CONTENTS

1 Introduction

1.1 General

1.2 Project Background

1.3 Purpose and Approach of the EIA Study

1.4 Structure of this EIA Study Report

2 project description

2.1 Key Project Requirements

2.2 Project History and Site Selection

2.3 Project Characteristics and Site Location

2.4 Nearby Projects

2.5 Likely Future Environmental Conditions Without the Project

3 Air Quality impact assessment

3.1 Introduction

3.2 Relevant Guidelines, Standards & Legislation

3.3 Baseline Conditions and Air Sensitive Receivers

3.4 Construction Dust Impact Assessment

3.5 Mitigation Measures

3.6 Environmental Monitoring and Audit Requirements

3.7 Conclusions and Recommendations

4 Noise impact assessment

4.1 Introduction

4.2 Relevant Guidelines, Standards & Legislation

4.3 Noise Sensitive Receivers

4.4 Noise Environment at Peng Chau

4.5 Construction Noise Impact Assessment

4.6 Operational Noise Impact Assessment

4.7 Environmental Monitoring and Audit Requirements

4.8 Conclusions and Recommendations

4.9 References

5 Waste MANAGEMENT aSSESSMENT

5.1 Introduction

5.2 Legislation & Standards

5.3 Baseline Conditions & Sensitive Receivers

5.4 Assessment Methodology

5.5 Waste Types

5.6 Impact Assessment and Evaluation

5.7 Summary of Waste Materials Generated

5.8 Impact Mitigation & Residual Impact Assessment

5.9 Environmental Monitoring and Audit Requirements

5.10 Conclusions and Recommendations

5.11 References

6 water quality impact assessment

6.1 Introduction

6.2 Assessment Approach

6.3 Regulations, Standards and Guidelines

6.4 Baseline Conditions

6.5 Assessment Approach & Methodology

6.6 Impact Assessment & Evaluation

6.7 Impact Mitigation & Residual Impact Assessment

6.8 Environmental Monitoring & Audit

6.9 Conclusions and Recommendations

6.10 References

7 Ecology

7.1 Introduction

7.2 Assessment Approach

7.3 Regulations, Standards and Guidelines

7.4 Ecological Baseline

7.5 Impact Assessment & Evaluation

7.6 Impact Mitigation & Residual Impact Assessment

7.7 Environmental Monitoring & Audit Requirements

7.8 Conclusions & Recommendations

7.9 References

8 fisheries

8.1 Introduction

8.2 Assessment Approach

8.3 Applicable Regulations, Standards and Guidelines

8.4 Assessment Methodology

8.5 Fisheries Baseline

8.6 Impact Assessment & Evaluation

8.7 Impact Mitigation & Residual Impact Assessment

8.8 Environmental Monitoring & Audit Requirements

8.9 Conclusions & Recommendations

8.10 References

9 CULTURAL HERITAGE IMPACT ASSESSMENT

9.1 Introduction

9.2 Assessment Approach

9.3 Regulations, Standards and Guideline

9.4 Assessment Methodology

9.5 Baseline Conditions

9.6 Impact Assessment and Evaluation

9.7 Impact Mitigation & Residual Impact Assessment

9.8 Environmental Monitoring & Audit

9.9 Conclusions & Recommendations

9.10 References

10 Implementation Schedule of Recommended Mitigation Measures

10.1 Introduction

11 summary Conclusion & recommendations

11.1 Summary Conclusion of Technical Assessments

11.2 Key Recommendations

11.3 Summary of Environmental Outcomes

LIST OF FIGURES

Figure 2.1 Peng Chau Helipad Siting Options

Figure 2.2 Peng Chau 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 Index Plan for Cross Sections between NSR and Helipad

Figure 4.4b Index Plan for Cross Sections between NSR and Flight Path

Figure 4.5a Cross Sectional View for NSR to the Helipad (NSR1, NSR2, NSR3)

Figure 4.5b Cross Sectional View for NSR to the Helipad (NSR4, NSR5, NSR6)

Figure 4.5c Cross Sectional View for NSR to Flight Path (NSR3, NSR4)

Figure 4.5d Cross Sectional View for NSR to Flight Path (NSR5, NSR6)

Figure 4.6 Illustration of Affected Area by Helicopter Noise

Figure 5.1 Cross Section of Helipad Footprint

Figure 5.2 EVA Footprint – Cross Section A

Figure 5.3 Helipad Footprint – Cross Section B and C

Figure 6.1 Frequency and Direction of Current Velocity at Peng Chau

Figure 6.2 Cumulative Spatial Extent of Construction Phase Mixing Zone

Figure 7.1 Ecology Assessment Area and Sensitive Receivers

Figure 7.2 Habitat Map of the Peng Chau Study Area

Figure 7.3 Habitat Photographs

Figure 8.1 Fisheries Areas of Peng Chau

Figure 9.1 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 Peng Chau 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 L_{eq(5 min)} dB(A)

Table 4.4 Helicopter Noise Standards for Planning Purposes

Table 4.5 Location of NSR Assessment Points in Peng Chau

Table 4.6 Noise Monitoring Results at Sea Crest Villa

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 L_{eq(30 min)} dB(A) - Unmitigated

Table 4.10 Sound Power Levels for the Silenced Equipment

Table 4.11 Predicted Construction Noise Levels L_{eq(30 min)} dB(A) – Mitigated

Table 4.12 Predicted Cumulative Construction Noise Levels L_{eq(30 min)} dB(A) at NSR1

Table 4.13 Helicopter Noise Data – Airborne Helicopter with Lateral Movements

Table 4.14 Measured L_max Noise Level of GFS Helicopters – Without Lateral Movements

Table 4.15 Helicopter Use for Peng Chau ‘Casevac’ Operations during years 2000 – 2004

Table 4.16 Worst-case Helicopter Noise Levels at NSRs during Helicopter Manoeuvring

Table 4.17 Worst-case Helicopter Approach / Departure Noise Levels at NSRs

Table 5.1 Material Import Requirements

Table 5.2 Summary of Construction Phase Waste Generation

Table 6.1 Relevant Water Quality Objectives for Southern WCZ

Table 6.2 Summary of Water Quality at ‘SM10’ between 1997 and 2001

Figure 6.1 Frequency and Direction of Current Velocity at Peng Chau

Table 6.3 Predicted SS Elevation

Table 7.1 Representative Species in the Peng Chau Marine Benthic Community (CityU, 2002)

Table 7.2 Univariate Statistics for S. Peng Chau & Similar HKSAR Survey Areas (CityU, 2002)

Table 7.3 Habitat Types in the Assessment Area

Table 7.4 Categorisation of Benthic Cover and Substrate

Table 7.5 Rank Abundance of Pak Wan Sub-tidal Benthic Community

Table 7.6 Inter-tidal Survey Data for Pak Wan (BMT, October 2002)

Table 7.7 Butterfly Survey Data for Pak Wan, Peng Chau (BMT, 2002 & 2003)

Table 7.8 Bird Survey Data for Northwest Peng Chau (BMT, 2002 & 2003)

Table 7.9 Ecological Evaluation of the Sub-tidal Habitat

Table 7.10 Ecological Evaluation of the Sandy Shore (Beach) habitat

Table 7.11 Ecological Evaluation of the Hard Shore habitat

Table 7.12 Ecological Evaluation of the Coastal Scrub habitat

Table 7.13 Ecological Evaluation of the Secondary Woodland habitat

Table 7.14 Ecological Evaluation of the Developed / Disturbed Area

Table 7.15 Summary of Ecological Impacts

Table 8.1 Top Ten Ranked Adult Fish / Crustacean Families (from AFCD, 2003)

Table 8.2 Top Adult Fish / Crustacean Species by Weight from Peng Chau (AFCD, 1998)

Table 8.3 Production of Peng Chau Fisheries Areas (AFCD, 1998)

Table 8.4 Production Range for Fishing Methods at Peng Chau (AFCD, 2003)

Table 8.5 Commercial Value of Top Adult Fish Species around Peng Chau (AFCD, 1998; BMT, 2003).

Table 8.6 Common Fish Catch species at Northwest Peng Chau (BMT, 2003)

Table 10.1 Air Quality – Implementation Schedule of Recommended Mitigation Measures

Table 10.2 Noise – Implementation Schedule of Recommended Mitigation Measures

Table 10.3 Waste Management – Implementation Schedule of Recommended Mitigation Measures

Table 10.4 Water Quality – Implementation Schedule of Recommended Mitigation Measures

Table 10.5 Ecology – Implementation Schedule of Recommended Mitigation Measures

Table 10.6 Fisheries – Implementation Schedule of Recommended Mitigation Measures

LIST OF Appendices

Appendix 2.1 Visual Illustrations

Appendix 2.2 Construction Schedule

Appendix 2.3 Construction Schedule for DSD’s Sewage Treatment Works Upgrade

Appendix 4.1 Construction Equipment Inventory

Appendix 4.2 Construction Noise Calculation – Unmitigated

Appendix 4.3 Construction Noise Calculation – Mitigated

Appendix 4.4 Cumulative Construction Noise Calculation

Appendix 4.5 Helicopter Noise Measurement Points and Noise Levels

Appendix 4.6 Helicopter Noise Survey Report

Appendix 4.7 Helicopter Noise Calculations

Appendix 5.1 Historical Sediment Quality Monitoring Locations & Results at Peng Chau

Appendix 5.2 Sediment Classification Flow Chart

Appendix 5.3 Actual Sediment Sampling Locations within Helipad Footprint

Appendix 6.1 Summary of Sediment Quality for Routine Marine Sediment Quality Monitoring Station ‘SS5’ (1997 - 2000)

Appendix 7.1 Rapid Ecological Assessment (REA) Evaluation Framework

Appendix 7.2 Inter-tidal Survey Data for Pak Wan (BMT, April 2003)

Appendix 7.3 Marine Habitat Loss / Disturbance Calculations

1 Introduction

1.1 General

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 & 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 Yung Shue Wan, Lamma Island.

1.1.3 This Report presents the approach to and findings of the EIA study for the proposed Peng Chau helipad, and follows the requirements of Environmental Impact Assessment Study Brief No. ESB-091/2001.

