bay (Figure 4a and b). Thus the surface, mid-water and bottom currents often
are observed to be flowing in different, and at times, opposite directions. While this is
expected in a highly stratified water column, observations of three-dimensional flow
structure are not restricted to strongly stratified conditions. Weeks et al. (1991b)
recorded an event in late winter (August 1990) where the flow was strongly
three-dimensional under well-mixed conditions.
During periods of slack winds, tidal currents dominate and are the sole mechanism for
flushing the bay. The tidal currents are generally weak, however strong tidal flows are
observed at the entrance to the lagoon, particularly during spring tides. During tidal
exchange, it is estimated that approximately half of the lagoon water passes through the
Lagoon entrance channels into Saldanha Bay (Shannon and Stander, 1977) and
velocities of up to 1.0 m.s-1 are observed in the two channels connecting Big Bay and
Langebaan Lagoon (Krug, 1999).
A number of oil spill scenarios have been investigated in an earlier study, which was
related to tanker activities in Saldanha Bay (CSIR, 1996, 1997a, 1997b).
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Figure 3a: Flood tide surface and bottom currents in Saldanha Bay during spring tide and under relatively calm conditions.
Figure 3b: Ebb tide surface and bottom currents in Saldanha Bay during spring tide and under relatively calm conditions.
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Figure 4a: Schematic of the wind driven and tidal currents in Saldanha Bay under S wind conditions.
Figure 4b: Schematic of the wind driven and tidal currents in Saldanha Bay under NW wind conditions.
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The transport and fate of spilled oil from the likely spill scenarios are as follows:
• Collision of an iron-ore carrier with a moored tanker could result in a oil spill
that potentially could be large. Such a spill is only likely to occur for Options 1, 3
and 4. A collision between a moored tanker and an ore carrier is not possible for
Option 2 as berths located in Big Bay will not require that the iron-ore bulk
carriers pass moored tankers. Small spills are likely to be confined to Small Bay,
particularly as mitigation measures can relatively easily be deployed in Small Bay
which is a relatively sheltered environment, However, large spills could easily
enter Big Bay due to the fact that such an oil spill is likely to occur at the end of
the causeway where ebb flow tidal currents and/or north-westerly wind conditions
(under which such a spill is the most likely to occur) could easily allow an oil spill
to enter Big Bay and possibly ultimately Langebaan Lagoon.
• Grounding of an iron-ore carrier or collision with a concrete structure (jetty
or quay) resulting in an oil spill (typically < 2000 tonnes) at the various proposed
berth locations is likely to have the following consequences. For Option 2 the
spill will occur in a relatively exposed conditions of Big Bay where the currents
and tides are such that there is a significant likelihood of an oil spill having some
impact on Langebaan Lagoon should adequate mitigation measures (e.g.
booming) not be possible or prove to be ineffective (e.g. due to environmental
conditions). The consequences of an oil spill at the berth locations for Option 1 is
likely to be less than for Option 2, but perhaps not as different as would be
expected, due to the fact that the outer extremity of Small Bay is strongly linked to
Big Bay by tidal and wind-driven flows (particularly the clockwise circulation that is
considered to prevail in Small Bay under both southerly and north-westerly wind
conditions). The jetty at the end of the causeway does not constitute an effective
barrier for flows between Small Bay and Big Bay. The likelihood of containing oil
spilt at berth locations for Options 3 and 4 are significantly higher, particularly for
Option 4. Consequently the potential impacts associated with oil spills at these
two locations is significantly less than for Options 1 and 2.
In terms of the likely efficacy of mitigation measures such as booming, these are likely to
be the most effective for Options 3 and 4, flowed by Option 1 and 2. The efficacy of
mitigation measures is likely to be the least for Option 2 due to the more exposed nature
of Big Bay due to prevailing wind and wave conditions.
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Sensitivity of the Receiving Environment
The sensitivity of the likely impact areas (Small Bay, Big Bay and Langebaan Lagoon)
due to both the ecological sensitivities of the various regions of the Saldanha Bay-
Langebaan Lagoon system and the various socio-economic activities occurring within the
system.
The town of Saldanha is located along the north and west shores of Small Bay. A naval
base and a fishing harbour are located in the west side of Small Bay. A small craft
harbour for port craft is located behind the sand breakwater, providing berthing for tugs
and pilot boats. The shores of Small Bay are very popular for recreation and tourism
(e.g. the beach at Bluewater Bay). Other activities in Small Bay that could be impacted
by an oil spill are the fish factories (that require clean seawater for food processing),
Gracileria harvesting in the northern sector of Small Bay and existing mariculture
activities in Small Bay. Small Bay could thus be considered to be highly sensitive to
the impacts of an oil spill, despite the fact that it comprises a relatively enclosed
embayment within which is would be relatively straightforward to undertake clean-up
operations if required. However, being a relatively quiescent region, natural recovery
from an oil spill will be slow.
Presently, the socio-economic activities in northern Big Bay are more limited than in
Small Bay, however the shores in the southern part of Big Bay (e.g. towards
Langebaan) are very popular for recreation and tourism. The marina and holiday resort
Club Mykonos, is located in the middle of Big Bay, due east of Marcus Island. The
northern peninsular section of the Langebaan Peninsula, opposite the town of
Langebaan, is a military area, which is not accessible for the public. While mitigation
measures are likely to be less effective in Big Bay compared to Small Bay, being an
more exposed location, natural recovery from oil spills is likely to be more rapid in Big
Bay than in Small Bay or Langebaan Lagoon. Big Bay itself can be considered to be
moderately to fairly highly sensitive to oil spills.
Langebaan Lagoon, being a RAMSAR site and an Marine Protected Area is considered
to be extremely sensitive to the effects of oil spills.
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Collision of an iron-ore carrier with a moored oil tanker
Option 1 Option2 Option 3 Option 4
Fate of an oil spill
Significance High n/a Medium Medium Risk of impact on Small Bay Confidence Medium High Medium Medium
Significance Medium n/a Low Low Risk of impact on Big Bay Confidence Medium High Medium Medium
Significance Low/Medium n/a Low Low Risk of impact on Langebaan Lagoon Confidence Medium High Medium Medium
The fate of an oil spill originating from a collision between an iron-ore carrier and an oil tanker is considered to be not applicable due to the fact that iron-ore carriers will not be passing moored tankers under development Option 2. Grounding of an iron-ore carrier or collision with a concrete structure Option 1 Option2 Option 3 Option 4
Fate of an oil spill
Significance High Medium Medium Low/Medium Risk of impact on Small Bay Confidence Medium Medium Medium Medium
Significance Medium Medium/High Low/Medium Low/Medium Risk of impact on Big Bay Confidence Medium Medium Medium Medium
Significance Low/Medium Medium Low Low Risk of impact on Langebaan Lagoon Confidence Medium Medium Medium Medium
The significance of the risk of impacts in the above tables are ranked as follows:
• High – will impact immediate area under most conditions;
• Medium – large volumes of oil will get there under some conditions;
• Low – little oil will get there under some conditions;
• Insignificant – no or very little oil will get there under any conditions
The probability of oil reaching a particular location in the bay increases with the size of
the oil spill and decreases with the efficacy of the mitigation measures implemented (i.e.
whether they are timeous, whether environmental conditions limit the containment of oil,
etc.). In the above assessment, a significant oil spill has been assumed.
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1.6 CONCLUSION
The conclusions to this screening study are as follows.
1.6.1 Long-term Ecological Consequences
Current understanding of the ecosystem functioning of the Saldanha Bay – Langebaan
Lagoon system is that Langebaan Lagoon is dependant on the physics and productivity
processes in Big Bay, particularly the flux of organic material into the latter system from
Big Bay. Being less directly linked, the ecosystem functioning of Small Bay is likely to
be of lesser importance to Langebaan Lagoon than that of Big Bay. Nevertheless there
are significant ecosystem services provided by Small Bay (e.g. mariculture, assimilation
of discharges, etc).
The quantitative aspects of the link between Big Bay and Langebaan Lagoon are not
fully understood. This requires that the precautionary principle be invoked when
assessing risks to Langebaan Lagoon. We have interpreted this as a requirement that
there be no change to the indices selected (i.e. phytoplankton production, dissolved
oxygen) at locations adjacent to and in the lagoon mouth. This implies that the
ecosystem thresholds in turn would not be threatened.
The indices used in this screening study have indicated that the morphological changes
(and linked changes in ecosystem function) associated with either of the Locations 1 and
2 development options do not pose any identified long-term risk to the Saldanha Bay –
Langebaan Lagoon system. Thus either of these development options (Options 1
and 2) could be acceptable, although each suggests a possible foreclosure of the
range of potential future development scenarios in both Small Bay (Option 1) and
Big Bay (Option 2) that need to be considered. These are addressed in more detail
in ERM (2008).
The overall consequences in terms of ecosystem function are likely to be significantly
greater for Options 3 and 4. The overall consequences of the changes for Option 3 are
likely to be insignificant in terms of the overall ecosystem functioning of the ecosystem of
Big Bay and the coupling of the Big Bay – Langebaan lagoon ecosystems. However, the
expansion of modified benthic habitat in Small Bay is appreciable and the loss of such
habitat under the reclaim in Big Bay is large relative to Option 1 and Option 2. The
consequences of these changes are uncertain. With regards to Option 4, when
compared to Option 1 and Option 2, habitat loss and/or modification is appreciable in
Small Bay and Big Bay. The latter specifically in the inter- and shallow subtidal area
which is known to be important as a fish nursery area. Option 4 is the least suitable of all
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alternatives put forward because of this and uncertainties of affects on other functions in
the Saldanha Bay-Langebaan Lagoon ecosystem.
We are uncertain where the ecosystem thresholds1 lie for the linkages between Big Bay
and Langebaan Lagoon. It is probable that extended development within in Big Bay, be
this port development or other operations such as mariculture, etc, may ultimately
threaten ecosystem thresholds2. The risk (in terms of linkages between Big Bay and
Langebaan Lagoon) of similar extended development in Small Bay is likely to be lower3.
Thus, within the context of present available knowledge of the functioning of the
Saldanha Bay – Langebaan lagoon ecosystem and associated ecosystem thresholds,
the selection of option 2 on this occasion should not be considered to set a precedent for
further development in Big Bay by either the port or other industry. Assessment of the
acceptability of any further or extended development in Big Bay will need to be based on
an improved understanding of potential ecosystem thresholds to ensure that the risks
posed by such further development in Big Bay on the Saldanha Bay – Langebaan
Lagoon ecosystems remain acceptable.
1.6.2 Shoreline Stability
The conclusion around shoreline stability are discussed in a companion study by WSP
Coastal Africa (Pty) Ltd (WSP, 2008).
1.6.3 Construction
Dredging and reclaim Activities
The observations made in Section 1.7.1 above are equally of relevance here.
Blasting
If a properly controlled blasting programme is undertaken, the risks will be so low that it
is not possible to differentiate between the various options in terms of the risks
associated with blasting activities.
(1) For example, fluxes of organic material into Langebaan Lagoon from Big Bay could drop below some threshold that could result in
significant impairment of components of the Langebaan Lagoon ecosystem.
(2) Under potential future development scenarios, it is likely that progressively larger modifications will be made to Big Bay (reclaim areas, shipping channels), This may ultimately result in a greater than 10% change to the status quo that, under the precautionary approach, is presently considered to represent a significant threshold of change in the Saldanha Bay-Langebaan Lagoon ecosystem.
(3) While the focus here is on the risks posed to linkages between Big Bay and the Langebaan Lagoon, an important Marine Protected Area and RAMSAR site), it should be noted that extended development in Small Bay may limit options in terms of both existing and future activities in Small Bay.
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Operational
1.6.4.1 Routine
Ballast Water
The scales and characteristics of Saldanha Bay does not enable us to differentiate the
various proposed locations in terms of risk of establishment of alien species.
Discharges from Site
The only likely differentiating factor between the various locations would be the receiving
environment in terms of dispersion of pollutants. It is not possible to differentiate
between the various proposed location in terms of the above.
1.6.4.2 Oil Spills
Collision of an iron-ore carrier with a moored tanker
Such a spill is only likely to occur for Options 1, 3 and 4. . A collision between a moored
tanker and an ore carrier is not possible for Option 2 as berths located in Big Bay will not
require that the iron-ore bulk carriers pass moored tankers. Small spills are likely to be
confined to Small Bay, particularly as mitigation measures can relatively easily be
deployed in Small Bay which is a relatively sheltered environment. However, under
development Option 1, large spills could enter Big Bay. Such an oil spill is likely to occur
at the end of the causeway where ebb flow tidal currents and/or north-westerly wind
conditions) could easily allow an oil spill to enter Big Bay and possibly ultimately
Langebaan Lagoon.
Oil spill due to the grounding of an iron-ore carrier or collision with a concrete
structure (jetty or quay).
The consequences of such an oil spill will be greatest for Option 2 as the oil will be
released into Big Bay where it will be more difficult to contain the oil spill and there is a
greater likelihood of the oil reaching Langebaan Lagoon. The consequences of an oil
spill at the berth locations for Option 1 is likely to be less than for Option 2, but perhaps
not as different as would be expected, due to the fact that the outer extremity of Small
Bay is strongly linked to Big Bay by tidal and wind-driven flows (particularly the clockwise
circulation that is considered to prevail in Small Bay under both southerly and north-
westerly wind conditions). The likelihood of containing oil spilt at berth locations for
Options 3 and 4 are significantly higher, particularly for Option 4. Consequently the
potential impacts associated with oil spills at these two locations is significantly less than
for Options 1 and 2.
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2. REFERENCES
CSIR,1996. Environmental Impact Assessment : Proposed changes to oil transfer
operations : SFF, Saldanha Bay. Specialist studies report, Vol 2(ii). CSIR Report
ENV-S-C 96005D, Stellenbosch, December
CSIR,1997a. Environmental Impact Assessment : Proposed changes to oil transfer
operations : SFF, Saldanha Bay. Environmental impact report. CSIR Report
ENV-S-C 96005B, Stellenbosch, April
CSIR,1997b. Environmental Impact Assessment : Proposed changes to oil transfer
operations : SFF, Saldanha Bay. Summary report. CSIR Report ENV-S-C
97082, Stellenbosch, July
CSIR (2008) Saldanha Iron Ore Export Terminal Evaluation Of Additional Berth Options
Considering Incremental Shipping Risks, CSIR Bulit Environment Memo, 22pp.
ERM (2008) Port of Saldanha expansion of iron-ore handling facilities: Phase 2
Environmental Screening Study, Environmental Resource Management (ERM)
Southern Africa.
Jury, M.R. and L. Guastella ( 1987) Coastal wind and dispersion conditions at Koeberg:
analysis of data with application to mesoscale forecasting, S. Afr. J. Sci., 83,
435-440.
Krug, M. (1999) Circulation through the mouth of the Langebaan Lagoon and
implications, MSc. Thesis, University of Cape Town, 133pp.
Moes, H. (2008) Saldanha Iron Ore Export Terminal Evaluation Of Additional Berth
Options Considering Incremental Shipping Risks, CSIR Report BE (Draft),
Monteiro, P.M.S. and J.L. Largier (1999). Thermal stratification in Saldanha Bay (South
Africa) and subtidal, density-driven exchange with the coastal waters of the
Benguela Upwelling System. Estuarine, Coastal and Shelf Science, 49, 877-890.
Shannon, L.V. and G.M. Stander (1977). Physical and chemical characteristics of water
in Saldanha Bay and Langebaan Lagoon. Transaction of the royal Society of
South Africa 42(3 & 4):411-461.
Spolander, B. (1996) Entrainment in Saldanha Bay. MSc thesis, Oceanography
Department, University of Cape Town, 67pp.
van Ballegooyen, R.C., S.A. Luger and P.M.S. Monteiro (2002) Integrated port design
using a suite of coupled numerical models. Proceedings of the International
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��� �� �
Conference on Coastal Zone Management and Development, 18-20 March 2002,
State of Kuwait, pp II-27-II-41.
Weeks, S.J., A.J. Boyd, P.M.S. Monteiro and G.B. Brundrit (1991a) The currents and
circulation in Saldanha Bay after 1975 deduced from historical measurements of
drogues S. Afr. J. mar. Sci., 11, 525-535.
Weeks, S.J., A.J. Boyd, G. Nelson and R.M. Cooper (1991b) A note on the wind-driven
replacement flow of the bottom layer in Saldanha Bay, South Africa: Implications
for pollution. S. Afr. J. mar. Sci. 11, 579-583.
