This Section presents a summary of the key
conclusions of this EIA associated with the construction and operation of two
submarine gas pipelines and two Gas Receiving Stations (GRSs) at the Black
Point Power Station (BPPS). The
purpose of the assessment was to thoroughly evaluate the proposed Project in
terms of predicted impacts to key environmental sensitive receivers and to
determine whether this option can meet the requirements of the EIAO-TM.
15.2
Consideration of
Alternatives
This EIA Study has examined a series of Alternatives
as follows:
·
Consideration
of Alternative GRS Locations (Section 2.1);
and
·
Consideration
of Alternative Construction Methods & Sequences (Sections 2.2 to 2.4).
15.2.1
Consideration of Alternative GRS Locations
An alternative site location study was conducted to
determine the most suitable location(s) in proximity to the BPPS for the GRSs. The study was conducted to investigate
not only the environmental considerations of each location, but to include an
in depth examination of the engineering and technical aspects of the GRSs at
each location. The preferred
location that was taken forward to the EIA stage was based on locating one GRS
on existing land within the site boundary of the BPPS, and locating the other
GRS on newly reclaimed land adjacent to the existing GRS at BPPS at the same
location proposed as part of the HKLNG EIA ([1]).
This location provided a series of environmental benefits when compared
to the other locations examined, including:
·
A
reduction in the seabed areal extent of the reclamation, as one of the new GRSs
will be located on existing land within BPPS;
·
Avoidance
of potential impacts on terrestrial ecology as vegetation clearance and slope
cutting is avoided; and
·
A
reduction in dredging volumes through siting one GRS on existing land and
through selection of reclamation design and construction methodology, hence reducing
off-site impacts during disposal of dredged muds.
15.2.2
Consideration of Alternative Construction
Methods & Sequences
·
Reclamation: Two
construction options have been considered, the Fully Dredged Option and the
Partially Dredged Option. In line
with local construction practice, the Partially Dredged Option will be adopted
for the Project.
·
Submarine Gas Pipelines:
The submarine gas pipelines will require protection measures against
anchor drop and drag and so trenching for pipelines will be necessary in some
sections. An evaluation of three
installation methods, including grab dredging, dredging by trailing suction
hopper dredger and jetting, was undertaken to evaluate their engineering
feasibility, schedule implications and overall environmental performance. It was concluded that although all three
methods are viable and environmentally acceptable, grab dredging and jetting
will be adopted for this Project.
The use of jetting for certain sections of the pipelines alignment will
reduce the volumes of dredged material substantially from 0.428 Mm3
to 0.253 Mm3 (bulk volume) per pipeline. The adoption of jetting will also
shorten the period for marine construction works and hence reduce the severity
of impacts to marine ecological resources
·
Phasing: The Project
will involve two phases of construction works:
o
First
Phase: installation of the first
pipeline (Pipeline 1) and construction of the co-located GRS; and
o
Second
Phase: installation of the second
pipeline (Pipeline 2) and construction of the reclamation and the associated
GRS.
The construction of the two phases is expected to be
separate with the First Phase construction commencing in 2011 in order to
receive the replacement gas in 2012.
The Second Phase of construction is expected to commence within 24
months following commissioning of the First Phase. By phasing the works the arisings of
dredged muds will be spread out over a longer time period.
The potential impacts to air quality caused by
construction and operational activities of this Project have been assessed in Section 4 of this EIA Report. The impacts have been identified and
analysed to be in compliance with the criteria and guidelines stated in the EIAO TM Annexes 4 and 12
respectively.
One Air Sensitive Receiver (ASR, at the
With the implementation of standard mitigation
measures, no adverse impact associated with potential dust nuisance from dust
generating activities is anticipated during the construction phase. Gaseous emissions from the construction
plant are also minimal and no adverse impact to the ASR is anticipated.
During the operation phase, air emissions from the
gas heaters at the Gas Receiving Stations at BPPS were identified as potential
sources of air quality impacts. As
a conservative assumption, it was assumed that the gas heaters were operating
continuously. Even with this set of
assumptions, the modelling indicated that the air quality impacts are low and
well within the respective criteria at the identified ASR. No unacceptable air quality impact is
thus anticipated during operation of the project.
The potential impacts of noise caused by construction
and operational activities of this Project have been assessed in Section 5 of this EIA Report. The impacts have been identified and
analysed to be in compliance with the criteria and guidelines stated in the EIAO TM Annexes 5 and 13 respectively.