1.2 Project Background

1.2.1 The Project involves the construction and operation of a permanent helipad at Peng Chau, and is ‘designated’ 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. 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.

1.2.3 The helipad is solely required for transporting Peng Chau residents to urban areas for medical treatment in emergency situations, and is not for commercial use. The current Peng Chau helipad is located on a soccer pitch near Tai Lung Tsuen and is the only landing site for the island. This site, located at the top of a hill, is still being used by Government Flying Service (GFS) for casualty evacuation (‘casevac’) operations but is not considered ideal on flight safety grounds, as the site constitutes a confined area – being surrounded by tall lighting posts.

1.2.4 Furthermore, the Tai Lung Tsuen landing site is only accessible by climbing long stairs. Vehicle access is impossible, and so the current helipad is very inconvenient for paramedics who presently must carry patients up the stairs by foot. The path to the existing landing site cannot be upgraded without significant reconstruction works, including partial demolition of village property. As such, the anticipated environmental and community impact associated with such upgrade works would be considerable. In view of the present situation, the Home Affairs Department (HAD) had commissioned CEDD to construct a permanent helipad to serve the local community.

1.2.5 A full description of the Project is presented in Section 2 of this Report.

1.3 Purpose and Approach of the EIA Study

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 minimize 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 Structure of this EIA Study Report

1.4.1 The EIA Report is divided into a total of 10 sections. Following this Section 1, Introduction, the Report is organised as follows:

· Section 2 – Project Description

· Section 3 – Air Quality Assessment

· Section 4 – Noise Assessment

· Section 5 – Waste Management Assessment

· Section 6 – Water Quality Assessment

· Section 7 – Ecological Assessment

· Section 8 – Fisheries Assessment

· Section 9 – Cultural Heritage Assessment

· Section 10 – Implementation Schedule of Recommended Mitigation Measures

· Section 11 – 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 referred to are at the back of the appropriate section for ease of reference, while all Appendices are together at the back of the EIA Report.

2 project description

2.1 Key Project Requirements

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 an ambulance. The Fire Services Department has requested a 4.5-metres wide EVA for the Peng Chau helipad, while the GFS has 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 Peng Chau Clinic in emergency situations. The helipad must also be operable and accessible at all times.

2.1.3 According to the GFS Helipad Specification Guidelines, the guiding factors for siting a ‘surface-level helipad’ are as follows:

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 Peng Chau 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 minimized.

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 Peng Chau Helipad is critical for accurate operational phase impact assessment, relevant flight data from GFS for the 2000 – 2004 period has been reviewed (Section 4.6 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 Peng Chau OZP No. S/I-PC/6 (dated April 15^th 2005) estimate a planned population of about 6,200 persons: up 1% from the population of around 6,130 persons estimated from the 2001 Census. Given that the GFS data for the year 2002 already represents a worst-case scenario for determining casevac flight frequency, this small population increase is considered insignificant.

2.1.6 There is no specific data available on tourist vists to Peng Chau, indicating that the island is not considered a significant tourist destination.

2.2 Project History and Site Selection

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:

· Helipad location and EVA link alignment;

· Project Design and construction methods; and

· Helicopter approach and departure paths.

2.2.2 As regards potential helipad siting options, three potential options identified through a site selection exercise initiated in 1997 by the then District Planning Office (DPO) for Sai Kung & Islands (now DPO for Lantau & Islands) were taken forward for consideration, namely Options A1, B1 and C.

2.2.3 A further ten site options / alternatives were identified under this Study for investigation. However, two of these additional ten sites – both located beyond the immediate Study Area (at east Peng Chau (Tung Wan) and southeast Peng Chau) – were found to be either of insufficient helicopter manoeuvring room or with unsuitable approach / departure paths and so were not taken forward for detailed consideration.

2.2.4 The characteristics of the eleven options / alternatives that were taken forward for more detailed consideration are summarised below. Figure 2.1 displays the locations of the eleven sites.

Option A: Alternative A1 - Pak Wan (Marine EVA)

2.2.5 The proposed ‘Option A: Alternative A1’ is situated on the north coast of Peng Chau, and would require construction of approximately 150 metres of new EVA along the natural existing rocky / sandy coastline from the junction of Peng Lei Road with the Tai Lei bridge crossing. The helipad would be constructed slightly offshore.

2.2.6 The proposed site is immediately adjacent to a natural rock wall that would provide some noise shielding from the construction and operation of the helipad.

Option A: Alternative A2 - Pak Wan (Land EVA)

2.2.7 The proposed ‘Option A: Alternative A2’ would access the same helipad as for ‘Option A: Alternative A1’ but by way of an inland coastal EVA that would follow the approximate alignment of the existing Pak Wan footpath and would thereby largely avoid disturbing the natural shoreline.

2.2.8 The start of this alternative EVA would also be from the Peng Lei Road / Tai Lei bridge crossing junction, and is also about 150 metres long.

Option B: Alternative B1 - Pei Lei

2.2.9 The proposed ‘Option B: Alternative B1’ would involve developing the helipad on top of the small islet of Pei Lei, off the northeast coast of Tai Lei. As the Pei Lei islet is on rocky ground, it was assumed that the construction of this alternative would require rock drilling / blasting activities to form a level platform for use by the helicopter.

2.2.10 There would also be a need to develop approximately 100m of EVA from the Tai Lei end of the bridge crossing, of which some 70m could be developed on existing formed land with the re-provisioning of a landscaped area. The remaining 30m of EVA would be developed by concrete on top of small diameter mini bored piles.

2.2.11 It was noted that there is a hard coral community of some ecological conservation value around Pei Lei that would need to be considered should there be any development of this option.

Option B: Alternative B2 - Pei Lei Southwest

2.2.12 The proposed ‘Option B: Alternative B2’ site would involve developing the helipad on a raised platform supported by small pre-bored mini piles on the relatively flat southwestern edge of Pei Lei. This alternative could avoid directly disturbing coral communities of ecological and conservation value around Pei Lei.

2.2.13 As with ‘Option B: Alternative B1’, there would be the need to construct an 80m long EVA link from the Tai Lei end of the bridge crossing, although most of this length can be developed relatively easily through re-provisioning of the existing landscaped area at the east of Tai Lei.

Option C – Kam Peng Estate

2.2.14 The proposed ‘Option C’ site is located to the west of Kam Peng Estate. As the land has been reclaimed, the construction works required would be relatively minor. However, this site is in close proximity to nearby residences.

Option D – Tai Lei South

2.2.15 The proposed ‘Option D’ site is located at the southern site of Tai Lei Island beside the existing Peng Chau Sewage Treatment Works (STW). The Drainage Services Department (DSD) is planning for an extension of the STW under which a submarine outfall would be constructed. Through liaison with DSD, it was determined that the alignment of the planned effluent outfall could still leave sufficient space for the development of a helipad at this location.

2.2.16 The helipad would be situated on the existing land between the STW and the seawall. It is required to extend the southern side of the landing area by about 15 metres to meet the minimum helipad size requirement. The EVA can be developed on existing formed land. As there are also coral communities of ecological conservation value adjacent to the ‘Option D’ site, these need to be considered should there be any development of this option.

Option E – Pak Wan

2.2.17 The ‘Option E’ site was proposed to minimise the potential loss of natural shoreline, and hence potential water quality, ecology and fisheries impacts, as compared with ‘Option A’ site. The helipad would be situated at a similar location to the ‘Option A’ site but closer to the existing Tai Lei bridge crossing so that only about 50 metres of EVA would be required. However, this site cannot take advantage of the noise shielding effect of the rock wall near ‘Option A’ site and so noise impacts to adjacent residences would be correspondingly greater.

Option F – Pak Wan Reclamation Area (Open Space)

2.2.18 The proposed ‘Option F’ site is an open space at the north end of the Pak Wan reclamation area. It was proposed to use part of the vacant area as a helipad site. As with the ‘Option C’ site, there are residential buildings nearby that would be particularly sensitive to helicopter noise.

Option G – Works Area of Highways Department on Tai Lei

2.2.19 The proposed ‘Option G’ site is currently used as a works area by a Highways Department (HyD) contractor and liquefied petroleum gas (LPG) cylinder storage area. If the site was to be adopted, an alternative site would need to be provided for a new LPG storage facility.

Option H – Existing Small Pier on Tai Lei

2.2.20 This proposed ‘Option H’ site comprises the existing small pier on the southern side of Tai Lei Island, primarily used for the delivery of LPG cylinders and other goods. The size of the pier deck has to be enlarged to comply with the minimum size requirements of the helipad.

2.2.21 There are also coral communities of ecological conservation value adjacent to the ‘Option H’ site that would need to be considered should there be development at this site.

Option I – Pak Wan (EVA East Extension)

2.2.22 This proposed ‘Option I’ helipad site would involve an eastwards extension to the ‘Option A: Alternative A1’ EVA by approximately 70 metres. The extended EVA would pass along a sandy beach and around a ‘Coastal Protection Area’, but would allow the helipad to be located beyond the helicopter noise impact zone.

Construction Methods

2.2.23 Three construction methods for forming the helipad platform and the EVA link have been considered and these are briefly summarized as follows:[*]

· The dredge and reclaim method 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 method 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.

Evaluation of Options / Alternatives

2.2.24 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.[†]

2.2.25 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 the local community and other stakeholders at an early stage of the Project and before detailed technical assessment had been undertaken. The VM exercise also took other non-environmental evaluation criteria, including time-frame, engineering feasibility, project cost, site availability, land ownership and community / social impacts into consideration.

2.2.26 The key community concerns identified through the consultation meetings and the VM exercise are listed below (in order of importance):

· Operational safety – the safety of the helicopter crew, passengers and the nearby community during helicopter activity were the main concern.

· Time frame – site availability and the speed of construction was raised as important factors due to the fact the helipad is for emergency casualty evacuation.

· Direct ground access – given the inconvenience of the existing helipad, proximity to and availability of direct and uninterrupted access to the Peng Chau Clinic is another issue of key concern.

