Report Ref: R8109/06 Issue 6
Date: September November 2005
Agreement No. CE 18/2002 (EP)
Environmental Impact Assessment
Study for
Construction of Helipads at
Peng Chau and Lamma Island -
Investigation
EIA Study for Helipad at
Yung Shue Wan, Lamma Island
Final EIA Study Report
BMT Asia Pacific Limited in Association With:
Hyder Consulting Limited
Asiatic Marine Limited
Archaeo-Environments Limited
Cosine Limited
Client:
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Civil Engineering and Development Department
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Title:
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EIA Study for Helipad at Yung Shue
Wan, Lamma Island
Final EIA Study Report
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Job No:
|
8109
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Ref:
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R/8109/06 Issue 6
|
Version:
|
Final
|
Date:
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September November 2005
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Prepared under the Management of:
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Signature:
|
|
Name
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Antony Wong
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Position
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Environmental Consultant
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Reviewed and Approved by:
|
|
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Name
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Ben Ridley
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Position
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Director
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Distribution: Original to Project Quality Records File
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Page: 1 of 1
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CONTENTS
1 Introduction 1-1
1.1 General 1-1
1.2 Project
Background 1-1
1.3 Purpose
and Approach of the EIA Study 1-2
1.4 Structure
of this EIA Study Report 1-3
2 Project
Description 2-12-12-12-12-3
2.1 Key
Project Requirements 2-12-12-12-12-3
2.2 Project
History and Site Selection 2-22-22-22-22-4
2.3 Project
Characteristics and Site Location 2-10
2.4 Nearby
Projects 2-11
2.5 Likely
Future Environmental Conditions Without the Project 2-12
3 Air
Quality Impact Assessment 3-1
3.1 Introduction 3-1
3.2 Relevant
Guidelines, Standards & Legislation 3-1
3.3 Baseline
Conditions and Air Sensitive Receivers 3-2
3.4 Construction
Dust Impact Assessment 3-4
3.5 Mitigation
Measures 3-5
3.6 Environmental
Monitoring and Audit Requirements 3-5
3.7 Conclusions
and Recommendations 3-5
4 Noise
Impact Assessment 4-1
4.1 Introduction 4-1
4.2 Relevant
Guidelines, Standards & Legislation 4-1
4.3 Noise
Sensitive Receivers 4-4
4.4 Noise
Environment at Yung Shue Wan 4-6
4.5 Construction
Noise Impact Assessment 4-6
4.6 Operational
Noise Impact Assessment 4-9
4.7 Environmental
Monitoring and Audit Requirements 4-194-194-194-194-20
4.8 Conclusions
and Recommendations 4-204-204-204-204-23
4.9 References 4-214-214-214-214-24
5 Waste
Management Assessment 5-1
5.1 Introduction 5-1
5.2 Legislation
& Standards 5-1
5.3 Baseline
Conditions & Sensitive Receivers 5-2
5.4 Assessment
Methodology 5-2
5.5 Waste
Types 5-3
5.6 Impact
Assessment and Evaluation 5-3
5.7 Summary
of Waste Materials Generated 5-85-85-85-85-9
5.8 Impact
Mitigation & Residual Impact Assessment 5-95-95-95-95-10
5.9 Environmental
Monitoring and Audit Requirements 5-105-105-105-105-11
5.10 Conclusions
and Recommendations 5-115-115-115-115-12
5.11 References 5-115-115-115-115-12
6 Water
Quality Impact Assessment 6-1
6.1 Introduction 6-1
6.2 Assessment
Approach 6-1
6.3 Regulations,
Standards and Guidelines 6-2
6.4 Baseline
Conditions 6-2
6.5 Impact
Assessment & Evaluation 6-56-56-56-56-6
6.6 Cumulative
Impacts 6-56-56-56-56-7
6.7 Impact
Mitigation & Residual Impact Assessment 6-66-66-66-66-8
6.8 Environmental
Monitoring & Audit (EM&A) 6-66-66-76-76-9
6.9 Conclusions
and Recommendations 6-66-66-76-76-9
6.10 References 6-76-76-76-76-9
7 Ecology 7-1
7.1 Introduction 7-1
7.2 Assessment
Approach 7-1
7.3 Regulations,
Standards and Guidelines 7-2
7.4 Ecological
Baseline 7-3
7.5 Ecological
Impact Assessment & Evaluation 7-157-157-157-157-16
7.6 Impact
Mitigation & Residual Impact Assessment 7-177-177-177-177-18
7.7 Environmental
Monitoring & Audit Requirements 7-177-177-177-177-18
7.8 Conclusions
& Recommendations 7-187-187-187-187-19
7.9 References 7-187-187-187-187-19
8 Cultural
Heritage Impact Assessment 8-1
8.1 Introduction 8-1
8.2 Assessment
Approach 8-1
8.3 Regulations,
Standards and Guidelines 8-1
8.4 Assessment
Methodology 8-2
8.5 Baseline
Conditions 8-3
8.6 Impact
Assessment and Evaluation 8-4
8.7 Impact
Mitigation & Residual Impact Assessment 8-6
8.8 Environmental
Monitoring & Audit 8-6
8.9 Conclusions
& Recommendations 8-6
8.10 References 8-6
9 Implementation Schedule of Recommended Mitigation Measures 9-1
9.1 Introduction 9-1
10 Summary
Conclusion & Recommendations 10-1
10.1 Summary
Conclusion of Technical Assessments 10-1
10.2 Key
Recommendations 10-1
10.3 Summary
of Environmental Outcomes 10-2
LIST OF FIGURES
Figure 2.1 Yung Shue Wan Helipad Siting Options
Figure 2.2 Yung Shue Wan Helipad – Site Location
Figure 3.1 Proposed Helipad Location and Environs
Figure 4.1 Representative Noise Sensitive
Receiver Locations
Figure 4.2 Geographical Centres of Construction
Activities
Figure 4.3 Approach and Departure Area and
Surface Profile
Figure 4.4a Illustration of Area Affected by
Helicopter Manoeuvring Noise
Figure 4.4b Illustration of Area Protected from
Helicopter Approach / Departure Noise
Figure 4.4c Helipad Relocation Distance Requirements
to Eliminate Residual Helicopter Manoeuvring Noise
Figure 4.5 Helicopter Noise Validation
Measurement Locations
Figure 6.1 Indicative Silt
Curtain alignment Alignment during
Marine Construction Works
Figure 7.1 Ecology & Water Quality Assessment
Area and Sensitive Receivers
Figure 7.2 Habitat Map of the Yung Shue Wan Study
Area
Figure 7.3 Habitat Photographs
Figure 8.1 Marine Geophysical / Marine
Archaeology Survey Area and Sea Floor Features of Note
LIST OF TABLES
Table 2.1 Summary Matrix for Evaluation
of Helipad Site Options & Alternatives
Table 2.2 Summary
of Yung Shue Wan Helipad Construction Programme
Table 3.1 Hong
Kong Air Quality Objectives
Table 3.2 Annual
Average Pollution Concentrations
Recorded in Tap Mun (Year 2002)
Table 4.1 Recommended
Construction Noise Levels (Non-restricted Hours)
Table 4.2 Area
Sensitivity Rating Criteria
Table 4.3 Acceptable
Noise Levels in Leq(5 min) dB(A)
Table 4.4 Acceptable
Noise Levels for Percussive Piling
Table 4.5 Helicopter
Noise Standards for Planning Purposes
Table 4.6 Location
of NSR Assessment Points in Yung Shue Wan
Table 4.7 Powered
Mechanical Equipment to be used for Construction of Helipad
Table 4.8 Construction
Activities
Table 4.9 Predicted
Construction Noise Levels Leq(30 min) dB(A) - Unmitigated
Table 4.10 Helicopter
Noise Data – Airborne Helicopter with Lateral Movements
Table 4.11 Measured
Lmax Noise Level of GFS Helicopters – Without Lateral Movements
Table 4.12 Helicopter
Use for Yung Shue Wan ‘Casevac’ Operations during years 2000 – 2004
Table 4.13 Worst-case
Helicopter Noise Levels at NSRs during Helicopter Manoeuvring
Table 4.14 Worst-case
Helicopter Approach / Departure Noise Levels at NSRs from the Super Puma AS332
L2 Type Helicopter
Table 4.15 Worst-case
Helicopter Approach / Departure Noise Levels at NSRs from the EC155 B1 Type
Helicopter
Table 4.16 Measured
Lmax Levels
Table 5.1 Analytical
Suite and Analytical Methods
Table 5.2 Sediment
Quality Criteria
Table 5.3 Material
Import Requirements
Table 5.4 Summary
of Construction Phase Waste Generation
Table 6.1 Relevant
Water Quality Objectives for Southern WCZ
Table 6.2 Summary
of Water Quality at ‘SM5’ between 1999 and 2003
Table 7.1 Representative
Species in the Ha Mei Wan Marine Benthic Community (CityU, 2002)
Table 7.2 Univariate
Statistics for Ha Mei Wan & Similar HKSAR Survey Areas (CityU, 2002)
Table 7.3 Top
Ten Ranked Adult Fish / Crustacean Families (from AFCD, 2003)
Table 7.4 Top
Ten Adult Fish Species Caught off Yung Shue Wan (from AFCD, 1998)
Table 7.5 Hard
Shore Benthic Fauna, Yung Shue Wan – Year 2001 Data (from Mouchel, 2002)
Table 7.6 Habitat
Types in the Assessment Area
Table 7.7 Hard
coral species, Yung Shue Wan (BMT, 27th April 2003)
Table 7.8 Ecological
Evaluation of the Sub-tidal habitat
Table 7.9 Ecological
Evaluation of the Granite Boulder Seawall
Table 7.10 Ecological
Evaluation of the Hard Shore habitat
Table 7.11 Ecological
Evaluation of the Developed / Disturbed Area
Table 7.12 Ecological
Evaluation of the Mixed Scrub / Secondary Woodland habitat
Table 9.1 Air Quality – Implementation Schedule
of Recommended Mitigation Measures
Table 9.2 Noise – Implementation Schedule of
Recommended Mitigation Measures
Table 9.3 Waste
Management – Implementation Schedule of Recommended Mitigation Measures
Table 9.4 Water
Quality – Implementation Schedule of Recommended Mitigation Measures
Table 9.5 Ecology – Implementation Schedule of
Recommended Mitigation Measures
LIST OF Appendices
Appendix 2.1 Visual Illustrations
Appendix 2.2 Construction Schedule
Appendix 4.1 Indicative Land Use Concept for Yung Shue
Wan
Appendix 4.2 Construction Equipment Inventory
Appendix 4.3 Construction Noise Calculation – Unmitigated
Appendix 4.4 Helicopter Noise Measurement Points and
Noise Levels
Appendix 4.5 Baseline Helicopter Noise Survey Report
Appendix 4.6 Helicopter Noise Calculations
Appendix 5.1 Sediment Classification Flow Chart
Appendix 5.2 Historical Marine Sediment Sampling
Locations at Yung Shue Wan
Appendix 5.3 Sampling Programme and Chemical Screening
Data at Yung Shue Wan
Appendix 6.1 Summary of Sediment Quality at Monitoring
Station ‘SS4’ (1999 – 2003)
1.1.1
In August 2002 BMT Asia Pacific
Limited (BMT) was awarded the contract for Agreement No. CE 18/2002: Environmental Impact Assessment Study for
Construction of Helipads at Peng Chau and Lamma Island / Investigation by
the Civil Engineering Office, Civil Engineering and Development Department
(CEDD).
1.1.2
The Agreement requires the completion
of Environmental Impact Assessment (EIA) studies for two proposed helipads: one
at Peng Chau and one at Yung Shue Wan, Lamma Island.
1.1.3
This Report presents the approach to
and findings of the EIA study for the proposed Yung Shue Wan helipad, and follows the requirements of
Environmental Impact Assessment Study Brief No.
ESB-089/2001.
1.2.1
The Project involves the construction
and operation of a permanent helipad at Yung Shue Wan, Lamma Island, and is a
‘designated project’ under Item B.2, Schedule 2 of the Environmental Impact
Assessment Ordinance (EIAO) by virtue of being: “A helipad within 300m of existing or planned residential development”. Accordingly, an Environmental Permit is
required for the Project.
1.2.2
The Project has
been planned and managed in-house by the Land Works Division of CEDD on behalf
of the Home Affairs Department (HAD). Construction works are to be completed by
contractors under CEDD’s supervision. CEDD will hand over the helipad to the
management department (yet to be determined) upon its commissioning.
1.2.5
A full description of the Project is
presented in Section 2 112 of
this Report.
1.3.1
The
purpose of this EIA Study is to provide information on the nature and extent of
environmental impacts arising from the Project and other concurrent works. This information will contribute to decisions by the Director of the
Environmental Protection Department (EPD) on:
(i)
The overall acceptability of
any adverse environmental consequences that are likely to arise as a result of
the proposed Project;
(ii)
The conditions and
requirements for the detailed design, construction and operation of the
proposed Project to mitigate against adverse environmental consequences
wherever practicable; and
(iii)
The acceptability of
residual impacts after implementation of proposed mitigation measures.
1.3.2
Satisfying the aims of the EIA Study has been managed by achieving a number of
more specific objectives as listed in the EIA Study Brief. The objectives of the EIA study are to:
(i)
Describe the proposed
Project and associated works together with the requirements for carrying out
the proposed Project;
(ii)
Consider alternative design and construction method(s) for the proposed
Project and to compare the environmental benefits and disadvantages of each of
the method(s) and design in selecting a preferred one;
(iii)
Identify and describe elements of community and environment likely to
be affected by the proposed Project and/or likely to cause adverse impacts to
the proposed Project, including natural and man-made environment;
(iv)
Identify and quantify emission sources and determine the significance
of impacts on sensitive receivers and potential affected uses;
(v)
Identify and quantify potential losses or damage to aquatic organism
and natural habitats and to propose measures to mitigate these impacts;
(vi)
Identify and quantify potential losses or damage to flora, fauna and
natural habitats and to propose measures to mitigate these impacts;
(vii)
Propose the provision of mitigation measures so as to minimise
pollution, environmental disturbance and nuisance during construction and
operation of the proposed Project;
(viii)
Identify, predict and evaluate the residual (i.e. after practicable
mitigation) environmental impacts and the cumulative effects expected to arise
during the construction and operation phases of the proposed Project in
relation to the sensitive receivers and potential affected uses;
(ix)
Identify, assess and specify methods, measures and standards, to be
included in the detailed design, construction and operation of the proposed
Project which are necessary to mitigate these environmental impacts and
reducing them to acceptable levels;
(x)
Investigate the extent of the secondary environmental impacts that may
arise from the proposed mitigation measures, and to identify the constraints
associated with the mitigation measures recommended in the EIA study as well as
the provision of any necessary modification;
(xi)
Design and specify environmental monitoring and audit requirements, if
required, to ensure the implementation and the effectiveness of the
environmental protection and pollution control measures adopted.
1.4.1
The EIA Report is divided into a total
of 9 sections. Following this Section 1, Introduction, the Report is
organised as follows:
·
Section 2 – Project Description
·
Section 3 – Air Quality Impact
Assessment
·
Section 4 – Noise Impact Assessment
·
Section 5 – Waste Management
Assessment
·
Section 6 – Water Quality Impact
Assessment
·
Section 7 – Ecology
·
Section 8 – Cultural Heritage Impact
Assessment
·
Section 9 – Implementation Schedule of
Recommended Mitigation Measures
·
Section 10 – Summary Conclusion &
Recommendations
1.4.2
The
respective assessments for each technical discipline follow the appropriate
requirements as set out in the Technical Memorandum on Environmental Impact Assessment Process
(EIA-TM).
1.4.3
For each section, all Figures are at
the back of the section for ease of reference, while all Appendices are
together at the back of the EIA Report.
2.1.1
The fundamental Project requirements
are the construction of an easily accessible and permanent helipad and an
associated Emergency Vehicle Access (EVA) link with sufficient width to allow
free movement of a mini-ambulance. The Fire Services Department has agreed to a
3.5 metres wide EVA for the Yung Shue Wan helipad. The GFS has also confirmed
that a round helipad of 25 metres diameter is sufficient for helicopter
operations.
2.1.2
The helipad is solely intended for emergency use and
associated essential ‘casevac’
training flights, and will not be used for commercial operations. As such, helipad use will be intermittent,
with no fixed flight schedule. The primary considerations for helipad development are flight operation
safety and its accessibility by ground emergency vehicles from the Lamma Clinic in
emergency situations. The helipad must also be operable and accessible at all
times.
a)
The design and the location should be
such that downwind operations are avoided and crosswind operations are kept to
minimum to maximise helicopter manoeuvrability and operational safety. It should have two approach surfaces,
separated by at least 150 degrees
(i.e., a minimum flight path angle of
150 degrees).
b)
The site should be conveniently
situated as regards ground transport access mainly for emergency service (e.g.
ambulance, fire engines) and adequate vehicle parking facilities.
c)
The ambient noise level should be
considered near noise sensitive receivers, and especially in relation to areas
below the helicopter approach / departure path(s). This means that the helicopter flight path should be situated away
from residential areas as far as is practicable, and for this reason the flight
path for the proposed Yung Shue Wan Helipad will approach and depart from the proposed
helipad across the sea.
d)
Ground conditions beneath the take-off
climb and approach surfaces should permit safe landings in the event of engine
failure or forced landings during which injury to persons on the ground and
damage to property is minimised.
e)
Consider, and assess with flight tests
if necessary, the potential for and effects of eddies and turbulence that may
be caused by any large structures close to the proposed helipad.
f)
Consider the presence of high terrain or other
obstacles, especially power lines, in the vicinity of the proposed site that
may pose a potential hazard.
2.1.4
As information on the usage frequency of the proposed Yung Shue Wan
Helipad is critical for accurate operational phase impact assessment, relevant
flight data from GFS for the 2000 – 2004 period has been reviewed (Table 4.12 refers). Data for the year 2002 represents the
greatest number of casevac flights in recent years, and so has been used as a
basis for the impact assessment.
2.1.5
Information
on possible future changes in the size of the resident population is also
important, and the Notes of the draft Lamma Island OZP
No. S/I-LI/6 (dated 1st April 2005) indicates a planned population
of about 12,000 persons compared with the population of around 5,500 persons
estimated from the 2001 Census. However, it is not anticipated that any such
future population growth will significantly increase the population exposed to
residual helicopter noise, given that the land closest to the proposed helipad
has already been developed.
2.1.6
There is no specific data available on
tourist visits to Lamma Island and there are no particular new tourist
attractions to be developed, suggesting that tourism numbers are not
anticipated to change significantly in the future.
Identification of Options / Alternatives
2.2.1
With reference to Clause 3.3 of the EIA Study Brief, a number of construction and
operational scenarios have been considered for the Project, with the preferred
option selected accordingly.
Consideration has been given to alternatives for:
(i)
Helipad location and EVA link alignment;
(ii)
Project design and construction methods; and
(iii)
Helicopter approach and departure paths.
2.2.2
As regards potential helipad siting
options, three potential options identified through a site selection exercise
initiated by the then District Planning Office (DPO) for Sai Kung & Islands
(now DPO for Lantau & Islands) were taken forward for consideration: Option
A, Option B (Alternative B1) and Option C.
2.2.3
A further four options / alternatives
were identified under this Study for investigation: Option B (Alternative B2),
Option D and Option E (Alternatives E1 and E2).
2.2.4
The characteristics of these seven
options / alternatives that were taken forward for more detailed consideration
are summarised below.
Figure 2.1 shows the locations of the seven sites.
2.2.5
The proposed ‘Option A’ site is located at the northern end of Yung Shue Wan,
near the existing shoreline and adjacent to a public library. It is close to a
number of residences that are located on the slope and foot of a hill.
2.2.6
The proposed ‘Option B, Alternative B1’ site is situated at the edge of reclaimed
land in the vicinity of Kam Lo Hom.
2.2.7
This option has the benefit of being
adjacent to an existing EVA, but would require the development of the helipad
platform in coastal waters and a short EVA link from the reclaimed land to the
helipad.
Option B: Alternative B2 - Kam Lo Hom North (EVA
Extension)
2.2.8
The proposed ‘Option B, Alternative B2’ site would involve extending the ‘Alternative B1’ EVA to locate the
helipad beyond the helicopter noise ‘impact zone’ [Sub-section 4.6 refers].
2.2.9
The proposed ‘Option C’ site is situated immediately southwest of and adjacent to
the ‘Alternative B1’ helipad on a
piece of recently reclaimed land.
2.2.10
The ‘Option C’ site is well located in terms of proximity to the North
Lamma Clinic and distance from the built area, but most of the reclaimed land
is already proposed for development of the Yung Shue Wan Sewage Treatment Works
(STW) by the Drainage Services Department (DSD).
2.2.11
The proposed ‘Option D’ site is located at the roof of the existing Ferry Pier at
Yung Shue Wan. The site would be accessible using the existing pier as an EVA.
It is also in the vicinity of a number of residences and other Noise Sensitive
Receivers.
Option E: Alternative E1 - Kam Lo Hom West (Marine EVA)
2.2.12
The proposed ‘Option E, Alternative E1’ site is located at the southwest of Kam
Lo Hom, approximately 150 metres from the ‘Alternative B1’ helipad, to locate
the helipad beyond the helicopter noise ‘impact zone’ [Sub-section 4.6 refers].
2.2.13
The ‘Alternative E1’ helipad would be accessed by way of a marine EVA to
be constructed parallel to the existing sloping boulder seawall.
Option E: Alternative E2 - Kam
Lo Hom West (Land EVA)
2.2.14
The proposed ‘Option E, Alternative E2’ helipad site is also located at the
southwest of Kam Lo Hom, and would have the same footprint as the ‘Alternative E1’ helipad. However, the ‘Alternative E2’ EVA would be land-based, being constructed around
the back of the reclaimed land and the future STW.
Construction Methods
2.2.15
Three
construction methods for forming the helipad platform and the EVA link have
been considered and these are briefly summarised as follows:
·
Reclamation would require dredging of
marine sediment to a suitable depth to allow construction of a stable
foundation, followed by deposition of filling materials up to the required
platform level.
·
Small
diameter pre-bored piling method involves sinking a
casing through the substrate and removing the material within. Concrete is then poured into the casing to
form the pile. A platform structure is then constructed on top of the piles.
·
Percussive piling involves driving steel
piles into the bedrock. As the piles are driven through to the bedrock,
sediments are laterally displaced without the need for dredging or excavation.
A platform is constructed similarly as for the pre-bored piling method.
Community Consultation
2.2.16
Under the broader remit of the Assignment, the
Consultants established a framework based on the basic
principles of the EIA process that collectively aim to protect the environment
through prevention.
2.2.17
The evaluation framework comprised an
initial assessment, mainly on environmental issues, through which environmental
impacts were predicted through joint consideration of helipad location and
construction method
/ programme.
This was followed by a Value Management (VM) exercise that involved
consultation with, and direct participation of, the local community and other
stakeholders at the early stage of the Project and before detailed technical
assessment had been undertaken.
2.2.18
The VM exercise involved a forum with
residents and community group members at a Yung Shue Wan Area Committee meeting
in February 2003. Nominees from this
meeting attended a formal VM workshop in March 2003 whereat various evaluation
criteria, including time frame, engineering feasibility, project cost, site
availability, land ownership and community / social impacts were taken
discussed and prioritised by participants.
2.2.19
The key community concerns raised
through the VM exercise are listed below (in order of importance):
a.
Operational
safety – the safety of the helicopter crew,
passengers and the nearby community during helicopter activity was the main
concern.
b.
Time
frame – site availability and the speed of
construction were raised as important factors due to the fact that the helipad
is for emergency casualty evacuation.
c.
Direct
ground access – given the inconvenience of the
existing helipad, proximity to and availability of direct and uninterrupted
access to the North Lamma Clinic is another issue of key concern.
2.2.20
ETWB Technical Circular (Works) No.
13/2003 on “Guidelines and Procedures for Environmental Impact Assessment of
Government Projects and Proposals” (September 2003) promotes Continuous Public
Involvement. Accordingly, ongoing
consultation has been conducted during the course of the study to present an
update on progress, discuss key issues and to obtain stakeholder feedback.
2.2.21
At the most recent meeting with the
Island District Council in February 2005, Council members reiterated their
support for the proposed helipad and requested that the works commence as early
as possible at the currently proposed site.
Community support for the project at the studied location was also
reiterated at the North Lamma Rural Committee meeting in April 2005, and the
Lamma Area Committee consultation in May 2005.
Evaluation of Options / Alternatives
2.2.22
A summary of the helicopter site
option evaluation in relation to environmental benefits, dis-benefits and other
key non-environmental considerations (e.g., access and safety issues) is
presented in Table 2.1. Elaboration on the factors affecting site
selection is provided in the following paragraphs.
2.2.23
As the ‘Option A’ site is in close proximity to the built-up area of Yung
Shue Wan and the helicopter approach and departure paths are partially
obstructed by natural topography, this option is considered unsuitable by the
GFS on flight safety grounds. Besides this, the proximity of this option
location to the built-up area means that the residual helicopter noise levels
from helicopter approach / departure to and from the helipad and from
helicopter manoeuvring at the helipad would likely be unacceptably high. Moreover, ambulance travel would be
necessary along the narrow and sometimes busy Yung Shue Wan Main Street before
it can reach the helipad from the Lamma North Clinic [Figure 2.1 refers]. This may cause undue delay in transporting
patient to the helipad.
2.2.24
Most of the reclaimed land at Kam Lo
Hom (South) has been scheduled for the development of the Yung Shue Wan STW [Sub-section 2.4 refers]. As such,
sufficient land is not available for further development of the ‘Option C’ site into a helipad.
2.2.25
A helipad at the ‘Option D’ location was also considered unsuitable by the GFS on
flight safety grounds due to the proximity of marine vessels, including public
ferries and fishing boats, that are moored in the area which may infringe upon
safe helicopter access / egress. The ‘Option D’ site also suffers similar
drawbacks to ‘Option A’ in terms of
accessibility and its close proximity to residences. Helicopter flight path noise and manoeuvring noise is also a key
concern for this option due to the central location of this site in Yung Shue
Wan and the absence of shielding / noise exposure of surrounding buildings.
2.2.26
The development of a helipad was
considered at ‘Option E’ location at
southwest Kam Lo Hom. Two alternatives
for EVA construction were reviewed:
Alternative E1 by way of marine EVA, and Alternative E2 by way of a land-based EVA [Figure 2.1 refers]. The Alternative E1 EVA would pass in front
of the proposed Yung Shue Wan STW and DSD has raised that this alignment is not
acceptable as it would exclude access to the STW and prevent construction and
maintenance of the proposed sewage outfall [Figure
2.1 refers]. As regards Alternative E2, this EVA route would
encroach on undisturbed woodland at the foot of Kam Lo Hom and would require
tree felling and land clearance and AFCD has stated that this alternative is
undesirable in terms of nature conservation. For Alternative E1 there may also be potential impacts on hard corals
found along the sloping boulder seawall due to construction and operation of
the marine EVA [Figure 2.1 refers].
2.2.27
As regards the Option B alternatives, a helicopter noise level of up to 87 dB(A) has been predicted at the ‘Alternative B1’ location when the
‘Eurocopter EC 155B1’ type helicopter is in use (compared with the helicopter
noise standard of 85dB(A)). The
helicopter noise level may reach 90 dB(A) when the preferred ‘Eurocopter EC
155B1’ type helicopter is not available for use, and the heavier / noisier ‘Eurocopter Super Puma AS332 L2’ type helicopter is in
operation. Accordingly, consideration
was also given to extending the EVA to locate the helipad further away from the
built environment and beyond the helicopter noise impact zone: ‘Alternative B2’.
2.2.29
As regards the predicted helicopter noise level
of 87dB(A) at ‘Alternative B1’ under
‘normal’ operating conditions (i.e., use of the ‘Eurocopter EC 155B1’), based
on actual ‘casevac’ and flight data for the year 2002 the impact duration is
predicted to last no longer than 5-10 seconds. The impact frequency (i.e.,
helipad use) is predicted to be once approximately every 3 days. If the ‘Super Puma
AS332 L2’ type helicopter were in operation then, while the noise level would
increase to 90 dB(A), the impact duration would be 5-10 seconds and the impact frequency would be
once approximately every 24 days [Sub-section
4.6 refers].
2.2.30
Consideration
was given to implementing direct and indirect mitigation measures to satisfy
the 85dB(A) helicopter noise standard.
As referred above with respect to ‘Option
E’ and ‘Alternative B2’, there
are various physical constraints that precluded these options / alternatives
from development, including adverse landscape impacts, increased waste handling
and habitat loss.
2.2.31
As the helipad is
intended mainly for emergency use there is no fixed flight schedule. As such, the use of indirect mitigation
measures, such as improved window glazing and installation of air conditioners,
was not considered feasible due to the short impact duration (<10 seconds)
and unpredictable timing of helicopter operations at the proposed helipad [Sub-section 4.6 refers].
Table 222222.111111 Summary
Matrix for Evaluation of Helipad Site Options & Alternatives
Option / Alternative
|
Location
|
Key
Environmental Benefit(s)
|
Key
Environmental Dis-benefit(s)
|
Other
Key Considerations (e.g., safety
& access)
|
Conclusion
|
A
|
Yung Shue Wan North
|
· No key environmental benefits.
|
· Residual helicopter noise
impacts from approach / departure to and from the helipad (i.e., flight path noise).
· Residual helicopter noise
impacts from helicopter manoeuvring
at the helipad.
· Construction noise impact.
|
· Helicopter flight safety
concerns due to proximity to built-up area in Yung Shue Wan.