No existing NSR has been identified within the Study
Area, and no planned NSR has been identified within 2 km from the Project
Site. Potential noise impacts
arising from the construction and operation phases have been evaluated and it
was considered that potential noise impacts arising from the Project are
expected to be insignificant and acceptable. In view of the insignificant
construction and operation noise impacts, mitigation measures are therefore not
required and noise monitoring is also not considered to be necessary.
The potential impacts to water quality caused by
construction and operational activities of this Project have been assessed in Section 6 of this EIA Report. The impacts have been identified and
analysed to be in compliance with the criteria and guidelines stated in the EIAO TM Annexes 6 and 14
respectively.
Sensitive receivers potentially affected by
construction and operational activities of the Project have been identified and
the potential impacts have been evaluated.
The key sensitive receivers include the Sha Chau
and
Potential impacts arising from the proposed marine
construction works are predicted to be mainly confined to the specific works
areas. Modelling results indicate
that the suspended solids elevations as a result of the proposed marine works
are expected to be compliant with the assessment criteria at the point specific
sensitive receivers in both seasons.
The predicted elevations of suspended sediment concentrations during the
construction phase are transient in nature and not predicted to cause adverse
impacts to water quality at the sensitive receivers.
Results of operation-phase computational modelling
indicated that unacceptable impacts to hydrodynamic regime, water quality and
sedimentation pattern as a result of the proposed reclamation are not expected
to occur as the reclamation is very small.
Projects that are planned to be constructed at the
same time of this Project have been evaluated for potential cumulative water
quality impacts and the assessment indicates that cumulative impacts are not
expected to occur due to the large separation distance of these concurrent
projects with this Project.
Water quality monitoring is recommended for the
construction phase and the specific monitoring requirements are detailed in the
Environmental Monitoring and Audit (EM&A) Manual associated with this EIA Report. As no unacceptable impacts have been predicted
to occur during the operation of the GRSs and submarine pipelines, no
mitigation measures or monitoring are considered necessary.
The potential impacts to waste management
caused by construction and operational activities of this Project have been
assessed in Section 7 of this EIA
Report. The impacts have been
identified and analysed to be in compliance with the criteria and guidelines
stated in the EIAO TM Annexes 7 and 15 respectively.
The key potential impacts during the construction
phase are related to wastes generated from dredging, reclamation, seawall
construction, filling and concreting.
The storage, handling, collection, transport, disposal and/or
re-utilisation of these materials and their associated environmental impacts
have been the primary focus of the assessment.
The Project is planned to take place in
phases. For the First Phase of the
Project, Sections 1 and 3 of the pipeline would be installed by dredging while
Sections 2 and 4 of the pipeline would be installed by jetting. About 0.253 Mm3 (bulk volume)
sediment will be generated from Sections 1 and 3 of the pipeline. The final volumes will be subject to
detailed sediment sampling, testing and analysis in accordance with the PNAP 252 and disposal method reviewed
prior to the commencement of the dredging activities. About 0.029 Mm3 (bulk volume)
of the dredged sediment is expected to be Category L sediment. MFC has no objection in-principle to
allocating disposal space for the Mfail sediment dredged from Sections
1 and 3 of the pipeline route (about 0.060 Mm3 bulk volume), subject
to the availability of disposal space at the time of CAPCO's application and at
the proposed programme for disposal.
CAPCO is exploring alternative disposal sites (such as cross boundary
disposal to Mainland
The Second Phase Project is expected to
also generate approximately 0.253 Mm3 (bulk volume) from the
installation of the submarine pipeline.
At present the dredging works for the reclamation for the second GRS are
expected to give rise to a bulked volume of 0.156 Mm3 of
contaminated mud.
It is estimated that a total bulk volume
of 0.828 Mm3 of fill materials are required for this Project, and
surplus public fill material is not anticipated. Other wastes produced during the
construction phase are of small quantity and will be disposed of according to
their nature, avoiding any potential adverse impact.
The operation of the GRSs will generate
minimal quantity of waste, and the potential environmental impacts associated
with the storage, handling, collection, transport and disposal of waste
produced during operational activities have been estimated to be not
significant and will therefore meet the criteria specified in the EIAO TM.
Potential
impacts as a result of the waste produced during the construction phase have
been reduced through the adoption of specific mitigation measures and in particular through the establishment
and implementation of a Waste Management Plan (WMP).