2.2.27 Cost is another factor to be considered as it may indirectly affect the project delivery schedule. If the project cost exceeds the available budget ceiling, a more lengthy funding allocation exercise will be required that will delay project development.

2.2.28 In accordance with ETWB Technical Circular (Works) No. 13/2003 on “Guidelines and Procedures for Environmental Impact Assessment of Government Projects and Proposals”, regular consultation has also been conducted with EPD and the local District Council throughout the duration of the EIA Study.

2.2.29 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.

2.2.30 For the ‘Option A: Alternative A2’ site, consideration had been given to combining the EVA construction works with those for the Pak Wan footpath. However, the result of the assessment and evaluation exercise indicated that this approach would give rise to a range of unacceptable environmental impacts. In particular:

· Widening the footpath to 4.5m wide to cater for the need of the EVA would require slope cutting some 3 metres into the natural hillside along the 150m long EVA. Assuming that the slope faces along the EVA are very stable rock and can be formed vertically to ~3m height, there would be a loss of at least 500m² of natural vegetation. There would also be a need to form a vertical strip of engineered slope some 3m high and 150m long across the middle of the hillside parallel to the coastline.

· The elevation of the footpath is at approximately 14mPD at its closest point to the proposed helipad. The helipad would be built to a final elevation of 5.15 mPD. In order to link up the EVA with the helipad to match the level difference while satisfying the maximum allowable gradient for use of the emergency vehicles, the length of the EVA has to be extended and the helipad would need to be located further offshore. Both requirements would increase the scale of the project and associated environmental impact potential.

2.2.31 The ‘Option B’ (both Alternatives B1 and B2) and ‘Option D’ sites were considered environmentally unacceptable, as they are too close to the ecologically sensitive coral communities that may be disturbed by sediment release during construction. The possible shading effect from the helipad platform could also adversely affect coral growth and survival. These three options would also give rise to a helicopter noise impact at the Sea Crest Villa Noise Sensitive Receiver (NSR) under normal operating conditions.

2.2.32 The ‘Option C’ and ‘Option F’ sites would give rise to unacceptable safety concerns and helicopter noise impacts due to their close proximity to built areas and infrastructure nearby. Similarly, the ‘Option E’ site –, as the closest to Sea Crest Villa – would generate unacceptable helicopter noise impacts on residents.

2.2.33 The ‘Option G’ and ‘Option H’ sites are not acceptable due to safety concerns over relocating the existing LPG storage / handling areas, while a helipad at either of these sites would also generate a helicopter noise impact at Sea Crest Villa under normal operating conditions.

2.2.34 As presented in more detail under sub-section 4.6, the coastal cliff adjacent to the ‘Option A: Alternative A1’ location effectively shields the Sea Crest Villa NSRs from helicopter ‘manoeuvring’ noise. This location is also sufficiently distant from Sea Crest Villa and other NSRs such that no helicopter ‘approach’ noise impacts are predicted during normal operations when the preferred ‘Eurocopter EC 155B1’ type helicopter is in use.

2.2.35 Helicopter ‘approach’ noise levels are predicted to reach up to 88dB(A) at Sea Crest Villa on occasions when the preferred ‘EC 155B1’ type helicopter is not available for use, and the ‘Super Puma AS332 L2’ type helicopter is required. However, the impact duration is predicted to last 5-10 seconds while the impact frequency is predicted to be just once approximately every 12 days.

2.2.36 Consideration was given to implementing direct and indirect mitigation measures to satisfy the 85dB(A) helicopter noise standard. It was found that if direct mitigation measures were pursued, involving relocation of the helipad further 70m to the east to eliminate residual helicopter noise generated by the ‘Super Puma’ type helicopter (i.e., ‘Option I’), such relocation would infringe upon an area zoned “Coastal Protection Area” on the draft Peng Chau OZP No. S/I-PC/6 and therefore give rise to adverse landscape impacts, increased waste handling, habitat loss and water quality impacts.

2.2.37 As the helipad is intended for emergency use there is no fixed flight schedule. Accordingly, the use of indirect mitigation, such as improved window glazing and installation of air conditioners, was not considered practicable due to the short impact duration (< 10 seconds) and unpredictable timing of helicopter operations at the proposed helipad.

2.2.38 Overall, in addition to consideration of the residual helicopter noise impact on the local community as mentioned in above paragraphs, as the residual helicopter noise impact is not predicted to cause significant adverse long-term effects on the local community, development at the ‘Option A: Alternative A1’ helipad location is preferred. It is also noted that the noise impact due to helicopter manoeuvring at the existing helipad is estimated to adversely affect over 100 residential buildings. Furthermore, the noise level at Sea Crest Villa from existing helicopter flight is 92 dB(A) when the ‘Super Puma’ is in operation and 89 dB(A) when the ‘EC 155B1’ is operational [sub-section 4.6 refers]. These levels are above the permissible noise standard of 85dB(A).

2.2.39 Reclamation was selected as the preferred construction method by virtue of the shorter time frame required for development in the absence of any significant adverse construction phase environmental impacts. Percussive piling would give rise to significant construction noise impacts due to the proximity of the works area to residences at Sea Crest Villa, while the main disadvantage of mini pre-bored piling is the slow rate of construction and hence delay in availability of the project to the local community. The footprints of the helipad and EVA are small due to the shallow water depth, and hence the scale of the reclamation is relatively minor. Reclamation also ensures there is no adverse construction noise impact at Sea Crest Villa [Section 4 refers].

Design Refinements to the Preferred Option

2.2.40 Consideration has been given to means by which the design could be refined to minimise the scale and duration of the works, and hence avoid or reduce the environmental impact potential. This approach of proactive avoidance and minimisation through design takes precedence over impact mitigation.

2.2.41 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 minimize their footprint, and hence the disturbance to the affected coastal waters.

· The sea-facing sloping boulder wall has been designed to a steeper gradient, resulting in a reduction in the size of the foundation.

· The construction sequence shall be optimised to avoid cumulative construction noise effects with works for the proposed upgrading works of the Peng Chau Sewage Treatment Works.

2.2.42 In addition, during the detailed design stage of the Project the alignment of the EVA shall be further refined to make it as close to the existing cliff-face as is practicable in order to minimise marine-based works and the loss of shallow sub-tidal habitat.

Operational Considerations

2.2.43 Helicopter noise is the main environmental concern during operation of the helipad. It is predicted that there would be residual noise impact of 3 dB(A) at Sea Crest Villas under the worst-case scenario, compared with the existing worst-case scenario exceedance of the noise criterion of 7 dB(A). Based on worst-case GFS data for ‘casevac’ operations at Peng Chau, the predicted frequency of the residual impact is approximately once every 12 days. The impact duration would last for not more than 5-10 seconds per event. A number of issues have been considered in this regard, and are discussed in greater detail in sub-section 4.6. They include:

Helipad distance from the built environment

2.2.44 It has been predicted that the helicopter flight noise impact ‘zone’ for the ‘Super Puma’ type helicopter is 221 metres [para. 4.6.19 refers]. Given the hilly nature of the topography at north and south Peng Chau and the relatively densely populated central isthmus that needs to be protected from helicopter noise impacts as far as is practicable, there are no suitable land-based helipad options. On the other hand, there is need to minimize the travelling time from the Clinic to the helipad. A suitable balance must be struck between these conflicting requirements.

2.2.45 Of all the Options / Alternatives considered, ‘Option A: Alternative 1’ offers the best noise environment as it is relatively remote from the built environment, while a natural rocky cliff-face will effectively shield Sea Crest Villa – the nearest Noise Sensitive Receiver – from adverse helicopter manoeuvring noise impacts. There will be no adverse helicopter noise impact under normal operating conditions.

Helicopter Type

2.2.46 Consideration has been given to use of helicopter types generating lower noise levels for casualty evacuation operations. However, GFS has confirmed that at present only the two helicopter types that have been assessed in this EIA Report (i.e., the ‘Eurocopter EC155 B1’ and ‘Eurocopter Super Puma AS332 L2’) are available for such operations.

2.2.47 For operational considerations, the GFS would not be able to exclude the ‘Super Puma’, the noisier of the two 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 in Peng Chau. As only one helicopter would be 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 quiter EC155 B1 type helicopter for night-time casevac operations and GFS has advised that this usage trend is expected to continue.

