1
Environmental Assessment
An
evaluation of the potential impacts identified in Part 3 – Section 2.1 as a result of the construction and operation
of each of the Black Point terminal options has been undertaken to determine
the key issues. The importance (ie
significance) of potential impacts has been evaluated using the concepts
described within the aforementioned section.
The result of this evaluation is presented below. From these results, a comparison of each
layout and design option is presented based on the number of important or
significant issues.
1.1
Accidental Spills/Leaks/Dropped Objects
Accidental
events such as spills and leaks, vessel grounding/ collisions, dropped objects
and loss of materials either on land or into the sea during construction or
operation of the LNG terminal may have the potential to result in adverse
impacts on the environment and personnel injury.
The
severity of impacts as a result of accidental events will depend on a number of
factors including the nature of the event (ie type of hazard – hazardous
material release, physical impact etc.), the magnitude of the event (eg
quantities of material actually released) as well as the sensitivity of the
environment at the accident location/ impact site.
Whilst the
consequences (ie scale of damage) resulting from accidental events may be
severe, the likelihood of their occurrence is typically unlikely to very
unlikely. However, this resultant low
level of risk associated with such events is traditionally only achieved by the
application of the highest standards of HSE management including hazard
identification, risk assessment and the implementation of extensive control and
recovery measures. Nevertheless,
regardless of the layout and design, each option is considered to have a
negligible impact due to the unlikely event of such an event occurring.
The
evaluation of impacts as a result of accidental spills/leaks/dropped objects for
each of the Black Point terminal layout options are presented in Table 1.1.
Table
1.1 Evaluation of Impacts for Accidental
Spills/Leaks/Dropped Objects
Air quality impacts may
potentially arise through the following:
·
Construction
vehicle/equipment/ vessels engine exhaust emissions (eg. primarily
·
Construction emissions from
concrete batching plant; and,
·
Operational emissions from
SCVs, LNG carrier generators during unloading of LNG, gas-turbine generators,
onsite vehicles, emergency generators, diesel-driven firewater pumps and the
hydrocarbon emissions from emergency venting (e.g., NOx, CO, SO2 and
HC).
Due to the
relatively remote location of the Black Point terminal the implementation of good site practice and
the control measures stipulated in the Air
Pollution Control (Construction Dust) Regulation, the adverse air quality
impact arising from the above potential sources during construction phase is not expected. Associated impacts are therefore considered
to be negligible for all options.
Emissions associated with the concrete batching plant to be located
during construction works may, however, result in low impacts to air quality,
regardless of layout design. Similarly,
as each layout would require the installation of provisions for emergency
venting of gas, potentially low impacts to air quality may result during
operations. Impacts to air quality may
also affect visibility, hence aesthetics, albeit likely to be of negligible
impact for all layout options.
The
evaluation of impacts to air emissions for each of the Black Point terminal
layout options are presented in Table 1.2.
Table
1.2 Evaluation of Impacts for Air Emissions
Potential
sources of impact through run-off during the construction and operation of the
LNG terminal may include:
·
Rainfall run-off from disturbed site areas/
construction material stockpiles; and,
·
Entrainment of debris and refuse in
stormwater run-off resulting in the fouling of receiving water resources.
Runoff and
drainage from the earthworks and construction areas may contain elevated
sediments loads resulting in increased turbidity in the surrounding
waters. Such increases may subsequently
affect marine organisms that inhabit these waters. Run-off may also contain debris (litter) as
well as other contaminants (eg oil, grease, fuels etc) unless effectively
controlled on-site.
It is
considered that although control measures will likely be enforced to reduce
surface run-off in each of the layout options, environmental impacts to
resources/receptors would range from negligible (ie aesthetics) to those which
may be considered to be of low impact (ie water quality, intertidal/ subtidal
habitats, etc) due to the ecological value of these sensitive receivers. Due to the extent of excavation works and
land based site formation associated with Option 3 – Full Excavation, impacts
to groundwater characteristics are considered to be potentially more severe for
this layout.