In order to confirm that the construction
Contractor(s) has implemented the recommendations of the EIA Report, regular
site inspections and audits will be conducted of the waste streams, to
determine if wastes are being managed in accordance with the approved
procedures and the site WMP. An
appropriate inspection programme should be undertaken with the first inspection
conducted at the commencement of the construction works. Routine site inspections should also
include waste management issues.
The potential impacts to marine ecology
caused by construction and operational activities of this Project have been
assessed in Section 8 of this EIA
Report. The impacts have been
identified and analysed to be in compliance with the criteria and guidelines
stated in the EIAO TM Annexes 8 and 16 respectively.
Ecologically
sensitive receivers have been identified and the key sensitive receivers
include the Sha Chau and
A
series of detailed field surveys were conducted during the dry and wet season
of 2009 to examine the baseline conditions of the habitats and assemblages
within and around the Project’s footprint.
A comprehensive data review of marine mammal baseline conditions was
also undertaken using data collected from January 2005 to June 2009 in the
Permanent habitat loss due to 0.5 ha of
reclamation and short-term disturbance of habitats are considered as
environmentally acceptable since the areas affected are relatively small in the
context of the extent of similar habitat available in the vicinity and the
generally low ecological value of the affected assemblages. Disturbed habitats are also expected to
be recolonised by similar assemblages.
Results of the water quality modelling activities indicate that the
impacts arising from the marine works will be transient and confined to the
works areas. It is therefore
predicted that there will be no unacceptable impacts to the marine ecology
(including marine mammals) of the Study Area as a result of construction
activities. During the operation
phase, since unacceptable impacts to water quality are unlikely to occur,
indirect impacts to marine ecology are also not anticipated.
Projects that are planned to be
constructed at the same time of this Project have been evaluated for potential
cumulative impacts and the assessment indicates that cumulative impacts are not
expected to occur due to the large separation distance of these concurrent
projects with this Project.
Potential
impacts to marine mammals, have been reduced through the adoption of specific
mitigation measures including the use of predefined/ regular routes and speed
limit for marine works vessels in
this Project, and the adoption of marine mammal exclusion zones during marine
dredging/ jetting works. Additional
marine mammal monitoring programme are also recommended for the construction
phase and details of the marine mammal monitoring programme are presented in
full in the EM&A
Manual associated with this EIA Report.
Marine ecology specific operation phase monitoring is not considered
necessary.
The mitigation measures designed to
mitigate impacts to water quality to acceptable levels (compliance with
assessment criteria) are also expected to mitigate impacts to marine ecological
resources. Monitoring activities
designed to detect and mitigate any unacceptable impacts to water quality
during construction phase are also expected to serve to protect against
unacceptable impacts to marine ecological resources. The water quality monitoring programme
will provide management actions and supplemental mitigation measures to be
employed should impacts arise, thereby ensuring the environmental acceptability
of the Project.
The potential impacts to commercial fisheries
caused by construction and operational activities of this Project have been
assessed in Section 9 of this EIA
Report. The impacts have been
identified and analysed to be in compliance with the criteria and guidelines
stated in the EIAO TM Annexes 9 and 17 respectively.
Fisheries
sensitive receivers have been identified and the key sensitive receivers
include spawning ground of commercial fisheries resources in north Lantau,
artificial reefs in the
Potential impacts to fisheries resources
and fishing operations during the construction phase may arise from the
permanent loss of habitat due to reclamation, short-term disturbances to
fishing grounds, and increased underwater sound, as a result of the marine
works. The water quality modelling
activities completed in Section 6
indicate that the impacts arising from the marine works are predicted to be
largely confined to the specific works areas and the predicted elevations in
suspended sediment concentrations are not predicted to cause large areal
exceedances of the assessment criterion.
Adverse impacts to water quality are thus not predicted and neither are
consequential impacts to any fishing grounds or species of importance to the
fisheries. During the operation
phase, since unacceptable impacts to water quality are unlikely to occur,
indirect impacts to fisheries are also not anticipated. Potential obstruction to fishing activities
due to pipeline armour rock placement is not anticipated as it will be
installed below or flush with the existing seabed. The seabed temporarily affected by the
pipeline works is, therefore, expected to be restored to its original
configuration.