Table 2.1 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
A1	Pak Wan – marine EVA	· No helicopter manoeuvring noise impact during any operations. · No helicopter flight path noise impacts under normal operations.^	· Helicopter flight path noise impact from use of ‘Super Puma’ type helicopter.	· Easy access from Clinic. · No flight safety concerns.	Residual flight path noise impact from Super Puma, but no helicopter noise impact under normal operations.
A2	Pak Wan – land EVA	· No helicopter flight path noise impacts under normal operations.	· Potential ecological impact from necessary slope works. · Manoeuvring noise impact from both helicopter types and flight path noise from ‘Super Puma’.	· Easy access from Clinic, although steep slopes to navigate to helipad. · No flight safety concerns.	Potential ecology impact from necessary EVA construction / slope works, and residual manoeuvring noise impacts for both helicopter types.
B1	Pei Lei	· Minimal construction works.	· Potential impacts on hard corals from construction works. · Helicopter flight path and manoeuvring noise impact.	· Easy access from Clinic. · No flight safety concerns.	Potential adverse impacts on hard corals, and likely residual helicopter noise impact under normal operations.
B2	Pei Lei Southwest	· Minimal construction works.	· Potential impacts on hard corals from construction works and shading effect of EVA & Helipad. · Helicopter flight path and manoeuvring noise impact.	· Easy access from Clinic. · No flight safety concerns.	Potential adverse impacts on hard corals, and likely residual helicopter noise impact under normal operations.
C	Kam Peng Estate	· No significant construction phase impacts (land already formed).	· Significant helicopter flight path and manoeuvring noise impact on nearby residences.	· Best access from Clinic. · Helicopter flight safety concerns due to proximity to built-up area.	No construction phase concerns, but likely significant residual helicopter noise impacts under normal operations. Unacceptable flight safety concerns.
D	Tai Lei South	· Minimal construction works.	· Potential impacts on hard corals from construction works. · Helicopter flight path and manoeuvring noise impact.	· Easy access from Clinic. · No flight safety concerns.	Potential adverse impacts on hard corals, and residual helicopter noise impact under normal operations.
E	Pak Wan	· No significant construction phase impacts.	· Significant helicopter flight path and manoeuvring noise impacts on nearby residences.	· Easy access from Clinic. · Some flight safety concern due to proximity of Sea Crest Villa.	Likely significant residual helicopter noise impacts under normal operations, and flight safety concerns.
F	Pak Wan Reclamation (Open Space)	· No significant construction phase impacts (land already formed).	· Significant helicopter flight path and manoeuvring noise impact on nearby residences.	· Best access from Clinic. · Helicopter flight safety concerns due to proximity to built-up area.	Likely significant residual helicopter noise impacts under normal operations. Unacceptable flight safety concerns.
G	Works Area of Highways Department on Tai Lei	· No significant construction phase impacts (land already formed).	· Helicopter flight path and manoeuvring noise impact.	· Easy access from Clinic. · Need to reprovision LPG storage / handling area, otherwise no flight safety concerns.	Likely significant residual helicopter noise impacts under normal operations.
H	Existing Small Pier on Tai Lei	· No significant construction phase impacts.	· Helicopter flight path and manoeuvring noise impact.	· Easy access from Clinic. · Need to reprovision LPG storage / handling area, otherwise no flight safety concerns.	Likely significant residual helicopter noise impacts under normal operations.
I	Pak Wan (EVA East Extension)	· No helicopter manoeuvring or flight path noise impact.	· Extended EVA will encroach into zoned “Coastal Protection Area” (CPA).	· Easy access from Clinic. · No flight safety concerns.	The extended EVA on to the ‘CPA’ zone would create a significant adverse landscape impact.

Notes: * Figure 2.1 refers. ^ Normal operation refers to the use of EC155 B1 type helicopter.

Helicopter Flight Path

2.2.48 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 2.1.3(a) refers) there is always one other option for safe helicopter approach / departure.

2.2.49 It was determined that a flight path separation angle of 150 degrees would adversely affect all residences at Sea Crest Villa. With the agreement of GFS, the angle of separation between the two flight paths for the ‘Option A: Alternative A1’ site has been reduced to 115 degrees [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 the ‘EC155 B1’ type helicopter can be reduced to within the 85dB(A) guideline at all noise sensitive receivers.

2.2.50 There will be a residual helicopter noise impact when the ‘Super Puma AS332 L2’ helicopter is used although this helicopter type is not frequently used.

2.3 Project Characteristics and Site Location

2.3.1 The Project involves the construction of a helipad by the ‘dredge and reclaim’ method in shallow coastal waters of 2-3 metres depth at Pak Wan, northwest Peng Chau. The project will be constructed off a natural, predominantly rocky coastline. The project location was selected after detailed consideration of the operational requirements and environmental impact potential of developing the Project at each of thirteen site locations. With reference to the current statutory Peng Chau Outline Zoning Plan (No. S/I-PC/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.

2.3.2 The helipad deck will be located approximately 10 metres from the back of the Pak Wan shore (i.e., existing land). An EVA will be constructed along the natural shoreline to link the proposed helipad with the existing EVA located adjacent to Sea Crest Villa. The works contractor shall install a standard 2.4m high solid corrugated metal hoarding along the Peng Lei Road site boundary, opposite to Sea Crest Villa, to fence the site and with the effect of also avoiding adverse visual impacts on pedestrians. Figure 2.2 shows the site location, while Appendix 2.1 presents a visual illustration of the Project.

2.3.3 The site location was selected after due consideration of the operational requirements and environmental impact potential of constructing and operating the Peng Chau helipad at each of eleven site locations. Specific Project details are as follows:

· Approximately 14,000m³ of fine to coarse marine sand will need to be dredged.

· The EVA link will be about 150 metres long and 4.5 metres wide.

· The helipad will have a diameter of 25 metres.

· The EVA link and helipad surfaces will be formed to a height of approximately +5.0 mPD.

· Wave deflectors will be installed around the helipad to enhance operational safety.

· An off-site works area (including site office) to be located on existing vacant land immediately south of Sea Crest Villa that will be required for about 2 years, from December 2005. No off-site pre-casting works are anticipated.

2.3.4 The construction programme can be broadly summarised as presented by Table 2.2.

Table 2.2 Summary of Peng Chau Helipad Construction Programme

Construction Activity	Construction Period
Site Clearance	Dec 2005 – Jan 2006
Reclamation	Feb 2006 – Sept 2006
Construction of Helipad	Jan 2006 – Nov 2006
Construction of EVA	Jul 2006 – Nov 2006

2.3.5 Further details of the construction works are presented in Section 4, while the full construction programme is presented in Appendix 2.2.

Landscape Treatment

2.3.6 Clause 3.4.8 of the ESB that requires the provision of landscape design proposals. On the advice of PlanD, it is proposed that vegetation cover be established beside the junction of the proposed new EVA with the existing Peng Lei Road, opposite the low-rise Sea Crest Villa residential development. This area is the only part of the proposed EVA alignment that will be visible to the general public from and occupants of some of the middle and upper floor residences at Sea Crest Villa. The coastal section of the proposed EVA comprises a natural vertical cliff face that does not require landscape treatment, while this section of the EVA and the actual helipad will be exposed to seawater splash where terrestrial vegetation cannot be established. Hard landscaping measures have been proposed in these areas with the sensitive design of a sloping boulder seawall (Figure A2.1b and Figure A2.1c in Appendix 2.1 refer).

2.3.7 For the soft landscaping works, it is proposed that the area immediately west of the EVA at the Peng Lei Road junction and the strip between the coastal EVA and the foot of the cliff be hydroseeded with a commercially available mix of grass seeds. A suitable composition of such a mixture that is currently being applied for hydroseeding works for CEDD’s Fill Bank at Tseung Kwan O Area 137 includes:

· Carpet Grass (Anoxopus compressus): 5 g/m²

· Bermuda Grass (Cynodon dactylon): 10 g/m²

· Bahia Grass (Paspalum notatum): 10 g/m²

· Mulch: 200 g/m²

· Fertilizer (NPK 15:15:15): 100 g/m²

2.3.8 The location of the proposed hydroseeding is illustrated on Figure A2.1a and covers an approximate area of 100 m².

2.3.9 Given the presence of a fairly diverse vegetation community at northwest Peng Chau, including a range of native trees and shrubs, it can be expected that natural colonisation of the hydroseeded area will occur in time, thereby adding to the 'greening' effect in the area.

2.4 Nearby Projects

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 are as follows:

Peng Chau Sewage Treatment Works Upgrade

2.4.2 The construction of DSD’s Peng Chau Sewage Treatment Works (STW) Upgrade is scheduled to commence in mid-2005 and is tentatively scheduled for completion by the end of 2007. In addition to DSD’s further advice, the associated marine works are tentatively scheduled from August 2005 to April 2006, although the programme is still under vetting. The latest agreed construction programme for the STW Upgrade project and DSD’s further information are presented in Appendix 2.3.

2.4.3 As the STW upgrading works may be implemented in parallel with the helipad project, the potential for, and magnitude of, cumulative impacts have been assessed in detail using a standard calculation based on the Gaussian theory, as presented in the following sections.

Drainage Improvement Works at Peng Chau

2.4.4 DSD is currently implementing a sewerage improvement scheme, mainly in the centre of Peng Chau town but also involving some works within the helipad project boundary. It has been confirmed with DSD that the overall works are scheduled for completion in early / mid 2005, while the portion within the Peng Chau helipad project boundary – involving mains upgrade and construction of a pumping station – was completed in 2004. As such, these works will not lead to any cumulative effects.

2.5 Likely Future Environmental Conditions Without the Project

2.5.1 Without the Project the existing helipad site on a hard surface soccer pitch located atop a hill near Tai Lung Tsuen will continue to be used. In addition to flight safety concerns (para. 1.2.3 refers) and access difficulty (para. 1.2.4 refers), use of the existing helipad will generate a significant helicopter noise impact on surrounding residents.

2.5.2 It has been estimated that over 100 village type and medium rise residential buildings, principally in Shan Ting Tsuen, Kam Peng and Tung Wan Villa are presently exposed to noise levels above the 85dB(A) helicopter noise standard under normal operating conditions (i.e., using the quieter EC155 B1 type helicopter). In particular, the flight path to the existing helipad passes over Sea Crest Villa.

2.5.3 The noise assessment detailed in Section 4 predicts that helicopter noise levels at Sea Crest Villa due to the existing flight path are greater than the 85dB(A) limit. Furthermore, the noise level is predicted to be greater than the corresponding helicopter flight noise level upon operation of the proposed helipad at Pak Wan due to a shorter distance separation. As such, if the project is not implemented a large number of residents will continue to be adversely affected by helicopter noise, including those at Sea Crest Villa.

3 Air Quality impact assessment

3.1 Introduction

3.1.1 It should be noted that the EIA Study Brief ESB-091/2001 issued under the Environmental Impact Assessment Ordinance does not include a requirement for an Air Quality Impact Assessment, as use of the proposed helipad will be limited.

3.1.2 This section shall give a brief account of the potential for the construction dust generation and recommendations on the appropriate remedial actions to minimise any potential impacts. This will be done to ensure compliance with the Air Pollution Control (Construction Dust) Regulation and to ensure effective control of any potential dust impacts.

3.1.3 Emissions from helicopter will be short-lived and occur infrequently during the operation of the helipad due to its emergency nature of use. No potential operational phase dust impacts are anticipated.

3.2 Relevant Guidelines, Standards & Legislation

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 3.1.

Table 3.1 Hong Kong Air Quality Objectives

	Concentration (mg/m^3)^(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	-

Notes:

(1) Measured at 298 K and 101.325 kPa (one atmosphere).

(2) Not to be exceeded more than three times per year.

(3) Not to be exceeded more than once per year.

(4) Arithmetic means.