WSP (2008) Shoreline Stability Study for the Iron Ore Berth Screening Study, Port of
Saldanha, WSP Report 207504E, August 2008, Stellenbosch
SALDANHA SCREENING STUDY: SHORELINE STABILITY 3 September 2008
QM
Issue/revision Issue 1 Revision 1 Revision 2 Revision 3
Remarks
Date 3 September 2008
Prepared by Geoff Smith
Signature
Checked by Koos Schoonees
Signature
Authorised by Koos Schoonees
Signature
Project number 207504E
File reference Saldanha Shoreline Workshop
WSP Africa Coastal Engineers (Pty) Ltd 2nd Floor Old College Building 35 Church Street/PO Box 413 Stellenbosch South Africa 7600 Tel: +27(0) 21 883 9260 Fax: +27(0) 21 883 3212 http://www.wspgroup.co.za Reg. No: 2007/001832/07
Contents
1 Introduction .................................................................................................... 1
2 Comparison of Options................................................................................... 3
2.1 Option 1 .................................................................................................... 3
2.2 Option 2 .................................................................................................... 3
2.3 Option 3 .................................................................................................... 4
2.4 Option 4 .................................................................................................... 4
3 Conclusion....................................................................................................... 6
4 References ....................................................................................................... 7
207504E Saldanha Screening Study 1
1 Introduction Mechanism of shoreline change: As waves approach the shore they travel with a velocity that is dependent on their period and on the water depth. The relationship of velocity to depth results in a “bending” (i.e. refraction) of wave fronts, which tend towards a shore-parallel direction as they travel shorewards. The case of wave refraction for depth contours that are straight and parallel to the shoreline is shown in the schematic example of Figure 1. The effects of sub-sea depressions or mounds are conceptually illustrated in Figure 2. As can be seen, changes in wave direction occur. In addition, convergence of wave orthogonals (lines perpendicular to wave fronts, indicating the direction of wave travel) results in a local increase in wave height, while divergence implies a decrease in local wave height. Thus, variations in the nearshore bed bathymetry affect both wave direction and height at the shoreline. If the water depth changes locally, e.g. over a dredged pit or depression in the sea-bed, the velocity and wavelength of waves will change. The behaviour resulting from a depression as shown in Figure 2 (b) provides a simplified idea of how wave angles (and height) could change in response to a dredged channel. In Saldanha Bay the effect of the dredged channel is further complicated by the effects of the bay configuration, and the configuration of harbour structures and possible reclamation areas. Induced changes in the angle and height of waves moving towards the beach may cause changes in the direction and height of breaking waves at the beach. Changes in the direction and height of breaking waves will, in turn, affect the speed of longshore currents and the extent of stirring and transport of sediment alongshore. Consequent changes in longshore transport can result in beach erosion and/or accretion. Influence of the status quo of the shoreline: The present (and future) status of the shoreline where a possible shoreline change could be induced is relevant. For example, increasing erosion (through dredging effects) of an already eroding shoreline would probably not be acceptable. On the other hand, decreasing accretion of an accreting shoreline may not be a problem. The detailed Shoreline Stability Specialist Study for the Environmental Impact Assessment (EIA) of the Phase 2 Expansion of the Saldanha Iron Ore Export Terminal (CSIR, 2008) and a related study of various engineering channel/reclamation combinations (CSIR, 2007) determined that the footprint of shoreline effects from dredging and reclamation activities on the south-east margin of the Ore Jetty would be restricted to the embayment extending from Lynch Point to the Reclamation Dam (Figure 3). It was also determined from surveys and aerial image analyses (CSIR, 2008) that, related to a substantial rate of northerly sand transport, the shoreline just north of Lynch Point is eroding (at a rate of about 1 m/year) and accreting adjacent to the Reclamation Dam (at a similar rate). Based on experience from modelling studies by the CSIR (2007, 2008), it is expected that a similar magnitude of channel dredging (to that investigated in Big Bay) within Small Bay would result in the footprint of shoreline effect being restricted to within Small Bay. The wave climate within Small Bay is subdued, longshore sediment transport rates are correspondingly small and consequent shoreline change is also very minor. Unlike the dynamically changing shoreline between Lynch Point and the Reclamation Dam, the shoreline within Small Bay is close to equilibrium. A very small rate of nett longshore sand transport (of 1800 m3/year) towards the Ore Jetty has been determined. The sand which is transported southward originates from the shoreline slightly further north, but the rate of transport is so small that consequent erosion from that shoreline is negligible. As the changes to the shoreline in Small Bay have been found to be negligible (CSIR, 2003) this
207504E Saldanha Screening Study 2
shoreline can be considered to be dynamically stable (in other words; although small, routine changes do occur with varying seasonal wave conditions the average shoreline position does not change significantly). Approach to this study: Reference is made to previous experience, particularly the recent engineering shoreline studies (CSIR, 2007, 2008), as well as published work (Luger et al, 2004). The CSIR (2007) engineering study is particularly useful since it involved a relative assessment of 10 different combinations of dredged channels and reclamation areas. These results provide the ideal background for the present assessment of shoreline effects. In this section of the study the risk of effect of both channel/berth dredging and of the reclamation are assessed. It is highlighted that this assessment focuses on the risk of effects on shoreline stability and beach amenity resulting only from the proposed dredging and reclamation associated with the Options 1 to 4. This section of the study does not evaluate the risk of effect of habitat lost as a result of reclamations extending south-eastward into Big Bay.
207504E Saldanha Screening Study 3
2 Comparison of Options
2.1 OPTION 1
Channel Dredging (Risk of shoreline erosion): The channel dredging footprint and depth is similar to some of the designs simulated in CSIR (2007), but is obviously situated on the Small Bay side of the jetty. Based on the results of CSIR (2007) it is expected that subtle changes in wave height (order of a few percent) and wave directions (possibly up to about 1 degree at the shoreline) would result from the proposed dredging. Furthermore based on the results of CSIR (2007), and taking into account the relatively diminished wave action in Small Bay, it is estimated that effects on the shoreline of channel dredging would be virtually undetectable after 50 years. The induced change will be such that the small southward longshore transport would be reduced or possibly slightly reversed. Based on the shoreline modelling as a result of dredging of the channel in Big Bay (CSIR, 2007), it is estimated that shoreline changes (both accretion and erosion) in Small Bay will be less than 5 m (the maximum determined in the more dynamic Big Bay), and will most likely be in the region of 2-3 m at most. Furthermore, it is certain that this equilibrium would be attained well after 100 years. Reclamation (Risk of loss of beach amenity): The reclamation footprint in Big Bay from Option 1 is relatively small. Wave and shoreline modelling in CSIR (2007) demonstrated that even a larger reclamation area (and extending further west) would have a negligible effect on the neighbouring shoreline. A negligible loss of beach amenity would result from implementation of Option 1. 2.2 OPTION 2
Channel Dredging (Risk of shoreline erosion): This dredging option is equivalent to the Final Large Revetment Design as assessed in CSIR (2008) with detailed, validated wave and shoreline models. This modelling demonstrated that changes to nearshore wave angles and heights are restricted to the northern half of the bay between Lynch Point and the Reclamation Dam. As a result of small changes to wave conditions, predicted accretion of 40 m on the beach just south of the reclamation dam was reduced to 36 m (after a 40 year period) and predicted localised erosion of 15 m (about a kilometre further south) was reduced to 10 m. Wave and shoreline changes were predicted to reach equilibrium with the proposed channel and revetment developments after 60 years, at which time shoreline changes were predicted to be no more than one metre different from conditions after 40 years. In summary, the effects of the channel dredging are very small and are actually positive, since predicted erosion is reduced. Reclamation (Risk of loss of beach amenity): The reclamation area is slightly bigger than the Final Large Revetment Design as assessed in CSIR (2008), as it extends some 60 m further south-east of the existing reclamation dam. However, considering that the case of “no revetment” compared to the case “with revetment” in CSIR (2007) showed no differences at all in the predicted shorelines, it is expected that the Option
207504E Saldanha Screening Study 4
2 revetment (which is very similar to the “with revetment” case) would have a negligible effect on the neighbouring shoreline. While the amenity of about 60 m length of beach would be lost, this effect can be considered to be very small or negligible, considering that the beach between the Reclamation Dam and Lynch Point is about 4.5 km long. As mentioned, this evaluation excludes the modification of habitat induced by the reclamation footprint on the shoreline – this has been dealt with elsewhere in the marine studies. 2.3 OPTION 3
Channel Dredging (Risk of shoreline erosion): The dredged channel for Option 3 is considerably longer than that for Option 1. The longer channel (compared to Option 1) would tend to have a greater effect on wave conditions (model tests demonstrated this in CSIR, 2007). In addition, the wide dredging area opposite the present multi-purpose quay would serve to change wave conditions. However, the decrease in channel width at the seaward end would mitigate the above two effects, and it is likely that the nett effect would be quite similar to that for the Option 1 dredging. Thus, as for the Option 1 case (and again referring to the experience of CSIR, 2007 modelling), it is expected that subtle changes in wave height (in the order of a few percent) and wave directions (possibly up to about 1 degree at the shoreline) would result from the proposed dredging. As a result, it is estimated that effects on the shoreline of channel dredging would be virtually undetectable after 50 years. The induced change will be such that the small southward longshore transport would be reduced or possibly slightly reversed. Based on the shoreline modelling, as a result of dredging of the channel in Big Bay, it is estimated that shoreline changes (both accretion and erosion) in Small Bay will be less than 5 m (the maximum determined in the more dynamic Big Bay), and will most likely be in the region of 2-3 m at most. Furthermore, it is certain that this equilibrium would be attained well after 100 years. Reclamation (Risk of loss of beach amenity): The reclamation area for Option 3 is considerably larger than that for Options 1 and 2 and extends some 200 m south-eastward of the existing reclamation dam. The effect of the south-eastward extension is that it occupies part of the accreting beach, where several tens of thousands of sand would have accumulated over the next few decades (based on transport predictions from CSIR, 2008). As this sand cannot accumulate on the reclamation footprint it becomes available to the neighbouring beach where it will marginally increase accretion and possibly also mitigate areas of erosion further south. The effect of the reclamation on shoreline stability can therefore be considered to be slightly positive to negligible. However, a loss of 200 m length of beach amenity will occur. As this represents roughly 4% of the beach between the Reclamation Dam and Lynch Point, such a loss may be considered marginal or slight. 2.4 OPTION 4
Channel Dredging (Risk of shoreline erosion): The dredged channel footprint for Option 4 is much longer than that for Options 1 and 3. As discussed above, this would tend to increase changes to wave conditions. In addition, the 21 m
207504E Saldanha Screening Study 5
deep channel extends (towards the coast) into shallow water (of some 7 m relative to Chart Datum) where effects on waves will be strongly felt. However, the channel is generally narrower than those for both Options 1 and 3. The relative influence of the Option 4 channel on waves is not easily quantified, but it is certain that the nett effect of the channel of Option 4 will not be significantly different to that for Options 1 and 3. Thus, as for the Option 1 and 3 cases, subtle changes in wave height (in the order of a few percent) and wave directions (up to about 1 degree at the shoreline) would result. As for Options 1 and 3 (and based on previous modelling in CSIR, 2007), it is estimated that effects on the shoreline of channel dredging would be virtually undetectable after 50 years. The induced change will be such that the small southward longshore transport would be reduced or possibly slightly reversed. Based on the shoreline modelling as a result of dredging of the channel in Big Bay, it is estimated that shoreline changes (both accretion and erosion) in Small Bay will be less than 5 m (the maximum determined in the more dynamic Big Bay), and will most likely be in the region of 2-3 m at most. Furthermore, it is certain that this equilibrium would be attained well after 100 years. Reclamation (Risk of loss of beach amenity): The reclamation area for Option 4 is the largest of all options by far, and extends about 1100 m south-eastward of the existing reclamation dam. The effect of the south-eastward extension is that it would occupy a significant part of the accreting beach, where over a hundred thousands cubic metres of sand would have accumulated over the next few decades (based on transport predictions from CSIR, 2008). As this sand cannot accumulate on the reclamation footprint it becomes available to the neighbouring beach where it will cause some accretion and possibly also mitigate areas of erosion (just north of Lynch Point). The effect of the reclamation on shoreline stability can therefore be considered to be slightly positive to negligible. However, a loss of 1100 m length of beach amenity will result. As this loss represents about ¼ of the beach between the Reclamation Dam and Lynch Point, the loss can be considered significant.
207504E Saldanha Screening Study 6
3 Conclusion With a view to comparing options against one another, a qualitative rating of the options is conducted in the table below. Option 2 is rated as the most favourable (i.e. 1st), because the shoreline effects (even though very small) are actually positive, and effects on beach amenity are negligible. The relative differences between shoreline stability effects for Options 1, 3 and 4 are estimated to be very small and cannot be estimated without more detailed studies. However, the negative effect of reclamation on beach amenity is negligible for Option 1, slight for Option 3 and significant for Option 4. This leads to the rating (2nd to 4th) as indicated below. Note that while the difference in rating between Options 1 and 3 is marginal, the effect of Option 4 on beach amenity convincingly puts this option in 4th place.
* It is assumed that any shoreline erosion (even if balanced by accretion) is negative. Note that , as the predicted shoreline changes for all options are estimated to be small, and in fact so small that they would probably not be detectable (against the background of natural beach processes) within several decades, it is deemed that the shoreline stability criterion has limited significance as a differentiator between the four options. However, criterion of beach amenity has significance as a differentiator between Option 4 (where the negative effect is considered significant) and the other three options.
Risk of effect of
dredged channel on
shoreline stability
Risk of effect of
reclamation on shoreline
stability
Risk of effect of
reclamation on beach
amenity
Rating of
the four
options
Option
Negative/
positive
Rating Negative/
positive
Rating Negative/
Positive
Rating
1 Negative Slight - Negligible - Negligible 2nd
2 Positive* Slight - Negligible - Negligible 1st
3 Negative Slight Positive Very slight Negative Slight 3rd
4 Negative Slight Positive Slight Negative Significant 4th
207504E Saldanha Screening Study 7
4 References CSIR (2003) Shoreline Stability and Sedimentation in Saldanha Bay. CSIR Report ENV-S-0C 2003-081. CSIR (2007) Assessment of the Effects of Channel and Reclamation Design on Shoreline Stability. CSIR Report CSIR/NRE/ECO/ER/2006/0188/C. CSIR (2008) Phase 2 Expansion of the Saldanha Iron Ore Export Handling Facility CSIR Report No. CSIR/NRE/WR/ER/2007/0132/C Luger, S., Smith, G G, and Schoonees, J.S. (2004). Minimizing the impacts of reclamation dredging at Cape Town. Proc of the 29th International Conf. On Coastal Engineering. World Scientific. pp 3354-3364. USACE (1977) Shore Protection Manual. US Army, Corps of Engineers, Coastal Engineering Research Center, Fort Belvoir Virginia.
207504E Saldanha Screening Study 8
Figure 1: Schematic diagram showing wave refraction over straight, parallel depth contours
1 m
2 m
3 m
4 mWAVE CREST
Faster
Slower
SHORELINE
207504E Saldanha Screening Study 9
Figure 2: Schematic diagram showing wave refraction (indicated by wave orthogonals) over a submerged (a) ridge and (b) depression/valley (indicated by bathymetry contours) After Shore Protection Manual, USACE
207504E Saldanha Screening Study 10
Ore Jetty
Lynch Point
Small Bay
Big Bay
Reclamation Dam
Figure 3: Location diagram
PORT OF SALDANHA BERTH POSITIONS
NOISE SCREENING
Prepared by:
Demos. A. Dracoulides
PO Box 60034
7439 Table View Tel: (021) 551 1836 Fax: (021) 557 1078
Submitted to:
ERM
2 September 2008
Report No: SP-SCR-0708
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 2 SEPTEMBER 2008 II
Table of Contents page
1� INTRODUCTION 3�
2� CONSTRUCTION 4�
2.1� BERTHING OPTION 1 4�2.2� BERTHING OPTION 2 4�2.3� BERTHING OPTION 3 5�2.4� BERTHING OPTION 4 5�2.5� NOISE SCREENING CONCLUSIONS DURING CONSTRUCTION 5�
3� OPERATION 7�
3.1� BERTHING OPTION 1 7�3.2� BERTHING OPTION 2 8�3.3� BERTHING OPTION 3 8�3.4� BERTHING OPTION 4 9�3.5� NOISE SCREENING CONCLUSIONS DURING OPERATION 9�
4� NOISE SCREENING RANKING 10�
List of Figures page Figure 1-1. Saldanha Port Berth Location Alternatives 3�
List of Tables page Table 4-1. Noise Screening Ranking 10�
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 3 2 SEPTEMBER 2008
1 INTRODUCTION
In order to ensure that the construction of a new iron ore berth at Port of Saldanha does not impact negatively on the future development potential of the port, four layout options (herein referred to as Locations 1 to 4) have been proposed. These locations are shown in Figure 1-1. The present study provides a screening evaluation of the four alternatives, with regard to their noise impact on the surrounding environment during the construction and operational phases. The four alternative berth locations involve different dredging quantities, different locations of the construction equipment, different positions of several operational equipment, as well as transportation of various quantities for the construction of the rock fill revetment for the reclamation area. A comparative discussion of the resulting noise level differences for the four alternatives, in view of the above-mentioned variations is presented in the following sections for the construction and operation of the berths.