· Potential limitations on land
accessibility from Clinic due to the narrow and sometimes busy Yung Shue Wan
Main Street.
|
Unacceptable in terms of flight
safety, accessibility and noise impacts.
|
B1
|
Kam Lo Hom North
|
· No significant construction
phase impacts.
· No helicopter flight path noise impact.
|
· Helicopter manoeuvring noise impact.
|
· Joint-closest to the Clinic
(i.e., highly accessible).
|
Residual helicopter manoeuvring noise impact, but no
construction or access concerns.
|
B2
|
Kam Lo Hom North
(EVA Extension)
|
· No helicopter flight path or manoeuvring noise impacts.
|
· Potentially significant visual
impact from 270m long marine EVA.
|
· Easy access from Clinic.
· Marine safety risk (vessel
collision) concerns due to EVA length.
|
Residual helicopter noise
impacts unlikely to be significant, but unacceptable marine risk concerns.
|
C
|
Kam Lo Hom (South)
|
· No significant construction
phase impacts (land already formed).
· Helicopter flight path or
manoeuvring noise impacts unlikely to be significant.
|
· No key environmental
dis-benefits.
|
· Joint-closest to the Clinic
(i.e., highly accessible).
· Land required for proposed
Sewage Treatment Works (STW).
|
Residual helicopter noise
impacts unlikely to be significant, but site required for proposed STW
development.
|
D
|
Ferry
Pier
|
· No key environmental benefits.
|
· Helicopter flight path and manoeuvring
noise impacts.
· Construction noise impact.
|
· Marine
vessels by the ferry pier may infringe upon safe helicopter access / egress.
· Potential limitations on land
accessibility from Clinic due to the narrow and sometimes busy Yung Shue Wan
Main Street.
|
Unacceptable in terms of flight
safety, accessibility and residual helicopter noise impacts.
|
E1
|
Kam Lo
Hom West
(Marine
EVA)
|
· Helicopter flight path or
manoeuvring noise impacts unlikely to be significant.7
|
· Potential impacts on hard coral
found along the sloping boulder seawall due to construction and operation of
the marine EVA.
|
· Easy access from Clinic.
· Prevents marine access to
proposed STW; interferes with sewage outfall construction & maintenance.
|
Residual
helicopter noise impacts unlikely to be significant, but unacceptable in
terms of access to proposed STW and sewage outfall.
|
E2
|
Kam Lo Hom West
(Land EVA)
|
· Helicopter flight path or
manoeuvring noise impacts unlikely to be significant.7
|
· Ecology impact from secondary
woodland clearance.
|
· Easy access from Clinic.
|
Residual helicopter noise
impacts unlikely to be significant, but likely adverse ecological and
landscape impacts.
|
2.2.32
Overall,
with the consideration of the residual helicopter noise
impact on the local community, development of the ‘Option B, Alternative B1’ helipad location is
preferred. Reasons for preference of
this option were its easy access from the North Lamma Clinic, avoidance of
travel through the built-up and sometimes congested areas of Yung Shue Wan and,
in particular, due to the relatively short time frame required for project
development and availability for community use. It is also noted that the proposed location provides a
significant improvement in terms of helicopter noise levels than the soccer
pitch in front of the Yung Shue Wan Clinic that was used as a landing site by
GFS up to May 1998.
2.2.33 Evaluation of the construction options concluded that ‘Option B, Alternative B1’ could preferably be constructed by small diameter pre-bored piling. This
offers a range of environmental benefits when compared
to the dredge and reclaim method, and particularly with respect to waste
management (Section 5), water quality
(Section 6) and marine ecology (Section 7).
The main benefits of small diameter pre-bored piling relate to absence
of marine dredging that minimises waste handling / management requirements.
There will be minimal disturbance to the seabed from pile installation, and
hence only highly localised water quality impacts and no marine ecology impacts
are anticipated.
Design Refinements to the Preferred Option
2.2.35
Consideration has been given to means
by which the design could be refined to minimise the scale and duration of the
works and optimise the position of the helipad, and hence avoid or reduce the
environmental impact potential. This approach of proactive avoidance and
minimisation through design takes precedence over impact mitigation.
2.2.36
During the course of the Study, the
following measures have been taken to refine the project design with a view to
avoiding potential impacts:
·
The elevation of the helipad and EVA
have been lowered as far as practicable in order to minimise their footprint,
and hence the disturbance to the affected coastal waters.
·
The construction sequence shall be
optimised to avoid cumulative construction noise effects with works for the
proposed construction works of the Yung Shue Wan Sewage Treatment Works.
·
The construction method by small
diameter pre-bored piling, as opposed to dredging and reclamation, was
proposed. The benefits of the chosen construction method are summarised in
para. 2.2.33.
·
The width of the EVA link has been
reduced from the standard 4.5m to 3.5m, with the effect that material
requirements for the project will be reduced as well as the footprint of the
EVA on the seabed.
2.2.37
In addition, during the detailed
design stage, effort shall be made to reduce the elevation of the proposed
helipad platform as far as practicable while satisfying the engineering
requirements to minimise visual impact. Futhermore, the position of the helipad
shall be refined as far as practicable in order to optimise the shielding
effect by natural topography on the helipad.
Operational Considerations
2.2.38
Helicopter noise is the main
environmental concern during operation of the helipad. It is predicted that there would be residual
noise impact of up to 5 dB(A) at the nearby noise sensitive receivers (NSRs)
under the worst-case scenario. Based on
worst-case GFS data for ‘casevac’ operations at Yung Shue Wan, the predicted
frequency of the residual impact is approximately once every 3 days. The impact duration would last for not more
than 5-10 seconds per event. A number
of issues were considered in this regard, and are discussed in greater detail
in Sub-section 4.6. They include:
Helipad distance from the built environment:
2.2.39
There are severe constraints on land
availability in Yung Shue Wan due to the need to satisfy the flight safety
requirements [Section 2.1 refers]. In particular, there are restrictions on flight paths and
helicopter manoeuvrability imposed by existing buildings, overhead power lines
and high terrain.
2.2.40
It is required to minimise the noise
impacts during helicopter operations as far as practicable. Based on the
results of helicopter noise assessment, it was found that the helipad has to be
at a minimum distance of 276m from the nearest Noise Sensitive Receiver in
order to control the noise level to below 85dB(A) under normal operating
conditions [para. 4.6.18 refers]. On the other hand, there is
need to minimise the travelling time from the Clinic to the helipad, bearing in
mind it takes one minute for the mini-ambulance to travel approximately 200
metres. A suitable balance must be struck between these conflicting
requirements.
2.2.41
Having considered various factors of
all the Options/Alternatives, ‘Option B, Alternative B1’ offers the best
location as it is relatively close to the Clinic. Assessment results indicated
that the helicopter noise impact due to flight path would comply with the noise
criterion albeit the manoeuvring noise impact would exceed the criterion by up
to 5 dB(A).
Helicopter Type
2.2.42
Consideration has been given to the
use of helicopter types generating lower noise levels for casualty evacuation operations. However, the GFS has confirmed that at
present only the two helicopter types that have been assessed in this EIA
Report (i.e., the ‘EC155 B1’ and ‘Super Puma AS332 L2’) are available for
such operations.
2.2.43
For operational considerations, the
GFS would not be able to
exclude the use of the ‘Super Puma AS332 L2’, the noisier of the two helicopter
types, from using the helipad although the GFS has agreed to give priority to
the quieter ‘EC155 B1’ type helicopter for ‘casevac’ operations wherever practicable.
This approach also follows the trend of current usage
of the two helicopter types at Yung Shue Wan. As only one helicopter is able to
operate at the helipad at any one time, no cumulative helicopter noise effects
will be generated. During the years
2003 and 2004, GFS has only used the smaller and quieter EC155 B1 type helicopter for
night-time casevac operations and GFS has advised that this usage trend is
expected to continue.
Helicopter Flight Path
2.2.44
The flight path is necessarily
constrained by the flight safety requirements of GFS. The GFS guideline states
that a surface level helipad should have two approach surfaces extending from
the helipad. In plan view, the
centreline of the two flight paths should ideally be separated by at least 150
degrees so that should wind conditions impose constraints on flight safety
(para 2.1.3a) refers) there is always one other option for safe
helicopter approach / departure.
2.2.45
It was determined that a flight path
separation angle of 150 degrees would adversely affect all residences at the
residential area. With the agreement of GFS, the angle of separation between
the two flight paths for the ‘Option B,
Alternative B1’ site has been reduced to 80 degrees for use of ‘EC155 B1’
type helicopter and to 70 degrees for use of the ‘Super Puma’ [Figure 4.3 refers]. The re-aligned
helicopter flight path will increase the distance between the noise source
(helicopter) and the noise sensitive receiver (residential area) so that
helicopter approach noise generated by both types helicopters can be reduced to
within the 85dB(A) guideline at all noise sensitive receivers.
2.3.1
The Project involves the construction
of a helipad by small diameter
pre-bored piling in coastal waters at Kam Lo Hom (North), Yung Shue Wan – ‘Option B, Alternative B1’. No
dredging or reclamation works are required for the construction. Minimal
excavation of slurry from within the pile casing will be required. However,
this process will be an entirely contained activity,
separated from the adjacent water column.
2.3.2
The project location was selected after detailed
consideration of the operational requirements and environmental impact
potential of developing the Project at each of seven site locations. With reference to the current statutory Lamma Island Outline Zoning Plan
(No. S/I-LI/6), the proposed site
is within a “Government, Institution or Community”
(“G/IC”) zone and has been identified as a possible helipad. According to the
Notes of the OZP, “Helicopter Landing Pad” is a Column 2 use that may be
permitted with or without conditions on application to the Town Planning Board.
2.3.3
The helipad deck will be located approximately 25
metres from existing formed land, and an EVA link will be constructed to
connect the proposed helipad with the existing EVA. Figure 2.2 shows the site
location.
2.3.4
As referred under Clause 3.4.7 of the
EIA Study Brief, visual illustration materials have been prepared to present
the as-built appearance of the Helipad and EVA. These materials are presented in Appendix 2.1, and specifically include a site layout plan,
diagrammatic section, elevation and photomontages of the Helipad and EVA from 3
locations at Yung Shue Wan that are representative of the views that residents
and visitors to Yung Shue Wan may encounter.
The perspective drawings referred to in the EIA Study Brief are
considered not necessary as the 3 photomontages adequately illustrate the project
appearance.
2.3.5
The site location was selected after
due consideration of the operational requirements and environmental impact
potential of constructing and operating the Yung Shue Wan helipad at each of
four site locations. Specific Project details are as
follows:
· A total of approximately twenty-six numbers of small diameter
pre-bored piles of about 610mm in diameter will be required for the
construction of the helipad and EVA link.
· The EVA link will be about 25 metres long and 3.5 metres wide, and
will incline slightly from the existing formed land at 4.9 mPD to the helipad
deck.
· The helipad will have a diameter of 25 metres.
· The helipad surface will be constructed to a height of about 7.85
mPD.
· Railings will be installed along the EVA link, and wave deflectors
will be installed around the helipad to enhance operational safety.
· An off-site works area (including site office) to be located on the
existing vacant land east of the Refuse Transfer Station will be required for
approximately 2.3 years, from April 2006.
2.3.6
The construction programme can be
broadly summarised as presented by Table
2.2Table
2.2Table 2.2Table
2.2Table 2.2Table 2.2Table 2.2Table 2.2.
Table 222222.222222 Summary of Yung Shue Wan
Helipad Construction Programme
Construction Activity
|
Construction Period
|
Site Clearance
|
16-May-2006 to 22-Jul-2006
|
Mobilisation
|
24-May-2006 to 16-Aug-2006
|
Pile Installation
|
17-Aug-2006 to 27-Jan-2007
|
Helipad Construction
|
29-Jan-2007 to 22-Jun-2007
|
E&M Works
|
30-May-2007 to 5-Jul-2007
|
Demobilisation
|
6-Jul-2007 to 30-Jul-2007
|
2.3.7
Further details of the construction
works are presented in Section 4, while the full construction programme is presented in Appendix 2.2.
2.4.1
Other projects identified in the
vicinity that require consideration for the purposes of identifying and
assessing as necessary the potential for cumulative effects.
Yung Shue Wan Development: Engineering Works, Phase 2
2.4.2
According to the tentative
construction programme obtained from the Civil Engineering and Development
Department, the Yung Shue Wan Development Engineering Works Phase 2 will not
commence until Year 2008. Therefore,
there will be no potential cumulative effects.
Yung Shue Wan Sewage Treatment Works
2.4.3
The tentative schedule for the
Drainage Services Department (DSD) to commence construction of the Yung Shue
Wan STW is in August 2007, and works would last for about 3 years. Therefore, the STW would not be constructed
in parallel with the Helipad project. However, if the proposed helipad is still
being constructed at the time that the STW construction commences, the existing
temporary helipad will need to be relocated back to the Lamma Power Station,
and this will cause a delay in casevac service. As such, CEDD and DSD have agreed to avoid overlapping these two
projects. Even under the unlikely
scenario that there are concurrent construction activities for the two
projects, assessment results indicate that no adverse cumulative construction
noise impacts are anticipated.
HEC’s Lamma Power Station Navigation Channel Improvement
2.4.4
Siltation in the main navigation
channel leading to the HEC Lamma Power Station requires that maintenance
dredging be conducted to ensure safe passage of coal delivery vessels. HEC has advised that the works were
completed in early 2004, and as such there will be no cumulative effects.
HEC’s Lamma Power
Station Extension Works
2.4.5
The marine works for the Power Station
Extension were completed in 2003 before the proposed navigation channel
dredging period, and therefore there will be no cumulative effects.
2.5.1
As the Helipad previously used by the
community is located at the HEC Lamma Power Station – a distance of 2.75 km
from Yung Shue Wan – there are presently no local environmental concerns that
the Project will resolve / improve.
2.5.2
Without the Project the predicted
operational helicopter noise impact would be avoided. However, should the helipad not be developed, and upon the commencement
of development of the Yung Shue Wan STW by DSD, the local community will be
required to continue using the HEC helipad that requires ~20 minutes of travel
time from the clinic [Para. 1.2.4 refers]. This
would be an undesirable situation as the travel time to reach emergency
services is unnecessarily prolonged.
2.5.3
Although there is an existing
temporary helipad that has been in use since October 2003 that does not pose
significant adverse environmental concerns, it is located at the proposed STW
site and will need to close before STW construction can commence. Based on consultations, this situation would
not be acceptable to the local community unless the permanent helipad is in place.
2.5.4
Given the project nature and anticipated
intermittence of helicopter use, with or without the project the ambient noise
environment at Yung Shue Wan will remain rural in character.
3.1.1
With reference to Clause 3.4.3 of the EIA Study Brief, the Applicant shall follow the
requirements stipulated under the Air Pollution Control (Construction Dust)
Regulation and propose any other remedies or mitigation measures in dust
control to ensure that construction dust impacts are controlled within the
relevant standards as stipulated in Section 1 of Annex 4 of the EIA-TM.
3.1.2
No operational Air Quality Impacts
Assessment is required under the EIA Study Brief as the use of the proposed
helipad will be limited, and there will be no other emissions associated with
helipad operation. No potential
operational phase air quality impacts are anticipated.
Air Pollution Control Ordinance (Cap.
311)
3.2.1
The Air Pollution Control Ordinance
(APCO) provides the statutory authority for controlling air pollutants from a
variety of stationary and mobile sources, including fugitive dust emissions
from construction sites. It encompasses
Air Quality Objectives (AQOs) for 7 common air pollutants. The AQOs are given in Table
3.1Table
3.1Table 3.1Table
3.1Table 3.1Table 3.1Table 3.1Table 3.1.
Table 333333.111111 Hong Kong Air Quality
Objectives
|
Concentration (mg/m3)(1) Averaging
Time
|
Pollutant
|
1 Hour(2)
|
8 Hour(3)
|
24 Hours(3)
|
3 Months(4)
|
1 Year(4)
|
Sulphur Dioxide SO2
|
800
|
-
|
350
|
-
|
80
|
Total Suspended Particulates (TSP)
|
-
|
-
|
260
|
-
|
80
|
Respirable Suspended Particulates
(RSP)(5)
|
-
|
-
|
180
|
-
|
55
|
Nitrogen Dioxide NO2
|
300
|
-
|
150
|
-
|
80
|
Carbon Monoxide CO
|
30000
|
10000
|
-
|
-
|
-
|
Photochemical Oxidants (as ozone(6))
|
240
|
-
|
-
|
-
|
-
|
Lead
|
-
|
-
|
-
|
1.5
|
-
|
3.2.2
Section 1, Annex 4 of EIA-TM
stipulates the hourly average Total Suspended Particulate (TSP) concentration
of 500 mg/m3 measured at 298 K
(25°C) and 101.325 kPa (1 atmosphere) for construction dust impacts. Mitigation measures for construction sites
specified in the Air Pollution Control (Construction Dust) Regulation should be
followed.
3.2.3
The APCO subsidiary regulation Air
Pollution Control (Construction Dust) Regulation defines notifiable and
regulatory works activities that are subject to construction dust control.
(a) Site formation;
(b) Reclamation;
(c) Demolition of a building;
(d) Work carried out in any part of a tunnel
that is within 100 m of any exit to the open air;
(e) Construction of the foundation of a
building;
(f) Construction of the superstructure of a
building; or
(g) Road construction work.
(a) Renovation carried out on the outer
surface of the external wall or the upper surface of the roof of a building;
(b) Road opening or resurfacing work;
(c) Slope stabilisation work; or
(d) Any work involving any of the following
activities-
·
Stockpiling of dusty materials;
·
Loading, unloading or transfer of
dusty materials;
·
Transfer of dusty materials using a
belt conveyor system;
·
Use of vehicles;
·
Pneumatic or power-driven drilling,
cutting and polishing;
·
Debris handling;
·
Excavation or earth moving;
·
Concrete production;
·
Site clearance; or
·
Blasting.
3.2.4
Notifiable works require that advance
notice of activities be given to EPD.
The Regulation also requires the works contractor to ensure that both
notifiable works and regulatory works will be conducted in accordance with the
Schedule of the Regulation, which provides dust control and suppression
measures.
Existing Environment
3.3.1
The existing air quality within the
Yung Shue Wan area is generally rural.
It is currently affected by the emissions from the Hongkong Electric Co.
Ltd’s Lamma Power Station, which is approximately 800 m due southwest to Yung
Shue Wan. There are no major road
networks within Lamma Island and therefore there are no vehicular emissions
related air quality impacts.
3.3.2
Environmental Protection Department
(EPD) operates a network of Air Quality Monitoring Stations in Hong Kong, but
none of these monitoring stations is located within or near Yung Shue Wan. As
such, air quality data collected at the Tap Mun monitoring station in Sai Kung
District – which resembles a rural area type setting similar to the environs of
Yung Shue Wan – has been selected as being broadly representative of the
existing ambient air quality conditions at Yung Shue Wan. These data are summarised in Table
3.2Table
3.2Table 3.2Table
3.2Table 3.2Table 3.2Table 3.2Table 3.2.
Table 333333.2222222 Annual Average
Pollution Concentrations Recorded in Tap Mun (Year 2002)
Pollutants
Monitored
|
Annual
Average in micrograms per cubic metre
|
Respirable Suspended Particulates
(RSP)
|
39
|
Sulphur
Dioxide (SO2)
|
11
|
Nitrogen Dioxide (NO2)
|
13
|
Carbon Monoxide (CO)
|
688
|
Ozone (O3)
|
63
|
3.3.3
The Hongkong Electric Co. Ltd. has operated
an air quality monitoring station at Pak Kok San Tsuen on Lamma Island for a
number of years. The monitored SO2
and NO2 annual average concentrations in year 2002 are 11 mg/m3 and
25 mg/m3, respectively. These results are comparable to the Tap Mun data.
Future Conditions
3.3.4
The Yung Shue Wan Phase 2 Reclamation
will likely be a potential fugitive dust-polluting source during its works
phase. However, this will only be a
short-term change in the ambient condition and will not alter the nature of the
air quality condition of Yung Shue Wan once the works are completed. Also it will commence after the completion
of the helipad construction and therefore will not affect the background air
quality condition during the helipad construction. A small sand depot has been planned to locate in the
Yung Shue Wan Phase 1 Reclamation area.
3.3.5
Based on the helicopter flight paths
advised by GFS, helicopters will not over-fly the Phase 1 Reclamation area and
the distance of the sand depot from the helipad would be too far for any dust
(wind-blown sand) impacts to be generated.
As such, no adverse air quality (dust) impacts are anticipated from
Project operation. There are no
distributor roads or other major infrastructure development planned in Yung
Shue Wan and therefore, the air quality conditions are not expected to have any
significant change in the future.
Air Sensitive Uses
3.3.6
Currently there are no occupied
domestic premises in the immediate environs of the helipad site. The potential air sensitive uses nearest to
the helipad are an existing football field and the cluster of buildings near
the football field, including low-rise (maximum 3-storey high) village houses,
North Lamma Clinic, and a Tin Hau Temple.
These are generally located over 200 metres from the helipad site and
over 50 metres from the off-site works area (adjacent to the refuse transfer
station). Village houses located along
the coast of the Yung Shue Wan bay are also air sensitive uses [Figure
3.1 refers].
Identification of Impacts
3.4.1
If uncontrolled, construction
activities may result in construction dust impacts. Construction of the helipad using a small diameter pre-bored
piling method will include dust generation activities, some of which are
notifiable / regulatory works. They are
described below.
3.4.2
The construction will begin with site
clearance, including breaking a short section (approximately 15 metres length)
of a landscape planter at the top of the seawall. This will be a regulatory
works procedure that requires appropriate dust suppression measures under the
Regulation to adequately control dust to within an acceptable level.
3.4.3
Erection of site office, hoarding and
fencing at the works area (approximately 50m x 25m) at the area adjacent to the
refuse transfer station may involve very minor excavation that is regulatory
work. Dusty material stockpiling and
handling will be done in the works area as well as at the site, for which dust
control measures will be implemented.
Therefore dust will be controlled within acceptable level.
3.4.4
Pile installation for the EVA and
helipad will be conducted through the water column, and therefore no dust
impacts will arise.
3.4.5
The construction of the helipad deck and EVA may
result in minor wind blown dust impacts.
However, this activity is a regulatory works procedure and requires
proper suppression measures to control dust to within an acceptable level.
3.4.6
There may be use of trucks for material transport
from the works area to the site via the short section of the existing concrete
paved EVA. Use of vehicles is a
regulatory work procedure and the required dust control measures shall ensure
dust levels are controlled to an acceptable level.
Cumulative Impacts
3.4.7
The construction of DSD’s Yung Shue
Wan STW and Outfall is tentatively scheduled to commence in August 2007 for
approximately 3 years. The Helipad and
STW developments have been scheduled to avoid concurrent works and cumulative
air quality impacts.
Evaluation of Potential Impacts
3.4.8
The small diameter pre-bored piling
works will be carried out entirely in coastal waters and no dust impacts are
anticipated. There will also be some
minor works carried out at the off-site works area on existing ground adjacent
to the refuse transfer station.
3.4.9
In view of small scale of the works,
construction dust impacts can be controlled with appropriate implementation of
dust suppression measures. Moreover,
dust control and suppression measures are statutory requirements under the Air
Pollution Control (Construction Dust) Regulation. As such, fugitive dust impacts during the construction can be
adequately controlled and no significant impacts are anticipated.
3.5.1
All the dust control measures as
recommended in the Air Pollution Control
(Construction Dust) Regulation, where applicable,
should be implemented. Typical dust
control measures include:
·
The working area for site clearance
shall be sprayed with water or a dust suppression chemicals immediately before,
during and after the operation so as to maintain the entire surface wet.
·
Restricting heights from which
materials are dropped, as far as practicable to minimise the fugitive dust
arising from unloading/loading.
·
Immediately before leaving a
construction site every vehicle shall be washed to remove any dusty materials
from its body and wheels.
·
All spraying of materials and surfaces
should avoid excessive water usage.
·
Where a vehicle leaving a construction
site is carrying a load of dusty materials, the load shall be covered entirely
by clean impervious sheeting to ensure that the dusty materials do not leak
from the vehicle.
· Travelling speeds should be controlled to reduce traffic induced
dust dispersion and re-suspension within the site from the operating haul
trucks.
·
Erection of hoarding of not less than
2.4 m high from ground level along the site boundary.
·
Any stockpile of dusty materials shall
be either:
a)
Covered entirely by impervious
sheeting;
b)
Placed in an area sheltered on the top
and the 3 sides; or
c)
Sprayed with water or a dust
suppression chemical so as to maintain the entire surface wet.
·
All dusty materials shall be sprayed
with water or a dust suppression chemical immediately prior to any loading,
unloading or transfer operation so as to maintain the dusty materials wet.
3.7.1
Through proper implementation of dust
control measures as required under the Air Pollution Control (Construction
Dust) Regulation, construction dust can be controlled to acceptable level and
no significant impacts are anticipated.
4.1.1
This Section provides an evaluation of
the potential noise impacts associated with the construction and operational
phases of the proposed development of a helipad at Yung Shue Wan, Lamma Island.
4.1.2
During the construction phase of the
helipad, power mechanical equipment (PME) used for the helipad construction
will be the primary noise sources. The
key noise generating activities include:
·
Site
clearance for the erection of site office, hoarding and fencing;
·
Temporary
staging construction and demolition;
·
Pile
installation; and
·
Construction
of helipad and EVA.
4.1.3
The helipad will solely be used for emergency use and associated
essential ‘casevac’ training flights, and will not be used for commercial
operations. The sole noise source
during the operational phase of the Project will be from helicopter activities,
as follows:
·
Helicopter
‘approaching’ the helipad while it is descending at an angle to the helipad
surface;
·
Helicopter
manoeuvring on and directly over the helipad; and
·
Helicopter
‘taking-off’ from the helipad while it is climbing up at an angle to the
helipad surface during departure.
4.1.4
Noise sensitive receivers (NSRs) have
been identified in accordance with Annex 13 of the EIA-TM. As required under Clause 3.4.2.2 (iii) (b) of the EIA
Study Brief, the selection of representative NSRs has been presented to and
agreed by the Authority prior to commencement of this noise impact assessment.
4.1.5
Where appropriate, practicable
mitigation measures are recommended to alleviate any potential noise impacts
identified during both the construction and operational phases of the helipad
so that the applicable noise guidelines and regulations can be achieved.
Construction Noise During Non-restricted Hours
4.2.1
Noise arising from construction for
designated projects during the non-restricted periods, i.e., between
07:00-19:00 hours of any days not being a Sunday or general holiday, is
assessed with reference to the noise criteria listed in Table 1B, Annex 5 of
the EIA-TM, which are summarised in Table
4.1Table
4.1Table 4.1Table
4.1Table 4.1Table 4.1Table 4.1Table 4.1. These criteria shall be met as far as
practicable according to Annex 5 of the EIA-TM.
Table 444444.111111 Recommended
Construction Noise Levels (Non-restricted Hours)
Noise Sensitive Receiver Uses
|
Noise Levels Leq(30 min) dB(A)
|
All domestic premises including
temporary housing accommodation, hotels and hostels
|
75
|
Schools
|
70 (normal school hours)
65 (during examination periods)
|
4.2.2
Subsidiary regulations of the Noise
Control Ordinance (NCO) include the Noise
Control (Hand Held Percussive Breakers) and Noise Control (Air Compressors) Regulations. These require compliance with relevant noise
emission standards and the fixing of noise emission labels to hand-held
percussive breakers and air compressor.
Whilst these requirements are not directly relevant to the construction
noise impact assessment, contractors must comply with these regulations during
the construction phase.
Construction Noise During Restricted Hours
Table 444444.2222222 Area
Sensitivity Rating Criteria
Type of area containing the NSR
|
Degree to which NSR is affected by IF(4)
|
Not Affected(1)
|
Indirectly Affected(2)
|
Directly Affected(3)
|
(i) Rural area, including
country parks or village type developments
|
A
|
B
|
B
|
(ii) Low density residential
area consisting of low rise or isolated high-rise developments
|
A
|
B
|
C
|
(iii) Urban area
|
B
|
C
|
C
|
(iv) Area other than those
above
|
B
|
B
|
C
|
4.2.5
The noise criteria for construction
noise during restricted hours for each ASR are given in Table
4.3Table
4.3Table 4.3Table
4.3Table 4.3Table 4.3Table 4.3Table 4.3.
Table 444444.3333333 Acceptable
Noise Levels in Leq(5 min) dB(A)
Time Period
|
Area Sensitivity Rating
|
A
|
B
|
C
|
All days during the evening (1900-2300) and general holidays
(including Sundays) during the day and evening (0700-2300)
|
60
|
65
|
70
|
All days during the night-time (2300-0700)
|
45
|
50
|
55
|
4.2.6
Percussive piling is only permitted
when the Noise Control Authority has granted a CNP. PP-TM sets out the permitted hours of operation of percussive
piling and Acceptable Noise Level (ANL) requirements, which are dependent on
the architectural characteristics of the NSR.
The ANL criteria for percussive piling are reproduced in Table
4.4Table
4.4Table 4.4Table
4.4Table 4.4Table 4.4Table 4.4Table 4.4. ANLs for hospitals, schools, clinics, courts
of law and other particularly sensitive receivers are 10 dB(A) below the
figures quoted in Table
4.4Table
4.4Table 4.4Table
4.4Table 4.4Table 4.4Table 4.4Table 4.4.