(5) Respirable suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 10 micrometers or less.

(6) Photochemical oxidants are determined by measurement of ozone only.

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.

Notifiable Works:

(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,

Regulatory Works:

(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 stabilization 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.

3.3 Baseline Conditions and Air Sensitive Receivers

Existing Environment

3.3.1 The existing air quality in Peng Chau is generally rural. No major air polluting sources are located near Peng Chau. The nearest potential source is the Penny’s Bay Gas Turbine Plant that is over 3.5km away, due north of Peng Chau. There are no major road networks within Peng Chau 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 Peng Chau. 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 Peng Chau – has been selected as being broadly representative of the existing ambient air quality conditions at Peng Chau. These data are summarised in Table 3.2. [§]

Table 3.2 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

Notes:

1. All concentrations are measured at 298K (25°C) and 101.325KPa (one atmosphere)

2. Data of the Tap Mun Monitoring Station are extracted from “Air Quality in Hong Kong 2002”, published by EPD

Future Conditions

3.3.3 Based on current information, the Drainage Services Department’s (DSD) project Peng Chau Sewage Treatment Works (STW) Upgrade at Tai Lei Island will commence in mid 2005. This STW upgrading work will be a potential fugitive dust source during the works phase. There may be other construction works to be carried out on the reclaimed area that may be a source of fugitive dust. However, these will only be a short-term change in the ambient condition locally and will not alter the nature of the air quality condition of Peng Chau once the works are completed.

3.3.4 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 Peng Chau and therefore, the air quality conditions are not expected to have any significant change in the future.

Air Sensitive Uses

3.3.5 Sea Crest Villa, a low-rise (3-storey high) residential development, is located at the junction of Peng Lei Road and the future helipad EVA link. This is the closest domestic air sensitive receiver to the proposed works. There are no domestic premises in the immediate environs of the helipad site. Another existing domestic air sensitive use is Kam Peng Estate that is located about 200 metres south east of Sea Crest Villa. Figure 3.1 displays the locations of Sea Crest Villa and Kam Peng Estate.

3.4 Construction Dust Impact Assessment

Identification of Impacts

3.4.1 If uncontrolled, construction activities dust may result in construction dust impacts. Construction of the helipad and the associated EVA using reclamation 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 of existing ground near the north of Sea Crest Villa. 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 will be required at the off-site works area (approximately 800 m²), which is located immediately south of Sea Crest Villa. Development of the off-site works area will not involve any dust-generating activities. However, the erection of hoarding and fencing at the works area may involve very minor excavation that comprises a regulatory works procedure, and for which dust control measures will be implemented. Dusty material stockpiling and handling will only be conducted in the works area and measures shall be implemented to ensure dust levels are controlled to within an acceptable level.

3.4.4 Reclamation includes dredging and placement of rocks / rubble, is a notifiable work and is controlled by the Regulation. The dredged materials will have a high moisture content that is unlikely to result in dust emissions. The fill materials will be directly placed into the water from barge and no fugitive dust impacts are anticipated.

3.4.5 The construction of the helipad 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 off-site works area to the works area via 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 Based on the tentative construction schedule of the Drainage Services Department's project Peng Chau Sewage Treatment Works (STW) Upgrade at Tai Lei Island that would commence construction in mid 2005, it would be a cumulative source of dust impacts. However, dust control measures will be implemented during the helipad construction of which the scale of work is relatively limited. Furthermore, the DSD’s project also will have to implement dust control measures during their construction phase. As a result, no significant cumulative dust impacts are anticipated.

Evaluation of Potential Impacts

3.4.8 In view of the small scale of 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 Mitigation Measures

3.5.1 All applicable dust control measures as recommended in the Air Pollution Control (Construction Dust) Regulation should be implemented. Typical dust control measures include:

· The working area for site clearance adjacent to Sea Crest Villa shall be sprayed with water or a dust suppression chemical immediately before, during and immediately 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.

· For reclamation works, if a stockpile of dusty materials is more than 1.2 m high and within 50m of Peng Lei Road or the Pak Wan footpath, the stockpile shall be properly treated and sealed with latex, vinyl, bitumen or other suitable surface stabilizer.

· 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.

3.6 Environmental Monitoring and Audit Requirements

3.6.1 It is necessary to ensure proper implementation of the dust control measures as required under the Air Pollution Control (Construction Dust) Regulation. No specific construction dust monitoring is necessary, although environmental audits will be carried out to ensure proper implementation of air quality control measures.

3.7 Conclusions and Recommendations

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 Noise impact assessment

4.1 Introduction

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 Peng Chau.

4.1.2 During the construction phase of the helipad, Powered 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;

· Reclamation for the helipad and the Emergency Vehicle Access (EVA); 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 3.4.5.2 (iii) (b) of the EIA Study Brief, the selection of representative NSRs has been presented to and agreed by the Authority prior 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.

4.2 Relevant Guidelines, Standards & Legislation

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 summarized in Table 4.1. These criteria shall be met as far as practicable according to Annex 5 of the EIA-TM.

Table 4.1 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

4.2.3 Construction noise is controlled during restricted hours (i.e., between 19:00-07:00 hours and on Sundays and public holidays (anytime for percussive piling) under the NCO and Technical Memoranda (TMs): Noise from Percussive Piling (PP-TM); Noise from Construction Work Other Than Percussive Piling (GW-TM); and Noise from Construction Work in Designated Areas (DA-TM).

4.2.4 A Construction Noise Permit (CNP) is required under the NCO for works involving the use of Power Mechanical Equipment (PME) during restricted hours. The noise criteria for the use of PME during restricted hours are determined upon the Area Sensitivity Rating (ASR), which ‘ranks’ the background noise conditions of the area in which the NSR is located. Table 4.2 shows the ASR selection criteria as stated in GW-TM.

Table 4.2 Area Sensitivity Rating Criteria

	Degree to which NSR is affected by IF(4)
Type of area containing the NSR	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

Notes:

(1) Not Affected means that the NSR is at such a location that the noise generated by the influencing factors⁽⁴⁾ (IFs) is not noticeable at the NSR.

(2) Indirectly Affected means that the NSR is at such a location that the noise generated by the IF, whilst noticeable at the NSR, is not a dominant feature of the noise climate of the NSR.

(3) Directly Affected means that the NSR is in such a location that the noise generated by the IF is readily noticeable at the NSR and is a dominant feature of the noise climate of the NSR.

(4) IFs are defined as industrial areas, major roads or the area within the boundary of Hong Kong International Airport.

4.2.5 The noise criteria for construction noise during restricted hours for each ASR are given in Table 4.3.

Table 4.3 Acceptable Noise Levels in L_{eq(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 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.

4.2.7 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

4.2.8 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 summarized in Table 4.4.

Table 4.4 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

Notes:

(1) The above standards apply to uses that rely on opened windows for ventilation.

(2) The above standards shall be viewed as the maximum permissible noise levels assessed at 1 m from the external façade.

4.2.9 There are no specified night-time helicopter noise guidelines for the HKSAR, and accordingly a document review was undertaken to determine international practice. The review included the US Federal Aviation Agency (US FAA), the International Civil Aviation Organization, the US-based National Organization to Insure a Sound-controlled Environment (NOISE), and various individual airport / heliport web-sites.

4.2.10 From this review it was identified that most literature on aircraft noise concerns relates to commercial airplane and helicopter noise. However, during the ‘US FAA [public] Hearings on [non-military] Helicopter Noise’ it was noted that noise from emergency medical services was to be exempted in the list of “Recommended Noise Reduction Approaches”.[**] In other words, after widespread consultation the public expressed their general tolerance of noise from emergency helicopter operations. This situation also applies to existing casevac operations for Peng Chau, which both GFS and CAD confirm have never received a noise complaint from the local community.

4.2.11 Recognising the tolerable necessity of emergency helicopter flights at night-time, during the US FAA hearings it was remarked that consideration might 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 Section 4.6.

4.3 Noise Sensitive Receivers

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 representative existing NSRs. A review of the latest Outline Zoning Plan (Peng Chau OZP No. S/I-PC/6), Outline Development Plan (Peng Chau ODP No. D/I-PC/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 3.4.5.2 (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 Receivers

4.3.4 Peng Chau has been developed mainly with low-rise developments that are located in the central portion of the island. At the northwest of Peng Chau close to the proposed helipad site, there are low-rise (3 storeys) apartment type residential buildings and a medium-rise (7 storeys) public housing estate that are NSRs. Given the natural hilly topography at northwest Peng Chau there is no direct line of sight between the NSRs and the proposed helipad (i.e., there is natural shielding of noise at NSRs).

4.3.5 Based on site visits, Blocks C and D of Sea Crest Villa (NSR1 and NSR2) are located approximately 160 metres west-southwest of the proposed helipad and are the closest NSRs to the proposed helipad. These two NSRs have a direct line of sight to part of the EVA works area. Kam Peng House at Kam Peng Estate (NSR3) is located further south (about 330m) of the proposed helipad and the line of sight is completely blocked by the northern ridgeline at Peng Chau. These existing NSRs have been selected as representative NSRs for the noise impact assessment.

4.3.6 Block A of Sea Crest Villa (NSR7) does not have a direct line of sight to the helipad, but is included to assess the impact of the off-site works area for the project that is located on reclaimed land approximately 15 metres to the south.[††] The noise impact for this NSR has been assessed for the construction phase only.

Planned Noise Sensitive Receivers

4.3.7 The main purpose of selecting planned NSRs is for the assessment of future noise impacts due to the operation of the helipad. Based on the current Peng Chau OZP No. S/I-PC/6 and the latest Peng Chau ODP No. D/I-PC/2, three potential future NSRs have been selected and agreed by the Authority.

4.3.8 One potential future NSR, denoted by NSR4, is located within a “Government, Institution or Community” zone to the southeast of the helipad site. It is designated for educational use and has been assumed to be a school with a maximum building height of 24 metres. Another NSR is located within a “Residential (Group B)” zone (assuming maximum 8-storey, 24 metres high), namely NSR5, and the third NSR is located within an “Other Specified Uses” zone annotated “Comprehensive Residential Development including a Commercial Complex”, namely NSR6, which is subjected to a maximum building height of 2 storeys not exceeding 6m and 8m for residential blocks and commercial complex, respectively.