Figure 1-1. Saldanha Port Berth Location Alternatives
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 4 2 SEPTEMBER 2008
2 CONSTRUCTION
During construction, the parameters that affect the generated noise and subsequent impact on the surrounding communities are:
• The proximity to community receptors. • The type and number of the berth construction equipment. • The duration of the berth construction. • The quantity of the dredged material and dredging duration. • The number of trucks required for the transportation of the rock material required
for the reclamation area revetment. 2.1 BERTHING OPTION 1
The location of berthing Option 1 is on the Small Bay side, between the existing iron ore berth and the Multiple Purpose Terminal (MPT) (see Figure 1-1). The dredge requirement at this location is approximately 4.1 million m3, and the total duration for the dredging is 24 weeks. The length of revetment required for the reclamation area is approximately 1,300 m, and its construction will take 52 weeks and 40,000 truck trips. The distance of the required dredging area from Blue Water Bay (BWB), the closest community to the port, is 2,400 m. The berth construction area is 2,700 m away from the BWB. The equipment to be used is the same for all the alternatives, and the construction activities are expected to take approximately 50 weeks. 2.2 BERTHING OPTION 2
The location of berthing Option 2 is on the Big Bay side between the existing iron ore berth and the iron ore stockpiles (see Figure 1-1). The dredge requirement at this location is approximately 6.25 million m3 , the total duration for the dredging is 40 weeks. The volume of rock required for the revetment of the reclamation area is 329,000 m3 and its construction will take 60 weeks and 46,000 truck trips. The distance of the required dredging area from the Blue Water Bay (BWB) is 3,600 m. The berth construction area is 3,000 m away from the BWB. The equipment to be used are the same for all the alternatives and the construction activities are expected to take approximately 60 weeks.
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 5 2 SEPTEMBER 2008
2.3 BERTHING OPTION 3
The location of berthing Option 3 is on the Small Bay side at the existing MPT position, which will need to be relocated. (see Figure 1-1). The dredge requirement at this location is approximately 7.7 million m3, with the total duration for the dredging being 46 weeks. The volume of rock required for the revetment area is 483,000 m3, and its construction will take 87 weeks and 67,000 truck trips. The distance of the required dredging area from Blue Water Bay (BWB) is 1,900 m. The berth construction area is 2,200 m away from the BWB. The equipment to be used is the same for all the alternatives, and the construction activities are expected to take the longest of all the options, since the relocation of the existing MPT will take place first. 2.4 BERTHING OPTION 4
The location of berthing Option 4 is on the Small Bay side between the MPT and the iron ore stockpiles (see Figure 1-1). The dredge requirement at this location is approximately 15.24 million m3, and the total duration for the dredging is 75 weeks. The volume of rock required for the revetment of the reclamation area is 513,000 m3, and its construction will take 93 weeks and 71,000 truck trips. The distance of the required dredging area from Blue Water Bay (BWB) is 1,500 m. The berth construction area is 2,100 m away from the BWB. The equipment to be used is the same for all the alternatives, and the construction activities are expected to take approximately 60 weeks. 2.5 NOISE SCREENING CONCLUSIONS DURING CONSTRUCTION
Based on the fact that the construction equipment and the dredging equipment are going to be similar in type and quantity, the most significant parameters affecting the noise impacts on the BWB area would be the proximity and duration of the construction and dredging operations. Option 4 is situated closest to the Blue Water Bay community and will also involve the longest duration for the dredging and berth construction activities. In addition, this option will require the largest number of trucks for the construction of the reclamation area revetment. Option 3 is second closest to the BWB and has the second largest construction duration requiring the second largest number of trucks for the revetment.
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 6 2 SEPTEMBER 2008
Options 1 and 2 are similar, but Option 2 is preferable from the noise impact point of view, since it is situated further away from the BWB, and the construction operations will be more sheltered by the existing port infrastructure, which lies between the BWB and the Option 2 location. It should be noted that the construction activities are not expected to have a significant contribution on the existing noise levels in the BWB, since beyond a 2 km distance the construction noise contribution is expected to be below 40 dBA. The only exception to this is possibly berth location Option 4, which is the closest to BWB. The noise impacts of all construction and dredging activities are also considered to be short-term, and in conjunction with the generated noise levels in the surrounding communities would probably carry a low impact significance.
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 7 2 SEPTEMBER 2008
3 OPERATION
During the operational phase of the project there are several differences in the equipment layout for each alternative that could potentially differentiate the noise impacts in the closest residential area of Blue Water Bay. Due to the large distance between the port and the other residential areas of Saldanha, Langebaan and Vredenburg, it is expected that the location variations of the port’s berth will make no difference to the resulting or the existing noise levels in these areas. The parameters that affect the generated noise and subsequent impact on the surrounding communities during operation are:
• The proximity to community receptors. • Type and number of noisy equipment relevant to the berth position, such as
conveyor belts, transfer points and ship loaders. • Horizontal and vertical positions of noisy equipment.
It should be noted that the majority of the equipment associated with noise generation during operation will remain the same for all alternative berth positions, such as the tipplers, the shunting lines after the tipplers, the stacker-reclaimers, the majority of the transfer points and conveyor belts. The infrastructure affected by the berth positions are the end portions of the conveyor belts towards the berths, the positions of 10 transfer points and the position of the ship loaders. 3.1 BERTHING OPTION 1
The location of berthing Option 1 is on the Small Bay side between the existing iron ore berth and the Multiple Purpose Terminal (MPT) (see Figure 1-1). The type and equipment to be used is the same for all the alternatives. The final lengths of the end of the conveyor belt system will change, the position of the last 10 transfer points towards the ship loader will also change, as well as the location of the 2 ship loaders. Therefore, the closer to the noise-sensitive receptors they move, the greater the effect on the resulting noise levels in these areas. The berth is situated approximately 2,700 m away from the BWB. The lengths of the affected conveyor belts will be: • Conveyor Cv-414 =1620 meters • Conveyor Cv-514 =1620 meters • Conveyor Cv-128 Elevated =96 meters • Conveyor Cv-129 Elevated =96 meters • Conveyor Cv-130=873 meters • Conveyor Cv-530 =873 meters • Total length = 5,178 meters
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 8 2 SEPTEMBER 2008
In addition, for this option the conveyor belts towards the ship loaders will have to be raised by approximately 10 m in order to pass over the existing service road. 3.2 BERTHING OPTION 2
The location of berthing Option 2 is on the Big Bay side between the existing iron ore berth and the iron ore stockpiles (see Figure 1-1). The berth is situated approximately 3,000 m away from the BWB. The type and number of equipment to be used is the same as in all options. The lengths of the affected conveyor belts will be: • Conveyor Cv-414 =2,470 meters • Conveyor Cv-514 =2,470 meters • Conveyor Cv-114 Extension = 396 meters • Conveyor Cv-214 Extension = 396 meters • Conveyor Cv-128 Flat = 115 meters • Conveyor Cv129 Flat =115 meters • Conveyor Cv-130 =823 meters • Conveyor Cv-530 =823 meters • Total length = 7,608 meters This is the only berth location that does not require raising of the conveyor belts and transfer points. 3.3 BERTHING OPTION 3
The location of berthing Option 3 is on the Small Bay side at the existing MPT position, which will need to be relocated. (see Figure 1-1). This berth position is approximately 2,200 m away from the BWB. The type and number of equipment to be used is the same as in all options. The lengths of the affected conveyor belts will be: • Conveyor Cv-414 =1,657 meters • Conveyor Cv-514=1,660 meters • Conveyor Cv-130 = 957 meters • Conveyor Cv-230 =967 meters • Conveyor Cv-128 Elevated =125 meters • Conveyor Cv- 129 Elevated =125 meters • Total length = 5,491 meters
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 9 2 SEPTEMBER 2008
For this option, the conveyor belts towards the ship loaders will have to be raised by approximately 10 m in order to pass over the existing service road. 3.4 BERTHING OPTION 4
The location of berthing Option 4 is on the Small Bay side between the MPT and the iron ore stockpiles (see Figure 1-1). The berth location for this option is 2,100 m away from the BWB. The type and number of equipment to be used are the same as in all options. The lengths of the affected conveyor belts will be: • Conveyor Cv-414 =740 meters • Conveyor Cv-514 =740 meters • Conveyor Cv-128 Elevated = 250 meters • Conveyor Cv-129 Elevated =250 meters • Conveyor Cv-130 =930 meters • Conveyor Cv-230 =930 meters • Total length = 3,840 meters The conveyor belts towards the ship loaders will also have to be raised for this option in order to pass over the existing service road. 3.5 NOISE SCREENING CONCLUSIONS DURING OPERATION
Based on the fact that the equipment to be utilised for all alternative positions is the same, the most significant parameters affecting the noise impacts on the BWB area would be the proximity and vertical positioning of the equipment. Option 4 is situated closest to the Blue Water Bay community, has the shortest conveyor belt system and will require raising some part of the conveyor belt. Option 3 is second closest to the BWB community, has the second shortest conveyor belt system and will also require raising some part of the conveyor belt. Options 1 and 2 are similar but Option 2 would be preferred from the noise impact point of view, since it is situated further away from the BWB and will not require any raising of the conveyor belts. It should be noted that the above-mentioned noise sources are not expected to add any significant variation to the resulting noise levels at the Blue Water Bay community area, since they are not the most predominant noise sources and their position variation in relation to the distance between the berths and BWB is small.
DDA PORT OF SALDANHA BERTH POSITIONS NOISE SCREENING
REP. NO: SP-SCR-0708 10 2 SEPTEMBER 2008
4 NOISE SCREENING RANKING
Based on the various considerations for noise generation and propagation during construction and operation, the following table summarises the preferred ranking of the various options. A ranking system of 1 – 5 (1 being least negative and 5 being most negative) was utilised in order to rank each option. From the noise screening analysis, it is evident that the preferred alternative berth location would be Option 2. It should be noted, however, that even though the noise impact rating can differentiate between the alternatives, the actual resulting overall (i.e. taking into consideration all noise sources) noise difference in the BWB area would be below 2 dBA. This means that from the noise point of view, the alternative berth locations will not cause any differences in the significance rating of the overall impact.
Table 4-1. Noise Screening Ranking
Option 1 Option 2 Option 3 Option 4 Construction 2 1 4 5
Operation 2 1 3 5
Prepared by: Mader van den Berg
For: ERM
Date
2008-09-02
Visual Impact - Comparative analysis of berth locations
CONSTRUCTION PHASE
Introduction Construction activities are generally regarded as a visual impact due to the temporary intrusion on observers’ views. The often disorganised, unsightly and blighted nature of a construction site detracts from the aesthetic quality of a visual resource. As a result of the berth construction, a number of subsequent visual impacts may occur. These impacts relate to the actual construction of the rock revetment and new reclamation area, the berths and associated ship loaders, as well as the dredging activity. An inherent mitigating factor is the relatively temporary nature of the construction phase and the presumably ephemeral visual impacts associated with it. One can partly assess the magnitude of the visual impact by describing the duration of the construction phase and the intensity of the subsequent visual impacts. A visual impact requires observers to witness it, therefore their exposure to the impact and their distance from the impact will also be taken into account. POTENTIAL IMPACTS DISCUSSION 1. Construction activity The type of construction activity will be similar for each option. The same type of equipment will be used and a similar construction
programme will be implemented to construct the berths, regardless of its location. The differentiating factor will undoubtedly be the duration of construction and the location of the construction activity, relative to the different observers in the Zone of Visual Influence (ZVI).
OPTION 1 A total construction period of 52 weeks is expected which includes 24 weeks of dredging. A dredger vessel will work along the approach channel south of the existing Multi-Purpose Terminal (MPT) in the Small Bay area. The construction of the superstructures and ship loaders will also be limited to the southern side of the MPT while the rock revetment and new reclamation area is constructed south of the existing stockyards, in Big Bay. The new reclamation area will be 392 000m². The closest observers to the construction of the superstructures will be residents from Bluewater Bay which will be 3km from the activity. Saldanha residents will be 4km away. At this distance even the largest construction equipment will seem minute. To explain this, a
simple comparison can be drawn; Say a hydraulic excavator will be at work at the new berth location. When its arm is fully extended up in the air, the height of the excavator is approximately 10m. From Bluewater Bay the excavator will have the same vertical dimension as a matchstick held 12.5m from one’s eye. Considering the panoramic view that is experienced by an observer, an excavator or even a number of excavators and trucks will hardly be noticeable and a minimum intrusion on the observers’ views will be experienced. Construction of the rock revetment and reclamation area will be completely out of sight from Bluewater Bay and the low lying areas of Saldanha, as it will be behind the existing quay. The elevated terrain west of Saldanha provides a raised vantage point for some residents, which allow them to see over the quay. This will expose them to the construction activity of the new reclamation area. Again, the distance is so great, that with the naked eye, the construction activity will be barely noticeable. A similar argument accounts for observers from Club Mykonos which will be 5km from the construction of the new reclamation area. The activity is expected to have a minimum intrusion on the observers’ views.
OPTION 2 A total construction period of 60 weeks is expected which includes 40 weeks of dredging. The dredger vessel will work along the approach channel to location 2 while the superstructures and ship loaders are constructed on the eastern side of the existing quay. The new reclamation area will be 560 000m², 30% larger than the area for option 1. Observers from Bluewater Bay and Saldanha will have very limited views to the construction activity due to the presence of the quay in between. Intrusion on their views is regarded as insignificant. The elevated vantage point of some Saldanha residents will marginally increase their exposure to the construction activity behind the quay, but the distance factor will mitigate the intrusion considerably. Observers from Club Mykonos will experience the greatest exposure to the activity. They will be 5km from the activity. Again, the distance is so great that construction activities will be hardly noticeable. No significant intrusion on their views is expected.
OPTION 3 A total construction period of 87 weeks is expected which includes 46 weeks of dredging. The dredger vessel will work along the approach channel to the MPT while the existing MPT is modified to support the superstructures and ship loaders. The new reclamation area will be 890 000m², 37% larger than option 2. Observers from Bluewater Bay will be the closest at 2.7km and Saldanha residents will be approximately 4km away. Even at 2.7km, the construction equipment will be barely noticeable. Construction of the new reclamation area will be completely out of sight from Bluewater Bay and the low lying areas of Saldanha, as it will be behind the existing quay. The elevated terrain west of Saldanha provides a raised vantage point for some residents, which allow them to see over the quay. This will expose them to the construction activity of the new reclamation area. The reclamation area will be much larger due to the greater volumes of dredging material that must be deposited, but the distance factor remains an effective mitigation element and construction activity is expected to be barely noticeable. Observers from Club Mykonos will experience the greatest exposure to the activity. They will be 5km from the activity. Even with the construction of the 890 000m² reclamation area, the distance is so great that construction activities will be hardly noticeable. No significant intrusion on their views is expected.
OPTION 4 A total construction period of 93 weeks is expected which includes 75 weeks of dredging. The dredger vessel will work along the approach channel to the north of the MPT. The new reclamation area will be 1 540 000m², 58% larger than option 3.
Observers from Bluewater Bay will be the closest at 2.4km and Saldanha residents will be approximately 4km away. At 2.4km an excavator will have the same vertical dimension as a matchstick held 10m away from one’s eye. This is still fairly minute and a minimum intrusion on the observers’ views is expected. Construction of the new reclamation area will be completely out of sight from Bluewater Bay and the low lying areas of Saldanha, as it will be behind the existing quay. The elevated terrain west of Saldanha provides a raised vantage point for some residents, which allow them to see over the quay. This will expose them to the construction activity of the new reclamation area. The reclamation area will be much larger due to the greater volumes of dredging material that must be deposited, but the distance factor remains an effective mitigation element and construction activity is expected to be barely noticeable. Observers from Club Mykonos will experience the greatest exposure to the activity. They will be 5km from the activity. Even with the construction of the 1 540 000m² reclamation area, the distance is so great that construction activities will be hardly noticeable. No significant intrusion on their views is expected.