No fisheries-specific mitigation measures
are required during construction or operation activities as impacts to the
fisheries resources and fishing operations are small and of short
duration. The mitigation measures
designed to mitigate impacts to water quality to acceptable levels (compliance
with assessment criteria) are expected to mitigate impacts to fisheries
resources. The water quality
monitoring programme will provide management actions and supplemental
mitigation measures to be employed should impacts arise, thereby ensuring the
environmental acceptability of the Project. To confirm that the seabed affected by
the pipeline works has restored to its original configuration, a geophysical
survey will be conducted following completion of pipeline works.
The potential impacts to the landscape and
visual sensitive receivers caused by the presence of the GRSs at BPPS have been
assessed in Section 10 of this EIA
Report. The impacts have been
identified and analysed to be in compliance with the criteria and guidelines
stated in the EIAO TM Annexes 9 and 17 respectively.
The assessment has covered a wide
range of potential landscape impacts including the alteration of the landscape caused by the reclamation, the
introduction of the GRSs in BPPS’s industrialised landscape and the impacts on
existing and planned sensitive receivers during construction and operation of
the GRSs. The overall residual
impacts on the Landscape Resources are assessed as negligible to slight.
There will be very limited views of the
GRSs from most land based viewing locations. The visual impacts will be larger for
the ocean based VSR’s from the
According to EIAO TM the
Landscape and Visual Impacts are considered acceptable
with mitigation. Measures have
been proposed to mitigate the effects of the development.
The potential impacts to cultural heritage
caused by construction and operational activities of this Project have been
assessed in Section 11 of this EIA
Report. The impacts have been
identified and analysed to be in compliance with the criteria and guidelines
stated in the EIAO TM Annexes 10 and 19 respectively. The
assessment has included a Marine Archaeological Investigation.
There
are no declared/ deemed monument, graded/ recorded heritage resources, Built
Heritage or Archaeological Sites located within the Project Area, and no sites
of cultural heritage protected under the AM
Ordinance have been identified.
Therefore construction and operational impacts to sites of cultural
heritage are not expected.
Findings
of the Marine Archaeological Investigation concluded that no marine sites of
cultural heritage/ archaeological value are present in waters surrounding Black
Point and along the proposed pipeline corridor. As such, no impacts to marine
archaeological resources are expected.
No
impacts on potential cultural heritage and archaeological resources are
expected to occur during the operation of the submarine pipelines and
GRSs. As no impacts are expected,
no mitigation measure is required.
The assessment has evaluated the hazards to life
associated with the submarine gas pipelines and the GRSs. The assessment has concluded that the
risks related to the operation of the submarine gas pipelines and the GRSs are
acceptable as per the individual and societal risk criteria set out in Annex 4 of the EIAO TM.
15.12
Environmental
Monitoring & Audit
The construction and operation of the proposed
Project has been demonstrated in this EIA Report to comply with the EIAO-TM requirements. Actual impacts during the construction
works will be monitored through a detailed Environmental Monitoring and Audit
(EM&A) programme. Full details
of the EM&A programme are presented in the EM&A Manual attached to this EIA Report. This programme will provide management
actions and supplemental mitigation measures to be employed should impacts
arise, thereby ensuring the environmental acceptability of the construction and
operation of this Project.
No unacceptable residual impacts have been predicted
for the construction and operation of this Project. It must be noted that for
each of the components assessed in the EIA
Report, the assessments and the residual impacts have all been shown to be
acceptable and in compliance with the relevant assessment standards/criteria of
the EIAO TM and the associated Annexes.
15.14
Environmental
& Other Benefits of the Project
There are a number of advantages to the commissioning
of this gas supply project for BPPS, which are summarized below.
1.
Support of Government policy:
Natural gas is widely recognised as a comparatively clean burning fuel
and its use is encouraged in the 2005 Policy Address and the current Air
Quality Objective Consultation to control emissions from existing power
stations in
2.
Fuel
security and reliable supply of electricity: Dependable
fuel sources are critical to maintain reliable power supply to our customers
while providing environmental benefits.
This Project allows CAPCO to secure sufficient and dependable
replacement gas in a timely manner and to meet ongoing and future needs.
3.
Environmental
benefits: With sufficient replacement natural gas,
CAPCO will be able to maintain compliance with air emission standards. As natural gas emits virtually no
particulates and negligible SO2, as well as less NOx and
CO2 than other fossil fuels, it will contribute to further
improvements in the regional and local air quality.