4.3.9 The characteristics of NSRs in the vicinity of the proposed Peng Chau Helipad are summarised in Table 4.5. Figure 4.1 illustrates their locations. Figures 4.5a and 4.5b display cross sections for NSRs 1-6.

Table 4.5 Location of NSR Assessment Points in Peng Chau

NSR Assessment Point	NSR Location	Number of storeys	Ground Level (mPD)	Land Use
NSR1	Sea Crest Villa - Block D, Flat A	3	4.8	Residential
NSR2	Sea Crest Villa - Block C, Flat A	3	4.8	Residential
NSR3	Kam Peng Estate – Kam Peng House	7	4.7	Residential
NSR4*	Future Development in “Government, Institution or Community” Zone	24 metres^#	20.0	School
NSR5*	Future Development in “Residential (Group B)” Zone	8 storey (maximum 24 metres)^#	6.0	Residential
NSR6*	Future Development in “Other Specified Uses” Zone	2 storey (residential: 6 m; commercial: 8 m)^#	3.9	Commercial & Residential
NSR7^	Sea Crest Villa - Block A, Flat B	3	4.8	Residential

Notes:

* Location of NSRs is based upon the most updated Peng Chau OZP No.S/I-PC/6 and ODP No. D/I-PC/2.

^# Maximum building height based upon the most updated Peng Chau OZP No.S/I-PC/6 (gazetted on 15.4.2005).

^ Existing NSR used for construction noise impact assessment only.

4.4 Noise Environment at Peng Chau

Existing Noise Environment at NSRs

4.4.1 Peng Chau is an outlying island with limited road network, and has no major road traffic related noise sources. However, it is observed from site visits that there are motorized carts travelling within Peng Chau, e.g., route to Tai Lei Island, which may generate potential noise impacts affecting the residences living along the routes such as Sea Crest Villa. The noise environment at Peng Chau is dominated by human activities, with most activities during daytime hours.

4.4.2 CEDD is monitoring noise levels at north Peng Chau (Sea Crest Villa) due to construction works at Penny’s Bay.[‡‡] The noise monitoring results for the three months June - August 2003 are summarised in Table 4.6 to demonstrate baseline noise levels at north Peng Chau. There has been no development in the area since this time that would have lead to a change in the baseline noise environment.

Table 4.6 Noise Monitoring Results at Sea Crest Villa

Time Period	June 2003	July 2003	August 2003
Day Time Leq(30 min)	54 – 66 dB(A)	51 – 64 dB(A)	55 – 62 dB(A)
Evening Time Leq(15 min)	49 – 57 dB(A)	52 – 57 dB(A)	45 – 52 dB(A)
Night Time Leq(15 min)	45 – 54 dB(A)	48 – 61 dB(A)	50 – 56 dB(A)

Source: Webpage http://www.pennysbaycontract1.com/noise1.html

Future Trend

4.4.3 Based on the latest planning information, the Peng Chau Sewage Treatment Works (STW) upgrading works are a potential noise source that may affect NSRs close to the works site during construction. There will be no significant change in the noise environment at Peng Chau upon completion of the upgrading works. Future increase in the population (upon occupancy of all planned developments) may result in more human activity and potentially a higher noise background.

4.5 Construction Noise Impact Assessment

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 4.1, respectively. The construction schedule provided by CEDD is based upon all works to be undertaken during non-restricted hours only. The construction noise impacts at representative NSRs were assessed using the methodology specified in Annex 13 of the EIA-TM. The noise level at the most affected floor (i.e., 1/F) has been assessed and appropriate corrections such as façade correction and barrier correction have been applied.

4.5.2 Based on the construction schedule, the noise assessment has been divided into 27 ‘assessment periods’ throughout a 12-month construction period 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 4.7 Powered Mechanical Equipment to be used for Construction of Helipad

Identification Code	Description	Sound Power Level, dB(A)
CNP 003	Air compressor	104
CNP 021	Bar bender (electric)	90
CNP 045	Concrete mixer (electric)	96
CNP 048	Crane, mobile (diesel)	112
CNP 061	Derrick barge/ Split barge	104
CNP 063	Dredger, grab	112
CNP 067	Dump truck	117
CNP 081	Excavator/ Backhoe	112
CNP 101	Generator, Standard	108
CNP 170	Poker, vibratory, hand-held	113
CNP 186	Roller, vibratory	108
CNP 221	Tug boat	110

Source: GW-TM.

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 4.8. The geographical centre for each activity to determination the equipment locations (i.e., Notional Source Position[§§]) for the calculation of construction noise levels are presented in Figure 4.2.

Table 4.8 Construction Activities

Construction Activities	Details of Works
Site Clearance	· Existing ground breaking; · Removal of demolition/ waste materials; and · Erection of office, hoarding and fencing
Reclamation	· Dredging; · Placing/ trimming of pell mell rubble; · Placing/ trimming of rock underlayer; and · Placing/ trimming of rock armour.
Construction of Helipad	· Casting pre-cast concrete wave deflector; · Installation of pre-cast wave deflector; · Filling the pad with granular material; · Compaction of foundation material; · Construct reinforced concrete slab; and · Install helipad facilities.
Construction of EVA	· Filling EVA with granular material; · Compaction of foundation material; · Construct reinforced concrete slab; · Associated drainage; · Install railing and other E&M facilities; and · Landscape work.

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 4.2.

Table 4.9 Predicted Construction Noise Levels L_{eq(30 min)} dB(A) - Unmitigated

Assessment Period #	NSR1	NSR2	NSR3	NSR4	NSR5	NSR6	NSR7
1	78*	80*	64	56	68	83*	80*
2	84*	85*	64	59	68	84*	80*
3	60	61	64	53	67	83*	80*
4	56	56	49	56	54	53	54
5	77*	77*	54	58	58	67	62
6	82*	82*	57	61	62	72	66
7	80*	80*	55	60	60	70	64
8	81*	81*	56	60	61	71	65
9	74	74	52	57	57	64	59
10	77*	77*	53	58	58	67	61
11	76*	77*	51	55	56	67	61
12	77*	77*	52	57	57	67	61
13	74	74	51	56	55	64	59
14	80*	81*	53	57	57	67	62
15	77*	77*	51	56	56	65	60
16	77*	77*	51	56	56	65	60
17	83*	84*	55	59	60	70	65
18	83*	84*	54	58	59	70	65
19	83*	84*	56	61	61	70	65
20	83*	84*	55	60	60	69	65
21	84*	85*	56	61	61	71	66
22	85*	86*	56	61	61	71	66
23	85*	86*	57	61	61	71	67
24	80*	82*	54	60	59	67	63
25	74	75	53	59	57	62	59
26	74	75	46	51	51	61	56
27	79*	80*	50	54	55	66	61

Notes:# * ‘Assessment Period’ refers to distinct construction tasks in the works programme [Appendix 4.2 refers].

* Predicted noise level exceeds the 75 dB(A) noise standard.

4.5.6 Due to the proximity of the site, the highest unmitigated construction noise levels at NSR1, NSR2, NSR6 and NSR7 (i.e. Sea Crest Villa and the planned development on the reclaimed land) are predicted to be more than 80 dB(A). As such, appropriate mitigation measures are required in order to reduce construction noise to an acceptable level. Given the distance separation and topography between NSR3, NSR4 and NSR5 (i.e. Kam Peng Estate, a planned school and a planned residential development) and the site, the predicted noise levels at these NSRs are within the noise standard.

Mitigation of Adverse Construction Noise Impacts

4.5.7 Given the mobile nature of the equipment (e.g. dump truck and backhoe), the use of silenced equipment is an effective option to alleviate the noise impacts. The maximum sound power levels for the proposed silenced equipment are presented in Table 4.10.

Table 4.10 Sound Power Levels for the Silenced Equipment

Identification Code	Description	Sound Power Level, dB(A)	Source of Information
CNP 001	Air compressor	100	NCO GW-TM, CNP 001
CNP 067	Dump truck	109	BS5228, Table C.3 Item 52
CNP 081	Excavator/ Backhoe	102	BS5228, Table C.8 Item 33
CNP 103	Generator, super silenced, 70 dB(A) at 7m	95	NCO GW-TM, CNP 103
CNP 170	Poker, vibratory, hand-held	100	BS5228, Table C.6 Item 32

4.5.8 Apart from the use of silenced equipment, other practicable mitigation measures were considered. However, given the small site area, only the erection of temporary movable noise barriers was identified as a possible solution to further mitigate the noise impacts. It is recommended the movable noise barriers should be positioned as close as possible to PMEs such that none of the PMEs will be visible when view from any noise sensitive façades.

4.5.9 The predicted construction noise levels with the implementation of the silenced equipment and the erection of noise barriers are summarised in Table 4.11. Detailed calculations are presented in Appendix 4.3.

Table 4.11 Predicted Construction Noise Levels L_{eq(30 min)} dB(A) – Mitigated

Assessment Period	NSR1	NSR2	NSR3	NSR4	NSR5	NSR6	NSR7
1	65	66	54	46	57	73	69
2	70	72	54	50	58	73	69
3	50	51	53	43	57	73	69
4	45	46	39	46	44	42	44
5	72	72	52	55	56	67	61
6	75	75	54	58	59	70	64
7	71	71	51	55	55	66	60
8	72	72	51	55	56	67	61
9	62	62	43	48	48	57	52
10	65	65	46	50	50	60	54
11	65	65	44	48	49	60	54
12	65	66	49	55	54	60	56
13	63	63	48	54	53	58	54
14	68	69	49	55	54	61	57
15	70	71	50	55	54	62	58
16	69	71	47	51	52	62	57
17	68	69	46	51	51	61	56
18	68	69	47	52	52	61	56
19	68	69	46	50	50	61	55
20	66	68	44	48	48	58	53
21	68	70	45	49	50	60	55
22	69	70	45	50	50	61	56
23	69	70	45	50	50	61	56
24	65	67	43	48	48	57	53
25	59	61	41	47	46	51	48
26	59	60	36	40	40	51	46
27	64	65	40	43	45	56	51

4.5.10 Table 4.11 illustrates that with the application of mitigation, the construction noise levels may be reduced to within acceptable limits. As such, there are no residual impacts. Nevertheless, it is recommended that the Contractor should also adopt good working practices in order to minimise construction noise as far as possible:

· Noisy equipment and noisy activities should be located as far away from the NSRs as is practical;

· Unused equipment should be turned off;

· Powered mechanical equipment should be kept to minimum and the parallel use of noisy equipment / machinery should be avoided;

· Regular maintenance of all plant and equipment; and

· The Contractor shall observe and comply with the statutory requirements and guidelines.