2. Turbidity plumes During dredging of the approach channels for the iron ore carriers, it is expected that visible turbidity plumes will be generated in the
water. Turbidity plumes will become visible when the concentration of suspended particles in the water, noticeably discolours the water. The following 6 factors influences the degree of visibility of a plume:
� Colour of suspended sediment; � Concentration of suspended sediment; � Background concentration of suspended sediment in the water, which may vary seasonally; � The condition of the sea; � Angel of the sun; and � Height of the viewer above the sea (Gebhardt, 20071).
A Cutter Suction Dredger (CSD) will presumably be utilised. A CSD consists of a cutter head at the suction inlet which loosens the sea bottom and transports the material to the suction mouth. A centrifugal pump discharges the material through a floating pipeline to the point of deposit, in this case the new reclamation area behind the stone revetment. Turbidity plumes will not only be limited to the dredging area but silt that will overflow from the reclamation area during deposition of the material, will also cause discolouration of the sea. At this stage it is not known what the extent of the plumes will be and how noticeable the colour contrast between the sea and the silt will be. For this assessment the distance factor and duration of dredging will be the differentiating factor between the different options. This will determine the exposure of observers to the visual impact.
OPTION 1 Dredging will continue for a period of 24 weeks and will be limited to the approach channel south of the MPT. Observers from Bluewater
1 Gebhardt, B (2007). Berth Deepening EIA: Visual Impact Assessment Report No: 367079/VIA January 2007: Unpublished report for Transnet. SRK Consulting, Cape Town.
Bay and Saldanha are expected to have a limited view of the turbidity plume due to their low viewing angle and their distance from the dredging. A severe discolouration will however be noticeable if the angle of the sun is favourable. The elevated terrain west of Saldanha provides a raised vantage point for some residents. They will experience a greater exposure to the turbidity plume and will be able to see over the quay and possibly witness turbidity on the southern side of the stone revetment during construction of the reclamation area. Observers from Club Mykonos will experience a very limited exposure to the plume that will originate from the dredging. Most of the dredging will occur in Small Bay which will be screened by the quay from Club Mykonos. The plume from the stone revetment is expected to be visible, but to a limited degree. The low viewing angle and considerable distance will limit the obviousness of the discolouration. Discolouration and a turbidity plume may even be noticeable from the elevated terrain at Langebaan and at Postberg viewpoint inside the West Coast National Park when the weather is favourable. The significant viewing distances should be taken into account as observers will be more than 10km away. The intrusion on these observers’ views will be considered minimal. The temporary discolouration of the water will intrude on the aesthetic quality of the visual resource, therefore impacting on the views of residents in Small Bay and Club Mykonos.
OPTION 2 Dredging will continue for a period of 40 weeks and will be limited to the approach channel east of the quay Observers from Bluewater Bay and Saldanha will be screened from the plume by the quay The elevated terrain west of Saldanha provides a raised vantage point for some residents. They will notice the turbidity plume from the dredging and possibly witness turbidity on the southern side of the stone revetment during construction of the reclamation area. Observers from Club Mykonos will be exposed to the plume that will originate from the dredging and from the stone revetment. The low viewing angle and considerable distance will limit the obviousness of the discolouration. A concern is that turbidity will originate from two nearby sources and that a considerable larger area of turbidity may occur. If so, the temporary discolouration of the water will cause a major intrusion on the aesthetic quality of the visual resource, therefore impacting on the views of observers at Club Mykonos. Discolouration and a turbidity plume may even be noticeable from the elevated terrain at Langebaan and at Postberg viewpoint inside the West Coast National Park when the weather is favourable. The significant viewing distances should be taken into account as observers will be more than 10km away. The intrusion on these observers’ views will be considered minimal.
OPTION 3 Dredging will continue for a period of 46 weeks and will be limited to the approach channel south of the MPT and up to the MPT. Observers from Bluewater Bay and Saldanha are expected to have a limited view of the turbidity plume due to their low viewing angle and their distance from the dredging. A severe discolouration will however be noticeable if the angle of the sun is favourable. The elevated terrain west of Saldanha provides a raised vantage point for some residents. They will experience a greater exposure to the turbidity plume and will be able to see over the quay and possibly witness turbidity on the southern side of the stone revetment during construction of the reclamation area.
Observers from Club Mykonos will experience a very limited exposure to the plume that will originate from the dredging. Most of the dredging will occur in Small Bay which will be screened by the quay from Club Mykonos. The plume from the stone revetment is expected to be visible, but to a limited degree. The low viewing angle and considerable distance will limit the obviousness of the discolouration. The temporary discolouration of the water will intrude on the aesthetic quality of the visual resource, therefore impacting on the views of residents in Small Bay and Club Mykonos. Discolouration and a turbidity plume may even be noticeable from the elevated terrain at Langebaan and at Postberg viewpoint inside the West Coast National Park when the weather is favourable. The significant viewing distances should be taken into account as observers will be more than 10km away. The intrusion on these observers’ views will be considered minimal.
OPTION 4 Dredging will continue for a period of 75 weeks and will be limited to the approach channel past the MPT and to the north of the MPT. Observers from Bluewater Bay and Saldanha are expected to have a limited view of the turbidity plume due to their low viewing angle and their distance from the dredging. A discolouration will however be noticeable if the angle of the sun is favourable. The elevated terrain west of Saldanha provides a raised vantage point for some residents. They will experience a greater exposure to the turbidity plume and will be able to see over the quay and possibly witness turbidity on the southern side of the stone revetment during construction of the reclamation area. Observers from Club Mykonos will experience a very limited exposure to the plume that will originate from the dredging. Most of the dredging will occur in Small Bay which will be screened by the quay from Club Mykonos. The plume from the stone revetment is expected to be visible, but to a limited degree. The low viewing angle and considerable distance will limit the obviousness of the discolouration. The temporary discolouration of the water will intrude on the aesthetic quality of the visual resource, therefore impacting on the views of residents in Small Bay and Club Mykonos. Residents from Bluewater Bay will experience the greatest exposure due to their closer proximity to the dredging activity. Discolouration will have an intrusion on the aesthetic quality of the visual resource and will impact on the views of the observers at Bluewater Bay. Discolouration and a large turbidity plume may even be noticeable from the elevated terrain at Langebaan and at Postberg viewpoint inside the West Coast National Park when the weather is favourable. The significant viewing distances should be taken into account as observers will be more than 10km away. The intrusion on these observers’ views will be considered minimal.
Conclusion The major issue during construction relates to the visibility of the turbidity plume. It has been established that the construction activity and equipment used, will have a very limited impact on any of the observers in the study area. Due to limited information available on the turbidity plume the differentiating factors between the different options are limited to the possible duration of the turbidity plume and the exposure of observers to the visual impact.
Although the presence of turbidity will be temporary, the period of dredging is quite considerable. Based on this, option 1 is the most preferred as dredging is limited to 24 weeks and viewers are exposed to impact for only 24 weeks. Option 2 and 3 has roughly the same time allocated for dredging. Option 2 will have a more intense impact on a smaller group of observers, as option 3 will have a less intense impact on a greater number of observers. Option 2 is marginally more preferred than option 3. Option 4 is the least preferred as it has a considerable longer dredging period and will expose a great number of observers over an extended period to the visual impact.
OPERATIONAL PHASE Introduction The operational phase will be compared to the status quo scenario that exists with only the current two operational berths. The aim is to understand what the apparent visual change will be once the additional berths are constructed and the reclamation area is complete. Consequently, a greater number of iron carrier ships can be handled at the Port of Saldanha which ultimately impacts on the sense of place. Under the impact on the sense of place, the presence of two additional ship loaders, increased traffic in the bay and the potential for dust at the ship loaders will also be discussed. POTENTIAL IMPACTS DISCUSSION 1. Sense of place The current sense of place that exists in Saldanha Bay is one of remoteness and tranquillity. Its character is greatly influenced by the
presence of the Port of Saldanha, but despite the major industrial development, the bay has managed to retain an open and highly appreciated character. The additional berths will allow for an increase in the number of carrier ships in the bay. Currently, the Port of Saldanha handles approximately 500 vessels per annum which include all types of vessels, including iron ore carriers. The Incremental Shipping Risk Assessment (CSIR, 2007) found that with the completion of Phase 1B the number of iron ore carriers will increase to 290 per annum. Phase 2 will see this number reaching 600 iron ore carriers per annum, effectively doubling the traffic. It is anticipated that a maximum of 3 ships will be moored in the bay at any point in time. The ship loaders are slender structures that are approximately 30m high. Visible dust clouds from the ship loaders are sporadically noticeable when excessive wind conditions are present. A reddish cloud escapes as ships are loaded. It quickly dissipates but the consequent discolouration of the landscape is severe. It is not the intension to discuss the degree or extent of discolouration in this report, the focus is mainly on the dust cloud and its visibility from surrounding viewpoints. The additional ship loaders, carrier ships and enlarged reclamation area will have an impact on the sense of place. The differentiating factors are the location of these elements relative to the observers and the size of the reclamation area for each option.
OPTION 1 The closest observers to the ship loaders will be the residents from Bluewater Bay, which will be 3km from the new superstructure. Saldanha residents will be 4km away. At 3km the 30m high ship loaders will be the equivalent visual size of a matchstick held at 4.2m
away. The slender character of the ship loaders makes it less noticeable than for instance a 30m high building that has a greater volumetric mass. The visual change will be marginal and no major impact is expected with the presence of 2 additional ship loaders. The quay has visually divided the northern part of Saldanha Bay in, what is locally referred to as the Big and Small Bay areas. The Small Bay is further defined by the breakwater and a much more intimate space is created. Most of the mari-culture industries are concentrated in Small Bay making it a hub for small fishing vessels. Additional iron ore carrier ships in Small Bay are considered to impact on the intimate, yet “uncrowded” character of Small Bay. Option 1 is located at the “mouth” of Small Bay and is considered to have a minimal impact on the sense of place in Small Bay. The visibility of iron ore dust from the ship loaders is greatly influenced by the background colour and the distance from the ship loaders. Residents from the Small Bay side will be able to notice dust due to the fact that the background colour is usually a light hazy grey. A fairly high degree of colour contrast makes it noticeable. The incidence of visible dust is dependant on weather conditions as well as the implementation of dust suppression mitigation. Accordingly, mitigation is suppose to significantly limit dust at the ship loaders. The new reclamation area will effectively reduce the area of open sea in the Big Bay. The 392 000m² of reclaimed land is a relatively small percentage of area in relation to the sea area. This is expected to have a minimal impact on the sense of place.
OPTION 2 Observers from Bluewater Bay and Saldanha will have limited views of the ship loaders due to the presence of the quay and other infrastructure in between the line of sight. Intrusion on their views is regarded as insignificant. The elevated vantage point of some Saldanha residents will marginally increase their visibility of the ship loaders, but the distance factor will mitigate the intrusion considerably. The visual change will be marginal and no major impact is expected with the presence of 2 additional ship loaders. As previously explained, the quay has visually divided the northern part of Saldanha Bay in, what is locally referred to as the Big and Small Bay areas. The quay acts as a visual screen that will partially block views from Small Bay to the additional carrier ships at the berths. The quay also forms a psychological threshold and it can be argued that with the location of the new berths on the Big Bay side, their intrusion on the intimate sense of place in Small Bay will be minimal. The vast expanse of water on Big Bay’s side will perceivably reduce the scale of the carrier ships thus limiting their impact on the sense of place. The visibility of iron ore dust from the ship loaders is greatly influenced by the background colour and the distance from the ship loaders. Residents from the Small Bay side will be able to notice dust due to the fact that the background colour is usually a light hazy grey. A fairly high degree of colour contrast makes it noticeable. The incidence of visible dust is dependant on weather conditions as well as the implementation of dust suppression mitigation. Accordingly, mitigation is suppose to significantly limit dust at the ship loaders. The new reclamation area will effectively reduce the area of open sea in Big Bay. The 560 000m² of reclaimed land is still a relatively small percentage of area in relation to the sea area, but will become noticeable from elevated views in the bay and especially from Club Mykonos. This is expected to have a minimal impact on the sense of place as the enormous water surface between the observers and the reclamation area dwarfs the scale of reclamation.
OPTION 3 The closest observers to the ship loaders will be the residents from Bluewater Bay, which will be 2.7km from the new superstructure. Saldanha residents will be 4km away. At 2.7km the 30m high ship loaders will be the equivalent visual size of a matchstick held at 3.8m away. The slender character of the ship loaders makes it less noticeable than for instance a structure that has a greater volumetric mass. It is assumed that the MPT will be altered to accommodate the new superstructures and ship loaders. The visual change will be noticeable if the shed structure is removed. At this distance the visual change is still considered marginal and no major impact is expected. As discussed in option 1, the additional iron ore carriers will enter Small Bay and disturb the intimate sense of place. Option 3 is still considered to be on the perimeter of Small Bay, but visually it is located more to the centre, therefore enforcing its prominence. It is expected that the presence of these carrier ships will have a marginally increased impact on the sense of place than option 1. The visibility of iron ore dust from the ship loaders is greatly influenced by the background colour and the distance from the ship loaders. Residents from the Small Bay side will be able to notice dust due to the fact that the background colour is usually a light hazy grey. A fairly high degree of colour contrast makes it noticeable. The incidence of visible dust is dependant on weather conditions as well as the implementation of dust suppression mitigation. Accordingly, mitigation is suppose to significantly limit dust at the ship loaders. The new reclamation area will effectively reduce the area of open sea in Big Bay. The 890 000m² of reclaimed land is still a relatively small percentage of area in relation to the sea area, but will become noticeable from elevated views in the bay and especially from Club Mykonos. This is expected to have an increased impact on the sense of place compared to option 2. Although the enormous water surface between the observers and the reclamation area dwarfs the scale of reclamation, it replaces a great area of seascape amenity.
OPTION 4 The closest observers to the ship loaders will be the residents from Bluewater Bay, which will be 2.4km from the new superstructure. Saldanha residents will be 4km away. At 2.4km the 30m high ship loaders will be the equivalent visual size of a matchstick held at 3.4m away. The slender character of the ship loaders makes it less noticeable than for instance a structure that has a greater volumetric mass. It is also considered that the ship loaders will visually blend with the background buildings and stockyards, thus making them even more difficult to detect. As discussed in option 1, the additional iron ore carriers will enter Small Bay and disturb the intimate sense of place. Option 4 is still considered to be on the perimeter of Small Bay. With the carrier ships closer to the stockyards it will tend to conglomerate a number of elements together. It is expected that the presence of these carrier ships will have a marginally increased impact on the sense of place than option 1. The visibility of iron ore dust from the ship loaders is greatly influenced by the background colour and the distance from the ship loaders. Residents from the Small Bay side will not be able to notice dust that easily as the background colour of the buildings and stockyards will reduce the colour contrast considerably. The incidence of visible dust is dependant on weather conditions as well as the implementation of dust suppression mitigation. Accordingly, mitigation is suppose to significantly limit dust at the ship loaders.
The new reclamation area will effectively reduce the area of open sea in Big Bay. The 1 540 000m² of reclaimed land is still a relatively small percentage of area in relation to the sea area, but will become noticeable from elevated views in the bay and especially from Club Mykonos. This is expected to have an increased impact on the sense of place compared to option 3. Although the enormous water surface between the observers and the reclamation area dwarfs the scale of reclamation, it replaces a great area of seascape amenity.
Conclusion The major impact of the operational phase is the impact on the sense of place. This impact relates to the increased carrier ship traffic and the encroachment of the reclamation area on the seascape amenity. It has been established that the additional berths will cause a relatively small visual change and that these project components will have a minimal impact on the sense of place. The differentiating factors are the location of these elements relative to the observers and the size of the reclamation area for each option. Option 2 is the most preferred option as the berths and the additional ships will be located outside Small Bay. It has been described that the quay brings a physical as well as a psychological division to the bay. The intimate sense of place of Small Bay will not be impacted on and the vast expanse of water on Big Bay’s side, will perceivably reduce the scale of these carrier ships. The area of reclamation is considered relatively small and is expected to have a minimal impact on the scale and sense of place of Big Bay. Option 1 is marginally less preferred than option 2. The smaller reclamation area and therefore a lesser impact on the seascape amenity is an advantage. However, the additional carrier ships will have a marginally greater impact on the intimate sense of place in Small Bay. Option 3 and 4 are the least preferred options, respectively. The much larger reclamation areas will encroach on the seascape amenity which will be visible from elevated areas in Saldanha Bay. The presence of additional carrier ships in Small Bay will have an increased impact on the intimate sense of place.