Table 444444.4444444 Acceptable Noise Levels for Percussive
Piling
Architectural Characteristics of NSR
|
ANL, dB(A)
|
No windows or other openings
|
100
|
With central air conditioning system
|
95
|
With windows or other openings but
without central air conditioning system
|
85
|
4.2.7
Regardless of any description or
assessment made in the following paragraphs, in assessing a filed application
for a CNP the Noise Control Authority will be guided by the relevant Technical
Memoranda. The Authority will consider all the factors affecting their decision
taking contemporary situations / conditions into account. Nothing in this Report shall bind the
Authority in making their decision, and there is no guarantee that a CNP will
be issued. If a CNP is to be issued,
the Authority shall include any conditions they consider appropriate, and such
conditions are to be followed while the works covered by the CNP are being
carried out. Failing to do so may lead
to cancellation of the permit and prosecution action under the NCO.
4.2.8
There are some factors affecting the
assessment results of a CNP application, such as the assigning of Area
Sensitivity Rating, Acceptable Noise Levels etc. The Noise Control Authority would decide these at the time of
assessment of such an application based on the contemporary situations/conditions. It should be noted that the situations /
conditions around the sites may change from time to time.
Helicopter Noise
4.2.9
Table 1A, Annex 5 of the EIA-TM
stipulates the noise standards of the helicopter noise (between 07:00 and 19:00 hours) for
planning purposes. These are summarised
in Table
4.5Table
4.5Table 4.5Table
4.5Table 4.5Table 4.5Table 4.5Table 4.5.
Table 444444.5555555 Helicopter Noise Standards
for Planning Purposes
Uses
|
Helicopter
Noise Lmax dB(A)
07:00
to 19:00 hours
|
- All domestic premises including
temporary housing accommodation;
- Hotels and hostels
- Educational institutions
including kindergartens, nurseries and all others where unaided voice
communication is required
- Place of public worship and
courts of law
- Hospitals, clinics,
convalescences and home for the aged, diagnostic rooms, wards
|
85
|
Offices
|
90
|
4.2.11 From this review it was identified that most literature on aircraft
noise concerns relates to commercial airplane
and helicopter noise. However, during
the public consultation exercise for the ‘US FAA [public] Hearings on
[non-military] Helicopter Noise’, there was a wide consensus among parties
consulted that noise from emergency
medical services was a tolerable necessity. This situation also applies to existing casevac operations for
Yung Shue Wan, which both GFS and CAD confirm have never received a noise complaint
from the local community during day-time or
night-time casevac operations. With
reference to the above consideration, the local environment and other EIA
reports on helicopter noise, it is expected that the 85dB(A) Lmax could be one of the
parameter to guage the possible noise impact on the residents during the
evening period. The current approach
adopted in Hong Kong is to curfew the general commercial helicopter activities
during night-time.
4.2.12
Recognising the tolerable necessity of
emergency helicopter flights it was suggested during the FAA hearings that
consideration be given to imposing some regulation on these operations to
reduce noise impacts to NSRs. Such
consideration has been given during the course of this EIA Study in determining
both the proposed helipad location and the proposed helicopter flight-path, and
such details are provided in Sub-section
4.6.
4.3.1
Noise sensitive receivers (NSRs) have
been identified in accordance with the criteria set out in Annex 13 of the EIA-TM. The spatial scope of the noise impact
assessment shall include all areas within 300 metres from the Project boundary
in accordance with the EIA Study Brief.
4.3.2
Site visits have been conducted to
ensure the selection of existing representative NSRs. A review of the latest Outline Zoning Plan (Lamma Island OZP No.
S/I-LI/6), Outline Development Plan (Lamma Island ODP No. D/I-LI/2), and
consultation with the Planning Department was conducted to identify the most
likely location for future / potential future NSRs.
4.3.3
As required under Clause 3.4.2.2 (iii) (b) of the EIA Study Brief, the selection of
representative NSRs has been presented to and agreed by the Authority prior to
commencement of this noise impact assessment.
A brief description of existing and planned NSRs is provided below,
while Figure 4.1 displays their
locations.
Existing Noise Sensitive Uses
4.3.4
The majority of the developments along
the coast of Yung Shue Wan are residential village houses, varying from single
to 3 storeys high. Some of these
buildings are used for commercial purpose on the ground floor, e.g., grocery
store and restaurant. There are isolated and dilapidated village houses located
at the north of Kam Lo Hom (currently a “Green Belt” zone) that are not
occupied, and hence are not noise sensitive.
4.3.5
The first tier buildings (i.e., those
with a direct line of sight to the proposed helipad) will be the most affected
by helicopter noise, but in turn they will provide some noise shielding to the
second tier buildings (i.e., those buildings situated behind them). The natural
topography of Kam Lo Hom also provides noise shielding to the buildings located
south of the existing football pitch that are laterally the closest to the
helipad site [Figure 4.1 refers].
4.3.6
The closest noise sensitive building
with a direct line of sight to the helipad footprint is No. 105 Yung Shue Wan
Main Street (NSR4), which is a residential village house about 220m southeast
of the helipad site. This NSR is
considered as the worst-case as it is not shielded and will thus be directly
affected by helicopter noise generated at the helipad. At about 250m from the site, the North Lamma
Clinic (NSR3) is the closest non-residential type NSR within direct line of
sight of the helipad.
4.3.7
The cluster of buildings near the
ferry pier also has direct line of sight to the helipad, of which the North
Lamma Public Library (NSR2) is the closest to the helipad footprint at about
260m. The North Lamma Public Library is
also closest to the possible helicopter flight path to / from the helipad. In addition, a village house at O Tsai
(NSR1) has been selected as a representative residential type NSR.
Planned Noise Sensitive Uses
4.3.8
The main purpose of selecting planned
NSRs is for the assessment of future noise impacts due to the operation of the
helipad. The current Lamma Island OZP
has designated a “Comprehensive Development Area (1)” (‘CDA(1)’) zone for the
land already reclaimed at the south of Yung Shue Wan and for the proposed
reclamation under the Yung Shue Wan Phase 2 Reclamation project west of the
bay. Based on the latest information
from the Planning Department [Appendix
4.1 refers], the scale of the Phase 2 Reclamation has been reduced and the
Reclamation will not be developed to the extent outlined on the current
approved OZP.
4.3.9
Planning Department has advised that
the land use review on the reduced reclamation at Yung Shue Wan has been
completed and amendment to the OZP would be made to reflect the land use
changes. Accordingly, the closest
potential future NSRs would be near the existing football field and / or near
the ferry pier (NSR5 and NSR6, respectively).
Planned NSRs will likely be residential type village houses (maximum
building height of 3 storeys) to be constructed on available land lots in the
existing “Village Type Development” (‘V’) zone.
4.3.10
The characteristics of NSRs in the
vicinity of the proposed Yung Shue Wan Helipad are summarised in Table
4.6Table
4.6Table 4.6Table
4.6Table 4.6Table 4.6Table 4.6Table 4.6. Figure
4.1 illustrates their locations.
Table 444444.6666666 Location of NSR Assessment Points in Yung
Shue Wan
NSR Assessment Point
|
NSR Location
|
Number of storeys
|
Ground Level (mPD)
|
Land Use
|
NSR1
|
Village
House at O Tsai
|
3
|
20.0
|
Residential
|
NSR2
|
North
Lamma Public Library
|
1
|
4.0
|
Library
|
NSR3
|
North
Lamma Clinic
|
1
|
3.3
|
Clinic
|
NSR4
|
No. 105
Yung Shue Wan Main Street
|
3
|
3.2
|
Residential
|
NSR5*
|
Future
Development in “Village
Type Development” Zone (near existing football pitch)
|
3#
|
3.1
|
Residential
|
NSR6*
|
Future Development in “Village Type Development” Zone
(near existing ferry pier)
|
3#
|
15.5
|
Residential
|
Existing Noise Environment at NSRs
Future Trend
4.4.2
Based on the latest planning
information, the Yung Shue Wan Phase 2 development work and Drainage Services
Department’s (DSD’s) Yung Shue Wan Sewage Treatment Works (STW) will be
potential noise sources. During the
Phase 2 development works and construction of the STW, NSRs close to the works
site will be subject to construction noise, although upon completion of the
works no significant change in the noise environment at Yung Shue Wan is
anticipated.
Assessment Methodology
4.5.1
This construction noise impact
assessment has been conducted based on the construction schedule and equipment
inventory as presented in Appendix 2.2 and
Appendix 4.2, respectively. The construction schedule provided by CEDD
is based upon all works to be undertaken during non-restricted hours only.
Construction noise impacts at representative NSRs were assessed in accordance
with Annex 13 of the EIA-TM. The noise
level at the most affected floor (i.e., 1/F) has been assessed and corrections
such as façade correction and barrier correction have been applied as appropriate.
4.5.2
Based on the construction schedule,
the noise assessment has been divided into 24 ‘assessment periods’ throughout
the 18-month construction programme in accordance with the worst-case sound
power level that may arise from the Site.
Each ‘assessment period’ represents a distinct construction task in the
overall programme that can be used as a basis for construction noise impact
assessment.
Identification of Potential Construction Noise Impacts
4.5.3
It is anticipated that the use of
Powered Mechanical Equipment (PME) during the construction phase will generate
potential noise impact upon the existing NSRs in the vicinity of the helipad
site. Based on a practicable equipment inventory provided by the Project
Proponent, Table 4.7 presents the
likely PME that shall be used to construct the Project according to schedule and the corresponding sound power levels.
Table 444444.7777777 Powered
Mechanical Equipment to be used for Construction of Helipad
Identification
Code
|
Description
|
Sound
Power Level, dB(A)
|
CNP
021
|
Bar
bender (electric)
|
90
|
CNP
044
|
Concrete
lorry mixer
|
109
|
CNP
047
|
Concrete
pump, stationary/ lorry mounted
|
109
|
CNP
048
|
Crane,
barge mounted (diesel)
|
112
|
CNP
061
|
Flat
top barge
|
104
|
CNP
081
|
Excavator/
Backhoe
|
112
|
CNP
102
|
Generator,
Silenced
|
100
|
CNP
068
|
Mini-truck
|
105
|
CNP
172
|
Vibrator
|
115
|
CNP
166
|
Piling,
large diameter bored, reverse circulation drill
|
100
|
CNP
167
|
Auger
|
114
|
CNP
170
|
Poker,
vibratory, hand-held
|
113
|
CNP
221
|
Tug
boat
|
110
|
4.5.4
The entire construction sequence can
be separated into four activities according to the construction schedule given
in Appendix 2.2 and as summarised in Table
4.8Table
4.8Table 4.8Table
4.8Table 4.8Table 4.8Table 4.8Table 4.8. The geographical centres of each activity
for determining equipment locations (i.e., notional source position) to calculate construction noise levels are presented in Figure 4.2.
Table 444444.8888888 Construction Activities
Construction
Activities
|
Details
of Works
|
Site Clearance
|
·
Erection
of office, hoarding and fencing
|
Mobilisation
|
·
Plant
set up;
·
Construction
of working platform;
·
Mobilising
and assembling of drilling machine; and
·
Ground
investigation.
|
Pile Installation
|
·
Pre-drilling;
·
Drilling
and installing casing;
·
Install
H-pile;
·
Concreting;
and
·
Preliminary/main
pile test.
|
Helipad Construction
|
·
Construction
of beams and slabs for helipad/EVA;
·
Construction
of wave return walls for helipad/EVA; and
·
Road
and drainage works.
|
E&M Works
|
·
E&M
installation; and
·
E&M
testing and commissioning.
|
Demobilisation
|
·
Demobilise
the working platform and plant.
|
Prediction and Evaluation of Construction Noise Impacts
4.5.5
Based on the construction schedule and
equipment inventory, the predicted unmitigated construction noise levels for
each assessment period is summarised in Table 4.9. Detailed calculations are presented in Appendix 4.3.
Table 444444.9999999 Predicted Construction Noise Levels Leq(30
min) dB(A) - Unmitigated
Assessment
Period †
|
NSR1
|
NSR2
|
NSR3
|
NSR4
|
NSR5
|
NSR6
|
1
|
59
|
60
|
69
|
71
|
69
|
60
|
2
|
66
|
68
|
71
|
73
|
71
|
67
|
3
|
65
|
67
|
71
|
73
|
71
|
66
|
4
|
65
|
67
|
71
|
73
|
71
|
66
|
5
|
68
|
69
|
72
|
74
|
72
|
68
|
6
|
64
|
66
|
67
|
69
|
67
|
65
|
7
|
64
|
66
|
67
|
69
|
67
|
65
|
8
|
60
|
61
|
63
|
64
|
62
|
60
|
9
|
60
|
61
|
63
|
64
|
62
|
60
|
10
|
63
|
64
|
66
|
67
|
65
|
63
|
11
|
67
|
68
|
70
|
71
|
69
|
67
|
12
|
66
|
67
|
69
|
70
|
68
|
66
|
13
|
68
|
69
|
71
|
72
|
70
|
68
|
14
|
67
|
68
|
70
|
71
|
69
|
67
|
15
|
66
|
67
|
69
|
70
|
68
|
66
|
16
|
65
|
66
|
68
|
69
|
67
|
65
|
17
|
60
|
61
|
63
|
64
|
62
|
60
|
18
|
68
|
69
|
71
|
72
|
71
|
68
|
19
|
68
|
69
|
71
|
72
|
71
|
68
|
20
|
68
|
69
|
71
|
72
|
71
|
69
|
21
|
68
|
69
|
71
|
72
|
71
|
69
|
22
|
59
|
60
|
62
|
63
|
62
|
59
|
23
|
52
|
53
|
55
|
56
|
54
|
52
|
24
|
63
|
64
|
66
|
67
|
65
|
63
|
4.5.6
The highest unmitigated construction
noise level at the closest NSR (i.e., NSR4) is predicted to be 74 dB(A). This level complies with the noise standard
stipulated in Table 1B, Annex 5 of the EIA-TM.
Mitigation of Adverse Construction Noise Impacts
a)
Noisy
equipment and noisy activities should be located as far away from the NSRs as
is practical;
b)
Unused
equipment should be turned off;
c)
Powered
mechanical equipment should be kept to a minimum and the parallel use of noisy
equipment / machinery should be avoided;
d)
Regular
maintenance of all plant and equipment; and
e)
The
Contractor shall observe and comply with the statutory requirements and
guidelines.
Cumulative Noise Impacts
4.5.8
As mentioned in Section 2 112, it is
identified that the Yung Shue Wan Phase 2 Development Engineering Works will
commence in Year 2008. Therefore, there
will be no cumulative impacts from the development works. However, the completed Phase 1 reclamation
immediately south of the proposed helipad is reserved for development of DSD’s
Sewage Treatment Works (STW). According
to the preliminary STW construction programme, the 3-year construction period
may commence in August 2007. Therefore,
both sites would not be constructed in parallel.
4.5.9
Furthermore, there is a temporary
helipad currently operated by GFS at the STW site. The permanent helipad will replace the temporary helipad for
emergency casevac. However, if the
permanent helipad construction is not completed before STW construction
commences, the temporary helipad will need to move back to the Lamma Power
Station. So as not to affect emergency
helicopter services, CEDD and DSD have agreed to avoid any overlap in the
development of these two projects. As
such, cumulative construction noise impacts are not anticipated.
Assessment Methodology
Without Lateral Movements
Helicopter manoeuvring above the helipad
within the Final Approach and Take-off Areas (FATO)[****] includes several modes:
·
‘Hovering’
– helicopter turns on the spot over the helipad to achieve the desirable
orientation for touchdown / lift-off;
·
‘Touchdown’
– helicopter descends on to the helipad surface;
·
‘Idling’
– helicopter remains on the helipad surface with its rotary blades kept
running; and
·
‘Lift-off’
– helicopter ascends vertically from the helipad surface to achieve a hover
before departure.
With Lateral Movements
a)
Helicopter
‘approaching’ the helipad while it is descending at an angle to the helipad
surface; and
b)
Helicopter
‘taking-off’ from the helipad while it is climbing up at an angle to the
helipad surface.
Noise Level Difference (dB) = 20 log10
4.6.3
Noise source terms (i.e., the Lmax
at a given distance) of each helicopter operation mode has been provided by the
Government Flying Service (GFS). On
site noise measurements have also been conducted to supplement the noise source
terms data.
4.6.4
The International Civil Aviation
Organization (ICAO) has stipulated noise standard for helicopters for different
flying modes, including ‘approach’, ‘take-off’ and ‘flyover’ (i.e., the maximum
noise level [in EPNdB] used as the noise certification standards adopted by the
Council of ICAO). The noise standards
for the two types of GFS’ helicopter used for ‘casevac’ operations are
summarised in Table
4.10Table
4.10Table 4.10Table
4.10Table 4.10Table 4.10Table 4.10Table 4.10,
with test noise measurement points for each flying mode illustrated in Appendix 4.4. Table
4.10Table
4.10Table 4.10Table
4.10Table 4.10Table 4.10Table 4.10Table 4.10
also presents the Demonstrated Noise Level data for the GFS helicopters as
tested by the helicopter manufacturer (i.e., the noise level for that
helicopter type measured by the manufacturer in accordance with standard
technical procedures in the ICAO noise
certification).
Table 444444.10101010101010 Helicopter Noise Data – Airborne Helicopter
with Lateral Movements
Reference Measurement Configurations
|
Super Puma AS332 L2
|
EC155 B1
|
ICAO Max. Noise Level EPNdB
|
Demonstrated Noise Level EPNdB
|
ICAO Max. Noise Level EPNdB
|
Demonstrated Noise Level EPNdB
|
Approach
|
100.7
(87.7)
|
96.1
(83.1)
|
97.9
(84.9)
|
95.7
(82.7)
|
Take-off
|
99.7
(86.7)
|
94.6
(81.6)
|
96.9
(83.9)
|
92.2
(79.2)
|
Flyover
|
98.7 (85.7)
|
93.5 (80.5)
|
95.9
(82.9)
|
88.9
(75.9)
|
4.6.5
Based on the given noise data in Table
4.10Table
4.10Table 4.10Table
4.10Table 4.10Table 4.10Table 4.10Table 4.10,
the ‘approach’ mode generates the highest noise level when the helicopter is
airborne with lateral movements.
Accordingly, the helicopter noise assessment makes reference to the ICAO
standard for the approach mode that represents the worst-case scenario. By
assessing the worst-case scenario any uncertainty in the quantitative
prediction has been taken into consideration.
4.6.6
According to GFS Helipad Specification
Guidelines, the helicopter approach and departure trajectory will be projected
at an 8% slope within 245 metres from the edge of the helipad. Beyond 245 metres the slope increases to 12.5%. GFS has advised that the approach and
departure angle is generally within the sector of 250-330 degrees from the
centre of the helipad for the EC155 B1 type helicopter, and 250-320 degrees for
the Super Puma AS332 L2 type helicopter [Figure
4.3 refers]. Accordingly, the
closest distance between the airborne helicopter and the identified NSR (on the
top floor) can be measured and used for evaluating the worst-case noise level.
4.6.7
The ICAO standards do not include
standards for helicopter manoeuvring on and over the helipad, i.e., hovering,
touchdown, idling and lift-off. As
such, on-site noise surveys on GFS’s helicopters were conducted at GFS helipad
at Chek Lap Kok on 24th June 2003 to generate supplementary noise
data. The noise survey involved
measuring the Lmax noise level generated by the GFS helicopters
simulating manoeuvring on and over a helipad.
The measurements were taken at the far-field region such that the
formula quoted below paragraph 4.6.2 can be applied.
The Lmax noise level measured has been used for assessing the
worst-case scenario when the helicopter is at the helipad. Details of the helicopter noise survey are
provided in Appendix 4.5.
4.6.8
It was found that the Lmax
noise level is less when the helicopter is idling (with rotors on) on the ground
than the Lmax noise level occurs when the helicopter is in the air
without lateral movements (either during hovering or lift-off mode). Table 4.11 displays the measured Lmax
noise levels.
Table 444444.11111111111111 Measured Lmax Noise Level of GFS
Helicopters – Without Lateral Movements
Measurement Configurations (Reference distance: 150m)
|
Super Puma AS332 L2
|
EC155 B1
|
Helicopter on ground, Idling
|
82.0
|
80.0
|
Helicopter in the air *
|
90.6
|
87.7
|
Identification of Potential Noise Impacts
4.6.9
Assessment of helicopter noise has
been conducted for each of the operational modes as introduced in paragraph 4.6.1.
4.6.10
The GFS will use the proposed helipad
for ‘casevac’ operations. GFS
helicopter fleet comprises two helicopter types: the ‘Super Puma AS332 L2’ and
the ‘EC155 B1’. The ‘Super Puma AS332
L2’ has a higher maximum operational weight than the ‘EC155 B1’, and hence
operates at a higher power output and generates a higher noise level. However, GFS has agreed to deploy the ‘EC
155 B1’ type helicopter whenever possible for ‘casevac’ operations, and only
under very special circumstances shall the ‘Super Puma AS332 L2’ be deployed.
4.6.11
The Super Puma was introduced into the
GFS helicopter fleet in November 2001, while the EC155 B1 was introduced into
the GFS fleet in November 2002. Prior
to this time the GFS relied on Sikorsky S76 / Sikorsky S70 type helicopters for
casevac operations, and these were phased out during 2003. Table
4.12Table
4.12Table 4.12Table 4.12Table 4.12Table 4.12Table 4.12Table 4.12
summarises actual GFS helicopter usage data for ‘casevac’ operations from 2000
through 2004.
Table 444444.12121212121212 Helicopter
Use for Yung Shue Wan ‘Casevac’ Operations during years 2000 – 2004
Year
|
Total
No. of Casevac from 0700 to 2200
hours1
|
Total
No. of Casevac from 2200 – 0700 hours2
|
No. of
Casevac Training Flights3
|
2000
|
51 (1)
|
30
|
3
|
2001
|
69 (7)
|
39
|
4
|
2002
|
104 (13)
|
37
|
6
|
2003
|
92 (7)
|
34
|
5
|
2004
|
66 (1)
|
29
|
4
|
Notes:
1.
The figures
in brackets ( ) are the number of casevac flights carried out by Super Puma (or
Sikorsky prior to 2004).
2.
Since 2003, all night-time casevac has
been undertaken using the EC155 B1 type helicopter only, although for the
purpose of this noise impact assessment it cannot be discounted that the Super
Puma may be required for night-time casevac in future years.
3.
Five casevac-training flights were
conducted to the Yung Shue Wan helipad in 2003 (i.e., an additional 4% of the
total casevac flights). As no such data
is available for other years, the number of casevac training flights for
2000-2002 and 2004 have been calculated using the same % contribution. It should be noted that GFS does not
anticipate any increase in training flights in the short to medium term as the
helicopter fleet was upgraded in 2001/02 and there are no plans to add
additional types of helicopters.’
4.6.12
Using the flight data for the year
2002 as a worst-case scenario, it has been assumed that there may be a total of
147 flights in a single year. Of this
total it has been assumed that the ‘Super Puma’ would be operated for up to 13
casevac flights a year. In the absence
of a specific data breakdown, it has also been assumed that two of the six
training flights would be using the Super Puma. Overall, as a worst-case scenario it is assumed that the Super
Puma would be used on no more than 15 occasions in a year: equivalent to one
flight every 24.3 days.
4.6.13
Using the same calculation method, and
including all nigh-time flights, it has been assumed that the EC155 B1 type
helicopter would be used for casevac at Yung Shue Wan on no more than 132
occasions in a year: equivalent to one flight every 2.8 days.
Cumulative Helicopter Noise Impacts
4.6.14
Upon commencement of operations at the
proposed Yung Shue Wan helipad, use of the currently temporary landing site on
the future STW will cease. The HEC
helipad located approximately 800 metres southwest of the proposed helipad is
infrequently used. In addition, GFS
also confirmed that only one helicopter will use the helipad at one time and
therefore no cumulative noise impacts are anticipated.
4.6.15
There is no other significant noise
source in the area that may contribute to a cumulative operational noise
effect.
Prediction and Evaluation of Noise Impacts
Without Lateral Movements
4.6.16
The assessment of helicopter noise
generated at the helipad is based on the Lmax noise levels of the
helicopter manoeuvring over the helipad and the horizontal separation between
the helipad and identified NSRs. Table
4.13Table
4.13Table 4.13Table
4.13Table 4.13Table 4.13Table 4.13Table 4.13
summarises the calculated Lmax noise levels at the identified
NSRs. Details of the calculation are
provided in Appendix 4.6.
Table 444444.13131313131313 Worst-case Helicopter Noise Levels at NSRs
during Helicopter Manoeuvring
NSR ID
|
Horizontal separation to centre of the
Helipad (metres)
|
Lmax @ NSR dB(A) 1
|
Façade Correction dB(A)
|
Corrected Lmax @ NSR dB(A)
|
Super Puma AS332 L2
|
EC155 B1
|
Super Puma AS332 L2
|
EC155 B1
|
NSR1
|
301
|
85 (76)
|
82 (74)
|
3
|
88 (79)
|
85 (77)
|
NSR2
|
257
|
86 (77)
|
83 (75)
|
3
|
89 (80)
|
86 (78)
|
NSR3
|
246
|
86 (78)
|
83 (76)
|
3
|
89 (81)
|
86 (79)
|
NSR4
|
221
|
87 (79)
|
84 (77)
|
3
|
90 (82)
|
87 (80)
|
NSR5*
|
263
|
86 (77)
|
83 (75)
|
3
|
89 (80)
|
86 (78)
|
NSR6*
|
292
|
85 (76)
|
82 (74)
|
3
|
88 (79)
|
85 (77)
|
4.6.17
The evaluation results in Table
4.13Table
4.13Table 4.13Table
4.13Table 4.13Table 4.13Table 4.13Table 4.13
show that the worst-case Lmax noise level during helicopter
manoeuvre above the helipad will be 90 dB(A) at NSR4 when a ‘Super Puma AS332
L2’ helicopter is in hovering mode, and 87 dB(A) when an ‘EC155 B1’ helicopter
is lifting off (i.e., ascending vertically) from the helipad. With both helicopter types the worst-case Lmax
exceeds the 85 dB(A) limit. The
worst-case Lmax noise level during the idling mode is less than the
85 dB(A) limit for both helicopter types.
With Lateral Movements
4.6.19
Regarding the helicopter approach
mode, the projected worst-case trajectory of the approach path (i.e., closest
to the NSR), is at the line with a bearing of 330 degrees to the centre of the
helipad for ‘EC155 B1’ helicopters and 320 degrees for ‘Super Puma AS332 L2’
helicopters. NSR1, NSR2 and NSR6 are
closest to the approach path and will therefore be the most affected by
helicopter noise during approach.
4.6.20
Table
4.14Table
4.14Table 4.14Table
4.14Table 4.14Table 4.14Table 4.14Table 4.14 and Table 4.15Table
4.15Table 4.15Table
4.15Table 4.15Table 4.15Table 4.15Table 4.15
display the worst-case Lmax noise levels based upon the closest
slant distance between the helicopter and the top floor of the NSRs. Calculations
are based on the ICAO maximum noise level. Calculation details are provided in Appendix 4.6.
Table 444444.14141414141414 Worst-case Helicopter
Approach / Departure Noise Levels at NSRs from the Super Puma AS332 L2 Type Helicopter
NSR
ID
|
Slant
distance between helicopter & NSR (metres)
|
Lmax
@ NSR dB(A) 1
|
Façade
Correction dB(A)
|
Corrected
Lmax @ NSR dB(A)
|
NSR1
|
253
|
81
|
3
|
84
|
NSR2
|
226
|
82
|
3
|
85
|
NSR3
|
246
|
82
|
3
|
85
|
NSR4
|
221
|
82
|
3
|
85
|
NSR5*
|
263
|
81
|
3
|
84
|
NSR6*
|
281
|
80
|
3
|
83
|
Table 444444.15151515151515 Worst-case Helicopter
Approach / Departure Noise Levels at NSRs from the EC155 B1 Type Helicopter
NSR
ID
|
Slant
distance between helicopter & NSR (metres)
|
Lmax
@ NSR dB(A) 1
|
Façade
Correction dB(A)
|
Corrected
Lmax @ NSR dB(A)
|
NSR1
|
220
|
80
|
3
|
83
|
NSR2
|
201
|
80
|
3
|
83
|
NSR3
|
246
|
79
|
3
|
82
|
NSR4
|
221
|
80
|
3
|
83
|
NSR5*
|
263
|
78
|
3
|
81
|
NSR6*
|
261
|
78
|
3
|
81
|
Mitigation of Adverse Noise Impacts
Alternative land use arrangement
and siting:
4.6.25
Considering the potential increase of
marine traffic risk and delay of helipad, further offshore extension of the EVA
from the proposed ‘Option B, Alternative
B1’ is infeasible.
4.6.26
In
order to completely contain the helicopter noise to within the 85dB(A)
standard, relocating the helipad approximately 150
metres further to the southwest from the proposed ‘Alternative B1’ site was considered (i.e., ‘Option E’). However, such
relocation via a marine EVA (i.e., ‘Alternative
E1’) would place the EVA directly in front of the proposed Yung Shue Wan
STW, and across the proposed marine outfall from the STW. Such an arrangement is not supported by
Drainage Services Department as it would impede construction and maintenance of
the marine outfall, and would prevent marine access to the proposed STW. The land-based EVA (i.e., ‘Alternative E2’; Figure 2.1 refers) would encroach on undisturbed woodland at the
foot of Kam Lo Hom requiring tree felling and land clearance, and AFCD has
stated that this alternative is undesirable in terms of ecology / nature
conservation.
Screening by Noise Tolerant
Buildings
Setback
4.6.28
The proposed helipad does not involve
any building development, so building
setback is not relevant.
4.6.29
A smaller re-positioning of the
proposed Option B, Alternative B1
location from the “G/IC” zone gazetted for the helipad on the latest OZP was
also investigated. The objective was to further refine the proposed location to
optimise shielding of NSRs by the natural topography of the Kam Lo Hom
headland. However, a minimum shift of
25m further west would be required to reduce residual noise impacts on
approximately eight NSRs. Ultimately,
such as shift would require amendment of the OZP under Section 12A of Town
Planning (Amendment) Ordinance 2004, and would delay project implementation and
may infringe marine access to the proposed STW.