The
evaluation of impacts from run-off for each of the Black Point terminal layout
options are presented in Table 1.3.
Table
1.3 Evaluation of Impacts for Run-off
Potential
sources of impact through blasting works during the construction of the LNG
terminal may include:
· Acute
increases in environmental noise and subsequent impacts to biological and human
sensitive receivers within proximity to works; and
· Exposure
to hazardous substances with subsequent concerns to health and safety.
Each of
the three layout options will involve the use of explosive materials to conduct
blasting operations during the excavation of rock from the existing
hillsides. Regardless of the volume of
blasting to be required, magazine storage and explosive manufacturing plant
will be temporarily located on site. The
storage and use of such materials have the potential to result in adverse
impacts through direct exposure to blast materials, ie habitat and terrestrial
flora and fauna, and indirect impacts through increased noise, vibration and
noise. Although underwater blasting is
not necessary for the construction of any of the potential layouts, it can be
expected that terrestrial works may have adverse consequences on marine
habitats and organisms, albeit likely to be of negligible consequence. Due to the extent of excavation works and
land based site formation associated with Option 3 – Full Excavation, impacts
from blasting are considered to be potentially more severe for this layout.
The
evaluation of impacts associated with blasting during construction for each of
the Black Point terminal layout options are presented in Table 1.4.
Table
1.4 Evaluation of Impacts for Blasting
1.5
Discharges to Soil/ Groundwater
Potential
sources of soil and groundwater contamination associated with the construction
and operation of the LNG terminal may include:
·
Inappropriate storage/ handling and
disposal of waste materials;
·
Accidental spills and leaks of
environmentally hazardous materials (oils, cleaning residues, hazardous
materials etc); and
·
Inappropriate management and control of
on-site operations (including effluents, fuel and hazardous material storage
and use etc).
Minor
spills during re-fuelling, lube/ hydraulic oil, oil filter etc. change-outs
from construction equipment (eg generator sets) and vehicles have the potential
to result in localised contamination. A
leak from a temporary fuel storage tank has the potential to cause significant
soil and groundwater contamination.
Risks of soil and groundwater contamination can be controlled via
effective operational and hardware control measures. Providing such measures are identified and
are implemented in an effective manner, risks of contamination can be
maintained to within acceptable levels.
Due to the extent of excavation works and land based site formation associated
with Option 3 – Full Excavation, impacts to groundwater characteristics are
considered to be potentially more severe for this layout..
The
evaluation of impacts associated with discharges to soil/groundwater for each
of the Black Point terminal layout options are presented in Table 1.5.
Table 1.5 Evaluation of Impacts for Discharges to
Soil/Groundwater
1.6
Effluents
(Cleaning/Recycling/Disposal)
Potential
impacts to resources/receptors through effluent (cleaning/recycling/disposal)
associated with the construction and operation of the LNG terminal may include:
· Wastewater
from typical construction activities (eg. concreting, dredged spoil storage/
removal, painting etc);
· Sanitary
effluents from temporary chemical toilets for construction workers’ day use;
and
· Routine
disposal of operational effluents (ie ‘black water’ composed of human body
wastes from toilets and urinals and ‘grey water’ from showers, sinks,
laundries, kitchens etc) from operational staff.
In order
to clean/recycle/dispose of effluents generated through the construction and
operation of the LNG terminal it is expected that all effluents will be treated
within the existing Black Point Power Station Terminal wastewater treatment
system. Effluents would then be
discharged in accordance with the existing discharge license to prevent any
unacceptable adverse impacts to the environment from occurring.
For the
purposes of this consideration of alternatives, it has been determined that
each layout would have the potential to result in similar low to negligible
environmental impacts to resources/receptors as a result of effluent generation
and discharge, regardless of configuration or design.
The
evaluation of impacts from effluents (cleaning/recycling/disposal) for each of
the Black Point terminal layout options are presented in Table 1.6.