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2 September 2008 394063\REDD\0708053 Senior Consultant ERM Block A, Silverwood House Silverwood Close, Silverwood Office Park Steenberg, 7945 Attention: Ms Zöe Day Dear Madam Port of Saldanha Screening Study – Air Quality Specialist Input
1 Introduction ERM was appointed by Transnet Capital Projects to undertake a screening study to determine the most suitable berthing locations for the proposed Phase 2 expansion at the Iron Ore Export Handling (IOEHF) facility at the Port of Saldanha. SRK Consulting (SRK) has been involved with air quality specialist study for the proposed Phase 1A, Phase 1B and Phase 2 expansion at the IOHEF. Based on SRK’s knowledge of the air quality issues associated with the port and predicted air quality impacts associated with the proposed expansion, SRK has been appointed to provide qualitative input into the screening study to determine the best possible location for the new berth during the construction and operation of the berth.
2 Assumptions and Limitations The following assumptions and limitations apply: • The project descriptions provided to SRK by Ms Zoe Day from ERM via e-mail between 19
June 2008 and 1 September 2008 was used for this assessment. • The findings of this screening assessment are based primarily on the air dispersion modelling
results for the proposed Phase 1B expansion.
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3 Construction Phase
3.1 Introduction
The following air quality issues of concern were for identified for the construction phase of the project: • Dust generated as a result of construction activities associated with the construction of the berths
and revetment areas; and • Exhaust emissions associated with the movement and operations of construction vehicles at the
site e.g. trucks, dredger etc. In light of the above, if any one of the options selected results in an increase in air emissions this will result in a deterioration in ambient air quality. Factors such as an increase in the duration of the construction activity and/or an increase in the footprint of the project area will result in an increase in air emissions or an increase in the period over which the ambient air is expected to be adversely affected.
3.2 Option 1
Based on the information provided by HMG Joint Venture (Document No. Doc No.H500107-MP-ZJ12-10019, Rev. 3, 21 August 2008), this option will result in the smallest amount of dredged material (4.1 million m3 unconsolidated volume) that needs to be removed and by implication will require the smallest revetment area. This will therefore result in the lowest amount of vehicle movements (especially trucks for the transportation of rocks for the construction of the revetment area), lowest exhaust emissions (trucks and dredgers), least amount of dust generated on the roads used and shortest project duration. Hence this option will be result in the lowest impact on ambient air quality.
3.3 Option 2
This option will require 6.25 million m3 of dredged material that will need to be removed and therefore require a larger area for disposal. The dredging and construction period will increase to 40 and 60 weeks respectively relative to the 24 and 52 weeks required for Option 1. Whilst daily ambient air quality is unlikely to be worse than that, which may be observed during the construction of Option 1, the duration of the construction period will be extended and hence the deterioration in air quality is likely to last longer. Hence from this perspective this option has a lower preference relative to Option 1 during the construction phase.
3.4 Options 3 and 4
Using the logic that Options 3 and 4 will require substantial increases in the amount of dredging and hence a larger disposal area, it is safe to assume that air quality and the increased duration of the construction of these two options will be worse than that could be observed during the construction of Options 1 and 2. Hence from an air quality perspective these will the least preferred options with the air quality during the construction of Option 4 being the worst.
4 Operational Phase The following air quality issues of concern were identified as differentiators for the operational phase of the project for the four different options: • The difference in the amount of dust generated during transfer of ore at transfer points, the
sampler buildings and ship loading; • The proximity of dust sources to off-site receptors; and • Height of conveyors
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Based on dispersion modelling results for Phase 1B1, dust emissions from transfer points after the sampler plant and the ship loader are lowest contributors of dust relative to the overall dust emission load from the IOEHF. While all options have the same number of transfer points and ship loaders, Option 4 will have two additional sampler buildings and Option 1, Option 3 and Option 4 will require the transfer points to be raised in order for the conveyor belts to cross existing infrastructure (e.g. roads). Although transfer points located high off the ground will generate a similar amount of dust released relative to points located close to the ground, the dispersion potential from the higher level points is greater due to the higher release height and increased exposure to wind. Options 1 and 2 are the furthermost location of the four options relative to receptors to the north-west and west of the loading berth. Based on the above discussion Option 2 is considered the most desirable option as it is likely to generate the least amount of dust and is further away from off-site receptors with Option 1 and Option 3 being less desirable and Option 4 being the least desirable due to the additional sampler buildings and proximity to off-site receptors.
5 Concluding Remarks
5.1 Air quality as a differentiator between options
During the construction phase the duration of the increase in ambient dust levels as a result of an increase in the quantity of materials handled will be a key differentiator. Hence Options 1 and 2 should be selected over Options 3 and 4. During the operational phase the difference in total dust emissions between the 4 options is not the only significant differentiator. The proximity to receptors, especially those to the west and north-west of the loading berth is also an important differentiator. Hence in this case Options 1 and 2 are the preferred over Options 3 and 4.
5.2 Air quality as a differentiator relative to the entire project
The main sources of dust during the operational phase are associated with the transfer points (after the sampler plant) and the ship loaders. Relative to other dust sources from the IOEHF, dust emissions from these sources theses sources are considered to be negligible. Therefore the significance of air quality issues as a differentiator between the four options is considered to be low relative to other issues that need to be considered when selecting a suitable berthing location.
5.3 Ranking for air quality
A ranking of the preferred option for construction and operational phases is presented in Table 1 with 1 being the least negative and 5 being the most negative. Table 1: Ranking for Air Option 1 Option 2 Option 3 Option 4 Construction 1 1 4 5 Operation 2 1 2 2
Based on the findings of this screening assessment with respect to air quality Option 2 is the preferred option for both the construction and operational phases.
1 (1) SRK Report No. 3753349, ENVIRONMENTAL IMPACT ASSESSMENT: PHASE 1B EXPANSION OF THE SALDANHA IRON ORE EXPORT HANDLING
FACILITY: Air Quality Impact Assessment for Phase 1B, August 2007.
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Yours faithfully, SRK Consulting VS Reddy (Pr. Sci. Nat.) Principal Scientist
PDNA/SRK JV Social Aspects
Screening study
Phase 2 Expansion of the Saldanha Iron Ore Export Terminal, Berthing options, June 2008
SCREENING FOR BERTHING OPTIONS:
PHASE 2 EXPANSION OF THE SALDANHA IRON ORE EXPORT TERMINAL
DRAFT SCREENING REPORT: SOCIAL ASPECTS
Prepared by: Ilse Aucamp
Ptersa Environmental Management Consultants
PO Box 915 751
Faerie Glen
0043
Contact person: Ilse Aucamp
Prepared for:
ERM
2 September 2008
PDNA/SRK JV Social Aspects
Screening study
Phase 2 Expansion of the Saldanha Iron Ore Export Terminal, Berthing options, June 2008
TABLE OF CONTENTS
1 INTRODUCTION............................................................................................................................. 1
2 CONSTRUCTION............................................................................................................................ 3
2.1 Introduction ............................................................................................................................. 3
2.2 Option 1 .................................................................................................................................. 4
2.3 Option 2 .................................................................................................................................. 4
2.4 Option 3 .................................................................................................................................. 5
2.5 Option 4 .................................................................................................................................. 5
2.6 Conclusion .............................................................................................................................. 6
3 OPERATION ................................................................................................................................... 7
3.1 Introduction ............................................................................................................................. 7
3.2 Option 1 .................................................................................................................................. 7
3.3 Option 2 .................................................................................................................................. 7
3.4 Option 3 .................................................................................................................................. 8
3.5 Option 4 .................................................................................................................................. 8
3.6 Conclusion .............................................................................................................................. 8
4 RECOMMENDATIONS ................................................................................................................... 8
5 REFERENCES................................................................................................................................ 9
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1 INTRODUCTION
The aim of this report is to identify the broad social impacts which may be associated with the construction
of a new iron ore berth at the Port of Saldanha. Four layout options (herein referred to as Options 1 to 4)
have been proposed, and each of these options will be discussed, from a social perspective, in the report.
The construction and operation phases of the new berths will be covered in the report. This report does
not replace the social impact assessment conducted for Phase 2 of the project, but can be used to
supplement that report. The report is focussing only on the possible impacts associated with each of the
berthing options, and aims to assist the environmental team with deciding which of the options in question
would be most suitable form a social perspective. An important consideration when looking at possible
impacts, whatever their source, is to appreciate that all impacts are social impacts and that people
experience the physical environment in human terms (Vanclay, 2003). Another consideration is the way in
which public perception are addressed. Perceptions, attitudes, and beliefs must be treated as real with
real consequences. While the public’s assessment of risk is perceptual in nature, their fears should not be
dismissed as irrational and therefore unimportant. Living with the fear and uncertainty is an impact in itself
(Burdge, 1998).
In order to contextualise the screening study from a social perspective, it is important to consider why the
need for an additional study was raised. The EIA process for the Phase 2 Expansion of the Port of
Saldanha commenced in 2006. During that time, via the public consultation process and the field work
conducted for the Social Impact Assessment, it became apparent that the public (used here in the broad
sense) does not have a good relationship with Transnet. Transnet responded to this feedback by trying to
put communication systems in place, or improving on existing systems, achieving mixed degrees of
success at this stage. Unfortunately, the view that Transnet is not transparent and does not care for the
environment remains part of the public perception, as can be seen in minutes from meetings conducted
with the public on 24 April 2008. This “negative” relationship with the surrounding communities can be
seen as one of the direct causes of the request for additional studies, as the public does not trust Transnet
to do “the right thing”. It should be noted, however, that Transnet has committed to undertake the
Screening Study in response to the request for further information from the public.
It needs to be considered that although people’s judgements about the riskiness of activities can be
updated through experience (which is what Transnet is aiming to do), such experience is typically
selective and incomplete. Attitudes and behaviour (risk perceptions and decisions) can also be influenced
by other people. Because our friends tend to share our attitudes, and we are more likely to accept advice
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from our friends, such influence can reinforce existing attitudes (Eiser, 2004). Thus, different interest
groups which may be affected by the project can influence each other regarding the functioning of
Transnet.
Another important aspect to consider in the entire process, especially when dealing with the public, is
trust. The public rely on Transnet to control risks associated with the project and to inform them about the
extent of the risks. Therefore, the trust the public have in Transnet will depend on implicit estimates of
Transnet’s competence, values or partiality and honesty and will be interpreted as consistent with the
public’s prior beliefs – which is that Transnet is not trustworthy. In order to try and re-build trust, some of
the following matters should be considered. If ‘experts’ are seen as having a vested interest (for example
if they are paid by Transnet, or committed to defending the standpoint of a pressure group), this may
undermine trust. Communicators (Experts, Transnet, EIA team) found to have withheld information lose
trust. Important evidence could be what, if anything, the communicator stands to gain or lose by dressing
up the information in a particular way. Expertise by itself is not enough to engender trust. Independence
and impartiality are also essential. Any communicator who is perceived, rightly or wrongly, to have a stake
in persuading the public either that something is safe or that it is dangerous is less likely to be trusted than
someone who is seen to provide the facts as they themselves interpret them. Risk inevitably involves a
concern with good and bad outcomes (Eiser, 2004). Such values will be implicit in any exchange. What
any audience will be listening for is an indication of what they need to do – not simply for a prediction of
what consequences may or may not happen, but also for an indication of how good or bad these
consequences will be, and what they, or anyone else, is expected to do about it. The best way to
communicate is to adopt a less didactic model of communication. It is already widely recognised that, to
be effective, the communication of risks cannot be merely one-way. It must involve exchange and
interaction between all parties (which is what Transnet is hoping to achieve through the Environmental
Management Committee, the Community Liaison Forum and the Port Consultative Forum). But there are
obstacles to putting such good intentions into practice. The ‘experts’ need to be prepared to give up not
only time, but some of their power (Eiser, 2004). The ‘public’ need to be willing to be engaged in the
decision process and take some responsibility for the outcomes, if these have been shaped to take
account of their views. All this can be costly, in terms of time, patience and the risk of disappointment if
not everything one wants can be achieved. The real advantage over the traditional, less consultative,
approach is that the debate or discussion can focus on what people want to know and issues of value,
rather than merely probability can be considered (Eiser, 2004).
Another important social factor to consider, which seem to be missing from this process, is the “social
licence to operate”. In 2003 Pierre Lassonde drew attention to the observation that “Without local
community support, your project is going nowhere.” He described social license as “…the acceptance and
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belief by society, and specifically local communities, in the value creation of activities”. Social licence
cannot be obtained by going to a government ministry and making an application or simply paying a fee. It
requires far more than money to truly become part of the communities in which a company operates
(Lassonde 2003). A primary objective of gaining a social license is to minimize project risk. “Successful
operations require the support of the communities in which they operate now, and in the future, to ensure
continued access to land and resources” (Render 2005). The social license to operate can be further
described as the degree of match between stakeholders’ individual expectations of corporate behaviour
and companies’ actual behaviour.
Earning a social licence to operate starts in the planning phase of any given project. First impressions are
long lasting and the company must recognize that community opinion will be conditioned by previous
experience, knowledge gained from elsewhere and the approach taken by the company. Conflict can arise
very quickly if there is a failure to respect local customs of land use and religious sites, give notice of
actions, pay fair market compensation and so on. Knowledge of the community and on-going
communications are prerequisites for good relations.
2 CONSTRUCTION
2.1 Introduction
The impacts in this section refer specifically to the construction period associated with the berths, as
opposed to the construction associated with the entire project. It must be stated that in general, from a
public perspective, the disruption related to the construction would be seen as resulting from the entire
project, as opposed to a specific activity. The social environment cannot be compartmentalised, and it is
difficult for the general public to look at impacts in isolation, as impacts tend to be inter-related, and bio-
physical impacts can lead to social impacts and vice-versa. Broadly speaking, the location of the berth will
not significantly change the social impacts caused by the berth, as many of the impacts will be
experienced irrespective of where it will be located. However, the severity of the social impacts will be
directly related to the severity of the environmental impacts, and therefore this study cannot be separated
from the other specialist studies. The noise, dust and visual effects may impact on the sense of place, and
the quality of the living environment, and possibly on the health of the local inhabitants. It is therefore
important to look at the severity and magnitude of these impacts taking the social environment in
consideration. Other impacts that may be expected are associated with increase in traffic – on sea and on
land. It is estimated that between 250 and 350 unsustainable jobs will be created at peak construction,
which have both positive and negative implications. It is expected that the majority of these jobs will be
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sourced from the local population. In addition, specialist construction crews and their families are
expected to enter the area and contribute to the local economy in numerous direct and indirect ways. This
could also cause social impacts associated to pressure on social and physical infrastructure and the local
culture. It is important to recognise that very few of these impacts are caused solely by the construction of
the berths, but are impacts generated by the project in general. Some of the most severe possible social
impacts can be associated with the potential impact of dredging. It should therefore be considered that the
longer the dredging period will be, the longer these negative impacts will be felt. The impact of the water
quality for example, may impact on the livelihoods of a number of people, and impacts on livelihoods are
seen as the worst possible social impacts. Some of the groups that may be affected will be tourism
establishments catering for recreational water users (fishing and other water sports), subsistence
fishermen, the mariculture sector and the diving school.
2.2 Option 1 Option 1 is the area on the Small Bay side of the causeway between the existing iron ore berth and the
Multi Purpose Terminal. Some of the I&APs have explicitly expressed their preference that the berth
should be located in Small Bay, even though this option is closer to the communities of Blue Water Bay
and Saldanha. The dredging period is estimated to be 24 weeks. The total construction activities will take
approximately 52 weeks, which will provide between 250 and 350 jobs, approximately, at peak
construction. It is expected that the majority of these jobs will be sourced from the local population.
Although these jobs are unsustainable, it will provide people with a temporary income for that period,
which can be seen as a positive impact. The rock required for the construction of the rock revetment to
quay wall reclamation face will require road transport. The size of the reclamation area and therefore
volume of rock required for face is directly linked to the volume of dredge material generated. This
material will be transported overland, and this can have an impact on traffic and safety of other road users
from a social perspective. This option will result in the least dredging material.
2.3 Option 2 Option 2 is the area on the Big Bay side of the causeway between the existing iron ore berth and the iron
ore stockpiles. An environmental concern for this option mentioned in the engineering report supplied by
the HMG JV and Transnet is the possible impact it may have on the beaches to the east of the Port. This
is a huge public concern. The perception of the public is that the Port activities are responsible for the
erosion of the beaches in Langebaan, and if the public perceive that this option may aggravate the
situation, choosing it will cause significant public opposition. This option is also closer to the Langebaan
Lagoon area, and there may be public concerns associated with the environmental effects of dredging on
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the lagoon-system. It is located further away from communities of Blue Water Bay and Saldanha, which is
a positive aspect. The dredging period is estimated to be 40 weeks. The total construction activities will
take approximately 60 weeks, which will provide between 250 and 350 jobs, approximately, at peak
construction for this duration. It is expected that the majority of these jobs will be sourced from the local
population. Although these jobs are unsustainable, it will provide people with a temporary income for that
period, which can be seen as a positive impact. The rock required for the construction of the rock
revetment to quay wall reclamation face will require road transport. The size of the reclamation area and
therefore volume of rock required for face is directly linked to the volume of dredge material generated. This material will be transported overland, and this can have an impact on traffic and safety of other road
users from a social perspective.