Decking Over
4.6.30
This measure relates to road traffic
noise control and is not applicable to helicopter noise control.
Extended Podium
4.6.31
The proposed helipad does not involve
any building development. This option is not applicable.
Building Orientation
4.6.32
The proposed helipad does not involve
any building development, so this measure is not applicable.
Treatment of Source
Alternative Alignment
4.6.35
A further reduction in the flight path
angle cannot eliminate the residual helicopter manoeuvring noise that is generated by the helicopter on or over
the helipad surface. The only way manoeuvring noise can be reduced / eliminated
is to locate the helipad further from noise sensitive buildings [paras. 4.6.23 – 4.6.27 refer].
Noise Barrier / Enclosure
Special Building Design
4.6.37
The proposed helipad does not involve
any building development, and therefore this measure is not applicable.
Architectural Features / Balcony
4.6.38
The proposed helipad does not involve
any building development, and therefore this measure is not applicable.
Open-textured Road Surfacing
4.6.39
This measure is not applicable to
helicopter noise control.
Indirect Mitigation Measures
4.6.40
The application of indirect mitigation
measures would require installation of acoustic insulation into all NSRs at
which the predicted Lmax exceeds 85 dB(A). Effective indirect
mitigation requires that NSR occupants comply with a ‘closed-window’ living
environment during helicopter manoeuvring.
Evaluation of Residual Impacts
4.6.42
Adverse helicopter noise impact is not
anticipated due to the short impact duration of 5 – 10 seconds. The significance of the residual helicopter
noise impact has been considered in accordance with appropriate factors
referred to under section 4.3.3 of the TM on the EIA Process, as set out below.
Effects on public health and
Risk to life
4.6.43
In terms of effect on public health,
the proposed helipad location and flight path will reduce the ambient noise
level on the exposed community compared with the currently tolerated situation.
As regards the duration of the residual impact, it is known that the sense of
hearing becomes less acute when the ear is exposed to intense loud noise for a
period of time (Ward et al, 1959).
Furthermore, the Factories and Industrial Undertakings (Noise at Work)
Regulation (CAP 59T) established a daily personal exposure (Lepd)
noise level of 85 dB(A), meaning that a person exposed to noise level of
85dB(A) for 8 hours may require hearing protection. As a basis for comparison
only, the anticipated duration of the residual helicopter noise impact will be
no more than 10 seconds, equivalent to a Lepd of 51 - 55 dB(A). As
such the effect of the residual helicopter noise on public health will be
insignificant.
4.6.44
As regards risk to life, the proposed
helipad is not a hazardous source and there shall be no storage of fuels or
other dangerous goods at the site. There is also no risk to life associated with
the construction of the helipad. However, it is considered that the improved
access to urban areas for medical treatment in emergency situations that the
proposed helipad offers when compared with the previous reliance on HEC Ltd’s
Lamma Power Station may potentially decrease the risk to life.
Magnitude, duration and
frequency of Impact
4.6.45
After taking into account all the
practicable direct mitigation measures, the worst-case Lmax noise
levels are predicted to be 90 dB(A) [residual noise is 5 dB(A)] resulting from
hovering of a ‘Super Puma AS332 L2’ type helicopter and 87 dB(A) [residual
noise is 2 dB(A)] due to lift-off by a ‘EC155 B1’ type helicopter at NSR4. The noise impact duration will last 5-10
seconds according to GFS. No adverse helicopter idling noise impact is
predicted.
4.6.46
It should be noted that GFS primarily
uses the EC155 B1 type helicopter for casevac operations at Yung Shue Wan. With
reference to the casevac data from GFS for the period 2000-2004, the flight
frequency of the Super Puma and EC155 B1 type helicopter is equivalent to one
flight every 24.3
days and 2.8 days, incurring a maximum 5 dB(A) and 2
dB(A) exceedance of the 85 dB(A) limit, respectively. The duration of the residual impact would be 5-10 seconds per
event.
4.6.47
GFS has been directly consulted
throughout the preparation of this EIA study report, and being fully aware of
the residual helicopter noise issue, has expressed a willingness to avoid use
of the Super Puma whenever practicable (i.e., provided the ‘EC155 B1’ is
available). Based on actual GFS casevac
data for 2003 and 2004, only the ‘EC155 B1’ has been used for night-time
casevac. However, it cannot be
discounted that under special circumstances (e.g., large-scale emergency) the
use of the ‘Super Puma’ may be required for night-time casevac.
4.6.48 The first tier buildings with facades directly facing the Yung Shue
Wan bay area would likely be subject to the residual helicopter noise
impact. Approximately 75 dwellings
within 276 metres of the helipad, and with a direct line of sight, would be
affected during lift-off of the ‘EC155 B1’ type helicopter. Similarly, approximately 360 dwellings
located at or within 386 metres, and with a direct line of sight, of the helipad
would be affected by the ‘Super Puma AS332 L2’ type helicopter during
hovering. Figure 4.4(a) displays the locations of these noise sensitive
buildings.
4.6.49
With reference to the Notes of the
draft Lamma Island OZP No. S/I-LI/6 (dated 1st April 2005), it
indicates the planned population for Lamma Island of about 12,000 persons
compared with the population of around 5,500 persons. However, it is not anticipated that any such future population
growth will significantly increase the population exposed to residual
helicopter noise, given that the land closest to the proposed helipad has
already been developed.
4.6.50
The predicted residual helicopter
noise impacts associated with the proposed helipad operation will only occur
locally, i.e., at Yung Shue Wan and within an affected zone. There will be no spread of such noise
impacts elsewhere.
Reversibility of Impact
4.6.51
The operational helicopter noise
impact shall be reversible. The impact
will occur on a less than daily basis, and each residual impact event shall be
of short duration.
Other Considerations
4.6.52
Consideration had been given to
eliminating this residual noise impact altogether, such as relocating the
proposed helipad further north or west.
However, such proposals are not acceptable due to environmental, risk
and accessibility concerns.
4.6.53
Consideration has been given to
constructing physical structures such as noise barriers / enclosures to provide
effective noise shielding of the helicopter noise (para.section 4.6.36), although the erection of such structures is not
practicable. Taking into account the various other mitigation measures that
have been considered / adopted as outlined in para.sections 4.6.22 to 4.6.41, it would appear that there would still be a residual
noise impact of up to 5 dB(A). Considering that this residual noise impact is
of short duration, lasting < 10 seconds per event, as well as occurring only
once about every 2.8 days for EC155 B1 and 24.3 days for Super Puma, this will
not cause long term noise nuisance to the nearby affected residents.
4.6.54
As residual noise may be audible
during night-time from 7pm to 7am, research was undertaken to identify a
suitable local or international guideline to govern helicopter noise at night.
The proposed use of the helipad is for emergency use. Research into the public
consultation exercise for the United States of America Federal Aviation Agency
Hearings on [Non-military] Helicopter Noise has indicated that noise from emergency
medical helicopter services was exempted from the list of ‘Recommended Noise
Reduction Approaches’. There was a wide consensus among stakeholders that
emergency helicopter service is a tolerable necessity, although consideration
may also be given to imposing some regulation on operations to reduce noise
impacts to NSRs. One example would be
to require helicopters to use flight routes that take them as a matter of
regulation over the least densely populated areas (paraSection
4.2.11 refers).
4.6.55
Locally there is no standard for
helicopter noise at night-time. In accordance with the Civil Aviation (Aircraft
Noise) Ordinance (Cap 312), which is the legislative means in Hong Kong to
control the helicopter noise arising from the operation of the helipad, administrative
means can be used to reduce the noise impact of the helipad operations on the
NSRs. However restrictions such as limiting the number of helicopter flights at
night time or restrictions on the operating hours of the helipad are not
practical as the use concerned is for emergency service, which will be on an as
needed basis that cannot be controlled.
4.6.56
Regarding the control of helicopter
flightpath, the proposed route displayed Figure 4.3 represents the best
arrangement to satisfy operational requirements. As the helipad is for emergency purposes, and considering that
this is a tolerable necessity, it is proposed that construction of the helipad
at the proposed location is acceptable. This view is supported not only by the
findings of the technical assessment, but also from community feedback from the
Value Management exercise [Sub-section
2.2 refers] and the fact that the pre-1998 landing site outside the North
Lamma Clinic did not lead to any recordedgistered
noise complaints.
4.6.57
The only environmental impact arising
from the proposed helipad is the residual noise impact. To totally remove the
residual noise impact will involve further relocating the proposed site
westwards which will not be acceptable as outlined above. Also, since the
residual noise impact has been identified as being of short duration and
infrequent occurrence, it will not lead to any long-term serious environmental
implications.
4.6.58
In August 2005, with the assistance of
GFS, validation noise measurements of the ‘EC155 B1’ and ‘Super Puma AS332
L2’ type helicopters were conducted at representative NSRs as the helicopters
simulated manoevring activities on and adjacent to the temporary and proposed
permanent helipads. Noise measurements were made at the four NSRs displayed by Figure 4.5, with two of the NSRs having been used in the impact assessment
(i.e., M1 (NSR2) and M4 (NSR4)). The measured and the corrected noise
levels
for these NSRsresults are presented in Table 4.16Table
4.16Table 4.16Table 4.16Table 4.16Table 4.16Table 4.16Table 4.16 belowfor reference.
Table 444444.16161616161616 Measured and Corrected Lmax
Levels
Measurement location
|
Measured Lmax, dB(A)
|
Predicted Noise Level, dB(A)
|
Lift-off
|
Hovering
|
EC155 B1
|
M1 (NSR2)
|
1st
|
71
|
‘NM’
|
86
|
2nd
|
76
|
82
|
M2
|
1st
|
73
|
84
|
NIL
|
2nd
|
78
|
83
|
M3
|
1st
|
68
|
73
|
NIL
|
2nd
|
71
|
74
|
M4(NSR4)
|
1st
|
65
|
69
|
87
|
2nd
|
65
|
69
|
Super Puma AS332 L2
|
M1(NSR2)
|
1st
|
75
|
86
|
89
|
2nd
|
80
|
87
|
M2
|
1st
|
82
|
87
|
NIL
|
2nd
|
85
|
86
|
M3
|
1st
|
79
|
79
|
NIL
|
2nd
|
81
|
76
|
M4 (NSR4)
|
1st
|
61
|
71
|
90
|
2nd
|
64
|
71
|
4.6.59
The survey was conducted on a single day based on
simulated operational events at a few selected locations only. The survey was
subject to the actual simulation and would have been affected by specific
site/environmental conditions during noise measurements. It would therefore be premature to draw any
conclusion about the actual helicopter noise impacts on the NSRs. According to Table 4.16,
the measured Lmax at
the worst affected measurement location is 87 dB(A).While the survey was
conducted on a single day only and at a small number of locations, the results
strongly suggest that the actual noise levels from helicopter manoevring
activities will not exceed the noise levels predicted in the technical
assessment [Table
4.13 also refers].
Construction Phase
4.7.1
No construction phase noise exceedance
is anticipated. However, regular
construction noise impact monitoring and audit is recommended during the
construction period in order to ensure the construction noise impacts at NSRs
are in an acceptable limit. As there is
no anticipated construction phase noise impact, there is no requirement for
real-time reporting of monitoring data as raised under Clause 4.2 of the EIA Study Brief.
4.7.2
The Environmental Monitoring and Audit
(EM&A) requirements are detailed in the stand-alone Project EM&A
Manual.
Operational Phase
4.7.3
The study has considered all
practicable means to minimise the potential operational helicopter noise
impacts, including realignment of helicopter flight paths to avoid helicopter
approach noise impacts without compromising flight safety. In accordance with the GFS guidelines and
current practice, the quieter ‘EC155 B1’ type helicopter shall be deployed
whenever practicable.
4.7.4
Accordingly, due to the small
magnitude and short duration of impacts, and the exhaustion of all practicable
means to mitigate residual helicopter noise impacts, operational phase noise
monitoring, including real-time reporting, is not recommended.
4.7.5
Should the need arise, the local community may
lodge noise complaints with the Islands District Office.
Should the need arise, the local community may
lodge noise complaints with the Islands District Office by the
following means:
·
Fax: 2815 2291
·
Email: dois@had.gov.hk
·
Address: Islands District Office, Harbour Building, 20th Floor, 38 Pier
road, Central.
Construction Phase
4.8.1
The potential noise levels arising
from daytime construction activities of the helipad during the period from May 2006
to October 2007 at the nearby NSRs have been evaluated. Based on the construction schedule and plant
inventory given, unmitigated construction noise levels at all NSRs will comply
with the daytime noise standards stated in Table 1B, Annex 5 of EIA-TM. Therefore, no specific mitigation measures
are required.
4.8.2
The cumulative noise impacts from the
construction of helipad and the Yung Shue Wan STW upon common NSRs has also
been considered, and no adverse cumulative noise impacts are anticipated.
Operational Phase
4.8.3
In accordance with Table 1A, Annex 5
of the EIA-TM, and with reference to noise data provided by GFS and obtained
through on-site measurements, helicopter noise impacts have been assessed based
on the maximum instantaneous sound pressure level at a specified NSR – i.e.,
the Lmax level. The Lmax
was calculated for two types of helicopter used for ‘casevac’ operations
by GFS during helipad approach / departure (i.e., with lateral movements) and
during a series of manoeuvring modes on and immediately over the helipad (i.e.,
without lateral movements).
4.8.4
An initial assessment of helicopter
noise levels from lateral movements predicted that the Lmax for both
helicopter types would exceed the limit of 85 dB(A). Accordingly, the flight path angle was reduced with the agreement
of GFS to eliminate the impact, with a subsequent Lmax of 85 dB(A)
from the ‘Super Puma AS332 L2’ and 83 dB(A) from the ‘EC155 B1’.
4.8.5
The worst-case Lmax noise
level during helicopter manoeuvring over the helipad is predicted to be 90 dB(A)
at NSR4 when a ‘Super Puma AS332 L2’ helicopter is in hovering mode, and 87
dB(A) from an ‘EC155 B1’ helicopter in lift-off mode. Accordingly, mitigation options have been investigated in
accordance with Annex 13 of the EIA-TM.
Of the applicable helicopter noise mitigation options, consideration was
given to helipad relocation further from the built environment, although
physical constraints to each of the options / alternatives precluded any
relocation. Installation of a noise
barrier around part of the helipad was considered, but this option was not
feasible on flight safety grounds.
4.8.6
After exhaustion of direct mitigation
measures, the application of indirect mitigation measures was considered.
Ultimately indirect mitigation measures were not recommended due to the
impracticability of providing prior notice of an impending helicopter arrival
and the very short impact duration (i.e., 5-10 seconds).
4.8.7
In summary, based on actual GFS flight
data for Yung Shue Wan, the residual helicopter noise impact from operation of
the ‘EC155 B1’ type helicopter would involve a 1-2 dB(A) exceedance of the 85
dB(A) limit approximately every 2.8 days, and would affect approximately 75
dwellings . The residual impact from
the ‘Super Puma AS332 L2’ type helicopter would involve a 3-5 dB(A) exceedance
of the 85 dB(A) limit approximately every 24.3 days, affecting approximately
360 dwellings [Figure 4.4(a)
refers]. The impact duration would last
for less than 10 seconds per event, and the predicted magnitude, frequency and duration
of residual impacts would not give rise to any serious long-term environmental
implications.
·
Nelson, P. M. (1987), Transportation Noise Reference Book,
Butterworths.
·
Ward, W.D., Glorig, A. & Sklar,
D.L. (1959). Temporary threshold shift
produced by
intermittent exposure to noise. Journal of the Acoustic Society of America
31, pp791 –794.
5.1.1
This section presents the approach to
and the findings of the waste management assessment. The aim of this assessment
is to analyse the type of activities associated with the construction of the
helipad and the likely types of waste to be generated in order to outline
measures to minimise impacts to the surrounding environment and where possible
to minimise generation in the first place.
5.2.1
In carrying out the assessment,
reference has been made to Hong Kong legislation governing waste management and
disposal. Directly relevant legislation
include:
·
The Waste Disposal Ordinance (Cap. 354) and subsidiary legislation such
as the Waste Disposal (Chemical Waste)
(General) Regulation sets out requirements for the storage, handling and
transportation of all types of wastes.
·
The Dumping at Sea Ordinance (Cap. 466) provides for the control on
marine dumping, extends control on marine pollution, and gives legal effect to
the Marine Dumping Action Plan.
·
Land (Miscellaneous Provisions)
Ordinance (Cap 28).
·
Public Health and Municipal Services
Ordinance (Cap 132) – Public Cleansing and Prevention of Nuisance Regulation –
control of disposal of general refuse.
·
EIAO
and EIA-TM (Annexes 7 and 15).
5.2.2
Other relevant documents and
guidelines are also applicable to waste management and disposal in Hong Kong:
·
Environmental, Transport and Works
Bureau Technical Circular (Works) No. 22/2003, Additional Measures to Improve
Site Cleanliness and Control Mosquito Breeding on Construction Sites;
·
Environmental, Transport and Works
Bureau Technical Circular (Works) No. 15/2003, Waste Management on Construction
Sites;
·
Buildings Department, Practice Note
for Authorised Person and Registered Structured Engineers 252, Management
Framework for Disposal of Dredged/Excavated Sediments;
·
Environment, Transport and Works
Bureau Technical Circular (Works) No. 33/2002, Management of Construction and
Demolition Material Including Rock;
·
Environmental, Transport and Works
Bureau (Works) Technical Circular No. 34/2002, Management of Dredged/Excavated
Sediment;
·
Environmental, Transport and Works
Bureau Technical Circular (Works) No. 31/2004 Trip-ticket System for Disposal
of Construction and Demolition Materials;
·
Works Bureau Technical Circular No.
6/2002, Enhanced Specification for Site Cleanliness and Tidiness;
·
Environment, Transport and Works
Bureau Technical Circular (Works) No. 6/2002A, Enhanced Specification for Site
Cleanliness and Tidiness;
·
Works Bureau Technical Circular No.
12/2000, Fill Management;
·
Environmental Guidelines for Planning
in Hong Kong (1990), Hong Kong Planning and Standards Guidelines, Hong Kong
Government;
·
New Disposal Arrangements for
Construction Waste (1992), Environmental Protection Department and Civil
Engineering Department; and
·
Waste Disposal Plan for Hong Kong
(December 1989), Planning Environment and Lands Branch, Hong Kong Government
Secretariat.
5.3.1
The closest sensitive receiver
building with a direct line of sight to the helipad footprint is No. 105 Yung
Shue Wan Main Street, which is a residential village house and about 220 metres
southeast of helipad site [(NSR4) in
Section 4, Figure 4.2 refers].
5.3.2
All waste generated on Lamma Island is
currently collected and transported to the refuse transfer station (for
landfill disposal) which is located immediately south east of the proposed
helipad Project site boundary.
Site Conditions
5.3.3
Sediment quality along the shoreline
of Yung Shue Wan was previously investigated in 2001 under the Engineering Works for the Yung Shue Wan
Development Phase II (Mouchel Asia Ltd, 2001).
5.3.4
A total of five locations were sampled,
the closest one of which is located approximately 220m east of the proposed
helipad. At this location, the top 2 metres of sediment was classified as
Category H, but contained less than 10x the LCEL. Below this depth, the sediments were graded Category L. A flow chart illustrating the categorisation
of sediments in accordance with Environmental, Transport and Works Bureau
Technical Circular (Works) (ETWB TCW) No. 34/2002, Management of
Dredged/Excavated Sediment is presented in Appendix
5.1.
5.3.5
In 2002, sampling and analysis of
sediments less than 100m west of the proposed helipad location was performed
under the Outlying Islands Sewage Stage
I, Phase I Works Package C (Mouchel Asia Ltd, 2002).
5.3.6
Five locations, equidistant and
extending in a straight line NW from the shore, were sampled. Only the 0.9 –
1.9m interval in the sample collected closest to shore containing any parameter
that exceeded Category L (according to the ETWB 34/2002). The sample contained 1.3 mg/kg of Mercury
(above the EPD’s UCEL) and therefore the sample was classified as Category
H. However, the Mercury concentration
was within 10x the LCEL, therefore careful dredging and disposal at East Sha
Chau was recommended. The remaining
sediments were passed for open sea disposal.
5.3.7
A plan indicating the historical
sampling locations is presented in Appendix
5.2.
5.4.1
In addition to Annexes 7 and 15 of the
EIA-TM, the waste management assessment has also been carried out in accordance
with the requirements of Clause 3.4.4 of the EIA Study Brief. This stipulates
the assessment
of waste management implications shall also cover analyses of works activities
and waste generation and propose options / measures for managing waste.
5.4.2
The waste management hierarchy has
been adopted in carrying out the assessment and in developing mitigation
measures for waste. The hierarchy is comprised of the following key elements in
order of their priority:
·
Avoidance;
·
Reduce;
·
Reuse/Recycle;
·
Bulk Waste Reduction; and
·
Dispose.
5.4.3
Opportunities for reducing waste
generation have been evaluated in the process of the assessment and have been
based on the following factors:
·
Avoiding or minimising the generation
of waste where possible during the design stage (i.e. use of prefabricated
elements);
·
Adopting better site management
practices in material control and promoting on site sorting of Construction and
Demolition (C&D) material;
·
Exploring the potential for
reuse/recycling of materials (i.e. reuse of inert C&D material); and
·
Diverting C&D material to Public Fill
Areas, Fill Banks or other construction sites (if it cannot be reused on site).
5.4.4
The types and quantities of waste have
been estimated and disposal options for each category of waste identified in
this assessment, having taken into account the existing or future spare
capacities of the waste disposal facilities and the environmental implications
of the handling, collection and disposal of waste material.
5.5.1
Use of the small diameter pre-bored
piling option has been proposed as the preferred construction method. This construction method requires
significantly less removal of marine sediments and import of fill materials
than would construction dredging and reclamation. It is estimated that approximately 100m3 per month of
slurry will be excavated from within the pile casing during the 5½ months of
piling works, although this activity will be entirely contained and separate
from the adjacent water column.
Approximately 80m3 of C&D material will also be generated
over the entire construction period.
5.5.2
In addition, the following types of
waste are also anticipated to be generated during the construction activities
although estimated to be in much smaller quantities:
(i)
General construction waste (e.g. wood,
scrap metal, concrete);
(ii)
Chemical wastes generated by general
site practices (e.g. vehicle and plant maintenance/ servicing); and
(iii)
Municipal wastes generated by site
workers.
Background
5.6.1
The generation of waste will primarily
arise from the construction of the helipad whilst during its operation, waste
generation is predicted to be minimal. The following sections present the
assessment conducted to evaluate the source and potential volumes of waste to
be generated during each of these two phases.
5.6.2
All waste materials shall be disposed
of to designated waste disposal facilities (i.e., landfills, Public Fill Banks,
Public Filling Areas, etc.) whose operations are covered under an approved EIA
report or environmental permit (issued under the EIAO) except where the
materials may be reused or recycled.
Construction Phase
5.6.3
Pre-bored H piles will be sunk to form
the supporting frame for the reinforced concrete structure of the helipad. This construction method is similar to the
small diameter pre-bored piling method that requires installation of a hollow
casing and excavation of the sediment within. Once the sediment is removed, the
steel H-piles will be inserted and cement grout poured into the casing to form
the final pile structure.
5.6.4
As sediment will be removed during the
piling process and given the uncertainty of the characteristic of sediments
below the helipad footprint, a Sediment Testing Proposal was prepared under
this study to carry out additional sediment sampling and analysis to more
accurately categorise the sediments.
Sediment Testing
5.6.5
A Sediment Testing Proposal was
prepared under this study and approved by the relevant Authority, including
EPD, to carry out sediment sampling to assess the quality of sediments within
the footprint of the proposed helipad.
Three locations were marked within the footprint for sampling –
conducted by vibrocore to allow a continuous sediment core to be retrieved with
minimal sample disturbance.
5.6.6
A plan illustrating the co-ordinates
of the sampling locations (H1/H1A, H2A and H3A) and the ETWB 34/2002 sediment
classification guidelines are presented in Appendix
5.3. The reference sample was collected from EPD’s routine marine mud
monitoring location within Port Shelter.
5.6.7
The chemical analytical suite and
methods adopted by the HOKLAS accredited laboratory for the analysis of these
samples is presented in Table 5.1.
5.6.8
Table
5.2Table
5.2Table 5.2Table
5.2Table 5.2Table 5.2Table 5.2Table 5.2 presents the sediment quality criteria (as adopted from ETWB 34/2002)
against which the analytical data were assessed.
5.6.9
A total of 14 sub-samples were
collected, however sub-samples H1/E, H1/F and H3A/E were held from chemical
analyses pending the results of those sub-samples collected at shallower depths
at the respective locations. Moreover,
under instruction from CEDD, sub-sample H2A/C was divided into two sub-samples,
H2A/C and H2A/D. Both sub-samples were
analysed and a summary of the chemical test results for the other 12
sub-samples collected (4 from each sampling location) are presented in Appendix 5.3.
5.6.10
All samples from H1/H1A, H2A and H3A
locations had metal concentrations below the respective LCELs while no samples
were found to contain PAH or PCB concentrations that exceeded the detection
limit of the respective analytical tests.
5.6.11
The results of the chemical screening
indicate that sediment at the proposed site is graded Category L and thus can
be considered as having little or no contamination and can be disposed to open
sea.
Table 555555.111111 Analytical Suite and
Analytical Methods
Parameters
|
Sample Preparation Method
(US EPA Method)
|
Analytical Method
(US EPA Method)
|
Reporting Limits
|
Metals (mg/kg dry wt.)
|
|
|
Cadmium
|
3050B
|
6020A or 7000A or 7131A
|
0.2
|
Chromium
|
3050B
|
6010C or 7000A or 7190
|
8
|
Copper
|
3050B
|
6010C or 7000A or 7210
|
7
|
Mercury
|
7471A
|
7471A
|
0.05
|
Nickel
|
3050B
|
6010C or 7000A or 7520
|
4
|
Lead
|
3050B
|
6010C or 7000A or 7420
|
8
|
Silver
|
3050B
|
6020A or 7000A or 7761
|
0.1
|
Zinc
|
3050B
|
6010C or 7000A or 7950
|
20
|
Arsenic
|
3050B
|
6020A or 7000A or 7061A
|
1
|
Organic PAHs (µg/kg dry wt.)
|
|
|
Low Molecular Weight PAHs
|
3550B or 3540C or 3630C
|
8260B or 8270C
|
55
|
High Molecular Weight PAHs
|
3550B or 3540C or 3630C
|
8260B or 8270C
|
170
|
Organic non-PAHs (µg/kg dry wt.)
|
|
|
Total PCB
|
3550B or 3540C or 3665A
|
8082
|
3
|
Table 555555.222222 Sediment Quality Criteria
Parameters
|
Lower
Chemical Exceedance Level (LCEL)
|
Upper
Chemical Exceedance Level (UCEL)
|
Metals (mg/kg dry wt.)
|
Cadmium
|
1.5
|
4
|
Chromium
|
80
|
160
|
Copper
|
65
|
110
|
Mercury
|
0.5
|
1
|
Nickel
|
40
|
40
|
Lead
|
75
|
110
|
Silver
|
1
|
2
|
Zinc
|
200
|
270
|
Arsenic
|
12
|
42
|
Organic PAHs (µg/kg dry wt.)
|
Low Molecular Weight PAHs
|
550
|
3160
|
High Molecular Weight PAHs
|
1700
|
9600
|
Organic non-PAHs (µg/kg dry wt.)
|
Total PCB
|
23
|
180
|
Piling Works
5.6.12
Spoil generation will be limited to
the material displaced by piling and will be a function of the size (diameter
and length) and the number of piles to be installed. The grabbed material from
inside the casing will be a muddy slurry/spoil and if dumped onto the ground
will result in runoff into the coastal waters and result in water quality
impacts. The spoil will therefore need to be properly handled to minimise
contamination to the marine water and any exposed ground areas due to leakage
or improper storage (i.e. onto bare ground instead of into tanks).
5.6.13
Although the volume of slurry
generated is estimated to be small (~200m3 total), the Contractor
will still need to obtain approval from the Marine Fill Committee (MFC) for
off-site disposal and allocation of disposal space. As at the issuing of this report, the Director of the
Environmental Protection (DEP) has indicated that it is acceptable to dispose
of the sediments at the South Cheung Chau Spoil Disposal Area. However, the Contractor is required to
reconfirm this once the final dredging volumes are confirmed and apply for a
dumping permit from EPD.
5.6.14
It is estimated that the number of
barge movements required for the off-site disposal of the marine sediments will
be 2 to 3 barges over the course of the piling works (August 2006 to January
2007) to remove the small volume of spoil anticipated to be generated. Given the nature of the works and the
duration at which it is conducted (07:00-19:00), this frequency is not
considered to cause any significant increase in marine traffic or impacts to
nearby sensitive receivers.
5.6.15
Alternatively, the Contractor may
consider passing the slurry through mud separators / de-silting tanks to remove
or settle out soil particles and/or other solid materials from the
wastewater. This inert material should
be regularly collected and delivered to a Public Fill Area and/or Public Fill
Bank. If the inert material is
delivered to other construction sites, this will require the consent of the
receiving site and prior written approval from EPD.
5.6.16
Any direct discharge of wastewater
arising from the construction activities / surface run-off within the site
boundary to the coral habitat shall be avoided by the Contractor. The Contractor will also need to obtain a
discharge licence issued under the Water Pollution Control Ordinance (WPCO) and
ensure that the effluent meets the statutory water quality standards set out in
the permit prior to discharge out to the open marine waters.