Table
1.6 Evaluation of Impacts for Effluents
(Cleaning/Recycling/Disposal)
Excavation
will be required for each layout option as part of the construction of the
Black Point terminal for the following reasons:
· To
enable the tanks to be founded directly onto rock which will permit the use of
pad/raft foundations, thus negating the need for deep foundations; and
· To
screen the tanks from the visually sensitive receivers at Lung Kwu Tan.
Impacts
associated with the excavation of material associated with the construction
will primarily occur through dust generated through excavation activities,
increased in terrestrial noise and visual and aesthetic impacts through
alteration of the existing landscape. In
addition, due to the identification of sites of archaeological interest and
cultural resources within the areas required to be excavated, impacts to such
will occur.
On
the basis of the designs of each layout, Options 1 and 3 will require the
excavation of a total of 0.99 Mm3 and 14.0 Mm3,
respectively, of soil and rock. In contrast,
Option 2 will only require minimal excavation.
As the location of the removal of material is relatively similar, ie
Black Point Headland, it would be fair to assume that the differences in
excavated material requirements would have similar differences in the potential
for impacts to occur. As such, Option 2
would be considered favourable over Options 1 and 3, with Option 3 least
favourable.
The
evaluation of impacts from excavation for each of the Black Point terminal
layout options are presented in Table 1.7.
Table
1.7 Evaluation of Impacts for Excavation
Vessel
anchoring (anchor deployment and recovery) within the vicinity of the
construction site will result in localised seabed sediment/ substrate
disturbance and alterations to the seabed profile. Anchor operations may also result in
secondary impacts on water quality (local increases in turbidity) and harm to
the subtidal marine fauna living in the seabed.
It is likely that any impacts that may occur would be more severe during
construction operations when there will be increased marine traffic to the site
and the higher likelihood of anchoring occurring. Impacts, however, would be expected to be
similar between options regardless of layout design.
The
evaluation of impacts from marine anchoring for each of the Black Point
terminal layout options are presented in Table
1.8.
Table
1.8 Evaluation of Impacts for Marine
Anchoring
1.9
Marine Dredging and Disposal
Marine
dredging operations during construction may release sediment into suspension
within the surrounding waters by the following mechanisms:
·
Impact of the dredging equipment (eg grab,
trailer arm) on the seabed as it is lowered;
·
Washing of sediment off the outside of the
grab as it is raised through the water column and when it is lowered again
after being emptied;
·
Leakage of water from the grab as it is
hauled above the water surface;
·
Spillage of sediment from over-full grabs;
·
Loss from grabs which cannot be fully
closed due to the presence of debris;
·
Release by splashing when loading barges by
careless, inaccurate methods;
·
Disturbance of the seabed as the closed grab
is removed, which may be exacerbated by the release of gas (if present) from
the disturbed sediments;
·
During the transport of dredging materials,
sediment may be lost through leakage from barges;
·
Changes in hydrodynamics due to changes in
bathymetry; and,
·
Aesthetic impacts through generation of
sediment plumes.
The
disposal of this dredged spoil material has the potential to result in a range
of direct and indirect adverse impacts including:
·
Water column impacts (elevated suspended
solids levels during spoil discharge);
·
Indirect effects on marine ecology due to
degraded water quality;
·
Alteration of seabed sediments
(accumulation of dredged material);
·
Smothering effects on benthic (seabed)
ecology;
·
Indirect effects on fisheries due to both
degraded water quality as well as seabed deposition of spoil; and,
·
Aesthetic impacts through generation of
sediment plumes.
Each of
the three options will require dredging of marine sediments through the
construction of the approach channel and turning circle. Due to the proximity of Black Point within
the Pearl River Estuary, it would be expected that maintenance dredging for
each of these sites would be relatively similar. Further more, as each layout is considered to
be relatively close to the Sha Chau and
The
evaluation of impacts from marine dredging and disposal for each of the Black
Point terminal layout options are presented in Table 1.9.