2.4 Option 3 Location 3 is the existing Multi Purpose Terminal which will need to be relocated. Some of the I&APs have
explicitly expressed their preference that the berth should be located in Small Bay. It must however, be
noted that this option is closer to the Blue Water Bay and Saldanha communities than Option 1 and
Option 2. The dredging period is estimated to be 46 weeks. The total construction activities will take 87
weeks, which will provide between 250 and 350 jobs, approximately, at peak construction for this duration.
It is expected that the majority of these jobs will be sourced from the local population. Although these jobs
are unsustainable, it will provide people with a temporary income for that period, which can be seen as a
positive impact. The rock required for the construction of the rock revetment to quay wall reclamation face
will require road transport. The size of the reclamation area and therefore volume of rock required for face
is directly linked to the volume of dredge material generated. This material will be transported overland,
and this can have an impact on traffic and safety of other road users from a social perspective. This option
will result in less dredging material than Option 4, but more than Options 1 & 2.
2.5 Option 4 Location 4 is the area on the Small Bay side of the causeway between the MPT and the iron ore
stockpiles. Some of the I&APs have explicitly expressed their preference that the berth should be located
in Small Bay. It must however, be noted that Option 4 is significantly closer to the Blue Water Bay and
Saldanha communities than Options 1, 2 and 3. The dredging period is estimated to be 75 weeks. The
total construction activities will take 93 weeks, which will provide between 250 and 350 jobs,
approximately, at peak construction for this duration. It is expected that the majority of these jobs will be
sourced from the local population. Although these jobs are unsustainable, it will provide people with a
temporary income for that period, which can be seen as a positive impact. The rock required for the
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construction of the rock revetment to quay wall reclamation face will require road transport. The size of the
reclamation area and therefore volume of rock required for face is directly linked to the volume of dredge
material generated. This material will be transported overland, and this can have an impact on traffic and
safety of other road users from a social perspective. This option will result in the largest amount of
dredging material of all the options.
2.6 Conclusion From a social perspective, in general, there is very little difference between the options. If the duration of
the period during which temporary jobs will be created are taken in consideration, Option 4 would be the
best option. Using only the period of employment would over-simplify the matter, but it could be used as a
very crude indicator. If, on the other hand, the duration of the dredging period is taken into account, the
best option would be Option 1. It must be understood that the public is not a homogeneous group, and
different sectors of society will view different options as the most suitable. Unemployed people will prefer
that Option 4 should be selected, since it will provide them with opportunities for income for the longest
period. People who rely on the quality of the water in the bay, and whose livelihoods depend on the
optimum “health” of the system, like fishermen and the diving school would prefer a shorter dredging
period, as associated with Option 1. The “general” public, may from a nuisance perspective, also prefer
the shortest possible construction period (Option 1). This may, however, not be the most environmentally
friendly or suitable option. Groupings in the community who feel that the environment should be protected
at all costs, will prefer the least environmentally damaging option, regardless of the length of the
construction period. It would be impossible to satisfy the needs of all the sectors of society, and there will
be a need for compromise. In a situation like this, the best way forward would be to look at the legislation
intended to protect the rights of the individual and the environment, namely the Constitution of South
Africa (Act No. 108 of 1996) and the National Environmental Management Act (No. 107 of 1998) and seek
the solution which would be most sustainable from an environmental perspective, since many of the social
systems in the area rely on the existing environmental systems.
In addition, the findings of the other studies will need to feed into the social study in order to make a more
accurate prediction. The findings of these studies will indicate which option will have the most impact in
terms of visual, noise, health, marine, avi-fauna etc – all of which can cause social impacts and affect the
sense of place. There is some public preference to locate the berths on the Small Bay side of the Port,
which is an important consideration when thinking of social licence to operate.
PDNA/SRK JV Social Aspects
Screening study
Phase 2 Expansion of the Saldanha Iron Ore Export Terminal, Berthing options, June 2008
7
3 OPERATION
3.1 Introduction
The impacts in this section refer specifically to the operation period associated with the berths, as
opposed to the operation associated with the entire project. It must be stated that in general, from a public
perspective, the disruption related to the operation would be seen as resulting from the entire project, as
opposed to a specific activity. Majority of the social impacts that can be expected during the operation
phase are mostly related to the sense of place. These impacts relates to dust – especially the visual and
health aspects associated with the dust, noise associated with loading the ships and other operational
activities, especially if this happens during the night or traditional “quiet” times like Sunday mornings and
possible emergencies like oil spills or explosions. It is unclear how many permanent new jobs will be
created by the operation of the berths, but it is assumed that this will not be a major impact, since it is an
expansion of normal activities.
3.2 Option 1 Location 1 is the area on the Small Bay side of the causeway between the existing iron ore berth and the
Multi Purpose Terminal. Some of the I&APs have explicitly expressed their preference that the berth
should be located in Small Bay. There may be safety implications associated with this option, given that
more iron ore vessels will have to pass the oil tanker berth. There will thus be an increase in the risks for
collisions which may result in oil spills. This option is also close to a residential area (Blouwaterbaai),
which can be seen as a sensitive receptor.
3.3 Option 2 Location 2 is the area on the Big Bay side of the causeway between the existing iron ore berth and the
iron ore stockpiles. It is the furthest away from residential areas of all the options, which make it a more
favourable choice. It will also not impact on the oil tanker berth, which reduces the public perception of
collision risks. Public perception however, is that the dredging associated with this option will lead to an
increase in the shoreline erosion that is being experienced along the beaches to the east of the Port. The
public also believe that there is an increased risk to the Langebaan Lagoon should an oil spill occur at or
near Option 2 due to the proximity of this option to the Lagoon.
PDNA/SRK JV Social Aspects
Screening study
Phase 2 Expansion of the Saldanha Iron Ore Export Terminal, Berthing options, June 2008
8
3.4 Option 3 Location 3 is the existing Multi Purpose Terminal which will need to be relocated. Some of the I&APs have
explicitly expressed their preference that the berth should be located in Small Bay. It must however, be
noted that it is closer to the sensitive receptors of the Blue Water Bay and Saldanha communities than
Option 1 and 2.. There may be safety implications associated with this option, given that more iron ore
vessels will have to pass the oil tanker berth. There will thus be an increase in the risks for collisions
which may result in oil spills.
3.5 Option 4 Location 4 is the area on the Small Bay side of the causeway between the MPT and the iron ore
stockpiles. Some of the I&APs have explicitly expressed their preference that the berth should be located
in Small Bay. It must however, be noted that it is closer to the sensitive receptors of Blue Water Bay and
Saldanha communities than Options 1, 2 and 3.There may be safety implications associated with this
option, given that more iron ore vessels will have to pass the oil tanker berth. There will thus be an
increase in the risks for collisions which may result in oil spills.
3.6 Conclusion From a social perspective, there is very little difference between the options, with Option 2 being seen as
the slightly better option. The most negative aspect of Option 2 will be the indication that some members
of the public prefer the berth in Small Bay. In addition, the findings of the other studies will need to feed
into the social study in order to make a more accurate prediction. The findings of these studies will
indicate which option will have the most impact in terms of visual, noise, health, marine, avi-fauna etc – all
of which can cause social impacts and affect the sense of place.
4 RECOMMENDATIONS
There are no clear preferences of which the most suitable alternative would be from a social perspective.
There are very small distinctions, if any between the options suggested. Clearer recommendations could
only be made if the findings of the other specialist studies, especially noise, dust and dredging were
available. Since those findings were not available at the time of writing this report, the report stands as it
is.
PDNA/SRK JV Social Aspects
Screening study
Phase 2 Expansion of the Saldanha Iron Ore Export Terminal, Berthing options, June 2008
9
5 REFERENCES
BURDGE, R.J. 1998. A Conceptual approach to Social Impact Assessment. Revised Edition. Social
Ecology Press: Middleton. 284p
Eiser, R. 2004 Public Perception of Risk Centre for Research in Social Attitudes. Department of
Psychology. University of Sheffield
Lassonde, Pierre., 2003. How to earn your Social Licence Mining Review, Summer, pp. 7-13.
Render, Jo. M., 2005. Mining and Indigenous Peoples Issues Review, pp. 1-82, (London: International
Council on Mining & Metals).
Salzmann, O; Ionescu-Somers, A and Steger, U. Undated Corporate license to operate (BCS) - review
of the literature and research options
Vanclay, F. 2003. Conceptual and methodological advances in Social Impact Assessment. In
Vanclay, F. & Becker, H.A. 2003. The International Handbook for Social Impact Assessment. Cheltenham:
Edward Elgar Publishing Limited
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
1
SALDANHA IRON ORE EXPORT TERMINAL
EVALUATION OF ADDITIONAL BERTH OPTIONS
CONSIDERING
INCREMENTAL SHIPPING RISKS
Prepared by:
J Moes
CSIR Built Environment
PO Box 320
Stellenbosch
7599
Prepared for:
ENVIRONMENTAL RESOURCES MANAGEMENT Ltd
Steenberg, 7945, Cape Town
August 2008
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
2
1. INTRODUCTION Transnet intends to increase the iron ore export through of the Port of Saldanha from about
45 million tonnes per annum (Mt/a) to 93 Mt/a. This port development is called Phase 2. To achieve
this export target, two new iron ore loading berths are required, in addition to the two existing berths
at either side of the jetty. The causeway leading to the jetty separates Saldanha Bay into Small Bay
and Big Bay (Figure 1). Four locations for these two new berths have been identified, that is, one
location in Big Bay (location 1) and three locations in Small Bay (locations 1, 3 and 4), as shown in
Figure 2. An evaluation study needs to be carried out to identify which location of these four is the
optimum location for these new berths, on the basis of environmental risks and impacts associated
with each of these locations.
Many aspects play a role in deciding which location would be the best. The present evaluation
report is limited to aspects related to shipping and its associated risks such as ship collisions,
grounding and oil spills. This study will only consider the differences in additional environmental
risks due to the increase in shipping for each of the four options. The possible environmental impact
differences due to actions such as dredging, ballast water discharge, quay construction, etc. will be
dealt with in other specialist studies. The Client (ERM) will have to integrate the results of all these
expert studies, so that final conclusions and recommendations can be formulated for Transnet.
These expert studies are limited to a one-day screening workshop, which was held on 11 June 2008,
and one day of compiling the various reports. This forms a restriction on the quality of the
evaluation, but it may be that this overall limited evaluation will form a sufficient basis to draw clear
conclusions and recommendations. If this is not the case, further detailed assessment of a number
of aspects may have to be carried out.
2. STUDY APPROACH
2.1 Information Base The basic information for this study was mainly derived from the earlier reports related to shipping in
Saldanha Bay (CSIR, 2000 and CSIR, 2005) and from information obtained from Transnet Projects
and Transnet National Ports Authority (TNPA) Saldanha. Interpretation of these data was based on
experience with the past developments at the Port of Saldanha and from a recent detailed EIA study
on Incremental Shipping Risks carried out for the berths at location 2 (CSIR Report, 2008).
2.2 Assumptions One assumption for this study is that for the near future the size distribution of ore carriers using the
two new berths will be about the same as that of the ships presently calling at the port, except that
the size of ore carriers using the two new berths will be limited to 225 000 dwt. Furthermore, it is
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
3
assumed that the size of ships that will call at Saldanha will reflect the size of the world fleet for ships
larger than 60 000 dwt (which represents 100% of all iron ore carriers calling at Saldanha). It is also
assumed that there will be no difference in the intensity of shipping to each of these new berth
locations.
Similar to the present situation, it is assumed that about 10% of all ore carriers calling at the Port of
Saldanha will be so-called top-up vessels, which arrive in a semi-laden condition and which are also
at arrival confined to the dredged channels in the port. The other ore carriers will arrive in ballast,
with a draught of between 9 m and 12 m, depending on the ship size. These ships can manoeuvre
outside the dredged channels in the port, in areas where the natural water depth will be sufficient.
A third assumption is that the present tanker terminal at the Saldanha side of the jetty will remain in
operation and will have a high percentage of usage. It is therefore conservatively assumed that
there will always be a tanker moored at the tanker terminal. The typical size of these tankers is
about 300 000 dwt.
It is also assumed that there will be a sufficient number of reliable tugs and qualified and well-trained
pilots available to assist the ore carriers to safely manoeuvre inside the port and in the confined
dredged channels.
The affected area under consideration is from the turning circle just south of the jetty, up to the berth.
Upon arrival, the ore carriers will either manoeuvre along the Langebaan side of the jetty and
causeway in Big Bay, or along the Saldanha side of the Jetty and causeway in Small Bay (see
Figure 2). The manoeuvring of ore carriers in the outer dredged entrance channel, south of the
turning circle, is assumed to be the same for all location options and is therefore not considered in
this report.
3. DESCRIPTION OF THE AFFECTED ENVIRONMENT
3.1 Environmental Conditions The predominant wind in the Saldanha Bay area is south-south-east. In the winter season, brief
periods of north-westerly winds occur, when frontal systems pass. The direct effect of wind,
especially on the departing laden deep-draught ships, is not very significant. However, the wind will
have a significant effect on the entering ships in ballast and also cause a flow of water at the surface
in the direction of the wind, while any floating material will drift towards the northern or southern
shorelines as a result of the two predominant wind directions.
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
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A wind speed of about 25 knots (about 13 m/s) is the limit for departing ships, if this wind is blowing
the vessel onto the jetty. A wind speed of 13 m/s is exceeded during about 10% of the time, this
wind is generally from the S or SSW directions. Under such conditions two of the presently available
tugs (with 42 tonne-force bollard pull) are not able to lift large ore carriers off the fenders into the
wind.
The wave penetration and the tidal current into and out of Saldanha Bay occur through the present
entrance to the Bay, between Marcus Island and Elands Point on the Langebaan Peninsula. In the
outer entrance channel, a significant wave height of 4 m is statistically exceeded during one storm
per year, as compared to a significant wave height of 8 m offshore in deep water. Due to wave
refraction into the bay, the wave heights gradually decrease towards the jetty and further along the
causeway towards the shoreline of the Bay. The wave conditions along the jetty are relatively
moderate, with swell wave heights exceeding 0,5 m only about 5% of the time.
The channel and jetty orientation has been designed in such a way that the direction of propagation
of the (refracted) swell is almost in line with the channel. There is a gradient in wave heights from
Club Mykonos towards Saldanha. This means that the swell wave heights at the Big Bay side of the
causeway will be slightly higher than at the Small Bay side. The wave-induced vertical ship motions
in the dredged channels will be mainly heave and pitch. Only during the turning manoeuvre will the
ship be exposed to beam waves, resulting in roll motion of the ship. However, in this case pitch
motions will be small.
Currents in Saldanha Bay are mainly generated by the wind and the tide. The tidal current
velocities between Marcus Island and Elands Point are amplified due to the constricted flow area.
But the current velocities in the entrance channel mostly remain well below 0,3 m/s. Inside the bay,
the tidal current velocities will be significantly smaller than at the bay entrance. The direction of the
tide-driven currents is mostly in line with the channel. The direction of the currents in the channel
due to the direct wind shear and the wind-driven bay circulation usually has a component across the
channel, but is also influenced by the presence of the causeway.
3.2 Ship Manoeuvring Conditions The width of the entrance channel only allows single-direction traffic for bulk carriers and tankers. If
two such vessels would have to use the channel at the same time, the departing vessel is taken out
first. Arriving vessels will have to wait outside the port, near the pilot station. If there is no berth
available for the arriving vessel, the ship can be asked to stay outside the port limits, or can be
allowed to anchor inside the bay. Therefore, only one tanker or bulk carrier will be manoeuvring in
the port at one time.
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
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There are two anchorage areas in the port for arriving ore carriers, one smaller vessel can be
anchored in Small Bay, while two vessels can be allowed to anchor in Big Bay. Only ore carriers
with a draught that is safe for mooring in these limited water depths will be allowed to anchor here.
Tankers and “top up” ore carriers or vessels with a large ballast draught will have to stay outside the
port. Some of these vessels even anchor in St Helena Bay.