5.6.17
According to information provided by
CEDD, it is estimated that the total volume of concrete required will be 1,500m3
throughout the entire construction period [Table
5.3Table
5.3Table 5.3Table
5.3Table 5.3Table 5.3Table 5.3Table 5.3
refers].
Table 555555.333333 Material Import
Requirements
Imported Material Type
|
Quantity
(m3)
|
|
Recycled
Material
|
Virgin
Material
|
Total
|
Rock fill
|
-
|
-
|
-
|
Sand fill
|
-
|
-
|
-
|
Sandy foreshore
|
-
|
-
|
-
|
Hardcore
|
-
|
-
|
-
|
General fill
|
-
|
-
|
-
|
Rock armour
|
-
|
-
|
-
|
Concrete
|
-
|
1,500
|
1,500
|
Total
|
-
|
1,500
|
1,500
|
5.6.18
The concrete material requirements consist
of cement grout (500m3) and ready-mix concrete (1,000m3).
The former will be used for the formation of piles whilst the latter will be
used to construct the helipad deck and EVA link.
5.6.19
While the cement grout will be
packaged, any stockpiling of the grout should be adequately protected to
prevent unnecessary wastage (from exposure to rain). Any storage is expected to be for a maximum duration of 5 to 5½
months. Upon completion of the piles,
the use of cement grout will no longer be necessary and as such strict material
control and storage should be adopted to avoid over ordering supplies and any
unnecessary wastage of the raw material.
5.6.20
There will be no need to store the
pre-mixed concrete on site as concrete will be used shortly after arrival delivery
at the site. However, the delivery and
handling of this material will need to be properly managed to prevent any
spillage from the transporting vessels into the marine waters or being spilled
out onto the works platform.
5.6.21
Based on the engineering design of the
helipad, the construction of the EVA extension and the landing pad itself will
likely generate various types of construction waste material including the
following:
·
Site clearance waste (vegetation,
rocks);
·
Waste metal (off cuts) from in-situ concrete casting work;
·
Spent concrete (from helipad and EVA
link decking); and
·
Material and equipment wrappings (from
packaging of cement grout).
5.6.22
It is estimated that site clearance
activities will result in the generation of 5m3 of C&D waste,
while another 30 - 40m3 of slurry will be generated monthly over a 6
month period and 80m3 of C&D materials over the entire duration
of the construction period. This will
include such wastes as formwork cut-offs, excess spent concrete, etc. All C&D materials generated on site
should be sorted into inert (public fill) and non-inert (C&D wastes)
material. Where possible, reuse of
these materials on site should be identified and implemented as far as
practicable to minimise material volumes requiring landfill disposal. Alternatively, outlets such as Public Fill
Banks should be identified for the inert material if no on-site reuse
opportunities exist.
5.6.23
Given the nature and the irregularity (in
size) of the waste material, reuse will not be likely. However, the Contractor should identify
likely arising quantities for recyclable materials and the possible recycling
options (i.e. waste metal, plastic film wrap, etc.) prior to considering landfill
disposal. Sufficient space and manpower
should be allocated to the storage, collection and disposal of such wastes.
5.6.24
Plant
and vehicle maintenance will likely be the primary source of chemical wastes
during the construction period. The majority of chemical waste produced is
therefore expected to consist of waste oils and solvents. Typical wastes may include the following:
·
Solid wastes (empty fuel/lubricant
drums, used oil/air filters, scrap batteries, brake clutch linings which may contain
asbestos); and
·
Liquid wastes (waste oils/grease,
spent solvents/detergents, which may be halogenated, and possibly spent
acid/alkali from battery maintenance).
5.6.25
The volume of chemical waste will
depend upon the total number of plant / vehicles and how much maintenance is
actually carried out on site. However based on the proposed plant list as
provided by CEDD [Section 4, Table 4.7 refers] it is unlikely that volumes of chemical waste will exceed
480 litres / month. These wastes may
pose environmental and safety hazards if not properly handled, stored and
disposed of. Given the small quantities anticipated, provided the waste is
properly handled, stored and disposed of, no impacts are predicted to arise.
5.6.26
The construction workforce will
generate general refuse such as waste paper (e.g., newspaper and office paper),
plastic packaging and possibly food waste.
Such refuse will generally be collected on site and brought to the
nearby refuse transfer station for disposal to landfill.
5.6.27
It is expected that no canteen will be
established for site workers given the close proximity of the site works area
to the commercial areas of Yung Shue Wan. However, as a worst case, it is
estimated that a factor of 1.06 kg/person/day of municipal waste will be
generated (EPD, 2000). The total
quantity of waste generated will thus be dependent on the number on site
workers that the contractor proposes to use.
For estimation purposes, we have assumed that the size of the work force
will be a maximum of 20 site workers. Based on these assumptions, the volume of
MSW likely to be generated on site will be 127 kg/week.
5.6.28
These wastes have the potential to
cause adverse impacts (environmental, health and nuisance) if not properly
handled, stored and disposed of. If the
waste is not regularly removed (for disposal), odour issues may arise. Given that the site is located along the
shoreline and in direct line of site of the ferry pier, any windblown debris
will cause water quality impacts if the debris lands in the water and result in
visual impacts. Moreover, if the storage area of these wastes are not regularly
cleaned and maintained, there is potential to attract vermin and pests to the
site. Sufficient covered waste bins
should be placed on site in convenient locations for site workers to dispose of
their waste. With proper on-site
handling and storage as well as regular disposal of these wastes to the nearby
refuse transfer station facility, no adverse impacts are predicted.
Sewage
5.6.29
The construction work force will
generate sewage on a daily basis and which will require proper disposal. It is anticipated that chemical toilets shall
be provided by the Contractor for the workforce, in which case night-soil will
need to be collected by an approved contractor for disposal on a regular basis
to avoid odour issues. Alternatively,
the use of a septic tank system may be acceptable provided that appropriate
connection is made to sewerage or sewage is treated prior to disposal.
5.6.31
During the operational phase of the
helipad, storage of maintenance materials will not be permitted at any time
either along the EVA or on the helipad itself.
It is envisaged that little or no waste will be generated during regular
maintenance of the helipad and thus is considered to have no adverse impact to
the environment.
5.7.1
The generation of waste will primarily
result from the construction phase of the helipad and EVA whilst negligible
volumes will be generated once the helipad becomes operational.
5.7.2
Based on the assessment above,
estimates for the amount of generated waste have been assigned for each waste
type and are presented in Table 5.4. In
general, the inert portion of C&D materials should be disposed of to Public
Fill Banks or other Public Filling Areas while the non-inert portion should be
sent to landfill for disposal. Any
potential for reuse of materials on site should be explored prior to disposal.
Table 555555.4444444 Summary of Construction
Phase Waste Generation
Activity
|
Material
Type
|
Likely
time of arising
|
Estimated
total volumes
generated
|
Disposal
/ Treatment Site
|
Ground preparation
|
Site clearance
|
Pre-construction
|
5 m3*
|
Landfill
(via Outlying Islands Transfer Facility located adjacent to the Project
site).
|
Piling
|
Slurry
|
August 2006 –
January 2007
|
~40 m3 / month
|
South
Cheung Chau Spoil Disposal Area ^
|
General works
|
Construction waste
|
Throughout
construction period
|
80 m3**
|
Public Fill Bank #
|
|
Chemical waste
|
Throughout
construction period
|
480 litres /
month**
|
Chemical Waste
Treatment Centre
|
|
General refuse
(generated by site staff)
|
Throughout construction
period
|
127kg / week
(assuming max. 20
staff & 6 day week)
|
Landfill
(via Outlying Islands Transfer Facility located adjacent to the Project
site).
|
i)
An on-site environmental co-ordinator
should be identified at the outset of the works. The co-ordinator shall prepare a Waste Management Plan (WMP) in
accordance with the requirements as set out in the ETWB TCW No. 15/2003, Waste
Management on Construction Sites. The
WMP shall include monthly and yearly Waste Flow Tables (WFT) that indicate the
amounts of waste generated, recycled and disposed of (including final disposal
site), and which should be regularly updated;
ii)
Spoil generated from the piling
activities will need to be properly handled to minimise contamination to the
marine water and any exposed ground areas due to leakage or improper storage
(i.e. onto bare ground instead of into tanks). Any dredged sediments generated
from the site works shall be handled in accordance with the ETWB TCW No.
34/2002;
iii)
The reuse/recycling of all materials
on site shall be investigated prior to treatment/disposal off site;
iv)
Good site practices shall be adopted
from the commencement of works to avoid the generation of waste, reduce cross
contamination of waste and to promote waste minimisation;
v)
All waste materials shall be sorted on
site into inert and non-inert C&D materials, and where the materials will be
recycled or reused, these shall be further segregated. Inert material, or public fill, is comprised
of stone, rock, masonry, brick, concrete and soil which is suitable for land
reclamation and site formation whilst non-inert material includes all other
waste generated from the construction process including items such as plastic
packaging and vegetation (from site clearance). The Contractor shall be responsible for identifying which
materials can be recycled/reused, whether on site or off site. In the event of
the latter, the Contractor shall make arrangements for the collection of the
recyclable materials. Any remaining
non-inert waste shall be collected and disposed of to the refuse transfer
station whilst any inert C&D material shall be re-used on site as far as
possible. Alternatively, if no use of
the inert material can be found on site, the material can be delivered to a
Public Fill Area or Public Fill Bank after obtaining the appropriate licence;
vi)
With reference to ETWBTC (W)
No.31/2004, Trip-ticket System for Disposal of Construction and Demolition Material,
a trip ticket system should be established at the outset of the construction of
the helipad to monitor the disposal of C&D and solid wastes from the site
to public filling facilities and landfills;
vii)
Under the Waste Disposal (Chemical
Waste) (General) Regulation, the Contractor shall register as a Chemical Waste
Producer if chemical wastes such as spent lubricants and paints are generated
on site. Only licensed chemical waste
collectors shall be employed to collect any chemical waste generated at
site. The handling, storage,
transportation and disposal of chemical wastes shall be conducted in accordance
with the Code of Practice on the
Packaging, Labelling and Storage of Chemical Wastes and A Guide to the Chemical Waste Control Scheme
both published by EPD;
viii)
A sufficient number of covered bins
shall be provided on site for the containment of general refuse to prevent
visual impacts and nuisance to sensitive receivers. These bins shall be cleared daily and the collected waste
disposed of to the refuse transfer station.
Further to the issue of ETWB TCW No. 6/2002A, Enhanced Specification for
Site Cleanliness and Tidiness, the Contractor is required to maintain a clean
and hygienic site throughout the Project works; and
ix)
All chemical toilets shall be
regularly cleaned and the night-soil collected and transported by a licensed
contractor to a Government Sewage Treatment Works facility for disposal; and
x)
Tool-box talks should be provided to
workers about the concepts of site cleanliness and appropriate waste management
procedures, including waste reduction, reuse and recycling.
5.9.1
The assessment has concluded that
under proper handling, storage, collection, transportation and disposal of
waste materials generated during construction of the helipad will not give rise
to any significant impacts to nearby sensitive receivers. While no specific
EM&A requirements have been identified, it is recommended that during the
construction phase, site inspections and supervisions of waste management
procedures and auditing of the effectiveness of implemented mitigation measures
be undertaken on a regular basis (weekly as a minimum). These tasks shall be scheduled in the WMP to
be prepared by the Contractor, and a summary of the site audits shall be
presented in the EM&A reports as required by the EM&A Manual.
5.9.2
Given the nature of use of the
helipad, there are no EM&A requirements for the project operational phase.
5.10.1
The proposed construction activities
associated with the proposed works will generate a number of waste
materials. These include:
·
Vegetation and demolition wastes from
site clearance;
·
Excavated materials;
·
Construction waste;
·
Chemical waste;
·
Marine sediments; and
·
Municipal waste.
5.10.2
Organic (vegetation) waste is
anticipated to be the only form of waste generated due to the operation of the
helipad (from intermittent maintenance works).
However, given that volume of such waste is expected to be negligible,
no adverse environmental impacts are anticipated during the operational phase
of the helipad.
5.10.3
In view of the HKSAR policy towards
the promotion recycling schemes and due to the clear environmental benefits this
will provide, recycling and waste reduction by site staff/contractors
(construction phase) and operators (operational phase) alike should be
encouraged.
5.10.4
While an estimate has been made on the
likely volumes and types of waste to be generated from the construction of the
helipad, the Contractor should regularly update and submit the details of their
WMP, including monthly and yearly WFT, to the Project Proponent. These WFT tables should provide a more
accurate estimate on volumes of waste generation on site.
5.10.5
The potential impacts of wastes
arising from the construction and operational phases of the Project have been
assessed. Provided that the mitigation
measures outlined above [Section 5.8 refers] are put in place and incorporated into the site specific
EM&A Manual, potential impacts to the environment associated with waste
generated by the construction and operational phases of the Project will be
controlled.
5.10.6
With the recommended procedures/measures
in place, the construction and operational wastes generated / disposed as part
of this Project, will not lead to any significant adverse environmental
impacts.
·
EPD (2000). Monitoring of Municipal Solid Waste 1999. Environmental Protection
Department.
·
Mouchel Asia Ltd. (2001). CE 33/2000: Yung Shue Wan Development,
Engineering Works, Phase 2. Preliminary Sediment Quality Report &
Biological Testing Proposal. July 2001. Civil Engineering Department.
·
Mouchel Asia Ltd. (2002). Outlying Islands Sewerage Stage 1,
Phase 1 Package C – Yung Shue Wan Sewage Treatment Works and Outfall. Sediment
Quality Report. May 2002. Drainage Services Department.
6.1.1
This section presents the approach to
and the findings of the water quality impact assessment, the aim of which is to
identify and examine all beneficial uses and sensitive receivers within the
assessment area in order to protect, maintain or rehabilitate the natural
environment.
6.1.2
The water quality assessment area is a
1-km radius around the Project site.
6.2.1
The water quality impact assessment
has been carried out in accordance with Annexes 6 and 14 of the EIA-TM under the EIAO, and the requirements set out in Clause 3.4.1 of the EIA Study Brief as follows:
(i)
Collect
and review relevant background information on the existing and planned water
system;
(ii)
Characterise
water and sediment quality based on existing information collected during the
last 5 years or the more recent information collected from appropriate site
surveys/tests;
(iii)
Identify
and analyse existing, planned/committed activities and beneficial uses related
to the water system and identify all water sensitive receivers;
(iv)
Evaluate
the possible impacts arising from the construction, including any possible
dredging, filling and/or piling works;
(v)
Identify
any alteration(s) / change(s) to bathymetry or flow regimes;
(vi)
Identify
and analyse all existing, future and other project(s) related water and
sediment pollution sources; and analyse these in relation to the provision and adequacy
of future facilities to reduce such pollution in terms of capacity and levels
of treatment;
(vii)
Calculate
the impacts on the affected water system and the sensitive receivers due to
those alterations and changes identified in (v) above and the pollution sources identified in (vi) above;
(viii)
Predicting
the cumulative impacts due to other construction activities within a radius of 2
km around the Project area (e.g., Yung Shue Wan Sewage Treatment Works);
(ix)
Propose
water pollution prevention and mitigation measures to be implemented during the
construction and operational stages so as to minimise the water / sediment
quality impacts;
(x)
Evaluate and quantify residual impacts on
the water system and sensitive receivers with regard to the appropriate water
quality criteria, standards or guidelines; and
(xi)
If
necessary, identify and quantify all dredging, fill
extraction, filling, mud/sediment transportation and disposal activities and
requirements as stipulated under Clause 3.4.1.3 (x) (a) – (c) of the EIA Study Brief.
Water Pollution Control Ordinance (Cap. 358)
6.3.1
The Water Pollution Control Ordinance (WPCO) is the principal
legislation for the control of water quality in the HKSAR. Under the Ordinance, HKSAR waters are
divided into 10 Water Control Zones (WCZs) – each with specific Water Quality
Objectives (WQOs).
6.3.2
The water quality study area for the
Yung Shue Wan helipad falls entirely within the Southern WCZ. The coastal waters around Yung Shue Wan are
designated as a secondary contact recreation sub-zone within Group 4a Southern
WCZ under the WPCO. The WQOs for this WCZ are presented in Table
6.1Table
6.1Table 6.1Table
6.1Table 6.1Table 6.1Table 6.1Table 6.1.
Table 666666.111111 Relevant Water Quality
Objectives for Southern WCZ
Parameters
|
WQOs
|
Dissolved
Oxygen (depth average, 90% of sampling occasions during the year)
|
4 mg/L
|
Dissolved Oxygen
(within 2m of seabed, 90% of sampling occasions during the year)
|
2 mg/L
|
Unionized
Ammonia (annual average)
|
0.021 mg/L
|
Total
Inorganic Nitrogen (annual depth average)
|
0.1 mg/L
|
E. coli
|
<610 cfu/100ml *
|
Suspended
Solids
|
<30% increase over the ambient
level
|
Technical Memorandum on Environmental
Impact Assessment Process
6.3.3
Annexes 6 and 14
of the Technical Memorandum sets out the criteria and guidelines for evaluating
and assessing water pollution.
Environmental
Transport and Works Branch Technical Circular (Works) No. 34/2002: Management
of Dredged/Excavated Sediment
6.3.4
This Technical Circular provides guidelines and procedures for obtaining
an approval to dredge / excavate sediment and the management framework for
marine disposal of such sediment.
Water Sensitive Receivers
6.4.1
Beneficial uses sensitive to water
pollution with a radius of 1km from the Project site have been identified in accordance
with Annex 14 of the EIA-TM.
6.4.2
The coastal waters around Yung Shue
Wan are designated as a secondary contact recreation sub-zone for recreation
uses, although no water sports or leisure boating activities were been observed
in the vicinity of the Project area during this Study. The Project site is within the Southern WCZ
– also a Water Sensitive Receiver (WSR).
6.4.3
The coral site at Shek Kok Tsui is
approximately 1 km to the northwest, while the Ecological Baseline Survey for
this Project also recorded that a hard coral community has become established
on the sloping seawall constructed under the Yung Shue Wan Phase 1 Reclamation
[Section 7 refers]. The locations of the WSRs are displayed on Figure 7.1.
6.4.4
There are no bathing beaches or
seawater abstraction / cooling water intakes in the assessment area.
6.4.5
The closest Fish Culture Zone (FCZ) to
the project area is the Lo Tik Wan FCZ on the eastern side of Lamma Island – some
4km from the proposed helipad. This distance separation, together with the
nature of the construction works and the Contractor’s compliance with the statutory
water quality standards set out in the discharge licenseWPCO, means that
the FCZ is not a WSR of concern for this assessment.
Ecology
6.4.6
Live hard coral communities have been identified
around the north of Yung Shue Wan and Shek Kok Tsui [Figure 7.1 refers]. These
coral communities are water sensitive receivers and have been subject to impact
assessment. The impact evaluation is presented in Section 7. There are no
other sites of ecological conservation importance within the assessment area.
Water
Quality
6.4.7
Yung Shue Wan has a semi-enclosed bay with
low tidal currents. It is relatively well protected from severe wave action
with respect to the main offshore storm wave directions, while locally
generated wind waves that may affect the bay have a very short fetch.
6.4.8
At present, diffuse polluted discharges
including domestic effluent and discharges from the numerous seafront
restaurants are having an impact on local water quality. Based upon the
Sewerage Master Plan for the Yung Shue Wan area, it was recommended that the
village areas be sewered and that a small treatment plant be constructed on the
Phase 1 reclamation for primary treatment prior to effluent discharge via a
dedicated marine outfall outside the bay. The interception of these discharges
and the proposed wastewater treatment facilities should result in an overall
improvement of the water quality in Yung Shue Wan. The operational helipad Project would not generate any
discharges.
6.4.9
Yung Shue Wan is located within the Southern
WCZ, for which the EPD collect routine water quality monitoring data. No
specific field data is available for Yung Shue Wan, although there are
monitoring stations located within the general water body west of Lamma Island.
The three closest stations to Yung Shue Wan are SM5, SM6 and SM7.
6.4.10
From EPD data collected in the year
2003, data from each of these stations were within the WQOs for Dissolved
Oxygen and Unionised Ammonia (NH3-N). However, all three stations failed the
WQOs for Total Inorganic Nitrogen (TIN).
6.4.11
Conditions within Yung Shue Wan bay
are expected to be less favourable than that measured at stations SM5, SM6 and
SM7 due to low water exchange rates and the diffuse discharges from septic tank
overflows and from restaurants into the bay.
6.4.12
The
monitoring station closest to the proposed Project site is ‘SM5’ located
approximately 2.5km south of the Project site (co-ordinate: 22o12.141’N,
114 o6.728’E). The water
quality of SM5 for the past 5 years as extracted from Marine Water Quality in
Hong Kong (1999-2003) is summarised in Table
6.2Table 6.2Table 6.2
Table 6.2Table
6.2Table 6.2Table
6.2Table 6.2.
Table 666666.2222222 Summary of Water Quality at ‘SM5’
between 1999 and 2003
Parameter
|
1999
|
2000
|
2001
|
2002
|
2003
|
DO
mg/L
|
6.4
(3.5-8.4)
|
7.0
(4.5-11.2)
|
6.4
(3.9-9.2)
|
7.3
(4.8 – 12)
|
6.3
(4.5 – 8.6)
|
DO
mg/L (bottom)
|
6.0
(3.5-7.9)
|
6.9
(5.0-9.8)
|
5.8
(4.0-7.9)
|
6.9
(5.3
– 9.1)
|
6.2
(5.1
– 7.9)
|
DO
% Saturation
|
91
(51-123)
|
99
(67-168)
|
89
(66-118)
|
103
(72 – 176)
|
90
(69 – 129)
|
DO
% Saturation (bottom)
|
85
(51-100)
|
98
(73-143)
|
82
(60-112)
|
98
(79 – 135)
|
88
(69 – 118)
|
Suspended
Solids (mg/L)
|
5.6
(1.9-16.0)
|
4.7
(0.5-16.0)
|
7.8
(3.3-17.3)
|
7.4
(1.8
– 30.0)
|
6.6
(1.5
– 17.0)
|
E. coli (cfu/100ml)
|
9.2
(1 – 68)
|
10
(1 – 110)
|
5.7
(1 – 18)
|
37
(1 – 420)
|
3.3
(1 – 16)
|
Unionised Ammonia (mg/L)
|
0.002
(0.001-0.004)
|
0.002
(0.001-0.007)
|
0.002
(0.001-0.007)
|
0.001
(0.001-0.008)
|
0.002
(0.001-0.009)
|
Total
Inorganic Nitrogen (mg/L)
|
0.18
(0.03-0.61)
|
0.15
(0.02-0.47)
|
0.18
(0.04-0.61)
|
0.17
(0.04-0.73)
|
0.09
(0.01-0.34)
|
Sediment
Quality
6.4.13
The
closest EPD monitoring station for sediment quality is station ‘SS4’, which is
located some 2.5km west of the Project site (co-ordinate: 22o11.500’N,
114o4.743’E). The sediment quality
of SS4 for the past 5 years as extracted from Marine Water Quality in Hong Kong
(1999 – 2003) is summarised in Appendix
6.1. It can be seen that the
sediment belongs to Category L (i.e., sediment contamination levels do not
exceed the Lower Chemical Exceedance Level (LCEL)).
6.4.14
A Sediment Testing Proposal was
prepared specifically for this Study, and approved by EPD. Accordingly,
sediment sampling was conducted within the proposed helipad footprint. Through chemical analysis it was determined
that the sediment had concentrations of all tested metals below the respective
LCELs, while levels of PAH’s or PCB’s were below the limit of detection [Section 5 refers].
Water Quality Criteria
6.4.15
The EPD sediment quality data shows
that the marine sediment around the Project site belongs to Category L (i.e.,
the contaminant level not exceeding the Lower Exceedance Level). Therefore, suspended solid (SS) is the only
parameter concerned in this water quality impact assessment.
6.4.16
Elevated SS levels may affect WSRs
through the formation and transport of sediment plume formation should dredging
works be required, and may potentially affect WSRs as described above. The level of elevation will determine
whether the impact is acceptable. The
WQOs in terms of SS for the Southern WCZs are defined as being an allowable
maximum elevation of 30% above the background level. The 90th percentile of the SS level over the last 5
years (1999 – 2003) is 13.6 mg/l, which was used as the background level. A 30%
increase above the background level is an elevation of ~4.1 mg/l, giving a
total SS limit of 17.7 mg/l.
1.1.1
Silt and clay, also
called cohesive sediment, will form large particles by the process of
flocculation after being released into the water column, which will then settle
back to the seabed, resulting in a smothering effect. This smothering effect can be detrimental to the corals. A limit
on the sedimentation rate of 0.1 kg/m2/day was applied to the
Project, following the study for Sand Dredging at the West Po Toi Marine Borrow
Area (ERM, 2001).
6.4.17
1.1.1
As presented in Section 2 112, the
construction of the helipad will not require dredging or back-filling, as it
will be a
reinforced concrete deck supported by a small on bored-pile structure.
6.5.1
The sequence of the
piling works requires that before permanent pile
installation a vibrator be used to install a temporary platform situated upon
temporary piles.
6.5.2
A temporary
platform will be requirederected
for the construction of the helipad
and associated EVAconstruction of permanent small bored piles, including drilling and
casing. Thise working
platform will be constructed by installing by vibrating steel
H or tubular piles into the
seabed to the required depth and then welding steel plankings on top of the steel piles to form a working deck. As permanent
casing will be used for the bored piles, bentonite shlurry will ies will not not be generatedbe necessary.necessary.
6.5.3
. During drilling for the permanent
casing, marine sediments shall be airlifted under pressure together with seawater through a side opening
at the top of the casing and channelled into via a hose connection into a
sedimentaion tank located on
the working platform. After settlement of solids and pH adjustment, and in accordance with ProPECC PN 1/94, the
effluent may be discharged into the foul sewer or into marine
waters. A disposal license under the WPCO may be
required for the respective discharge methods and the license conditions
complied with prior to discharge. , provided
a disposal license
under the WPCO is first obtained and the license conditions complied with. It is proposed that the settled uncontaminated marine sediment
be disposed at the South Cheung Chau spoil disposal area. After installation of tThe permanent casing, will be installed with an opening at the top at
one side of the casing. After the permanent casing is drilled into position, grout shall be is pumped
into the bottom of the
casing to displaceing the muddy seawater into the same slurry contained
therein. The
slurry will rise up the casing during the grouting process and will be
discharged through the side opening at the top of the casing, which is
connected by a hose to a sedimentation
tank with the on the
working platform. The effluent and sediment to sedimentsbe in the sedimention tank will be disposed as outlined above.of at landfill and the effluent
will be returned to the
sea upon obtaining WPCO
discharge license with
the quality satisfying the license requirements. The effulent quality will be checked by the regular self-monitoring in accordance with
the discharge license.
6.5.4
After
completion of all works the temporary working platform including the temporary
piles will be removed by cranes from a barge. During pile installationplacing and
extraction, the marine
sediments
shallwill be disturbed and will cause a highly localised causing water quality impact to the immediate vicinity. A silt curtain shall be installedconstructed around surrounding the works area to contain mobilised sediment and whole of the site to trap
the disturbed sediment. This
will also ensure no potential
adverse impacts on the hard coral community at the sloping boulder seawall [Section 777777 refers]. The silt curtain shall
not impinge on the hard coral community at the sloping boulder seawall. The silt curtain shall surrounding the whole site will be removed after
pile extraction once and the sediment has settled.settling of the disturbed
sediments. Such a
procedure has been adopted successfully in CEDD’s
recent pier construction at Stanley Beach. The
location of the temporary working
platform is indicated in Figure 6.1. After completion of all works the temporary
works platform
/ piles shall
be removed by a barge-mounted crane.
1.1.1
There is little
information for quantifying sediment suspension from piling activities,
although it is generally accepted that piling activities do not pose unacceptable
water quality impacts. The piling activity may cause some disturbance to the
seabed sediment in the immediate vicinity of the works, although based on
observations of similar construction methods the mixing zone will be spatially
limited. This is
because as the tidal circulation in Yung Shue Wan is weak the suspended
sediment will be confined to the bottom layer of the water column and will
settle quickly back to the seabed in the vicinity of the works area.
1.1.1
It is possible that
there may be some minor leakage of sediment during excavation, although this
would be restricted to within the pile casing and no water quality impacts
would arise. There is some potential for leakage into the receiving waters
during the transfer of the excavated sediment to the holding tank should the
grab of the excavator not be tightly sealed.
The Contractor should check the tightness of the grab seal before
commencing excavation. Under normal
working practice it can be expected that minor leakage of sediment may arise,
although any such volume for this Project would be negligible, and disturbance
of the water column would be restricted to immediately around the pile
location. As such, no adverse
significant water quality impacts are anticipated.
1.1.1
As a standard good working
practice, the use of silt curtains during the construction works is
recommended. This will ensure no
potential adverse impacts on the hard coral community at the sloping boulder
seawall [Section 7
refers].
6.5.5
During operation the water flow through
the piled structure will generally be maintained as at present, although there
may be localised effects due to the physical resistance of the piles. However, no significant impact on the flow
regime or water quality will arise during operation.
6.6.1
As regards potential for marine
ecology impacts, Phase 2 of the Yung Shue Wan Development Engineering Works
will commence in Year 2008, by which time all construction works for the Yung
Shue Wan Helipad will be complete.
6.6.2
The construction of DSD’s Yung Shue
Wan STW and Outfall is tentatively scheduled to commence in August 2007 for
approximately 3 years. The Helipad and
STW developments have been scheduled to avoid concurrent works and cumulative
water quality impacts.
6.7.1
In view of the construction method, no
significant adverse water quality impacts are predicted and no specific mitigation is considered necessary.