Table
1.9 Evaluation of Impacts for Marine
Dredging and Disposal
Construction
will generate additional marine traffic within and into the study area. Marine vessel traffic generated by the
project will include vessels for dredging, construction barges, delivery of
equipment, materials and supplies and removal of marine dredged material. These additional vessel movements have the
potential to cause:
·
Increased marine accidents;
·
Interference with vessels approaching,
departing and moored in the immediate surroundings;
·
Interference with other marine vessels, eg
recreational, fishing vessels etc.;
·
Increase in terrestrial and underwater
noise; and
·
Increase in likelihood for collision with
marine mammals.
For the
purposes of this consideration of alternatives, it has been determined that
each layout would have the potential to result in similar environmental impacts
to resources/receptors as a result of marine traffic, regardless of
configuration or design.
The
evaluation of impacts from marine traffic for each of the Black Point terminal
layout options are presented in Table
1.10.
Table
1.10 Evaluation of Impacts for Marine Traffic
The
principal sources of noise during construction activities will include:
·
Piling (hydraulic hammer type piling rig);
·
Blasting (explosives);
·
General construction equipment (eg. compressors,
cranes, generators sets etc.) and activities (hammering, cutting, grinding,
welding etc.); and
·
Transport vehicles (cars and
trucks)/construction vessels.
It is
assumed that the equipment to be employed during the construction of the site
would be similar regardless of which layout design would be constructed. Operational noise associated with the
terminal is not expected to be severe.
For the
purposes of this consideration of alternatives, it has been determined that
each layout would have the potential to result in similar environmental impacts
to resources/receptors as a result of noise, regardless of configuration or
design.
Note that
potential ecological impacts and impacts on fisheries associated with
underwater noise generated during piling works are included in Section 1.12 below.
The
evaluation of impacts from noise for each of the Black Point terminal layout
options are presented in Table 1.11.
Table
1.11 Evaluation of Impacts for Noise
Piling
will cause vibration in the surrounding seabed/ ground. Driving of piles in water will generate a
certain amount of underwater sound.
Other underwater sound generation will occur from additional marine
construction activity, such as dredging as well as support vessel operations
(eg. propeller/ engine noise etc.).
Excessive
underwater sound generation has the potential to disturb marine life (eg. fish,
turtles, mammals etc.). Marine mammals
rely on acoustic information to communicate and to explore their
environment. Therefore, it is desirable
to attenuate intensive sounds.
Piling
operations will be required for all layouts in order to construct the jetty and
trestle for the LNG carrier.
The
evaluation of impacts from piling activities for each of the Black Point
terminal layout options are presented in Table
1.12.
Table
1.12 Evaluation of Impacts for Piling
The engineering
design of Option 1 – Base Case and Option 2 – Full Reclamation will require the
reclamation of approximately 16 hectares (ha) and 19 ha, respectively, of
existing marine habitats. In comparison,
Option 3 – Full Excavation will require only minimal reclamation of marine
habitats.
The
differences in reclamation area will result in subsequent increases in
potential impacts to resources and receptors, such as those to water quality,
marine habitats (both intertidal and subtidal), marine mammals, fisheries
resources and operations as well as visual and aesthetics. These differences have been reflected in the
impact severity and likelihood assessments.
The
evaluation of impacts from reclamation for each of the Black Point terminal
layout options are presented in Table
1.13.
Table
1.13 Evaluation of Impacts for Reclamation
Site
formation works at each option will involve the consideration of the volume of
excavated materials, the potential for afteruse, slope stabilisation and
maintenance. It is noted that volumes of
excavated material and afteruse are considered under excavation and waste
generation and disposal, therefore for the purposes of assessing the
environmental consequences of site formation the focus has been to identify any
key differences between overall site formation, stabilisation and maintenance.