Cumulative Noise Impacts

4.5.11 Based on the information obtained from the Drainage Services Department, works for the STW upgrading project at Tai Lei Island are tentatively scheduled to commence in mid-2005. The works programme is presented in Appendix 2.3.

4.5.12 According to the construction schedule of the helipad site, the 12-month works will commence in December 2005. Therefore, both sites will be constructed in parallel throughout the entire construction period of the helipad. Given the proximity of two sites, there is potential for cumulative construction noise impacts upon common NSRs.

4.5.13 It has been identified that NSR1 (Block D, Flat A of Sea Crest Villa) will be the closest and therefore the most affected NSR for both sites, and was therefore selected for cumulative noise impact assessment. Based on the DSD’s EIA Study for the STW upgrade project, the unmitigated cumulative construction noise impacts at NSR1 during the 12-month construction period of the helipad will exceed the noise standard of 75 dB(A). Accordingly, mitigation measures should be implemented for both projects to reduce their individual noise contribution down to 72 dB(A) or below at the common NSR1.

4.5.14 The construction equipment to be used during Assessment Period 6 (i.e., reclamation works from 20 February 2006 to 7 March 2006) are tugboats, derrick barges, split barges and a grab dredger for which no silenced type models are available. Moreover, as these PME are to be operated on the sea, mitigation options are limited. However, erecting a 3m high mobile barrier along the coastline north of Peng Lei Road can mitigate construction noise. As the reclamation works progress along the coastline to the east, the distance separation between PMEs and NSR1 will increase and hence noise levels will decrease until PME are screened from sight by the hilly terrain immediately northeast of Sea Crest Villa.

4.5.15 According to Appendix 4.4, it has been identified that NSR1 will be exposed to a construction noise level of 74.5 dB(A) during ‘Period 6’. As such, it is anticipated that the cumulative noise level may exceed the 75 dB(A) standard if the noise contribution from the STW Upgrade project exceeds 68 dB(A). However, in consultation with DSD it has been determined that the noise contribution from the STW Upgrade project during ‘Period 6’ is 67.4 dB(A).[***] As such, the cumulative noise impact is predicted to be below 75 dB(A) at all NSRs, and accordingly no residual impacts are anticipated. The predicted cumulative construction noise levels at the common NSR1 are summarised in Table 4.12 and detailed calculations are presented in Appendix 4.4.

Table 4.12 Predicted Cumulative Construction Noise Levels L_{eq(30 min)} dB(A) at NSR1

Assessment Period	Predicted Noise Level (Leq(30 min)) dB(A)	Assessment Period	Predicted Noise Level (Leq(30 min)) dB(A)	Assessment Period	Predicted Noise Level (Leq(30 min)) dB(A)
1	70	10	71	19	72
2	72	11	71	20	71
3	68	12	71	21	72
4	68	13	70	22	72
5	73	14	72	23	72
6	75	15	73	24	70
7	73	16	73	25	69
8	74	17	72	26	69
9	70	18	72	27	70

4.6 Operational Noise Impact Assessment

Assessment Methodology

4.6.1 Noise associated with the proposed helipad at Peng Chau will be generated during helicopter manoeuvring over the helipad and during lateral (approach / departure) flight. The different operational modes that may generate noise are summarised as follows:

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

· Helicopter ‘approaching’ the helipad while it is descending at an angle to the helipad surface; and

· Helicopter ‘taking-off’ from the helipad while it is climbing up at an angle to the helipad surface.

4.6.2 According to Table 1A, Annex 5 of the EIA-TM, helicopter noise impacts shall be assessed in terms of the L_max level, which is the maximum instantaneous sound pressure level at the noise sensitive receiver. Since all the identified NSRs are located at considerable distances (over 150 m) from the helipad, helicopter noise can be considered as a ‘point’ source. Therefore, the sound pressure level at NSRs can be evaluated based on standard acoustic principle of a ‘point’ source, i.e., the sound pressure level in any direction (in the open) will decrease at a rate of 6 dB per doubling of distance away from the source. The difference in noise levels at two different distances, r₁ and r₂, can be calculated using the following formula:

Noise Level Difference (dB) = 20 log₁₀

4.6.3 Noise source terms (i.e., the L_max at a given distance) for each helicopter operation mode have 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 summarized in Table 4.13, with test noise measurement points for each flying mode illustrated in Appendix 4.5. Table 4.13 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 4.13 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)

Notes:

Figures in brackets are the L_max dB(A) values.

L_max = EPNdB – 13, with reference to the ‘Transportation Noise Reference Book’ (Nelson, 1987).

4.6.5 Based on the given noise data in Table 4.13, 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 between the bearings of 300 and 055 degrees from the centre of the helipad [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 24 June 2003 to generate supplementary noise data. The noise survey involved measuring the L_max noise level generated by 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 L_max noise level measured has been used for assessing the worst-case scenario when the helicopter is at the helipad. Details of the noise survey are provided in Appendix 4.6.

4.6.1 It was found that the L_max noise level is less when helicopter is idling (with rotors on) on ground and the L_max noise level occurs when the helicopter is in the air without lateral movements (either during lift-off mode or hovering mode). Table 4.14 displays the measured L_max noise levels.

Table 4.14 Measured L_max 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

Notes:

L_max noise levels in dB(A).

* For ‘Super Puma AS332 L2’, the L_max noise level is measured during the hovering mode.

For ‘EC155 B1’, the L_max noise level is measured during the lift-off mode.

Identification of Potential Noise Impacts

4.6.2 Assessment of helicopter noise has been conducted for each of the operational modes as introduced in paragraph 4.6.1.

4.6.3 The GFS will use the proposed helipad for ‘casevac’ operations. GFS’ helicopter fleet comprises two helicopter types: the Super Puma AS332 L2 and EC155 B1. The Super Puma 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 ‘EC155 B1’ type helicopter whenever possible for ‘casevac’ operations, and only under very special circumstances shall the Super Puma be deployed.

4.6.4 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 4.15 summarises actual GFS helicopter usage data for ‘casevac’ operations from 2000 through 2004.

Table 4.15 Helicopter Use for Peng Chau ‘Casevac’ Operations during years 2000 – 2004

Year	Total No. of Casevac from 0700 to 2200 hours^1	Total No. of Casevac from 2200 – 0700 hours^2	No. of Casevac Training Flights^3
2000	97 (1)	51	2
2001	125 (9)	57	3
2002	234 (29)	56	5
2003	167 (4)	42	5
2004	140 (5)	37	3

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 nighttime 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 nighttime casevac in future years.

3. Five casevac training flights were conducted to the Peng Chau helipad in 2003 (i.e., an additional 2.3% 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.’

4.6.5 Using the flight data for the year 2002 as a worst-case scenario, it has been assumed that there may be a total of 295 flights in a single year. Of this total it has been assumed that the ‘Super Puma’ would be operated for up to 29 casevac flights a year. In the absence of a specific data breakdown, it has also been assumed that two of the five 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 31 ocassions in a year: equivalent to one flight every 12 days.

4.6.6 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 Peng Chau on no more than 264 ocassions in a year: equivalent to one flight every 1.4 days.

Cumulative Helicopter Noise Impacts

4.6.7 Upon commencement of operations at the proposed Peng Chau helipad, use of the currently used landing site on the soccer pitch near Tai Lung Tsuen will cease. There are no other helipads located in the vicinity of the proposed helipad that would cause any cumulative helicopter noise impacts. GFS also confirmed that only one helicopter will use the helipad at one time and therefore no cumulative noise impacts are anticipated.

4.6.8 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

4.6.9 The assessment of helicopter noise generated at the helipad is based on the L_max noise levels of the helicopter manoeuvring over the helipad and the horizontal separation between the helipad and identified NSRs. Table 4.16 summarises the calculated L_max noise levels at the identified NSRs. Details of the calculation, including terrain cross-sections relevant for noise level calculations for the NSRs are provided in Appendix 4.7.

Table 4.16 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)	Topographical Correction dB(A) ^2	Corrected Lmax @ NSR dB(A)
		Super Puma AS332 L2	EC155 B1			Super Puma AS332 L2	EC155 B1
NSR1	167	90 (81)	87 (79)	3	-10	83 (74)	80 (72)
NSR2	156	90 (82)	87 (80)	3	-10	83 (75)	80 (73)
NSR3	336	84 (75)	81 (73)	3	-10	77 (68)	74 (66)
NSR4*	162	90 (81)	87 (79)	3	-10	83 (74)	80 (72)
NSR5*	193	88 (80)	86 (78)	3	-10	81 (73)	79 (71)
NSR6*	238	87 (78)	84 (76)	3	-10	80 (71)	77 (69)

Notes:

¹ Calculated with reference to measured Lmax noise level at reference distance of 150m.

² By standard acoustic principles, if the noise source is totally screened such that none will be visible when viewed from any façade of the NSR, a negative topography correction of 10 dB(A) shall be applied.

* Future NSR.

Figures in brackets are the L_max during the idling mode.

4.6.10 The evaluation results in Table 4.16 show that the worst-case L_max noise level during helicopter manoeuvre above the helipad without lateral movements complies with the 85 dB(A) limit for both helicopter types.