·
The environmental
guidelines for the handling and
disposal of construction site discharges as stated in EPD’s Practice Note for
Professional Persons – Construction Site Drainage (ProPECC
PN 1/94)
should be followed;
·
The holding tank should be fitted with
a tight fitting seal to prevent sediment leakage; and
·
The contractor should
ensure that excavator grab seal is tightly closed and the hoist speed is
suitably low;
·
The holding tank should
not be filled to a level which will cause overflow of sediment during loading
and transportation.; and
·
Large objects should be
removed from the excavator grab to avoid sediment spills.
Figure 6.1 Indicative Silt
Curtain alignment Alignment during
Marine Construction Works
6.8.1
Given the nature of the construction
method, and given that a silt curtain shall be installed surrounding
the whole works site, no water quality impacts are anticipated. However, a if construction
wastewater discharge to seawater is adopted, then compliance with the conditions of
the and no water quality monitoring is proposed. Nevertheless, regular self-monitoring of
potential pollutants including suspended solids and pH values for the effluent
shall be conducted upon
obtaining WPCO issued under the WPCO will be necessarywith the quality
satisfying the license requirements.licence under the WPCO may be necessary
for the various discharges and the license conditions should be complied with
prior to discharge.
6.9.1
It can be concluded that the assessed
construction method will not generate adverse water quality impacts. There may be some minor spillage during the
transfer of excavated sediment, although such a volume would be negligible and
restricted to the waters immediately around the pile location. As such, no adverse significant water
quality impacts are anticipated.
6.9.2
Hydrodynamic effects of the
constructed Project will be negligible, while there will be no operational
discharges that could potentially translate into impacts on the marine
environment.
6.9.3
No specific mitigation measures are
considered to be necessary, although the use of a silt curtain is recommended
as a good working practice for marine piling works.
·
EPD (2000). Hong Kong Marine Water
Quality.
·
EPD (2001). Hong Kong Marine Water
Quality.
·
EPD (2002). Hong Kong Marine Water Quality.
·
EPD (2003). Hong Kong Marine Water Quality.
·
ERM (2001). Focused Cumulative Water Quality Impact Assessment of Sand Dredging at
the West Po Toi Marine Borrow Area. Final report submitted to Civil
Engineering Department, HKSAR Government.
7.1.1
This section presents the approach to
and the findings of the ecological impact assessment. The aim of the ecological
impact assessment is to examine all marine ecosystem components (including sub-tidal
and inter-tidal habitats) within the assessment area in order to protect,
maintain or rehabilitate the natural environment.
7.1.2
For the purpose of the marine
ecological assessment the ‘assessment area’ is the same as that for the water quality impact
assessment, i.e., a 1 km radius around the Project
site.
7.1.3
There is no requirement in the Study
Brief for a terrestrial ecological
impact assessment. However, a broad
assessment has been conducted to support presentation of a complete ecological baseline
for the area. Given the scale, nature
and location of the works, the terrestrial ecology assessment area has been
defined as an area of 100 metres radius from the proposed helipad to take
account of wildlife disturbance during the operational phase. Any direct impacts during the construction
phase of the Project would be within this area.
7.1.4
Figure 7.1 illustrates the boundaries of the marine and terrestrial ecology
assessment areas.
7.2.1
The ecological assessment has been undertaken
in accordance with the criteria and guidelines in Annexes 8 and 16 respectively
of the EIA-TM, and with reference to the requirements of Clause 3.4.6 of the
EIA Study Brief as follows:
(i)
Review the findings of relevant
studies and collate all the available information regarding the ecological
characters of the assessment area;
(ii)
Evaluate the information collected and
identify any information gap relating to the assessment of potential ecological
impacts to the aquatic environment;
(iii)
Carry out necessary ecological field
surveys of at least four months duration and investigations to verify the
information collected and fill the information gaps identified;
(iv)
Establish the general ecological profile
of the assessment area and describe the characteristics of each habitat found;
(v)
Using suitable methodology, and
considering cumulative effects, identify and quantify as far as possible any
direct, indirect, on-site, off-site, primary, secondary and cumulative
ecological impacts;
(vi)
Determine that the ecological impacts
are avoided by design to the maximum practicable extent;
(vii)
Evaluate the significance and
acceptability of the ecological impacts identified using well-defined criteria;
(viii)
Recommend all possible alternatives
and practicable mitigation measures to avoid, minimise and/or compensate for
the adverse ecological impacts identified;
(ix)
Evaluate the feasibility and
effectiveness of the recommended mitigation measures and define the scope,
type, location, implementation arrangement, subsequent management and
maintenance of such measures;
(x)
Determine and quantify as far as
possible the residual ecological impacts after implementation of the proposed
mitigation measures;
(xi)
Evaluate the severity and
acceptability of the residual ecological impacts using well-defined criteria;
and
(xii)
Review the need for and recommend any
ecological monitoring programme required.
7.3.1
In order to evaluate the significance
of any potential impact upon the ecological components within the assessment
area, it is necessary to understand which components are of ‘conservation
importance’. This is defined as any species and / or habitat regularly
occurring in the Study Area that is globally, regionally threatened /
important, protected in the HKSAR, and /or locally or regionally endemic, rare
or restricted.
7.3.2
In addition to the requirements of the
EIAO (Cap. 499), those regulations, standards and guidelines applicable to the
ecological evaluation are summarised as follows:
7.3.3
In accordance with Section 4(1)(g) of
the Town Planning Ordinance (the Ordinance), draft plans prepared under Section
3(1)(a) of the Ordinance for the lay-out of any such area may show or make
provision for country parks, coastal protection areas, Sites of Special
Scientific Interest, green belts or other specified uses that promote
conservation or protection of the environment.
7.3.4
Under Chapter 10 of the Hong Kong Planning Standards & Guidelines there are
guidelines for the identification and protection of Natural Landscapes and
Habitats.
7.3.5
This Ordinance protects both natural
and planted forests, and the Forestry Regulations under this Ordinance provide
for the protection of specified local wild plant species.
Wild Animals
Protection Ordinance (Cap. 170)
7.3.6
The Wild Animals Protection Ordinance provides
for the protection of species listed in ‘Schedule 2’ of the Ordinance by
prohibiting the disturbance, taking or removal of such animals, their nests and
eggs.
7.3.7
This Ordinance excludes fish and
marine invertebrates, but does allow for the protection of all marine mammals
found in Hong Kong waters.
7.3.8
This Ordinance controls the local
possession of any endangered species of animals and plants listed in its
schedules. These include various types
of coral, including Stony (hard) corals (order Scleractinia) and Black corals
(order Antipatharia). Soft coral is not
protected under this Ordinance.
Fisheries Protection Ordinance and Regulations (Cap. 171)
7.3.9
Through the regulation of fishing
practices and the prevention of activities detrimental to the fishing industry,
this Ordinance aims to protect fishes and other marine biota in HKSAR waters.
Regionally / Internationally protected species
7.3.10
Chinese White Dolphin and Finless
Porpoise are listed as “Insufficiently Known” in the International Union for
Conservation of Nature and Natural Resources (IUCN) Red Data Book, and both
species are listed in Appendix I (i.e., highest protection) of the Convention
on International Trade in Endangered Species (CITES) [of Wild Flora and Fauna].
7.3.11
In the Mainland PRC, the Chinese White
Dolphin is listed as a Grade I National Key Protected Species, whilst the
Finless Porpoise is listed as a Grade II protected species.
7.3.12
Both CITES and the international Convention on Biological Diversity both
include provisions for the protection of corals.
7.4.1
Clause 3.4.6.4 (iv) (a) – (e) of the
EIA Study Brief provides guidelines for establishing a general ecological profile
of the study area. To this end, the
characteristics of the general area and the key habitats are described under
the sub-sections below.
7.4.2
Where appropriate, sensitive receivers
referred to under the literature review and identified through the field survey
are displayed on Figure 7.1 and / or Figure 7.2.
Literature Review
General
7.4.3
A literature review has been
undertaken to collate relevant data and information regarding ecological resources
within the assessment area – including the locations of recognised sites of
conservation importance and other ecologically sensitive areas.
7.4.4
Literature reviewed is from both
public and private sector studies, and includes the following:
·
Consultancy Study on Marine Benthic
Communities in Hong Kong (CityU Professional Services Limited, 2002).
·
EIA Study for Lamma Power Station
Navigation Channel Improvement (Hyder, 2003).
·
EIA Study for Yung Shue Wan Development,
Engineering Works, Phase 2 (Mouchel, 2002).
·
EIA Study for Lamma Power Station Extension (ERM,
1999).
·
EIA Study for Yung Shue Wan Sewage Treatment Works and
Outfall (CES, 1997).
·
SEA for ‘Landfill Extension Study’ – North Lamma
option (Scott Wilson / BMT, 2002).
Sub-tidal Ecology
7.4.5
Sub-tidal benthic
survey was conducted adjacent to the proposed helipad site in October 1996 for the EIA Study
for Yung Shue Wan Sewage Treatment Works and Outfall (CES, 1997). This survey,
conducted prior to reclamation works, recorded the sediment to be comprised of
fine mud and silt mixed with occasional shell fragments. The most abundant benthic infauna taxa were
of the Order Polychaeta. Polychaete
worms favour muds for burrowing, and particularly abundant were species of the
Family Capitellidae that are indicators of low oxygen environments. No coral was identified in the immediate vicinity of the proposed
site from this past ecological survey, although there are scattered coral
communities in the broader area.
7.4.6
A comprehensive survey of the HKSAR’s
marine benthic community was undertaken on behalf of AFCD throughout 2001, and
included a sampling station located in Ha Mei Wan approximately 1 km to the
south of the HEC Lamma Power Station – the closest such sampling location to
the Project area. The survey station is
slightly outside the marine ecology assessment area, although the survey
results were that the marine benthic community in Ha Mei Wan is broadly
characteristic of most of the sampling stations in western and southern HKSAR
waters and represents a typical soft-bottom infauna.
7.4.7
The community was characterised by a
number of polychaetes and other species that were represented in at least half
of the 120 sampling stations across the HKSAR (CityU, 2002). Table
7.1Table
7.1Table 7.1Table
7.1Table 7.1Table 7.1Table 7.1Table 7.1
below summarises these representative species and shows their presence / absence in the seabed community at Ha
Mei Wan from summer and winter surveys.
Table 777777.111111 Representative Species in
the Ha Mei Wan Marine Benthic Community (CityU,
2002)
Family
|
Species
|
Summer
Survey
|
Winter
Survey
|
Polychaete
|
Mediomastus spp.
|
Ö
|
Ö
|
|
Sigambra hanaokai
|
Ö
|
-
|
|
Agalaophamus dibranchis
|
Ö
|
Ö
|
|
|
Ö
|
-
|
|
Ophiodromus angustifrons
|
Ö
|
-
|
|
Paraprionospio pinnata
|
Ö
|
Ö
|
|
Prinospio malmgreni
|
-
|
Ö
|
|
Prinospio ehlersi
|
-
|
Ö
|
|
Otopsis sp.
|
-
|
Ö
|
Crustaceae
|
Callianassa japonica
|
Ö
|
-
|
|
Neoxenophthalamus obscuris
|
Ö
|
Ö
|
Echinoderm
|
Amphiodia obtecta
|
-
|
Ö
|
Sipunculan
|
Apionsoma trichocephalus
|
Ö
|
Ö
|
|
Total
Species Richness (0.5 m2)
|
39
|
34
|
|
Total
Individuals (m2)
|
284
|
142
|
|
Total Wet
Weight (g/m2)
|
54.70
|
81.20
|
7.4.8
To appreciate the ecological significance
of the marine benthic community at Ha Mei Wan a comparison was made of the
univariate indices (d, H’ and J) at this location with the mean values for other stations in
western and southern (W & S) HKSAR waters [Table
7.2Table
7.2Table 7.2Table
7.2Table 7.2Table 7.2Table 7.2Table 7.2refers].
Table 777777.2222222 Univariate Statistics for
Ha Mei Wan & Similar HKSAR Survey Areas (CityU,
2002)
Index
|
Summer
|
Winter
|
Ha
Mei Wan
|
W
& S HKSAR
|
Ha
Mai Wan
|
W
& S HKSAR
|
Species
Richness index (d)
|
7.67
|
7.26
|
7.74
|
4.90
|
Species
Diversity index (H’)
|
3.02
|
2.87
|
3.24
|
2.32
|
Species
Evenness index (J)
|
0.83
|
0.82
|
0.93
|
0.73
|
7.4.9
Table
7.2Table
7.2Table 7.2Table
7.2Table 7.2Table 7.2Table 7.2Table 7.2
shows that there is no significant difference
(p>0.05) between the summer and winter indices for species richness (d), diversity (H’) or evenness (J) at Ha
Mei Wan. Compared to other survey stations with similar characteristics (mainly
in western and southern waters) the Ha Mei Wan community generally has higher
species richness, diversity and evenness – particularly in the winter period –
indicating it is broadly of above average ecological value. Despite this, no marine benthic species of
particular note were found in the Ha Mei Wan area, nor would be expected at
Yung Shue Wan where the sediment is more disturbed and the water quality
poorer.
7.4.10
As regards corals, Figure 7.1 illustrates the location of the
closest coral community to the proposed helipad site. This is a west-facing
rocky headland at the north of Yung Shue Wan, approximately 400 metres north of the proposed
helipad site (Mouchel, 2002).
7.4.11
From a qualitative dive survey around
this headland small and scattered colonies comprising four species of
encrusting hard coral were observed: Montipora peltiformis; Favites abdita; Favia speciosa, and Plesiastrea verispora.
These species are commonly found in HKSAR waters. Around the southern part of the headland,
upon entering Yung Shue Wan, there was reportedly a fairly sudden change in the
benthic community composition, with the oyster Saccostrea cucullata becoming dominant (ibid.).
7.4.12
Hard corals have previously also been
recorded from the coastline of Shek Kok Tsui, some 800m north of the proposed helipad, where the encrusting hard coral Psammocora superficialis and small
colonies of Faviidae species were observed.
The coral density at this site was reported as <2% and was not
considered to be of any particular conservation importance (ERM, 1999).
7.4.13
A
more diverse coral community, including soft corals and gorgonians, exists at
Pak Kok, northeast Lamma. Here the
cover of the coral community is in the order of 13%, and the site has conservation
value (Binnie, 1995).
7.4.14
An incidental observation of the Green
Turtle Chelonia mydas – one of 4
species of sea turtle found in Hong Kong – has also been observed in waters
around Pak Kok (Scott Wilson / BMT, 2002).
The Green
Turtle is the only turtle species known to breed locally, with nesting only
reported thus far at the sandy beach at Sham Wan, south Lamma, approximately 9
km from the Project area. The Green
Turtle is protected under the Wild Animals Protection Ordinance, Cap.170 and is
listed under Appendix I of CITES. The beach at Sham Wan and the nearby shallow
waters were designated a SSSI in June 1999, whilst (since 1999) approximately
0.5ha of the nesting area including the beach is a ‘Restricted Area’ from 1st June to 31st
October each year.
7.4.15
Given that the Project is now to be
developed by small diameter pre-bored piling structures, the water quality
impact will be negligible and highly localised around the piles. As such, the Pak Kok area, at 2.5 km distance,
will not be affected by the Project.
Likewise, the Green Turtle nesting beach and nearby shallow waters at
Sham Wan will not be affected by the Project.
7.4.16
Based on records accumulated by AFCD
between October 1995 and April 2003, there is only one ‘official’ record of the
Chinese White Dolphin Sousa chinensis
in the general area, and that close to the Power Station – some 1.5 km from the
proposed Yung Shue Wan helipad site (AFCD, 2003a).
7.4.17
The scenario is similar for the
Finless Porpoise Neophocaena phocaenoides. From records accumulated by AFCD between
February 1996 and April 2003 there is one official record – again, in waters
just off the Power Station (AFCD, 2003b).
However, an undated casual observation of a group of some 10 porpoises
was made to the north of the Yung Shue
Wan ferry pier, as reported in Mouchel (2002).
Despite this observation, it was concluded that the waters in the
vicinity of Yung Shue Wan are not of particular importance to the Finless
Porpoise.
7.4.18
Porpoises move into the waters of West
Lamma, around Ha Mei Wan, in December and reach their peak abundance around
southwest Lamma between March and May (ibid.).
This core area for the Finless Porpoise is approximately 5 km from Yung Shue
Wan (Scott Wilson /
BMT, 2002).
7.4.19
Fisheries resources of potential ecological
significance in the broader area are present around the south of Lamma Island
where there are important spawning and nursery grounds for a range of fish and
crustacean species (ERM, 1998). These
waters also support the squid Loligo sp., the lion-head
fish Collichthys lucida and the
tiger-tooth croaker Otolithes argenteus
that comprise the most common and numerically important prey
species of the Finless Porpoise (Jefferson, 2001).
7.4.20
The results of Port Survey 2001/2002
(AFCD, 2003c) provide adult fish catch data (kg / hectare) throughout HKSAR
waters for the top ten families, and also provides data for specific areas.
Accordingly, catch data for the top ten HKSAR families in waters to the
northwest and southwest of Yung Shue Wan provides an indication of fish /
crustacean family abundance in the area.
The adult catch data for these two Yung Shue Wan areas has been combined
and ranked against the HKSAR average, as presented in Table
7.3Table
7.3Table 7.3Table 7.3Table 7.3Table 7.3Table 7.3Table 7.3.
Table 777777.3333333 Top Ten Ranked Adult Fish
/ Crustacean Families (from AFCD,
2003)
Family
|
Rank
|
HKSAR
|
Yung Shue
Wan
|
Rabbitfish
(SIGANIDAE)
|
1
|
2
|
Sardine
(CLUPEIDAE)
|
2
|
9
|
Croaker
(SCIAENIDAE)
|
3
|
2
|
Scad (CARANGIDAE),
|
4
|
5
|
Squid
|
5
|
5
|
Shrimp
|
6
|
1
|
Anchovy
(ENGRAULIDAE)
|
7
|
10
|
Crab
|
8
|
7
|
Seabream (SPARIDAE)
|
9
|
2
|
Threadfin
bream (NEMIPTERIDAE)
|
10
|
7
|
7.4.21
Fisheries data from the Port Survey
1996/97 (AFCD, 1998) are more detailed in terms of indicative species abundance
(from catch data) at two defined fishing zones in waters adjacent to Yung Shue Wan: Pak Kok and Po Lo Tsui. Together these zones cover a
sea area of over 1 km to the north, west and south of Yung Shue Wan. On a unit area basis the Po Lo Tsui zone is the most
productive for both adult and fry fish, ranking 43rd of 210 zones
and 29th of 89 zones respectively (ibid.). The top ten adult species caught (by weight) in each of these zones is
as presented in Table
7.4Table 7.4Table 7.4 Table 7.4Table
7.4Table 7.4Table
7.4Table 7.4.
Table 777777.4444444 Top Ten Adult Fish Species Caught off Yung Shue Wan (from AFCD,
1998)
Species
|
Common Name
|
Zone / Rank
|
|
|
Pak Kok
|
Po Law Tsui
|
Mixed
Species
|
N/A
(various)
|
1
|
1
|
Siganus oramin
|
Rabbitfish
|
2
|
6
|
Caranx spp.
|
Scad /
Crevalle
|
6
|
2
|
Pseudosciaena
crocea
|
Yellow Croaker
|
4
|
5
|
Sebasticus marmoratus
|
Rockfish
|
5
|
4
|
Eleutheronema tetradactlyus
|
Threadfin
|
3
|
-
|
Sardinella jussieu
|
Sardine
|
-
|
3
|
Clupanodon punctatus
|
Gizzard
Shad
|
7
|
-
|
Stolephorus spp.
|
Anchovy
|
-
|
7
|
Leiognathus brevirostris
|
Pony Fish
|
8
|
-
|
Argyrosomus spp.
|
Croaker
|
-
|
8
|
Trachurus japonicus
|
Scad
|
9
|
-
|
Sparid spp.
|
Sea Bream
|
-
|
9
|
Mixed
Crabs
|
N/A
(various)
|
10
|
-
|
Ambassis gymnocephalus
|
N/A
|
-
|
10
|
7.4.22
From
the above ‘Port Survey 1996/97’ data it is of note that 5 of the top 6 species
were caught in both fishing zones. Due to
differences in raw data presentation, a direct comparison cannot be made
between data from the two Port Surveys.
However, the two tables above provide an idea of abundant fish /
crustacean taxa in the Yung Shue Wan area.
Inter-tidal / Terrestrial
Habitat
7.4.23
From a review of work conducted by CES
(1997), prior to reclamation for the proposed Yung Shue Wan STW site the inter-tidal zone was surveyed by line transect. The transect closest to the proposed Yung Shue
Wan helipad site was comprised of granite boulders and sand, and the
predominant species recorded were common gastropods, crabs and algae.
7.4.24
More recent inter-tidal survey work at
the north of Yung Shue Wan conducted by Mouchel (2002) gathered data from three
hard shore and three soft shore locations mainly around the north / northeast
of the bay.
7.4.25
The soft shore areas comprised sandy
beach and soft muds, with shell fragments present. Of the three areas investigated, benthic fauna were only recorded
from the location beside a culvert at the northeast of the bay. The community was similar for both wet and
dry season survey, being dominated by Capitellid polychaetes, with Nephytid and
Cossurid polychaetes also present.
7.4.26
The hard shore communities were more diverse,
comprising 4 – 9 species in the dry season and 4 – 10 species in the wet
season. The lowest species richness and
abundance in both wet and dry seasons was from the hard shore adjacent to the
culvert at the northeast of the bay – a probable response to chronic water
pollution at this area and the data for the soft shore area would suggest. It was noted that the two hard shore
locations at the fringes of Yung Shue Wan displayed relatively high species
diversity and abundance (ibid.). A characteristic seasonal decline in
abundance was recorded from the dry to the wet season, although there was an
increase in species diversity.
7.4.27
The type, zonation and seasonality of
representative benthic fauna species at the two hard shore areas north and
northwest of Yung Shue Wan (i.e., remote from the polluted culvert discharge)
is summarised in Table 7.5. None of the species recorded are of
particular conservation importance.
Table 777777.5555555 Hard Shore Benthic Fauna,
Yung Shue Wan – Year 2001 Data (from
Mouchel, 2002)
Species
|
North
YSW
|
Northwest
YSW
|
|
January
|
June
|
January
|
June
|
Monodonta
australis
|
H, M, L
|
H
|
/
|
/
|
Nodolittorina
trochoides
|
H
|
/
|
H
|
H
|
Nodolittorina
radiata
|
H
|
H
|
H, M
|
H
|
Thais clavigera
|
M
|
M, L
|
L
|
H
|
Liolophura japonica
|
M
|
/
|
M, L
|
H, M
|
Nerita albicilla
|
/
|
/
|
L
|
/
|
Cellana toreuma
|
M, L
|
H
|
M, L
|
H, M
|
Patelloida pygmaea
|
/
|
/
|
L
|
/
|
Patelloida
saccharina
|
M
|
H
|
M, L
|
H, M
|
Saccostrea
cucullata
|
M, L
|
M
|
/
|
/
|
Teraclita squamosa
|
M, L
|
H, M
|
M, L
|
M
|
Pollicepes mitella
|
/
|
H
|
M
|
H
|
Septifer
bilocularis
|
/
|
/
|
M
|
/
|
Ornithichiton
hirasei
|
/
|
H, M
|
/
|
/
|
7.4.28
Given
that reclamation works in the immediate vicinity of the Yung Shue Wan helipad site
are only recently complete, there is no natural (or planted) inter-tidal
vegetation community present. However,
behind the area reclaimed for the Yung Shue Wan STW the natural coastal
scrub / secondary woodland community has been largely retained. Species in this coastal community include
the grass Pennisetum sp., the
ubiquitous exotic shrub Lantana camara
and the very common trees Macaranga
tanarius and Ficus hispida (CES,
1997). A few
small banana (Musa paradisiaca)
groves in this community are characteristic of abandoned cultivation, and are not of conservation importance (ibid.).
7.4.29
No
records of terrestrial fauna in the immediate area were presented in past study
reports. However, there are records for
the broader environs of Yung Shue Wan as presented by Mouchel
(2002). Given their mobility,
observations of birds are potentially of most significance to the proposed
helipad site, with one record (2 specimens) of the Reef Egret Egretta sacra and two records (4
specimens) of the Night Heron Nycticorax
nycticorax recorded from within Yung Shue Wan on 9th January
2001 and 20th June 2001, respectively. Both species are local but not uncommon.
Field Survey Methodologies
7.4.30
The Ecological Baseline Survey was
conducted in March and April 2003.
Details of the mapping and survey methodologies and findings are
presented under the following headings.
Habitat Mapping
7.4.31
A Habitat Map of the immediate area around
the proposed helipad was developed with reference to land use maps and aerial
photographs of the assessment area taken and supplied by GFS. This was supported by ‘ground truthing’
conducted on 25th March 2003, which involves systematically surveying
the assessment area to verify the accuracy of the initial interpretation of
maps and photographs.
Sub-tidal Habitat
7.4.32
Recently completed survey work by
Mouchel (2002) has generated an updated sub-tidal ecology profile for much of
the Yung Shue Wan area, although the survey area did not specifically include
the area around the helipad. Accordingly, a dive survey was conducted under
this Assignment on 27th April 2003 to verify the assumed status of
the seabed benthic community and the site of the proposed helipad footprint,
and to inspect the boulder seawall that has previously not been surveyed.
7.4.33
A series of spot-check reconnaissance
dives were initially conducted from a ‘P4’ boat
by two qualified marine biologists. The objective of the reconnaissance dives
was to gain familiarity with the underwater terrain, following which a decision
was made as to where best to conduct qualitative survey transects.
7.4.34
There was nothing of particular note in
the immediate vicinity of the proposed helipad footprint, although there were
signs of a potentially interesting benthic community on the boulder
seawall. Accordingly a dive transect
was surveyed along 400m of coastline starting at the vertical seawall by the
Refuse Transfer Station (RTS) and covering the length of the sloping boulder
seawall (130m) and part of the natural rocky shoreline [Figure 7.2 refers].
7.4.35
The transect depth was close to the
surface, at approximately -0.5m CD. A
second transect was followed back to the RTS, at approximately -5.0m CD, and
hence a total transect distance of approximately 800 metres was surveyed. Visibility on the day of survey was greater
than 4m and so observations from the two transects were able to cover the
entire sub-tidal area of the seawall (i.e., approximately 4.5m length [down
from the water surface level] by 130m wide).
7.4.36
This method was employed to assess the
substrate for the presence of coral communities and to update any existing
desktop studies and previous site surveys.
The following detailed information was categorised: Location, depth,
visibility, substrate type, distance surveyed, % hard coral and soft coral
cover, coral species and other biota present.
Representative video footage and digital images were
taken on mini digital-video format, using a 3CCD camera system.
Inter-tidal / Terrestrial
Habitat
7.4.37
To complete an ecological profile for the area, a
qualitative survey of vegetation, birds and butterflies present in terrestrial habitat
behind the reclamation was completed on 25th March 2003. Survey involved walking a line-transect
along the base of and up the foot-slope behind the reclamation [Figure 7.2 refers]. Weather on the day was dry and warm, 22
degrees Celsius – conditions that are generally conducive to wildlife activity.
7.4.38
A qualitative survey of benthic species found on the
sloping boulder seawall adjacent to the proposed helipad location was also
conducted on the same day. This element
of the survey was conducted by walking along the lower part of the sloping
seawall that forms the front of the proposed STW reclamation (there being no
biota at the middle or upper seawall area) [Figure
7.2 refers]. Observations were also
made for biota colonising the vertical seawall adjoining the sloping seawall to
the north (i.e., fronting the RTS).
Field Survey Results
Habitat Mapping
7.4.39
From the Habitat Mapping exercise, a
total of five discreet habitat types were identified in the assessment
area. Table
7.6Table
7.6Table 7.6Table
7.6Table 7.6Table 7.6Table 7.6Table 7.6
summarises their respective areas.
7.4.40
Figure
7.2 presents the delineation of the five habitats
in the assessment area. For
completeness, the figure also shows the delineation of a small area of
cultivated land to the east (outside) of the assessment area, although this
land is not subject to impact assessment – being too remote from the Project to
be affected.
Table 777777.6666666 Habitat Types in the
Assessment Area
Habitat Type
|
Approximate Area (hectares)
|
Sub-tidal
|
~ 150 ^
|
Granite
Boulder Seawall
|
0.1
|
Rocky
Shore
|
~ 0.5 ^
|
Developed
/ Disturbed Area
|
0.8
|
Mixed
Scrub / Secondary Woodland
|
0.8
|
7.4.41
A brief summary of the five habitat
categories in the assessment area is provided below, with further details
provided under “Evaluation of Ecological
Value”. Representative colour photographs of the habitats are presented as Figure 7.3.
1.
Sub-tidal [The seabed around Kam Lo Hom is predominantly of silty muds, with
erratic boulders to around 10 metres from the foot of the sloping seawall. No benthic fauna was observed on the silty
seabed, although several fish species were observed].
2.
Granite
Boulder Seawall [present as a uniform sloping
seawall across the inter-tidal zone, with more irregularity in shallow
sub-tidal waters by the seawall].
3.
Rocky
Shore [natural granite shoreline slab adjoining the
boulder seawall to the south / southeast of the proposed works area].
4.
Developed
/ Disturbed Area [This category includes reclaimed
land that has been set aside for the development of the proposed Yung Shue Wan sewage
treatment works, and a length of vertical concrete seawall around the existing
Refuse Transfer Station that extends into and around much of the main bay of
Yung Shue Wan].
5.
Mixed
Scrub / Secondary Woodland [Behind and around the
reclaimed platform is vegetated land, characterised by mixed scrub and
secondary woodland].