Ships with a maximum draught of up to 20,5 m are only allowed entry into the port if the significant
wave height at the wave buoy position is lower than 2 m, irrespective of the tide (this relates almost
exclusively to tankers). This safety criterion for wave height leads to a relatively small actual
percentage of environmental downtime, since a significant wave height of 2 m is only exceeded
about 10% of the time (mostly during the winter months), while the intensity of shipping and
presence of these large size ships in the navigation channel is low. The combined occurrence of
these two random factors, which constitutes the actual shipping downtime due to waves, is,
therefore, low. Departure of ships with draughts between 20,5 m and up to 21,5 m (this relates to
ore carriers as well) is dependent on high tide.
The ore loading jetty and the entrance channel have been designed to accommodate ore carriers of
up to 250 000 dwt, with a maximum draught of about 20,5 m. The berth at the Langebaan side of
the jetty has been designed to accommodate the larger vessels. In practice, ore carriers of up to
about 350 000 dwt, with a maximum actual draught of up to 21,5 m and a length of up to 350 m, are
being accommodated. The open concrete caisson jetty, at the end of the causeway, has a total
length of about 1 km, with one ore berth on either side of the jetty and a tanker terminal at the end of
the jetty, at the Saldanha side. The jetty has been built in line with the entrance channel, in a more
or less north-south direction.
A channel with a bed width of 300 m has been dredged along the west (Saldanha) side of the jetty
and a channel with a bed width of 250 m has been dredged along its east (Langebaan) side. This
difference is due to the fact that ore carriers at the Saldanha side have to pass the tanker terminal,
often with a tanker moored here. The typical beam width of these tankers is about 50 m. At the
Langebaan side no moored tankers have to be passed in the present situation. Ships manoeuvring
to and from the new berths will have to often pass a moored ore carrier at close distance, either at
the Langebaan or Saldanha side of the jetty.
A closed causeway of about 3,3 km has been built into the bay, leading straight to and in line with
the jetty (Figure 1). An oil pipeline runs along the Saldanha side of the jetty up to the tanker terminal
at the end of the jetty. This pipeline is next to the concrete deck of the jetty and is protected from
ship impacts by about 5 m of extending solid concrete caissons with large-size pneumatic fenders.
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
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3.3 Big Bay and Small Bay The causeway separates the northern sector of Saldanha Bay, called Small Bay, from the southern
sector, called Big Bay (Figure 1). Because the causeway is a closed structure, this means that the
water circulation patterns in these two bay sectors have changed compared to the conditions before
the construction of the causeway (and before the northern entrance to Saldanha Bay, between
Marcus Island and Hoedjies Point was closed by a sand breakwater).
The northern area of Big Bay, east of the causeway and jetty, as well as the southern area of Small
Bay, just behind the sand breakwater, are frequently used by oyster and mussel farmers. The young
oysters and mussels are attached to wires, suspended from floating anchored rafts in the bay. The
success of this type of sea farming depends to a large extent on the quality and nutrients of the sea
water and on the wave climate.
The shores of Small Bay and Big Bay are very popular for recreation and tourism. Well known
beaches are located at Bluewater Bay, in the northern sector of Small Bay, and at Langebaan, in the
southern part of Big Bay. The marina and holiday resort Club Mykonos, is located in the middle of
Big Bay, due east of Marcus Island. The northern peninsular section of the Langebaan Peninsula,
opposite the town of Langebaan, is a military area, which is not accessible to the public.
The town of Saldanha is located along the north and west shores of Small Bay. A naval base and a
fishing harbour are located on the west side of Small Bay. A small craft harbour for port craft is
located behind the sand breakwater, providing berthing for tugs and pilot boats.
Oil pollution in Saldanha Bay, in the form of oil floating at the water surface, is a specific threat.
Should a strong north-westerly wind be blowing during an oil spill, floating oil may be blown into
Langebaan Lagoon, even if there was no tidal current flow towards the lagoon. A number of
scenarios have been investigated in an earlier study, which was related to tanker activities in
Saldanha Bay (CSIR, 1996, 1997a, 1997b).
The Phase 2 port expansion development will involve the creation of two new berths, either along
the Langebaan side of the causeway, opposite the general cargo quay (Location 2), or along the
Saldanha side of the causeway, between the Multi Purpose Terminal (MPT) and the jetty (Location
1), or north of the MPT (Location 3), or in the place of the MPT (Location 4), as shown in Figure 2.
These additional quays will be designed for vessels of up to 225 000 dwt, which typically have a
draught of 19,8 m, a length of 325 m and a beam width of 50,5 m. To allow the manoeuvring of
ships to these quays, the dredged channel along either the Langebaan or Saldanha side of the jetty
will have to be widened and extended northward to these quays. A channel with a depth of -21 m
CD and a width of about 350 m will be needed for the safe sailing of these loaded vessels. The
locations of the proposed new berths are also shown in Photo 1 below.
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
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The present loading infrastructure and intensity at the jetty will remain the same, with an export
capacity of about 45 Mt/a, or about 22,5 Mt/a per berth. The additional 48 Mt/a, to realise a total iron
ore export of 93 Mt/a from the port, will be exported from the two new berths, i.e. with an export
capacity of 24 Mt/a per new berth. This will imply that the additional number of ships, relative to the
number of ships associated with Phase 1, will use the extended channel and the two new berths.
Photo 1 : Overview of the present conditions at the Saldanha jetty and the proposed four alternative location options for two new berths
The vessels using the new berths and channel will have to pass vessels moored at the jetty.
Passing vessels will impact upon the motions and mooring forces of moored vessels. This impact
will be larger if the passing vessel has a larger displacement, has a higher speed or is passing
closer. This aspect should be investigated as part of the design study and a safe minimum passing
distance and maximum passing speed should be defined for ship operations at the new berths in
relation to the available channel bed width at this passing area. It is assumed that the passing
distances for all four options will be the same, although the types of ships to be passed will be
Location 3 �
� Location 2
� Location 1
Location 1 �
Location 2 �
Location 4 �
� Location 4
� Location 3
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
8
different, that is, bulk carriers for Option 2, tankers and bulk carriers for Options 1 and 4, and
tankers, bulk carriers and general cargo vessels for Option 3.
3.4 Present and Future Shipping After the full realization of Phase 1, with dual ship loading and an export of about 45 Mt/a, it is
expected that about 290 ore carriers will call at the port per year. From the total number of ships that
sail into and out of Saldanha Bay, the ore carriers only form a limited proportion. The average
number of piloted ships in 2006 at Saldanha was about 420 ships, of which about 40% were ore
carriers. The large number of fishing vessels from Saldanha is not included in these figures. The
Port of Saldanha has three tugs of 42 tf bollard pull, but it has been decided that a fourth similar tug
will be added to this fleet.
Ore carriers enter the port through the entrance channel and are turned 180 degrees with the
assistance of two tugs before being berthed. The turning manoeuvre of the incoming vessel does
not necessarily take place inside the turning circle area, if the water depth around the jetty does not
form a restriction on the (ballast) draught of the ore carriers (up to about 12 m). Ships in ballast for
the new berths will, therefore, often be turned off their berth. The tugs then manoeuvre the ship,
after turning, sternward to their berth, where the ship is berthed and moored. Turning is done before
berthing and loading as it is easier to turn a ship in ballast than to turn a fully laden vessel (at
departure). Furthermore, in a case of emergency, a departure manoeuvre with a ship moored with
the bow seaward is much easier and faster. The bulk carriers are, therefore, always moored in
Saldanha with their bow towards the sea.
It appears from an analysis of the world fleet of ore carriers in 2006 that there is no clear trend that
would lead to a change in ship size of these vessels. The size range of ore carriers calling at
Saldanha, i.e. between 60 000 dwt and 350 000 dwt, represents the top 25% of the world fleet of ore
carriers. The 2006 order book for this class of ships appears to follow the same trend as the existing
fleet, although four bulk carriers of 388 000 dwt and two more of 350 000 dwt are presently (2008)
under construction. It is accepted that in the near future there will not be a drastic change in the size
of ore carriers that will call at Saldanha. This means that the average volume of cargo that will be
exported per ore carrier will remain about 156 000 t, with a maximum for the two new berths of
225 000 dwt. It is accepted that the limited number of bulk carriers which are larger than
225 000 dwt can be berthed at the existing jetty berth on the Langebaan side.
After the realization of Phase 2, with an export capacity of 93 Mt/a, it is expected that the average
volume of cargo per ore carrier will remain about the same (i.e. about 156 000 t). This means that
the number of calling ore carriers will increase from about 290 for Phase 1 to about 600 for Phase 2,
that is, by about 107%, with no increase in average ship size. The incremental shipping will,
therefore, be realized with an additional 310 calling ore carriers to be loaded at the two new berths.
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
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The larger bulk carriers, with a draught that will constrain them to the dredged channel, or “top up”
vessels, for Location 2 in Big Bay will have to be turned in or near the existing turning area. While
backing in to one of the new berths, they may pass an ore carrier moored at the Langebaan side of
the jetty. The channel width in the present conceptual design will be increased gradually from the
existing 250 m to about 350 m. This would appear to allow adequate safety for manoeuvring, but
downtime due to strong southerly winds may be experienced for channel-bound ships in ballast and
using the present 42 tf tugs.
The larger bulk carriers, with a draught that will restrict them to the dredged channel, or “top up”
vessels, for Locations 1, 3 and 4 will have to sail ahead past a moored tanker and be turned at or
near the berth. This may require a turning area near the new berths in Small Bay. The bulk carriers
with a ballast draught of less than 12 m can sail to their berth in Small Bay mostly outside the
dredged channel and at a larger distance from the moored ships.
4. COMPARISON OF BERTH OPTIONS
4.1 Risk Sources The risks associated with the increase in export volume can be related to two main categories, that
is, the risks per ship and the risks associated with the increase in ore export, which is the increase in
the number of ships and their interaction. The risk sources associated with each individual ship in
the areas which are relevant for a comparison of the four berth options are :
1. ship leaving the channel boundaries or safe anchorage area leading to grounding
2. accident or fire on board
3. collision with the jetty
4. collision with other ships (small or big), at anchorage or moored
5. accident with the tugs or the tug crew
6. severe ship motions or breaking of mooring lines due to passing ships
7. accident with dredger or pipelines during construction
8. disturbance of the bio-environment
9. spill of contaminated ballast water
10. supplies of food, supplies, etc. to the ship
11. solid and liquid waste (sewage) from the ship
12. illegal activities of the crew, spreading of diseases like HIV/AIDS
13. “horizon pollution”, i.e. visible disturbance of a natural environment
14. smoke and noise
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
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Since risk sources 8 and 9 will be the subject of separate specialist studies. Risk sources 10 to 14
have a spatial extent which is wider than the spatial extent of the four berth options and are thus
considered to be the same for all four options. Risk sources 8 to 14 are therefore ignored in the
present study. The remaining seven risk sources 1 to 7 are discussed below.
Most of the above risks will increase largely proportionally with the number of ore carriers handled in
the port, which is an expected increase of 107%. A non-proportional increase due to the increase in
shipping intensity will be a collision with or impact on a moored ship, since for access to the new
berths ore carriers will usually have to pass a bulk carrier or tanker moored at the jetty. Furthermore,
the partially laden or fully laden ore carriers will have to manoeuvre to the new berths in a confined
channel over a longer distance, which is close to harbour structures. A major effect of a grounding,
fire, collision or accident would be the potential spill of bunker oil. The worst case scenario would
be a spill of bunker oil of about 2 000 t, which is the typical load of bunker oil carried by the ore
carriers calling at Saldanha.
During the turning of an ore carrier in the existing turning basin, with the presence of a tanker at the
oil terminal, an accident could occur which may, in extreme conditions, involve the tanker. This
could lead to an oil spill from the tanker, either from its bunker fuel or its cargo. But it is more likely
that if a ship that is being turned is out of control, it will hit the outer caisson first.
To remove a grounded ship from a submerged bank of the navigation channel would be an urgent
and major operation, with a major impact on shipping operations and port revenue, and may have
serious environmental consequences should the ship’s hull be damaged.
There are risks which are directly related to the increase in iron ore transfer to the ships. Such risk
factors are, for example, an accident with the ship loader, iron ore spill at the quay or dust. Iron ore
in the port is mainly contaminating the environment through the dust generation associated with the
transfer of the iron ore from the trains to the stockpile, from the stockpile to the conveyor belt system,
at the conveyor belt transfer stations, from the conveyor belt system to the ship loader and from the
ship loader into the ship’s holds. Sea water pollution by spilled iron ore will most likely be dealt with
by another specialist.
4.2 Risk Impacts On the basis of their often combined impacts, the seven listed risk sources can be summarised into
the following categories : oil pollution, ship collision, tug accident, mooring problem due to passing
ships or environmental conditions and construction activities. An assessment of these impacts on
each of the four berth options will be presented in the following sections.
4.2.1 Oil pollution
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Oil pollution in the bay is usually caused by damage to the hull of the vessel, but can also be caused
by accidental operation of bunker or cargo pumps. At present, there are no bunkering facilities in
Saldanha and the risks of oil pollution due to bunkering are therefore not considered. The main
threat of oil pollution relates to the tankers moored at the tanker terminal. For Location 2, the
incremental shipping traffic will take place along the Langebaan side of the jetty, while the tankers
are moored on the Saldanha side, at the other side of the concrete jetty. Therefore, Location 2 will
have no impact on oil pollution risks involving tankers. However, for the other three locations, ore
carriers will have to pass moored tankers and oil spills from tankers could be a factor in these cases.
Most modern tankers have a double hull, so that rupture of the cargo tanks would only occur at a
high-speed collision or when the vessel breaks. Most modern bulk carriers also have a double hull
to protect their bunker tanks. The most likely cause of oil spill would be when the manifold coupling
between the tanker and the quay becomes dislocated. This could happen due to severe motions of
the moored tanker, e.g. due to a passing vessel.
A collision between a tanker and an ore carrier could occur if the bulk carrier, in ballast or partially
laden, were on its way to or from a berth of locations 1, 3 or 4 or to anchorage in Small Bay. During
this process, the bulk carrier could become out of control and collide with a moored tanker. This
would be most likely to occur during a north-westerly or westerly storm when the bulk carrier could
drift against the tanker (or against an ore carrier moored at the Saldanha side of the ore berth at the
jetty or against the concrete caisson structure or against the fenders). If this involves a tanker, it
could then happen that, due to the impact, the manifold connection between the tanker and the quay
would become dislocated and oil would leak into the water. Due to the almost immediate and
automatic shut down of the pumping of oil, the spill would be small and should be contained within
the floating oil boom which is always deployed around the tanker during oil transfer operations.
If such an accident should involve a bulk carrier, this may, in the worst case scenario, cause a
rupture of the bunker fuel tanks and subsequent leaking of bunker oil in the bay. The maximum load
of bunker fuel that an ore vessel in Saldanha would carry is about 2 000 tonnes. The fuel tanks are
at the forward and aft section of the vessel, usually with double-hull and double-bottom protection.
It is considered that oil pollution is the most severe of the potential impacts and is accepted to be
directly related to the intensity of shipping. The port operations risks of tankers have been related by
Capt Gilchrist and Dr Ian Borthwick (Specialist Study S10 in CSIR, 1996) to grounding, collision and
berthing / unberthing. These risks have been determined by fault-tree analysis to be 6,67.10-3/year
for grounding, with a minor oil spill, on the basis of 25 tanker visits to the port per year. This means
a probability of a serious course deviation of 2,7.10-4 per tanker. If this grounding or course
deviation risk value was also related to the iron ore bulk carriers, with the present maximum of 290
bulk carrier visits per year, the total risk per year would become 0,077 or statistically one spill every
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
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13 years. However, to apply these tanker oil spill risks to bulk carriers, which have much better
protected bunker tanks, is very conservative. On the other hand, the distance of channel
manoeuvring of the bulk carriers to the new berths will be more than for the tankers to the oil
terminal and the risks would therefore increase. Nevertheless, accepting this tanker probability also
for the increase in bulk carrier shipping to 600 ships per year, would result in an increase of one oil
spill to statistically once every 6,5 years. For bulk carriers, this would be a spill of bunker oil.
Over the past 30 years of port operations, with on average about 200 bulk carriers calling at the port
per year, no significant bunker oil spills related to bulk carriers have been reported. This is an
indication that bunker oil spills from bulk carriers would probably not be more than 1,7.10-4 per bulk
carrier, or about one spill per 10 years with a shipping intensity of 600 bulk carriers per year. Of this
total probability, the incremental effect of the two new berths, compared to the existing two berths,
will only be half, or statistically one accident of an individual ship with an oil spill every 20 years.