Each of
the three layout options will be prepared, excavated and stabilised in similar
formats (see Section 1.7 above). As such, it is expected that the differences
between the three layouts will not be significant to differentiate between in
terms of environmental impacts. Similar
impacts to waste generation and disposal as well as landscape, aesthetics and
archaeological resources may then be expected to occur for each layout. Thus, for the purposes of this consideration
of alternatives, it has been determined that each layout would have the
potential to result in similar environmental impacts to resources/receptors as
a result of site formation , regardless of configuration or design.
The
evaluation of impacts from site formation for each of the Black Point terminal
layout options are presented in Table
1.14.
Table
1.14 Evaluation of Impacts for Site Formation
1.15
Waste Generation and Disposal
All
options will require the excavation of rock from the existing hillsides in
order to provide sufficient flat land to meet the functional requirements of
the LNG terminal. However, as the Option
2 layout design will only require negligible excavation, it is assumed that
this material can be re-used onsite. In
addition, it is expected that up to 6.5 Mm3 of rockfill will need to
be imported, possibly from existing construction and demolition (C&D) waste
storage facilities.
In
contrast to Option 2, the design of Option 3 - Full Excavation will result in a
surplus of approximately 14.0 Mm3 of rock following excavation and
construction works. This material will
be exported to allocated waste disposal facilities and would be considered as a
potentially high impact to such facilities.
The
evaluation of impacts waste generation and disposal for each of the Black Point
terminal layout options are presented in Table
1.15.
Table
1.15 Evaluation of Impacts for Waste Generation
and Disposal
During the
operation of the LNG terminal discharges will include cooled water, as seawater
will be used for warming the LNG in the Open Rack Vaporizers. For operational reasons, the discharges will
likely contain antifoulants. Although
all discharges will be designed to comply with the Water Pollution Control Ordinance Technical Memorandum on Standards
for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal
Waters there is the potential for impacts to occur to marine ecological and
fisheries habitats within the surrounding waters.
For the
purposes of this consideration of alternatives, it has been determined that each
layout would have the potential to result in similar environmental impacts to
resources/receptors as a result of antifoulant discharge, regardless of
configuration or design.
The
evaluation of impacts from antifoulants for each of the Black Point terminal
layout options are presented in Table
1.16.
Table
1.16 Evaluation of Impacts for Antifoulants
As
mentioned above, the operation of the terminal is expected to involve the intake
of seawater into open rack vaporisers and the discharge of cooled
seawater. The volume of seawater intake
and the cooled seawater in the effluent has the potential to impact marine
ecological and fisheries habitats in the surrounding waters through a localised
reduction in water temperature.
As with
antifoulants, for the purposes of this consideration of alternatives, it has
been determined that each layout would have the potential to result in similar
environmental impacts to resources/receptors as a result cooled water
discharge, regardless of configuration or design.
The
evaluation of impacts from cooled water discharge for each of the Black Point
terminal layout options are presented in Table
1.17.
Table
1.17 Evaluation of Impacts for Cooled Water
Discharge
The
construction of the reclamation, jetty and dredged areas will result in
localised alterations in the water flows (both in terms of velocity and
direction). Altered water flows have the
potential to result in secondary effects on the sedimentary regime in the
vicinity of the site; increased or changed water flow patterns have the
potential to result in localised scour (ie. resuspension) of seabed sediments. Conversely the creation of areas of calmer or
lower velocity water flows have the potential to result in increased
sedimentation effects.
The
reclamation requirements for layout Options 1 and 2 may be expected to
potentially change the hydrodynamics in the surrounding waters. Impacts as a result of these changes may
occur to water quality, marine ecological and fisheries sensitive
receivers. In addition, the extended
footprint of Option 2 – Full Reclamation would likely increase the exposure to
visual sensitive receivers south of the site.
Such operational impacts are considered to be a disadvantage of this
layout in comparison to the others under investigation.
The
evaluation of impacts from the layout characteristics for each of the Black
Point terminal layout options are presented in Table 1.18.
Table
1.18 Evaluation of Impacts for Layout
Characteristics