Sub-tidal Ecology
7.4.42
Three major habitat types were studied
during the dive survey: granite boulder habitat (inter-tidal and sub-tidal), granite
rocky shore (inter-tidal and sub-tidal) and silty marine muds (sub-tidal only).
7.4.43
The spatial extent of the sloping
boulder seawall was to a maximum depth of -4.0m CD, whilst in deeper waters
(-4.0 to -6.0m CD) scattered boulders and fine silt were predominant. It was also noted that boulders in deeper
waters were smothered with silt. Below
–6.0m CD silty muds were dominant and visibility was poor due to natural
sediment re-suspension from wave action.
No benthic taxa were recorded from the seabed areas inspected.
7.4.44
The recorded benthic community was
entirely confined to the hard boulder and rocky shore habitat types only, with
typical hard community taxa such as bryozoans, encrusting sponges, mussels and
barnacles present. These taxa were, however,
far more abundant on the shallow sub-tidal face of the sloping seawall than the
flatter and smother rocky shore habitat, and were particularly found in the
-0.5 to -3.0m CD depth band. A high %
cover of turf and calcareous algae was also widespread in the same depth range
on the sloping seawall.
7.4.45
Of particular note, the dive survey
also recorded a total of 15 species from four families of hard coral found on
the sloping granite seawall and the rocky headland at the southwest end of the seawall [Table 7.7Table
7.7Table 7.7Table
7.7Table 7.7Table 7.7Table 7.7Table 7.7
refers]. All hard coral species in
the community are common in the HKSAR, with the dominant family being the
Faviidae.
Table 777777.7777777 Hard coral species, Yung
Shue Wan (BMT, 27th April 2003)
Family
|
Scientific
Name
|
|
Favites pentagona
|
|
Favites chinensis
|
|
Favites flexuosa
|
|
Favites abdita
|
|
Goniastrea aspera
|
|
Favia rotumana
|
|
Oulastrea crispata
|
|
Cyphastrea serailia
|
|
Platygyra carnosus
|
|
Plesiastrea
versipora
|
Siderasteriidae
|
Psammocora haimeana
|
|
Psammocora
profundacella
|
|
Psammocora
superficialis
|
Dendrophyllia
|
Turbinaria peltata
|
Poritidae
|
Porites cf lutea / lobata
|
7.4.46
The corals were present in numerous
isolated sub-massive and encrusting colonies, with several colonies > 0.5m
diameter. Within the confines of the
baseline survey it was not possible to allocate a particular percentage cover
to each coral species due to the tightly integrated character of the colonies.
7.4.47
Most of the corals were found on the
upper surface of large boulders (i.e., boulders typically with a surface area
> 1.0m2), with the corals generally being confined to a depth
range of -1.5m to -2.0m CD. The distribution
of hard corals was scattered but generally uniform along the length of the survey transects.
7.4.48
In summary, the live coral cover on
the sloping boulder seawall and adjacent rocky headland was 6 – 10% of the surveyed
area (i.e., an area cover in the range of 35.1 – 58.5m2 [of a total sub-tidal boulder seawall surface area
of 585m2]).
7.4.49
During the dive survey, a checklist of fish seen
around the sloping boulder seawall and over the adjacent seabed was
recorded. Species recorded include:
Waspfish (Paracentropogon longispinus),
Hong Kong butterfly fish (Cheatodon
wiebeli), Silver sweeper (Pempheris
oualensis), Cardinalfish (Apogon
spp.), Wrasse (Labridae spp.) and
Pearl-spot chromis (Chromis notata).
7.4.50
All these fish species are common and are generally
found in boulder / silt habitats.
Inter-tidal / Terrestrial
habitat
7.4.51
Despite
the loss of the natural inter-tidal shoreline some common and versatile species were recorded colonising the sloping
rock-armour seawall
adjacent to the proposed Helipad site. The sloping seawall is
approximately 200 metres long and an epifauna community was present only at the
lower part, within the tidal range. The
limpet Cellana toreuma and the top shell Monodonta australis dominate the community. Other species widespread on the lower wall,
but less abundant, were the amphipod Ligia exotica and the acorn barnacle Teraclita squamosa. The pockets between the boulders of the
sloping seawall were barren and no vegetation had become established.
7.4.52
No
epifauna or vegetation was recorded from the vertical seawall off which the EVA
link is to be constructed.
7.4.53
Along
the top of the sloping and vertical seawall (as far as the RTS) a landscaped
planting area has been developed. This supported
only ornamental species, with most of these being exotic (e.g., Bougainvillia sp. and Lantana sp.). None of the ornamental
species are of ecological conservation value.
7.4.54
In
the mixed scrub / secondary woodland community at the back of the reclaimed
land there was a diverse community of grasses, herbs, shrubs and trees. The most abundant species immediately behind
the reclaimed land included the grasses Eleusine indica, Paspalum sp., Chloris barbata, Miscanthus floridulus, Rhynchelytrum repens and Pennisetum sp., and a number of common herbs and climbers (e.g., Ageratum conyzoides, Bidens
pilosa, Hedyotis sp., and Ipomoea cairica).
7.4.55
Further
upslope, where the land levels out somewhat and the soil is deeper, there is a
diverse tree community – part of a continuous habitat up the north-facing
slope. There are some abandoned village
houses in this area and evidence of past cultivation, with several exotic
ornamental plants (e.g., Bougainvillia
spp. and Thevetia peruviana) and
stands of the banana Musa paradisiaca
growing wild. However, most species are
native, and include Ficus microcarpa,
F. virens, F. variagata, Sterculia
lanceolata and Schefflera octophylla. There are also a number of sizable bamboo
stands in this habitat.
7.4.56
Due
to its naturalness and size, the mixed scrub / secondary woodland community
also supports a range of butterflies and birds. The most abundant butterfly
species observed included the Large Faun Faunis
eumeus, Common Tiger Danaus genutia,
Glassy Tiger Parantica aglea, Lime
Blue Chilades lajus, Red Helen Papilo helenus, Paris Peacock P. paris, and the Common Mormon P. polytes. All butterflies observed are common and widespread species.
7.4.57
Bird
species in the mixed scrub / secondary woodland habitat included the Crested Bulbul (Pycnonotus
jocosus), Chinese Bulbul (P. sinensis),
Red-vented Bulbul (P. aurigaster),
Magpie (Pica pica), Rufous backed
shrike (Lanius schach), Large
hawk-cuckoo (Cuculus sparverioides)
and the Greater coucal (Centropus
sinensis). All bird species
observed around the fringes of the vegetated area, closest to the coastal works
area, are locally common and widespread species.
7.4.58
The
foot of the vegetated slope is approximately 30 metres from the edge of the EVA
link works area, and will not be physically disturbed by the Project.
7.4.59
Observations
were made of birds around the south of the Yung Shue Wan coastal area, in the
vicinity of the proposed helipad works area.
A total of four bird species were noted within an approximate radius of 200
metres from the proposed helipad. Most
notably, there were 14 Little Egrets (Egretta garzetta) recorded – most of these resting
on small boats and exposed rocks within the bay. The other species were 2 individuals of Black Kite (Milvus migrans) flying overhead, a solitary
Cattle Egret (Bubulcus
ibis) also
resting on a floating pontoon in the bay, and a number of crested mynahs (Acridotheres cristatellus) flying
through the area.
Recognised Sites of Conservation Importance
7.4.60
With reference to Appendix A (Note 1)
of Annex 16 of the EIA-TM, there are no recognised sites of conservation
importance at or in the vicinity of the Project site.
Habitat Evaluation
7.4.61
Based on the data / information for the assessment area as
presented in the literature review and field surveys results, an ecological evaluation of each habitat type within the assessment
area has been conducted in accordance with the criteria listed in Annex 8 of
the EIA-TM, as follows.
Sub-tidal (Pelagic and Benthic) Habitat
7.4.62
The
evaluation of the ecological value of the sub-tidal habitat is presented in Table
7.8Table
7.8Table 7.8Table
7.8Table 7.8Table 7.8Table 7.8Table 7.8 below.
Table 777777.8888888 Ecological Evaluation of the Sub-tidal habitat
Criteria
|
Evaluation
|
Naturalness
|
Largely
natural, but influenced by local and regional human activities, including discharges
from Yung Shue Wan and sediment contamination.
|
Size
|
Approximately
0.50 hectares of marine benthic habitat in the Project area.
Contiguous
with surrounding seabed.
|
Diversity
|
Pelagic –
Moderate diversity due to linkage with coastal / marine waters.
Benthic –
Very low diversity; dominated by polychaete worms in the Yung Shue Wan bay
area.
|
Rarity
|
|
Re-creatability
|
Pelagic habitat
cannot be re-created, but potential for recreation of benthic habitat.
|
Fragmentation
|
N/A
|
Linkage
|
Potential
linkage with adjacent hard shore, and contiguous with surrounding coastal
waters.
|
Potential
Value
|
Mainly limited
by very high turbidity / natural seabed re-suspension (and possibly effluent
discharge).
|
Nursery /
Breeding Ground
|
Not of any
particular value.
|
Age
|
|
Wildlife
Abundance / Richness
|
Reported abundance
from the general Yung Shue Wan bay area is high, but with a very low species
richness as is typical of low oxygen / polluted waters.
|
Ecological Value
|
|
Granite Boulder Seawall
7.4.63
The ecological evaluation of the sloping
boulder seawall is presented in Table
7.9Table
7.9Table 7.9Table
7.9Table 7.9Table
7.9Table 7.9Table 7.9 below.
Table 777777.9999999 Ecological Evaluation of the Granite Boulder Seawall
Criteria
|
Evaluation
|
Naturalness
|
Entirely
artificial habitat, but naturally colonised.
|
Size
|
The wall has
a length of 130 metres, and is approximately 8 metres ‘high’ (~4.5m sub-tidal
‘height’ at high water).
|
Diversity
|
The seawall
coral community was moderately diverse, although other benthic species
diversity was low.
|
Rarity
|
|
Re-creatability
|
The habitat
can be easily recreated.
|
Fragmentation
|
N/A.
|
Linkage
|
Contiguous
with rocky shore habitat to the southwest.
Various common gastropods recorded.
|
Potential
Value
|
|
Nursery / Breeding
Ground
|
Of local
significance to hard corals and possibly fish fry, but otherwise not of any
particular note.
|
Age
|
|
Wildlife
Abundance / Richness
|
Abundant
coral growth, and fair species richness (n=15). Otherwise, moderate / high abundance and low richness of
gastropods.
|
Ecological Value
|
|
Rocky Shore
7.4.64
The ecological evaluation of the rocky shore
is presented in Table
7.10Table
7.10Table 7.10Table
7.10Table 7.10Table 7.10Table 7.10Table 7.10 below.
Table 777777.10101010101010 Ecological Evaluation of the Hard Shore habitat
Criteria
|
Evaluation
|
Naturalness
|
The
remaining rocky hard shore in the assessment area is natural and physically intact,
although its naturalness has been partly affected by past reclamation at both
ends.
|
Size
|
Hard shore
in the marine ecology assessment area covers approximately 0.5 hectares, with
a total length of approximately 1.8 km.
|
Diversity
|
Low diversity
epifauna community, supporting a range of common species –mainly gastropods.
|
Rarity
|
|
Re-creatability
|
Can be
recreated using boulder seawall as a proxy.
|
Fragmentation
|
Fragmented
by reclamation at Yung Shue Wan and typhoon shelter to the southwest.
|
Linkage
|
The length
of rocky shore in the assessment area is contiguous with similar habitat that
continues along the coastline to the southwest as far as to HEC power
station.
|
Potential
Value
|
|
Nursery /
Breeding Ground
|
Of local significance
to hard shore organisms, but no special value.
|
Age
|
|
Wildlife
Abundance / Richness
|
High
abundance of gastropods, but low species richness.
|
Ecological Value
|
|
Developed / Disturbed Area
7.4.65
The ecological evaluation of the developed /
disturbed area is presented in Table
7.11Table
7.11Table 7.11Table
7.11Table 7.11Table 7.11Table 7.11Table 7.11 below.
Table 777777.11111111111111 Ecological Evaluation of the Developed / Disturbed Area
Criteria
|
Evaluation
|
Naturalness
|
Completely
artificial habitat.
|
Size
|
The
developed / disturbed area in the assessment area covers approximately 0.8
hectares.
|
Diversity
|
Very low – few
weed and ornamental flora species and common birds / butterfly species
present. Vertical reclamation seawall
all but devoid of biota.
|
Rarity
|
|
Re-creatability
|
N/A
|
Fragmentation
|
N/A
|
Linkage
|
N/A
|
Potential
Value
|
Some
potential for enhancement through revegetation, particularly with native
vegetation,
|
Nursery /
Breeding Ground
|
None
identified.
|
Age
|
|
Wildlife
Abundance / Richness
|
|
Ecological Value
|
|
Mixed Scrub / Secondary Woodland
7.4.66
The ecological evaluation of the mixed scrub
/ secondary woodland habitat is presented in Table
7.12Table
7.12Table 7.12Table
7.12Table 7.12Table 7.12Table 7.12Table 7.12 below.
Table 777777.12121212121212 Ecological Evaluation of the Mixed Scrub / Secondary Woodland habitat
Criteria
|
Evaluation
|
Naturalness
|
Largely natural
and is physically intact, although would have been subject to localised part
disturbance (e.g., as evident from derelict housing and remnants of
ornamental / orchard species). No
evidence of fire damage.
|
Size
|
|
Diversity
|
Supports a
range of grasses, ferns, shrubs and tree species.
|
Rarity
|
|
Re-creatability
|
Not easily recreated
given the age and stratification of the habitat.
|
Fragmentation
|
Not
fragmented, but bound by the coastline and existing development. Very little
human activity / disturbance potential in the vicinity.
|
Linkage
|
Part of a
contiguous area of similar habitat, but generally confined by the natural
coastline and existing developed land.
|
Potential
Value
|
|
Nursery /
Breeding Ground
|
No breeding
grounds were noted during survey, but this habitat will support such a role
for various insects, reptiles and likely resident birds.
|
Age
|
|
Wildlife
Abundance / Richness
|
|
Ecological Value
|
|
Methodology
7.5.1
The assessment of ecological impacts
has been conducted with reference to Annex 16 of the EIA-TM, and is based on the
scale and duration of the Project, and the ecological significance (importance)
of habitats and / or species that may be affected.
Construction Phase
Sub-tidal Ecology
7.5.2
As the Project is of a small scale and
is to be constructed by small diameter pre-bored piling, it will not result in
any significant sub-tidal habitat loss. The area of habitat permanently lost
will be limited to the cumulative footprint area of the piles that support the
EVA link and the helipad – approximately 16m2 (i.e., 26 no’s. of 0.610m
diameter piles).
7.5.3
As determined through the water
quality impact assessment, there will be localised seabed disturbance during
the installation of the small diameter pre-bored piles in the immediate vicinity
of the works. However, given the construction method and the weak tidal
circulation around Yung Shue Wan, seabed sediment will be confined to the
bottom of the water column and will re-settle quickly.
7.5.4
The construction will require
excavation of marine sediment from within pile casing. While there may potentially be some minor
sediment leakage during excavation, this would be restricted to within the pile
casing and no water quality impacts would arise. There is some potential for
leakage into the receiving waters during the transfer of the excavated sediment
to the holding tank, although this can be avoided by using a tightly sealed
grab. In addition, a silt curtain shall be installed during the marine
construction works. As such, no
significant water quality-induced ecological impacts are anticipated.
7.5.5
Given the small scale of the project,
the localised nature of the impacts and that the piling installation works
would only be conducted off the existing seawall, there would not be any direct
loss of hard coral communities as identified along the artificial boulder
seawall. The
contractor would be expected to maintain a tidy works area at this working
location closest to the sloping seawall to ensure there are no water
quality-induced impacts in the vicinity of the hard coral community. The good site practices are
summarized in paragraph 7.6.27.6.27.6.27.6.27.6.27.6.2.
Inter-tidal / Terrestrial Ecology
7.5.6
The Project is to be constructed in coastal
waters by small diameter pre-bored piling.
The vertical seawall off which the Project will be developed does not
support any marine biota and will not be affected by the works, while there is
no terrestrial habitat in the vicinity that will be physically impacted. As such, the Project will not result in any
direct loss of inter-tidal or terrestrial habitat.
7.5.7
There would be the need to remove a
small length of the landscaped planter.
The species in the planter are exotic and of no ecological value. However, demolition of the planter must be
carefully conducted so that demolition material does not enter the adjacent
waters.
7.5.8
As the Project will be constructed off
the existing vertical seawall, the closest pile location to the sloping seawall
where there is a basic inter-tidal community is approximately 10 metres. Given the works method, there will be no
water quality-induced effects on inter-tidal habitat. In any event, a silt curtain will be used during the works as a
good practice measure and to ensure no adverse effect on the coral
community. The silt curtain would also
ensure that sediment does not affect the inter-tidal community.
Operation Phase
Sub-tidal Ecology
7.5.9
Given the nature of the Project, there
will be no waste / materials generated during the operational phase, and
therefore no water quality impacts are anticipated that could potentially
translate into impacts on the marine environment.
7.5.10
As concluded in the water quality impact
assessment, the absence of any significant constraint to water flow in the
Project area means that no hydrodynamic and / or associated water quality
impacts are anticipated during the operational phase of the Project.
Inter-tidal / Terrestrial Ecology
7.5.11
Regarding inter-tidal ecology, as with
sub-tidal ecology there will be no waste / materials generated and no water
quality impacts are anticipated that could affect adjacent inter-tidal
areas. Similarly, there will be no
hydrodynamic and / or associated water quality impacts are anticipated during
the operational phase of the Project.
7.5.12
Regarding terrestrial ecology, while
the operational helipad will be a source of noise when in use that has the
potential to disturb birds, and potentially affect butterflies through air
turbulence, the helipad will be located approximately 50 metres from the
closest part of the vegetated habitat where most observations of birds and
butterflies were made. Furthermore, the
absence of suitable shoreline in the vicinity of the Project area means that
bird activity is very limited. There were no observations of birds on
the artificial sloping seawall or on the rocky shore to the west of the
Project, while those birds observed around Yung Shue Wan to the east and
southeast would be able to freely move inshore (within the bay) if disturbed by
helicopter noise. As such, no significant ecological
impacts are anticipated during the operational phase of the Project.
Cumulative Impacts
7.5.13
As regards potential for marine ecology
impacts, Phase 2 of the Yung Shue Wan Development Engineering Works will
commence in Year 2008, by which time all construction works for the Yung Shue
Wan Helipad will be complete.
7.5.14
Construction of the Yung Shue Wan
Sewage Treatment Works (STW) is tentatively scheduled to commence in August
2007 for approximately 3 years. The
Helipad and STW developments have been scheduled to avoid concurrent works. No
cumulative water quality-induced effects will be generated.
Sub-tidal Ecology
7.6.1
While the water quality assessment
does do not predict any adverse impact on the live coral community on the
sloping boulder seawall, a silt curtain shall be installed surrounding
the whole of the site as indicated in Figure
6.1as a
precautionary good practice measure to ensure no adverse water
quality-induced ecological impacts it is recommended that. a
silt curtain be installed surrounding the whole of
the site as indicated in Figure 6.1.along the western side of the Project boundary from
the vertical seawall (off which the EVA link is to be developed) to the edge of
the helipad footprint.
·
Particular care should be taken when
demolishing the existing concrete planter to ensure no waste enters the water
column;
·
Particular care should be taken when
decommissioning the silt curtain to avoid sudden dispersion of muddy water that
may cause adverse impact to the nearby marine life.
·
Materials storage areas should be
located well away from the seawall, and any such areas should be covered during
the works;
·
The holding tank for sediment excavated
from within the pile casing should be fitted with a tight fitting seal to
prevent leakage;
·
The contractor should ensure that
excavator grab seal is tightly closed and the hoist speed
is suitably low;
·
The holding tank should not be filled
to a level which will cause overflow of sediment during loading and
transportation; and
·
Large objects should be removed from
the excavator grab to avoid sediment spills.
7.7.1
Given the nature of the construction
method and the Project scale, no significant adverse ecological impacts have
been identified and as such no ecological monitoring is considered necessary.
In particular, the water quality impact assessment has confirmed that no
significant adverse impacts will arise from Project development that could
potentially induce adverse impacts on the marine ecosystem, including corals.
7.8.1
As the Project is of a small scale and
is to be constructed by small diameter pre-bored piling, it will not result in
any significant sub-tidal habitat loss, while there is not anticipated to be
any impact on the hard coral community from pile installation so long as good
working practices are followed. No
specific mitigation measures are considered to be necessary, although the use
of a silt curtain has been recommended. Accordingly, there is no ecological
monitoring requirement.
7.8.2
Similarly, the vertical seawall off
which the Project will be developed does not support any marine biota and will
not be affected by the works, while there is no terrestrial habitat in the
vicinity that will be physically impacted.
As such, no inter-tidal or terrestrial ecology impacts are anticipated
given the construction method and distance to sensitive receivers. Likewise,
there is no ecological monitoring requirement.
7.8.3
Hydrodynamic effects of the
constructed Project will be negligible, while there will be no operational discharges
that could potentially translate into impacts on the marine environment.
·
AFCD (1998). Port Survey 1996/97.
Fisheries Management Division, AFCD.
·
AFCD (2003a). Sightings of Chinese White
Dolphin in Waters Around Lamma Island (from Oct. 1995 to April 2003). Marine
Conservation Division, AFCD.
·
AFCD (2003b). Sightings of Finless
Porpoise in Waters Around Lamma Island (from Feb. 1996 to April 2003). Marine
Conservation Division, AFCD.
·
AFCD (2003c). Port Survey 2001/2002.
Fisheries Management Division, AFCD.
·
Binnie Consultants Ltd. (1995). Fill Management Study, Phase IV – Marine Ecology of Hong Kong: Report on
Underwater Dive Surveys. Volume I, January 1995. Civil Engineering
Department, HKSAR Government.
·
CES (Asia) Ltd. (1997). Outlying Islands Sewerage Stage 1,
Phase 1. EIA Study – Final Assessment
Report. Drainage Services Department, HKSAR Government.
·
CityU Professional Services Limited
(2002). Agreement No. CE 69/2000.
Consultancy Study on Marine Benthic Communities in Hong Kong. Final report
for the Agriculture & Fisheries Department, HKSAR Government. Centre for
Coastal Pollution and Conservation, City University of Hong Kong.
·
ERM (1998). Fisheries Resources and Fishing Operations in Hong Kong Waters.
Final report for the Agriculture & Fisheries Department, HKSAR Government.
·
Jefferson, T. A. (2001). Conservation Biology of the Finless Porpoise
in Hong Kong Waters. Final report to Agriculture, Fisheries &
Conservation Department, HKSAR Government.
·
McCorry, D. (2003). Pers. comm. regarding the conservation
significance of the coral community found on the sloping boulder seawall at
Yung Shue Wan.
·
Mouchel Asia Ltd. (2002). EIA Study for Yung Shue Wan Development,
Engineering Works, Phase 2. Civil Engineering Department, HKSAR Government.
·
Oceanway Corporation Ltd. (2001). Underwater Survey at Peng Chau and
Neighbouring Islands.. Unpublished final report submitted to the
Agriculture, Fisheries and Conservation Department, HKSAR Government.
·
Scott Wilson / BMT (2002). Extension
of Existing Landfills and Identification of Potential New Waste Disposal Sites:
Strategic Environmental Assessment Report (Final). Environmental Protection
Department, HKSAR Government.
8.1.1
This section presents the approach to
and the findings of the cultural
heritage impact assessment; the aim of which is to
identify and examine the nature and extent of potential impacts of the helipad development
at Yung Shue Wan on cultural
heritage and terrestrial and marine archaeology.
8.1.2
For the purpose of the marine
archaeology assessment the ‘assessment area’ occupies a semi-circular area with
a 50m radius that extends from the seawall at the far southern end of the Yung
Shue Wan foreshore. The assessment area for the marine archaeological
investigation is provided on Figure 8.1.
8.1.3
For terrestrial archaeology and
cultural heritage assessment, Clause 3.4.5.2 of the EIA Study Brief states that
the assessment area should be “at or close to the proposed Project”. As such, given the nature and scale of the
Project, and the absence of any sites of archaeological or cultural heritage
value in the vicinity, a nominal radius of 100m was used as the assessment
area.
8.2.1
The cultural heritage impact
assessment has been carried out in accordance with Annex 10 and 19 of the
EIA-TM which pertain to criteria for evaluating the impacts on sites of cultural
heritage and guidelines for impact assessment, respectively; and the
requirements referred under Clause 3.4.5 and presented in Appendix A of the EIA
Study Brief, as follows:
·
The cultural heritage study shall
assess both direct and indirect impacts on the marine archaeology, as well as
identifying other unknown items of archaeological and historical interests at
or close to the proposed Project, and propose appropriate mitigation measures.
·
Assessment requirements for the Marine
Archaeological Investigation (MAI) are detailed in Sub-section 8.4 below.
8.3.1
The legislation directly relevant to
the protection and preservation of the local cultural heritage is the Antiquities
and Monuments Ordinance (Cap. 53). This
Ordinance, enacted in January 1976, provides for the preservation of any “site
of cultural heritage”. This refers to
the following:
·
Historical
buildings and structures, i.e. currently pre-1950 buildings
and structures that possess definite heritage value.
·
Archaeological sites and structures.
·
Palaeontological
sites, i.e. pre-Holocene geological beds of
sedimentary rocks containing fossil remains and their impressions.
·
Other
cultural features, e.g. in the assessment area
these may include amongst others, stone engravings, foundation and boundary
stones, graves and track ways.
8.3.2
The Ordinance provides for two main
areas of heritage protection:
·
The statutory declaration of sites of cultural
heritage of exceptional qualities and significance in the Government Gazette as
Monuments, Historical Buildings, Archaeological Sites, etc., under the
Antiquities and Monuments (Declaration of Historical Building) Notice.
·
Relics, (defined under the Ordinance
as fossils and objects/artefacts created, modified, etc. by human agency before
1800 AD) discovered after 1976 are, by law, properties of the Hong Kong SAR
Government. Search and excavation for
relics should comply with the Ordinance. All discoveries of antiquities or
supposed antiquities must also be reported.
8.3.3
Annexes 10(2) and 19(2) of EIA-TM
present guidelines for the evaluation and assessment of impacts on cultural
heritage, respectively. In addition,
Guidance Notes on Assessment of Impact on
Sites of Cultural Heritage in Environmental Impact Assessment Studies under
the Environmental Impact Assessment Ordinance (Cap. 499) are applicable.
8.3.4
Other legislation that supplements the
work of heritage preservation includes the Lord Wilson Heritage Trust Ordinance
(Cap. 425) that came into operation in 1992.
Marine Archaeology
8.4.1
As detailed in Appendix A of the EIA
Study Brief, marine archaeology assessment involves four stages, as follows:
Baseline Study
8.4.2
A review was undertaken to identify
the potential for archaeological resources and, if identified, their likely
character, extent, quality and value. This includes:
·
Historical land use and settlement
data as well as archive records such as seabed survey data collected from
previous geological research (GEO).
·
Marine Department, Hydrographic Office
- the Department holds a substantial archive of hydrographic data and charts;
and
·
Royal Naval Hydrographic Department in
the UK.
8.4.3
The above data sources – including
dredging history - will provide historical records and more detailed geological
analysis of submarine features which may have been subsequently masked by more
recent sediment deposits and accumulated debris.
8.4.4
Throughout the course of the
assessment meetings and discussions were held with representatives of the
Antiquities and Monuments Office (AMO).
Geophysical Survey
8.4.5
In accordance with marine
archaeological investigation (MAI) guidelines a marine geophysical survey was carried
out in the assessment area in November 2002 with the following aims:
(a) Providing exact definition of greatest archaeological potential;
(b) Assessment of the depth and nature of the
seabed sediments to define which areas consist of suitable material to bury and
preserve archaeological material; and
(c) Detailed examination of the geophysical
records to map anomalies on the seabed that may be archaeological material.
8.4.6
The geophysical survey involved the
use of side scan sonar and a seismic boomer. Echo sounding was conducted in
conjunction with the seismic survey to be able to get reasonably detailed
coverage (side scan sonar survey lines are more widely separated). Further
details of the geophysical survey and equipment involved are presented in Sub-section 8.6.
8.4.7
Prior to the geophysical survey a tide
gauge was installed and checked for correct operation at the southeast corner
of Cheung Chau typhoon shelter. The tide
gauge data was required to calibrate the distance range between the survey
vessel / equipment and the seabed, and to refer all data acquired to the Hong
Kong Principal Datum (HKPD). Position
fixing was carried out by differential GPS (DGPS) system. The system was checked for correct
calibration at a known co-ordinated point onshore prior to installation on the
survey vessel. A professional geophysicist has interpreted the data to identify
potential areas of archaeological interest.
Establishing Archaeological Potential
8.4.8
The data examined during the desktop
review and geophysical survey will be analysed to provide an indication of the
likely character and extent of archaeological resources within the assessment
area. This would facilitate formulation of a strategy for investigation.
Remote Operated Vehicle (ROV) / Visual Diver Survey /
Watching Brief
8.4.9
Subject to the outcome of the above
tasks, a field evaluation programme may be planned to acquire more detailed
data on areas identified as having archaeological potential. Either ROV or
divers could be employed to conduct inspection given that the marine traffic in
the vicinity of the proposed helipad at Yung Shue Wan is not heavy. Alternatively, an archaeological watching
brief can be used to monitor dredging operations should any area of high
potential be identified through previous survey.
Cultural Heritage
Desktop Study
8.4.10
The aim of the desktop study is to
identify archaeological and cultural heritage resources in the assessment area
from previous studies / investigations relevant to terrestrial
archaeology. The assessment initially
involves compiling details of geology
and geomorphology through reference to geological maps; available bore hole
data, early maps of the area and aerial photographs.