If a ship should run aground or hit a concrete structure (jetty or quay), it is likely, due to its relatively
low speed, that only the ship’s hull will be damaged and that the ship will remain afloat. Only
significant damage at critical locations at the lower hull would lead to grounding and/or bunker oil
spill. Should a bulk carrier collide with a tanker, as could be the case for location options 1, 3 and 4,
the consequence of the resulting oil spill could be larger, since a larger volume of oil could be spilled
and the crude oil could be more damaging to the environment. The floating oil spill would be spread
by wind and tidal currents, which would make containment more difficult in time after the accident.
Therefore, fast, efficient and effective response would be required to prevent the oil spill reaching the
shorelines.
On the basis of its track record, the Port of Saldanha is a safe port for shipping under the present
shipping and port operational guidelines. It is emphasised that the safety guidelines, rules and
regulations should be reviewed regularly by the marine staff of the port, as well as by experienced
and senior marine advisors, using feed back on critical situations. There should also be a constant
effort to further improve safety standards according to international practice, such as those reflected
in various IMO and ALA guidelines. In this way the port should be able to maintain its present safety
profile at world class standards. This requires that oil spill combat measures at the port, including
those for bulk carriers, should be at a highly operational level. The emphasis should be on
avoidance of oil spills and on reducing the scale of the impact.
4.2.2 Collision
During manoeuvring, a bulk carrier could collide with another vessel or a floating or fixed structure.
Such an incident could be caused by human error (the main factor of all shipping accidents) or by
technical failure of the vessel’s rudder or navigation or propulsion or manoeuvring support system.
In the case of Saldanha, a collision could take place with another manoeuvring vessel (e.g. a small
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craft, sailing boat, pilot boat, tug) or with a moored vessel. In the case of a small vessel, this vessel
will sustain most of the damage, with a possibility of loss of life. If an ore carrier was to collide with a
moored ship or with a hard structure like the jetty, the consequences could be much more severe.
The largest risk would be a collision between a manoeuvring bulk carrier and a moored tanker. At
present, up to 145 bulk carriers pass the oil terminal per year (half of the 290 per year, which are
moored at the Saldanha side of the jetty). This would stay the same for a realisation of location
option 2, but would increase about threefold to 455 (= 310 + 145) passing bulk carriers in the case of
location options 1, 3 or 4. This would therefore also increase the risk of a collision with the moored
tanker by a factor of about three. This is a significant increase in the risk of an oil spill in the Bay. In
the case of option 2, the probability of such a collision may remain (conservatively) once in 30 years,
but in the case of locations 1, 3 or 4 this may reduce to a probability of once in ten years. The
consequence of a possible resulting oil spill has been discussed in Section 4.2.1.
Human or navigation system failure and/or adverse weather conditions may lead to a collision. The
consequences will be less severe if the speed of the manoeuvring vessel is low. This should be an
important safety aspect of manoeuvring with the bulk carriers, that on passing other floating or fixed
structures the speed should be low enough (only a few knots) so that there would be time to take
counter measures and diminish the impact. For example, if navigation failure was to occur, the
assisting tugboats should be activated immediately to avert a collision. At reduced speeds, it is very
unlikely that the ship’s hull would be damaged to such an extent that the ship would sink. It would be
more likely that hull damage would occur which in the worst case would lead to water intake.
After experiencing hull damage, bulk carriers in ballast could proceed to anchor in the Bay for local
repairs. Laden bulk carriers have to stay in deep enough water, possibly in the dredged channel or
at a berth, to undertake the repairs. In the case where a laden vessel cannot continue its departure,
the cargo would have to be transferred into another bulk carrier (e.g. by floating grab crane).
4.2.3 Accidents with tugs
Tugs have to manoeuvre closely to the bulk carriers to provide manoeuvring assistance. Due to
human error or navigation system failure, tugs could collide with the bulk carrier. During line
handling or towing, a towing line could break and this could cause injury or death to one of the
tugboat crew members. Tugboat deck personnel should always be protected during towing activities
from being injured by breaking towing lines. Furthermore, the personnel should inspect the towing
line provided by the bulk carrier to make sure that this line is in good condition. For longer channels
and distances where tugs have to provide assistance, the risks of an accident are higher. Therefore,
these risks for locations 3 and 4 are somewhat higher than for locations 1 and 2.
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4.2.4 Mooring problems due to passing vessels
One of the potentially important shipping risks is related to the passing of fully laden ore carriers from
the new terminal past bulk carriers or a tanker moored at the jetty. Due to its draught, the laden
departing ore carrier has to navigate within the proposed widened dredged channel. The limited
channel bed width at this passing location at the jetty will result in a close passage of the ships, at a
distance of about twice the beam width of the vessels.
The channel bed width has been determined earlier as part of the engineering design of the required
safe bed width for 350 000 dwt ore carriers, on the basis of the required safe manoeuvring path
width of such a vessel. It has been realised that for the new terminal the design ship size is a
smaller-class ore carrier of 225 000 dwt, with a smaller beam width than the 350 000 dwt, and that
the channel bed width could consequently also be smaller. As part of the detailed engineering
design, this should be confirmed and quantified by ship manoeuvring simulations for the present
design ship size of 225 000 dwt. For this, the safe minimum distance from the passing vessel to the
moored ship should be determined first. Initial calculations indicate that the present conceptual
channel width design allows ships to pass at a safe distance (CSIR, 2006).
The safe channel bed width of the section where the channel passes the jetty should, besides the
safe width for navigation, also be based on the safe minimum distance from the manoeuvring vessel
relative to the moored vessel. It has been realised in studies for other similar ports (e.g. Newcastle
and Mermaid Sound in Australia, Europort – Rotterdam, Nordenham and Kiel in Germany, Milford
Haven in the UK and Durban) that the effect of a passing vessel on a moored ship is strongly related
to the passing distance, the speed of the manoeuvring vessel, the water depth and the displacement
of both vessels. If the passing distance is too small, the manoeuvring ship speed too high and the
water depth limited, the moored ship can be subject to strong hydrodynamic forces (up to several
thousand kN for surge and sway). These forces could lead to excessive mooring loads and the
breaking of mooring lines. If the moored ship would break loose, damage to this ship, to other ships
and to structures could occur, with associated risks of severe impacts on the environment. This has
indeed happened in reality as reported by Pinkster (2004).
Several researchers have investigated the effect of passing ships on moored ships, for various port
authorities, at different levels of sophistication. In most cases, for the detailed design of a channel
width, numerical and/or physical model tests have been performed. In addition, empirical
relationships have been established, that can be used to obtain a first level of quantitative results of
the forces involved as function of the various parameters.
In the present case, fully laden ships that depart from one of the new terminals may already have a
significant speed when they pass the jetty area, as the departing ship will have travelled over several
ship lengths. Due to cost and negative impacts of dredging, the access channel to the proposed
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
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new berths past the jetty should have a minimum safe bed width. One of the components of this
width should be determined by the maximum acceptable hydrodynamic forces generated by the
passing vessel. If these conditions are not investigated and quantified, this may lead to increased
risk above the present conditions. It is accepted that this aspect will be investigated and quantified
in more detail, as part of the engineering design.
4.2.5 Environmental mooring problems
Swell and particularly long-wave impacts on moored ships in Saldanha Bay have been experienced
and investigated (Moes et al, 2003). The mooring conditions at the new berths, deeper into the Bay,
are expected to be better than at the jetty, since the reflected long waves from the beaches of the
Bay will be more focussed on the jetty area. Therefore, the mooring conditions at locations 3 and 4
will be better than at locations 1 and 2.
Some ships have a very sensitive degree of stability. This is particularly the case with ferries, car
carriers and container vessels. Iron ore has a relative high density which means that the centre of
gravity of a loaded ore carrier lies very low. The height of the metacentric point is determined by the
hull shape, which in the case of bulk carriers with a large block coefficient is relatively high.
Therefore, the metacentric height, that is, the distance between the centre of gravity and the
metacentre point, is large. This means a high degree of stability. It is, therefore, very unlikely that
during normal loading operations a bulk carrier with iron ore will capsize. The loading of iron ore is
usually done by a limited degree of spreading from the centre of the hold. This means that only by
wilful and persistent incorrect loading at one side of the vessel the ship can start to heel. But even in
such a case, it is unlikely that an ore carrier will capsize at the berth.
An ore carrier is loaded by spreading the cargo of iron ore fairly evenly over the length of the vessel
or in alternated holds. Holds are loaded only partially before the ship loader moves to another hold,
according to a specific pattern. This would guarantee that the cargo loading on the ship’s structure
and the hydrostatic loads on the hull do not lead to overstressing of the ship’s structure. However, if
the prescribed fairly even loading pattern is not followed and a particular hold receives more iron ore
than should be allowed in accordance with the loading of the other holds, the stresses in the vessel’s
structure can become excessive. In the case of old ships, this could lead to breaking of the ship. If
this happened, iron ore in the hold where the break has occurred would be discharged on the
channel bed in front of the quay. It would require a grab crane to remove the iron ore from the
channel bed and a large crane vessel to remove the sections of the broken ship.
Since only certain compartments of the vessel may become flooded, while the bunker tanks will
remain closed, there is only a small chance that pollution will spread from the sunken vessel. The
bunker fuel should be well protected in its own tanks and should not be prone to bursting at an
external water pressure of up to 20 m head.
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4.2.6 Dredging and construction
Dredging work for new ore berths in Big Bay (location 2) will be mostly away from present shipping
activities, but if this takes place in Small Bay (for locations 1, 3 or 4), it will interfere with shipping to
the MPT and the offshore quay. This will be as a result of the presence of dredgers, floating
pipelines and quay wall construction vessels in the present dredged channel on the Saldanha side of
the causeway. The risk of accidents during construction is mainly related to material damage, bit in
the worst case, personal injuries could happen. The dredging and construction risks are only
present during the limited construction period. Maintenance dredging in the Port of Saldanha is
hardly required.
It should be noted that the volumes and cost of dredging and the implications and costs of relocation
of the Multi Purpose Terminal for location 3 are not considered in this report. These aspects will be
evaluated by other specialists or consultants.
5. CONCLUSIONS
The main environmental risks due to shipping in the Port of Saldanha are related to spillage of oil
due to shipping accidents and disruption of tanker (un)loading. Statistically, the occurrence of a
minor bunker oil spill due to the extended port facilities would be about once every 20 years. In
comparison with the oil spills that have occurred this figure appears to be conservative and could
also be mitigated by further precautionary measures and improved safety procedures. The risks of
oils spills due to the realisation of berth locations 1, 3 or 4 are significant higher than for location 2,
due to the presence of a moored tanker adjacent to the navigation channel for the ore carriers. It
should be noted that the probability of an oil spill in general is low and that good measures have
been implemented in preventing and combating any oil spills involving tankers.
Concerning each of the berth location options, the following can be concluded with respect to the
manoeuvring with bulk carriers to these new berths :
Location 1 :
� passing moored tankers, with the risk of a crude oil spill
� passing moored tankers and bulk carriers, with the risk of a collision and with hydrodynamic
impact on the moored vessels
� relatively short dredged channel, with turning at the berth and the risk of an accident with a
tugboat
� medium exposure to swell and long-wave action, berthing mostly into the wind
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
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� construction and dredging will interfere with sailing general cargo ships
Location 2 :
� no passing moored tankers and no risk of a crude oil spill
� passing moored bulk carriers, with the risk of a collision and with hydrodynamic impact on
the moored vessels
� relative short dredged channel, with turning in the turning circle or at the berth and the risk of
an accident with a tugboat
� exposure to swell and long-wave action, berthing mostly with the wind
� construction and dredging will hardly interfere with shipping
Location 3 :
� passing moored tankers, with the risk of a crude oil spill.
� passing moored tankers, bulk carriers and general cargo ships, with the risk of a collision
and with hydrodynamic impact on the moored vessels
� relative long dredged channel, with turning at the berth and the risk of an accident with a
tugboat
� low exposure to swell and long-wave action, berthing mostly into the wind
� construction and dredging will interfere with sailing general cargo ships
Location 4 :
� passing moored tankers, with the risk of a crude oil spill.
� passing moored tankers and bulk carriers, with the risk of a collision and with hydrodynamic
impact on the moored vessels
� medium length dredged channel, with turning at the berth and the risk of an accident with a
tugboat
� medium to low exposure to swell and long-wave action, berthing mostly into the wind
� relocation of Multi Purpose Terminal, construction and dredging will interfere with sailing
general cargo ships
The following table provides a quantitative overview of the environmental risks for a comparison of
each of the four berth location options. Each number, under the options, indicates the probability
score for each type of risk. A high score means a (relatively) high probability of occurrence. For a
comparison of the overall scores, the impact or consequences of each of the risks has been
indicated, with an associated weighting factor in the third column. A moderate impact leads to a
weight factor of 1, a moderate to large impact leads to a weight of 2 and a large impact leads to a
score of 3. The total score is indicated as the number at the bottom of the table.
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
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Table 0.1 Comparison of Environmental Risks
Type of Risk Option 1 Option 2 Option 3 Option 4
C P R C P R C P R C P R
Oil Spill L (3) 1 3 L (3) 0 0 L (3) 2 6 L (3) 2 6
Collision M (1) 2 2 M (1) 1 1 M (1) 2 2 M (1) 3 3
Accidents with
Tugs
MtL
(2)
1 2 MtL
(2)
1 2 MtL
(2)
2 4 MtL
(2)
2 4
Mooring
Problems Due to
Passing Ships
M (1) 1 1 M (1) 1 1 M (1) 2 2 M (1) 2 2
Mooring
Problems Due to
the Environment
M (1) 2 2 M (1) 2 2 M (1) 1 1 M (1) 1 1
Construction M (1) 1 1 M (1) 0 0 M (1) 1 1 M (1) 1 1
Total Risk
Score
11 6 16 17
C – Consequence
P – Probability
M - Moderate
L – Large
MtL – Moderate to Large
R - Risk
Although the probability of an oil spill for option 2 would not be exactly zero, the probability of an oil
spill occurring when no tanker would be involved is so small compared to the other options where a
moored tanker would have to be passed both upon arrival and at departure, that the probability for
option 2 can be rounded off to zero.
From the total risk score in this table it can be seen that Locations 3 and 4 score the highest and that
Location 2 scores the lowest on the overall comparison of risks associated with shipping impacts.
From these results and the conclusion from this comparison, it can be remarked that this outcome is
in agreement with the comments made in the perceived risks due to shipping. In most ports, tanker
terminals are dedicated and separated facilities, where the movement of other vessels nearby is
restricted as much as possible. In the case of the Port of Saldanha, passing of large ships along
moored tankers should be reduced to the absolute minimum for minimum risk. Although the risks in
absolute sense are small, they are not insignificant, as discussed in Section 4.2.2. This outcome
should weigh considerably in the overall outcome of the evaluation of the berth location options.
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
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7. REFERENCES
CSIR,1996. Environmental Impact Assessment : Proposed changes to oil transfer
operations : SFF, Saldanha Bay. Specialist studies report, Vol 2(ii). CSIR Report
ENV-S-C 96005D, Stellenbosch, December
CSIR,1997a. Environmental Impact Assessment : Proposed changes to oil transfer
operations : SFF, Saldanha Bay. Environmental impact report. CSIR Report ENV-
S-C 96005B, Stellenbosch, April
CSIR,1997b. Environmental Impact Assessment : Proposed changes to oil transfer
operations : SFF, Saldanha Bay. Summary report. CSIR Report ENV-S-C 97082,
Stellenbosch, July
CSIR, 2000. Portnet Saldanha : Environmental Impact Assessment : Specialist
report on shipping traffic risks. CSIR Report ENV-S-C 2000-139, Stellenbosch,
November
CSIR, 2006. Saldanha Bay iron ore export extension : channel design and ship
manoeuvring. CSIR Report CSIR/BE/IE/ER/2006/0093/B, Stellenbosch
CSIR, 2008. Environmental Impact Assessment: Phase 2 expansion of the
Saldanha iron ore export terminal: incremental shipping risks. CSIR Report,
Stellenbosch
Pinkster, 2004. The influence of passing ships on ships moored in restrictive
waters. Proc. OTC, Paper No. 16719, Houston
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
Figure 1 : Layout of the Port of Saldanha
Saldanha Bay
Saldanha
Big Bay
Small Bay
Ore loading
jetty
Langebaan
Lagoon
Atlantic
Ocean
Marcus I
BIG BAY
SMALL BAY
Port of Saldanha : Evaluation of Options for Additional Berth Location J Moes, August 2008
Incremental Shipping Risks
Figure 2 : Berth location options