8.4.11
Any unpublished papers, records,
archives and historical documents or archaeological investigation and
excavation reports kept by the AMO were also reviewed where appropriate and possible.
For information on historic buildings and other structures, reference was made
to the list of declared monuments (via the AMO’s Internet pages). The list of deemed (but not declared)
monuments and the list of sites of cultural heritage identified by the AMO were
also reviewed.
Field Evaluation
8.4.12
Verification of historical buildings
and structures as well as existing and potential archaeological sites has been
carried out in and around the assessment area.
Geological and Topographical Setting
8.5.1
The geology of
the area is medium grained granite with debris flow in and around the lower
slopes of the valley at Yung Shue Wan.
Land use history: Historic background
8.5.2
Lamma Island lies 2 nautical miles south
west of Hong Kong. The village of Yung Shue Wan occupies an alluvial plain
behind a former raised sand bar. Yung Shue Wan has a long history as a fishing
harbour.
8.5.3
Due to its proximity to major shipping
channels (East Lamma Channel) and access to Hong Kong and Canton, Lamma Island
has been recorded in nautical surveys as early as 1806-19 (James Horsburgh,
East India Company) and 1816 (Sayer, 1975). The earliest recorded settlement on
Lamma Island occurred in the 17th-18th Century with
relocation of the Chow clan and later the Tsang clan from Aberdeen to Sha Po
Tsuen. Yung Shue Wan was settled first by the Sum and Fong clans engaged
primarily in farming and fishing.
8.5.4
During World War II the area around
Lamma was heavily mined and the British ship HMS Indomitable launched attacks on Japanese suicide bombers in the
bays around Lamma (Melson, 1997).
Land use history: Prehistoric background
8.5.5
Lamma Island and Yung Shue Wan in
particular has a long tradition of archaeological study dating to early 1920’s.
The primary archaeological sites in and around Yung Shue Wan include:
·
Sha
Po Tsuen – A rich site producing middle and late
Neolithic artefacts, Bronze Age, Han, Six Dynasties and Tang dynasty pottery
and artefacts.
·
North
Lamma Public School – Neolithic and Bronze Age
pottery artefact.
·
Wang
Long – Neolithic pottery and artefacts.
8.5.6
Nearby sites of significance include
Tai Wan – located approximately 1.5 km from the beach at Yung Shue Wan – which
was the site of the first prehistoric findings on Lamma, in 1932. This site has
produced bronze artefacts and other important remains.
Historical Building and Structures
8.5.7
A comprehensive historic buildings /
structures survey conducted for the EIA Study for the Yung Shue Wan Development
Phase 2 project recorded and documented twenty houses, temples, shrines and
banyan trees were recorded and documented (Mouchel, 2002). However, none of these buildings /
structures are within the cultural heritage assessment area for the helipad
Project, and there will be no impacts on historic buildings / structures or
cultural heritage.
8.5.8
The closest such building to the
Project area is the North Lamma Medical Clinic, situated approximately 200
metres to the southeast. The Clinic was
built in 1957 and is of local heritage value.
Marine Archaeology
8.6.1
The geophysical survey recorded
shallow water depths (1 - 5 metres deep) adjacent to the existing seawall. Useful seismic data were diminished or precluded
in this area due to the presence of the seawall and the apron of broken rock
armour. Small areas of locally elevated
seabed can be attributed to isolated rocks / boulders as the rock-head does not
rise to the sea floor within the area of the site.
8.6.2
Reduced seabed levels vary within the
range -2.7 to -5.0 mPD, and the thickness of sediment varies between 3.6 and
15.9 metres (Cosine Ltd., 2003). The sea floor sediments are unconsolidated
materials transported, deposited and accumulated on the seabed as products of
erosion. Typically they can comprise muds, silts, sands, sandy silts and larger
cobbles.
8.6.3
From an archaeological perspective,
finer sediments including muds and silts are deposited in relatively calm or sheltered
waters and therefore tend to offer better conditions for burial and
preservation of artefacts. In contrast,
turbulent water conditions would be physically detrimental to archaeological
preservation, keeping silts and muds in suspension and selectively depositing
coarse sands and cobbles.
8.6.4
From the geophysical survey it was
observed that fine-layered sea floor sediments are confined to the outer part
of the proposed helipad and they thin toward the coastline, wedging out
completely at the dredged channel.
Those sediments are seismically characteristic of fine sands or silty
sands, indicating that the sediment is of a suitable thickness and nature to
bury and preserve archaeological material.
However, no discrete objects were seismically defined. Beneath that wedge of fine material, the
sediments are coarse and probably less suitable for the preservation of
archaeological materials. Small
individual items within these coarse deposits generally would not be seismically
recognisable.
8.6.5
The seismic and echo sounder data
indicate a sharply defined channel, 1 to 2 metres deep and at least 20 metres
wide, crossing the proposed helipad site in an East - West direction. The sea floor appears to have been dredged
and the edges of the channel are distinct and abrupt, suggesting moderate
cohesion in the material. Piles of
dredged sediments may have been deposited on the margins of the channel in some
places, evident as a local ‘lip’. The probability of archaeological items
remaining intact in this presumed dredged area would seem to be lower than
elsewhere in the site.
8.6.6
The focus of the evaluation was
therefore placed on those areas with the greatest marine archaeological
potential. An evaluation of these areas
is summarised in the following paragraphs.
8.6.7
Side-scan sonar data identified three
items in the assessment area. These
‘items’, labelled A, B and C, are displayed by Figure 8.1, and the evaluation of these items is as follows:
·
Item A is approximately 20 metres long
and is considered most likely to be a drag mark associated with the dredged
channel into which it extends. In other
words, Item A overlies the dredged channel, and so was developed more recently
(i.e., in the last few years).
·
Item B is situated in the seawall dredge
zone to the west of the proposed helipad footprint. This item is most likely to
be either sediment deposits or a local depression from past dredging, and / or
boulders.
·
Item C is situated in the seawall
dredge zone to the east of the proposed helipad footprint. Similar to Item B,
Item C is most likely to be either sediment deposits or a local depression from
past dredging, and / or boulders.
8.6.8
Prior to the construction of the sea
wall, part of the seabed was dredged. With reference to the dredging plans for
the seawall, it was concluded that the dredged zone extended outwards from the
rock rubble / armour in front of the seawall.
As such, the potential for submerged cultural remains in the vicinity of
this dredged area is minimal.
8.6.9
To summarise, no objects or items of
potential marine archaeological value were identified in the assessment
area. As such, no further field
investigation through ROV / visual diver survey or implementation of a watching
brief is necessary.
Historical Buildings and Structures
8.6.10
The nearest terrestrial archaeological
site to the proposed helipad is some 200m away and separated by substantial
recent seawall and harbour development.
In addition the new seawall and harbour at Yung Shue Wan from which the
proposed helipad will extend is at least 200m from the nearest building of
historic interest.
8.6.11
Accordingly, the Project has no
potential to impact upon terrestrial archaeological sites, historical buildings
or structures.
8.7.1
No potential impacts on resources of
cultural heritage or archaeological value will arise from the proposed
Project. As such, there is no
mitigation requirement.
8.8.1
There are no archaeological / cultural
heritage monitoring and audit requirements for the Project.
8.9.1
Three items / objects were recorded by
the marine geophysical survey. Based on
the geophysical survey data interpretation, and given the recent history of the
area adjacent to the seawall, it was concluded that none of these are of
archaeological value.
8.9.2
Desktop review
and brief field evaluation in and around the proposed helipad at Yung Shue Wan revealed
no existing or potential archaeological sites, historic buildings or structures
within 200m of the assessment area.
·
Cosine Ltd. (2003). Island Helipads
EIA Study: Yung Shue Wan, Lamma Island and Peng Chau – Geophysical
Investigation.
·
Horsburgh, James (1809—11).
“Directions for sailing to and from the East Indies, China, New Holland, Cape
of Good Hope, and the interjacent ports [compiled chiefly from original
journals at the East India House, and from journals and observations, made during
twenty-one years experience navigating in those seas].” Parts I/II and II/II.
East India Company, London.
·
Melson, Peter J. (1997) [Ed.]. White Ensign - Red Dragon: The History
of the Royal Navy in Hong Kong (1841-1997).
·
Mouchel Asia Ltd. (2002). EIA Study for Yung Shue Wan Development,
Engineering Works, Phase 2. Civil Engineering Department, HKSAR.
·
Sayer, G.R. (1975). Hong Kong 1862-1919. Hong Kong
University Press.
9.1.1
The
implementation schedules of the recommended mitigation measures for each environmental aspect assessed in this EIA are given in the
following Table 9.1 – Table 9.5, as
appropriate.
Table 999999.111111 Air Quality – Implementation Schedule of
Recommended Mitigation Measures
EIA
Ref.
|
EM&A
Ref.
|
Recommended
Environmental Protection Measures / Mitigation Measures
|
Objectives of the recommended
measures & main concerns to address
|
Who to implement the measures?
|
Location / Timing
of implementation of Measures
|
What requirements or standards for
the measures to achieve?
|
S.3.6.1
|
S.4.2.3
|
All the dust
control measures as recommended in the Air Pollution Control (Construction
Dust) Regulation, where applicable, should be implemented.
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
Typical dust control measures include:
·
Restricting
heights from which materials are dropped, as far as practicable to minimise
the fugitive dust arising from unloading / loading;
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
·
All stockpiles
of excavated materials or spoil of more than 50 m3 should be
enclosed, covered or dampened during dry or windy conditions;
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
·
Effective
water sprays should be used to control potential dust emission sources such as
unpaved haul roads and active construction areas;
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
·
All spraying
of materials and surfaces should avoid excessive water usage;
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of the
construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
·
Vehicles
that have the potential to create dust while transporting materials should be
covered, with the cover properly secured and extended over the edges of the
side and tail boards;
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
·
Materials
should be dampened, if necessary, before transportation;
|
Air Quality During Construction
|
Contractors
|
At all construction work sites,
throughout the whole duration of the construction period
|
EIA-TM, Air Pollution Control
(Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
·
Travelling speeds
should be controlled to reduce traffic induced dust dispersion and
re-suspension from the operating haul trucks; and
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of the
construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
·
Vehicle
washing facilities will be provided to minimise the quantity of material deposited
on public roads.
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
S.3.6.1
|
S.4.2.2
|
·
Erection of
hoarding not less than 2.4m high from ground level along the site boundary.
|
Air
Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
EIA-TM, Air Pollution Control (Construction Dust) Regulation
|
Table 999999.222222 Noise
– Implementation Schedule of Recommended Mitigation Measures
Table 999999.333333 Waste Management –
Implementation Schedule of Recommended Mitigation Measures
EIA
Ref.
|
EM&A
Ref.
|
Recommended mitigation measures
|
Objectives of the recommended
measures & main concerns to address
|
Who to implement the measures?
|
Location / Timing of
implementation of Measures
|
What requirements or standards for
the measures to achieve?
|
S.5.8.1
|
S.6.1.2
|
Ensure that proper handling, storage, transportation and disposal
of materials is implemented at the outset and throughout the construction
phase of the helipad.
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period.
|
Annex 7 of EIA-TM
|
S.5.8.1
|
S.6.2.2
|
In line with Government’s position on waste minimisation, the
practice of avoiding and minimising waste generation and waste recycling
should be adopted as far as practicable.
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period.
|
Annex 7 of EIA-TM
|
S.5.8.2
|
-
|
Recommended mitigation measures to be implemented include:
·
An on-site
environmental co-ordinator should be identified at the outset of the
works. The co-ordinator shall prepare
a Waste Management Plan
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
Environmental, Transport and Works Bureau Technical Circular
(ETWBTC) No. 15/2003
|
S.5.8.2
|
S.6.2.2
|
·
Spoil
generated from the piling activities will need to be properly handled to
minimise contamination to the marine water and any exposed ground areas due
to leakage or improper storage (i.e. onto bare ground instead of into tanks).
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
Environment, Transport and Works Bureau Technical Circular (Works)
(ETWBTCW) No. 34/2002
|
S.5.8.2
|
S.6.2.2
|
·
The
reuse/recycling of all materials on site shall be investigated prior to
treatment/disposal off site;
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
ETWBTCW No. 33/2002,
ETWBTC No. 15/2003
|
S.5.8.2
|
S.6.2.2
|
·
Good site
practices shall be adopted from the commencement of works to avoid the
generation of waste and to promote waste minimisation practices;
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
ETWBTCW No. 33/2002
|
S.5.8.2
|
S.6.2.2
|
·
All waste
materials shall be sorted on site into inert and non-inert C&D materials,
and where the materials will be recycled or reused, these shall be further
segregated. The Contractor shall be
responsible for identifying which materials can be recycled/reused, whether
on site or off site. In the event of the latter, the Contractor shall make
arrangements for the collection of the recyclable materials. Any remaining non-inert waste shall be
collected and disposed of to the refuse transfer station whilst any non-inert
C&D material shall be re-used on site as far as possible. Alternatively, if no use of the material
can be found on site, the inert C&D material can be delivered to a public
filling area, public barging point or public stockpile area after obtaining
the appropriate licence;
|
Waste
Management During Construction
|
Contractors
|
At all construction work sites,
throughout the whole duration of the construction period
|
ETWBTCW No. 33/2002, ETWBTCW No.
34/2002
|
S.5.8.2
|
S.6.2.2
|
·
A trip
ticket system should be established at the outset of the construction of the
helipad to monitor the disposal of C&D and solid wastes from the site to
public filling facilities and landfills;
|
Monitor the disposal of C&D and
solid wastes from the site
|
Contractors
|
At the outset of the construction of the helipad, throughout the whole duration of the construction period
|
ETWB TC(W) 31/2004
|
S.5.8.2
|
S.6.2.2
|
·
The
Contractor shall register with EPD as a Chemical Waste Producer if there is
any use of chemicals on site including lubricants, paints, diesel fuel,
etc. Only licensed chemical waste
collectors shall be employed to collect any chemical waste generated at
site. The handling, storage,
transportation and disposal of chemical wastes shall be conducted in
accordance with the relevant guidelines as published by Government.
|
Waste
Management During Construction
|
Contractors
|
At all construction work sites,
throughout the whole duration of the construction period
|
Waste Disposal (Chemical Waste)
(General) Regulation, Code of Practice on the Packaging, Labelling and
Storage of Chemical Wastes, Guide to the Chemical Waste Control Scheme
|
S.5.8.2
|
S.6.2.2
|
·
A sufficient
number of covered bins shall be provided on site for the containment of
general refuse to prevent visual impacts and nuisance to sensitive
receivers. These bins shall be
cleared daily and the collected waste disposed of to the refuse transfer
station. Further to the issue of
Environment, Transport and Works Bureau Technical Circular (Works) No.
6/2002A, Enhanced Specification for Site Cleanliness and Tidiness, the
Contractor is required to maintain a clean and hygienic site throughout the
Project works.
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
ETWBTCW No. 6/2002A, ETWBTC No. 15/2003
|
S.5.8.2
|
S.6.2.2
|
·
All chemical
toilets shall be regularly cleaned and the night-soil collected and
transported by a licensed contractor to a Government Sewage Treatment Works
facility for disposal.
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
ETWBTCW No. 6/2002A, ETWBTC No. 15/2003
|
S.5.8.2
|
S.6.2.2
|
·
Tool box
talks shall be provided to workers about the concepts of site cleanliness and
appropriate waste management procedures, including waste reduction, reuse and
recycling.
|
Waste
Management During Construction
|
Contractors
|
Throughout construction period
|
ETWBTCW No. 15/2003
|
S.5.8.3
|
S.6.2.3
|
Contractor shall comply with all
relevant statutory requirements and guidelines and their updated versions.
|
Waste Management During Construction
|
Contractors
|
At all construction work sites, throughout
construction period
|
EIAO - TM
|
S.2.2.33
|
-
|
The helipad shall be constructed by
using small diameter pre-bored piling instead of dredging and reclamation.
|
Construction method
|
Contractors
|
At all construction work sites, throughout
construction period
|
-
|
S.5.6.30
|
-
|
The helipad will only be used for
emergency purposes. No equipment will
be placed on the landing pad or along the EVA. Helicopters will not be parked
at the landing pad and all repair and maintenance works (on the helicopters)
will be conducted off site. As such
the only source of waste generation during the operation of the helipad is
anticipated to be from the long-term maintenance of the pad.
|
Operation
|
GFS/HAD
|
At all time during operations
|
-
|
Table 999999.444444 Water Quality – Implementation
Schedule of Recommended Mitigation Measures
EIA
Ref.
|
EM&A
Ref.
|
Recommended mitigation measures
|
Objectives of the recommended
measures & main concerns to address
|
Who to implement the measures?
|
Location / Timing of
implementation of Measures
|
What requirements or standards for
the measures to achieve?
|
S.6.7.2
|
S.7.2.3
|
Silt
curtain to be installed surrounding
the whole of the sitealong the western
side of the Project boundary from the vertical seawall (off which the access
road link is to be developed) to the edge of the helipad footprint.
|
Water Quality During Construction
|
Contractors
|
Around
long the whole western
works
area side of the Project boundary from the vertical
seawall to the edge of the helipad footprint, prior to commencement
of the piling works.
|
Water
Pollution Control Ordinance (Cap. 358), Water Quality Objectives for Southern
WCZ if direct
discharge to sea is adopted.
|
S.6.7.3
|
S.7.2.4
|
The following good site practices are recommended:
·
The holding tank should be fitted
with a tight fitting seal to prevent sediment leakage;
|
Water Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period.
|
Not
applicable
(good
practice only)
|
S.6.7.3
|
S.7.2.4
|
·
Ensure that
excavator grab seal is tightly closed and the hoist speed is suitably low;
|
Water Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
Not
applicable
(good
practice only)
|
S.6.7.3
|
S.7.2.4
|
·
The holding tank
should not be filled to a level which will cause overflow of sediment during loading and
transportation;
|
Water Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
Not
applicable
(good
practice only)
|
S.6.7.3
|
S.7.2.4
|
·
Large objects should
be removed from the excavator grab to avoid sediment spills.
|
Water Quality During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
Not
applicable
(good
practice only)
|
S.2.2.33
|
-
|
·
The helipad
shall be constructed by using small diameter pre-bored piling instead of
dredging and reclamation.
|
Construction method
|
Contractors
|
At all construction work sites, throughout
construction period
|
-
|
Table 999999.555555 Ecology – Implementation Schedule of
Recommended Mitigation Measures
EIA
Ref.
|
EM&A
Ref.
|
Recommended mitigation measures
|
Objectives of the recommended
measures & main concerns to address
|
Who to implement the measures?
|
Location / Timing of
implementation of Measures
|
What requirements or standards for
the measures to achieve?
|
S.7.6.1
|
S.8.2.3
|
Silt
curtain to be installed surrounding
the whole of the sitealong the western
side of the Project boundary from the vertical seawall (off which the access
road link is to be developed) to the edge of the helipad footprint for the
protection of hard corals from sedimentation.
|
Ecology During Construction
|
Contractors
|
Around
the whole works area prior to commencement of the piling works.Along the western side of the Project boundary from
the vertical seawall to the edge of the helipad footprint, prior commencement
of the piling works.
|
Animals & Plants Ordinance (Protection of Endangered Species)
(Cap. 187)
|
S.7.6.2
|
S.8.2.4
|
Good practice measures to control water quality-induced ecological
impacts:
·
Particular care should be taken when
demolishing the existing concrete planter to ensure no waste enters the water
column;
|
Ecology During Construction
|
Contractors
|
At the existing concrete planter, throughout the whole duration of
the construction period.
|
Not
applicable
(good
practice only)
|
S.7.6.2
|
S.8.2.4
|
·
Particular care should be taken when
decommissioning the silt curtain to avoid sudden dispersion of muddy water
which may cause adverse impact to the nearby marine life;
|
Ecology During Construction
|
Contractors
|
Along the western side of the Project boundary, on the completion
of piling.
|
Not
applicable
(good
practice only)
|
S.7.6.2
|
S.8.2.4
|
·
Materials storage
areas should be located well away from the seawall, and any such areas should
be covered during the works;
|
Ecology During Construction
|
Contractors
|
At all construction work sites, throughout the whole duration of
the construction period
|
ProPECC Note PN 1/94 on Construction
Site Drainage
|
S.7.6.2
|
S.7.2.4
|
·
The holding tank for
sediment excavated from within the pile casing should be fitted with a tight fitting seal to
prevent leakage;
|
Ecology During Construction
|
Contractors
|
At the piling areas, throughout the whole duration of the piling
period
|
Not
applicable
(good
practice only)
|
S.7.6.2
|
S.7.2.4
|
·
Ensure that excavator seal is tightly closed and
the hoist speed is suitably low;
|
Ecology During Construction
|
Contractors
|
At the marine areas, throughout the whole duration of the
construction period
|
Not
applicable
(good
practice only)
|
S.7.6.2
|
S.7.2.4
|
·
The holding tank
should not be filled to a level which will cause overflow of sediment during
loading and transportation;
|
Ecology
During Construction
|
Contractors
|
At the marine areas, throughout the whole
duration of the construction period
|
Not applicable
(good practice only)
|
S.7.6.2
|
S.7.2.4
|
·
Large objects should
be removed from the excavator grab to avoid sediment spills.
|
Ecology
During Construction
|
Contractors
|
At all construction work areas,
throughout the whole duration of the construction period
|
Not applicable
(good practice only)
|
S.2.2.33
|
-
|
·
The helipad
shall be constructed by using small diameter pre-bored piling instead of
dredging and reclamation.
|
Construction
method
|
Contractors
|
At all construction work sites, throughout
construction period
|
-
|
10.1.1
The Project will involve the
construction of a permanent helipad at Kam Lo Hom (North), Yung Shue Wan to
serve the local community in the absence of an existing permanent facility. The helipad is required mainly for emergency
use. The Kam Lo Hom (North) site
selected for the Project is the optimal as of all sitesites considered
it is the most remote from the built environment, but is also easily accessible
from the Lamma Clinic.
10.1.2
The Helipad will be constructed by
small diameter pre-bored piling that offers environmental advantages compared
to the dredge and reclaim construction method. In particular, there will be
minimal waste handling / management requirements and minimal disturbance to the
seabed from pile installation, and hence only highly localised water quality
impacts and no marine ecology impacts.
Similarly, no construction dust impacts nor marine archaeology /
cultural heritage impacts are anticipated.
10.1.3
Based on the construction schedule and
plant inventory given, the unmitigated construction noise levels at all Noise
Sensitive Receivers (NSRs) comply with the daytime noise standards stated in
Table 1B, Annex 5 of EIA-TM. No cumulative
noise impacts are predicted with the construction of the Yung Shue Wan Sewage
Treatment Works. Accordingly, there are no specific mitigation measures or
monitoring requirements.
10.1.4
Helicopter noise is the key issue of
the Project. Through liaison with the Government Flying Service the helicopter
flight path approach angle has been adjusted to eliminate noise impacts during
helicopter approach, while not compromising flight safety. During helicopter manoeuvring at and over
the helipad a worst-case scenario impact of up to 5 dB(A) is predicted when the
‘Super Puma AS L2’ type helicopter is used. However, the frequency of such an
occurrence would be approximately once every 24.3 days, and the impact duration
would be in the order of 5-10 seconds.
10.1.5
Under normal operating conditions the
quieter type ‘EC155 B1’ helicopter will be used and will generate a residual
impact of up to 2dB(A) during lift-off from the helipad surface. The residual
impact duration under normal operations would be approximately 5-10 seconds,
while the impact frequency would be approximately once every 2.8 days. This level of impact is not considered
significant given the nature of the Project and the overall convenience of the
proposed site to the local community.
10.1.6
Consideration was given to helicopter
noise mitigation. However it was found that there are no options for direct
mitigation of helicopter noise, while indirect measures, such as use of
increased window glazing and installation of air conditioners, was considered
impracticable due to the intermittent / unpredictable helicopter use and the
short impact duration.
10.2.1
Although no construction phase noise
exceedance is predicted, noise impact monitoring and audit is recommended
during throughout the construction period to ensure noise levels at NSRs are
kept within an acceptable limit. The Environmental Monitoring and Audit
(EM&A) requirements are detailed in the stand-alone Project EM&A
Manual. As regards helicopter noise,
all practicable measures have been taken to avoid / minimise impacts, and as
such EM&A is not recommended.
However, should the need arise, the local community may lodge noise
complaints with the Islands District Office.
10.2.2
No waste management impacts are
predicted, and EM&A is not recommended. However, good site practise
measures have been proposed to ensure the proper handling, storage,
transportation and disposal of materials throughout the works. Although not
predicted, these waste management control measures, and additional good
practice measures proposed in Section 3, will
ensure there are no construction dust impacts.
10.2.3
Likewise, although no water quality or
marine ecology impacts are predicted, precautionary good site practice measures
are recommended to further minimise the potential for water quality / marine
ecology impacts. In particular, placement of a silt curtain surrounding the whole of the site along the western side of the Project boundary is
recommended to ensure no adverse effects on the hard coral community that was
identified growing on and along the bottom of the boulder seawall.
10.3.1
The key environmental outcomes of the
Project may be summarised as follows:
10.3.2
Population and environmentally sensitive
area protected: An optimum Project site has been selected that
that is relatively distant from the built environs of Yung Shue Wan but which
is also readily accessible from the Lamma Clinic. The chosen helipad site offers the local community a time saving
of approximately 20 minutes compared with the travel time to the previous
helipad at the HEC Lamma Power Station.
Furthermore, due to the availability of existing access road, the
helipad can be developed relatively quickly for available to / use by the local
community.
10.3.3
The realignment of the helicopter
flight path to avoid flight over residential areas at north Yung Shue Wan has
had a ‘net impact avoidance’ of adverse helicopter flight noise impacts on
approximately 420 dwellings from operation of the ‘EC155 B1’ type helicopter. For the ‘Super Puma’ type
helicopter, flight path realignment is predicted to result in net impact
avoidance on approximately 300 dwellings [Figure
4.4(b) refers].
10.3.4
Environmentally friendly designs
recommended: The design makes the best use of the existing infrastructure in Yung
Shue Wan by locating the helipad at the edge of the built environment. This minimises the amount of construction
phase disturbance that is necessary.
The helipad location has been selected to avoid encroachment on
secondary woodland habitat or the hard coral community.
10.3.5
Project construction will be by small
diameter pre-bored piling that represents the environmentally preferred method
in terms of practically eliminating concerns over potential waste management,
water quality and marine ecology impacts.
The precautionary use of silt curtains will ensure there are no adverse
water quality-induced impacts on the ecologically sensitive hard corals. The EVA width has been reduced from the standard
4.5m to 3.5m, with the effect that construction material requirements for the
Project will be minimised.
10.3.6
Key environmental problems
avoided: As referred above, the nature of the project and the construction
method will minimise the potential for waste
management, water quality and both direct and water quality-induced marine
ecology impacts. The site location avoids the secondary woodland at the foot of
the Kam Lo Hom slope, and hence avoids potential ecology and landscape
concerns. Realignment of the helicopter flight path has allowed the avoidance
of residual helicopter noise impacts on approximately 420 dwellings from
operation of the ‘EC155 B1’ type helicopter that will mainly be used [Figure 4.4(b) refers].
10.3.7
Compensation areas included: There is no significant habitat
loss as a consequence of the Project, and there are no specific compensation
areas. However, it can be expected that
the helipad and EVA structure will bring about some benefit to inshore
fisheries and marine ecology in terms of providing new hard habitat for
colonisation by marine benthic organisms and by providing shelter for fry and
juvenile fish.
10.3.8
Environmental benefits of
environmental protection measures recommended: Initial
residual helicopter noise impacts associated with helicopter approach /
departure have been effectively eliminated through realignment of the
helicopter flight path. Without helicopter flight path realignment, noise
levels at approximately 420 additional
noise sensitive dwellings at north Yung Shue Wan would exceed the helicopter
noise guideline of Lmax 85 dB(A) under the normal operating scenario
(i.e., use of the ‘EC155 B1’ type helicopter).
10.3.9
There will be a residual helicopter
manoeuvring noise impact under normal operating conditions of up to 2 dB(A)
associated with helicopter lift-off.
The impact duration would be 5-10 seconds and, based on actual
helicopter use data for Yung Shue Wan in the year 2003, the impact frequency is
predicted to occur approximately every 2.8 days. GFS will make use of the quieter ‘EC155 B1’ type helicopter
(rather than the noisier ‘Super Puma AS L2’ type helicopter) wherever possible.
Appendix 2.1
Visual Illustrations
Appendix
2.2
Construction Schedule
Appendix 4.1
indicative Land Use Concept
for Yung Shue Wan
Appendix
4.2
construction Equipment Inventory
Appendix
4.3
Construction Noise Calculation –
Unmitigated
Appendix
4.4
Helicopter Noise Measurement
Points and Noise Levels
Appendix
4.5
Helicopter Noise Survey report
Appendix
4.6
Helicopter Noise Calculations
Appendix
5.1
Sediment Classification Flow Chart
Appendix
5.2
Historical marine sediment Sampling Locations at yung
shue wan
Appendix
5.3
sediment Sampling Programme &
Chemical Screening Data
at yung shue wan
Appendix
6.1
Summary of Sediment Quality at
Monitoring Station ‘SS4’ (1997 1999 – 20003)
In the year 2000 the US FAA was requested to report to the US Congress
on the effects of nonmilitary helicopter noise in densely populated areas in
the U.S. and ways of reducing that noise. Verbal feedback on the unpublished
report of the public consultation was provided in a telecon with Mr Sandy Liu
of the US FAA (Noise Division) on 24th August 2005.