With Lateral Movements

4.6.11 Regarding the helicopter approach mode, the projected worst-case trajectory of the approach path (i.e., closest to the NSR), is at the bearing of 300 degrees to the centre of the proposed helipad. NSR1, NSR2, NSR4 and NSR5 are closest to the approach path and will therefore be the most affected by helicopter noise during approach. While NSR1 and NSR2 are exposed to helicopter flight noise, shielding by the natural terrain reduces the predicted noise level at NSR 4 and NSR5 to an acceptable level. Cross-sections showing the influence of topography on NSRs 3-4 and NSRs 5-6 are displayed by Figure 4.5c and Figure 4.5d, respectively. Figure 4.4b presents a plan of the cross-sections. Table 4.17 displays the worst-case L_max noise levels, based on the ICAO maximum noise level. Calculation details are provided in Appendix 4.7.

Table 4.17 Worst-case Helicopter Approach / Departure Noise Levels at NSRs

NSR ID	Slant distance between helicopter & NSR (m)	Lmax @ NSR dB(A) ^1		Façade Correction dB(A)	Topographical Correction dB(A) ^2	Corrected Lmax @ NSR dB(A)
		Super Puma	EC155 B1			Super Puma	EC155 B1
NSR1	163	85	82	3	0	88	85
NSR2	161	85	82	3	0	88	85
NSR3	336	79	76	3	-10	72	69
NSR4	165	85	82	3	-10	78	75
NSR5	193	84	81	3	-10	77	74
NSR6	238	82	79	3	-10	75	72

Notes:

¹ Calculated with reference to ICAO maximum noise level (i.e., noise standard) at a reference distance of 120m.

² A topography correction of 10 dB(A) has been applied if the noise source is totally screened from any façade of the NSR.

Bold figures indicate exceedance of the Lmax 85 dB(A) limit.

4.6.12 With reference to Table 4.17, the worst-case L_max noise level for the helicopter approach mode complies with the 85 dB(A) limit for the ‘EC155 B1’. However, the worst-case L_max noise level is predicted to be 88 dB(A) at NSR1 and NSR2 during approach by the ‘Super Puma AS332 L2’ type helicopter. In order to comply with the 85 dB(A) helicopter noise limit, the minimum distance separation between the ‘Super Puma AS332 L2’ in flight and Sea Crest Villa is 221 metres. Note that while compliance with the 85 dB(A) daytime standard is anticipated, helicopter noise nuisance may still be experienced.

Mitigation of Adverse Noise Impacts

4.6.13 Noise levels from helicopter manoeuvring over the helipad will likely exceed the L_max 85 dB(A) limit at the existing NSR1 and NSR2 with the ‘Super Puma AS332 L2’ helicopter type only. Accordingly, the feasibility of adopting various direct mitigation measures has been investigated with reference to Annex 13 of the EIA-TM. These measures are discussed below. As the predominant user of the proposed helipad, GFS has been consulted on the various measures and has advised on the practicality of mitigation measures in terms of helicopter operations, as appropriate.

Alternative Land Use Arrangement and Siting

4.6.14 With reference to the current statutory Peng Chau Outline Zoning Plan OZP No. S/I-PC/6, the selected helipad site is located within a “Government, Institution or Community” (“G/IC”) zone. 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. This site is considered to be optimally located in terms of operational safety, and environmental implications, while the site is distant from the built environment but still accessible to the Peng Chau community. In particular, shielding by the natural rocky cliff at north Peng Chau will eliminate helicopter-manoeuvring noise at all NSRs in the assessment area.

4.6.15 In order to completely contain the helicopter noise (i.e., approach / departure noise) to within the 85dB(A) standard, relocating the helipad approximately 70 metres further eastwards from the proposed ‘Option A, Alternative A1’ site was considered: ‘Option I’. However, such relocation would encroach onto the “Coastal Protection Area” zone and would introduce and ecological impacts, including the complete loss of a sandy beach and part of a rocky shore, and increased water quality impact potential.

4.6.16 It is estimated that over 100 residential buildings, principally in Shan Ting Tsuen, Kam Peng and Tung Wan Villa, are exposed to noise levels considerably greater than 85dB(A) from use of the existing helipad near Tai Lung Tsuen. In particular, the flight path to the existing helipad passes over Sea Crest Villa where noise levels at the NSR nearest to the flight-path have been calculated to be 89dB(A) for the ‘EC 155B1’ type helicopter and up to 92 dB(A) for the ‘Super Puma’ type helicopter.

4.6.17 Based on the predicted extent of the impact zone (para. 4.6.17 refers), the noise level at Sea Crest Villa with the current helicopter flight path exceeds the 85dB(A) limit for both helicopter types. This is due to the closer distance between Sea Crest Villa and the existing helicopter flight path (slant distance: 104m)[‡‡‡] compared to the greater distance between Sea Crest Villa and the proposed new helicopter flight path (slant distance: 161m; Table 4.17 refers). Accordingly, the predicted existing helicopter flight noise level at Sea Crest Villa is 92dB(A) for the ‘Super Puma’ and 89dB(A) for the ‘EC 155B1’ type helicopter.

4.6.18 These existing levels are less favourable than the maximum predicted noise levels for the proposed helipad of 88dB(A) and 85dB(A) from the ‘Super Puma’ and ‘EC 155B1’ type helicopters, respectively. The predicted 4dB(A) improvement for both helicopter types that the proposed new helipad can provide corresponds to a 100% improvement for the Super Puma (i.e., a 3dB(A) residual impact is predicted); and corresponds to 100% compliance with the noise standard for the EC155 B1.

Screening by Noise Tolerant Buildings

4.6.19 There are no noise tolerant buildings nearby to form any effective noise screen to the NSR at Sea Crest Villa. Since the predicted noise exceedance is caused by airborne helicopter flying above ground, there are no options to effectively mitigate the helicopter noise by constructing physical noise tolerant buildings.

Setback of Buildings

4.6.20 The proposed helipad does not involve any building development, and therefore this measure is not applicable.

Decking Over

4.6.21 This measure relates to road traffic noise control and is not applicable to helicopter noise control.

Extended Podium

4.6.22 The proposed helipad does not involve any building development. This option is not applicable.

Building Orientation

4.6.23 The proposed helipad does not involve any building development, so this measure is not applicable.

Treatment at Source

4.6.24 GFS has agreed to give priority to deploying the quieter ‘EC155 B1’ type helicopter for ‘casevac’ and emergency operations at Peng Chau wherever practicable [Table 4.15 refers]. However, it is not possible to exclude the ‘Super Puma AS332 L2’ from using the helipad in serious emergency situations when a larger capacity helicopter type is required. As the ‘Super Puma AS332 L2’ and ‘EC155 B1’ type helicopters were only introduced into the GFS fleet late in 2001 and 2002 respectively, there are no plans at this time to replace the existing helicopter fleet.

Alternative Alignment

4.6.25 GFS has already agreed to reduce the angle of the helicopter flight path from the standard 150 degrees to 115 degrees. This re-alignment of the helicopter flight had the effect of increasing the distance between the noise source (helicopter) and the noise sensitive receiver (residential area) so that helicopter approach noise from the ‘EC155 B1’ type helicopter was reduced to within the 85 dB(A) guideline. Proximity of the proposed helipad to Sea Crest Villa means that no further reduction in flight path angle is possible to reduce helicopter noise impact from the Super Puma type helicopter.

Noise Barrier / Enclosure

4.6.26 In the case of the Peng Chau helipad, physical structures such as noise barriers / enclosures cannot be constructed to provide effective noise shielding of the helicopter noise. This is because the noise is airborne (at an elevation of approximately 17 mPD) and will be emitted when the helicopter is at a linear distance of approximately 30 metres from the helipad.

Special Building Design

4.6.27 The proposed helipad does not involve any building development, and therefore this measure is not applicable.

Architectural Features / Balcony

4.6.28 The proposed helipad does not involve any building development, and therefore this measure is not applicable.

Open-textured Road Surfacing

4.6.29 This measure is not applicable to helicopter noise control.

Indirect Mitigation Measures

4.6.30 The application of indirect mitigation measures would require installation of acoustic insulation into all NSRs at which the predicted L_max exceeds 85 dB(A). Effective indirect mitigation requires that NSR occupants comply with a ‘closed-window’ living environment during helicopter manoeuvring.

4.6.31 It is considered that such measures would not be effective, as local residents would receive no prior notice of an impending helicopter arrival. In addition, the short impact duration (5-10 seconds) means that the impact event would be over by the time a response could be made. Accordingly, mitigation measures would not be a practicable means of noise mitigation and they are not recommended.

Evaluation of Residual Noise Impact

4.6.32 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

4.6.33 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). In accordance with this principle, the Factories and Industrial Undertakings (Noise at Work) Regulation (CAP 59T) established a daily personal exposure (L_epd) 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 comparision only, the anticipated duration of the residual helicopter noise impact will be no more than 10 seconds, equivalent to a L_epd of 53 dB(A). As such the effect of the residual helicopter noise on public health will be insignificant.

4.6.34 As regards risk to life, it is considered that the quicker and far easier access to the proposed helipad / emergency helicopter compared with the current situation may potentially decrease the risk to life.

Magnitude, duration and frequency of Impact

4.6.35 After taking into account all the practicable direct mitigation measures, the worst-case L_max noise level is predicted to be 88 dB(A) (residual noise is 3dB(A)) at NSR1 and NSR2 resulting from the approach / departure of a ‘Super Puma AS332 L2’ type helicopter along the flight path of 300 degrees bearing. The noise impact duration will last 5-10 seconds according to GFS. No adverse helicopter manoeuvring noise impact is predicted. It is also noted that noise levels at Sea Crest Villa from the existing flight path are predicted to be in the range 89 – 92 dB(A) (residual noise ranges from 4 to 7dB(A)), and so while there will remain a residual impact from the proposed new helipad, both the impact magnitude and duration will be less than at present and hence improved.

4.6.36 It should be noted that GFS primarily uses the EC155 B1 type helicopter for casevac operations at Peng Chau. With reference to the casevac data from GFS for the period 200-2004, the flight frequency of the Super Puma type helicopter is equivalent to one flight every 12 days, incurring a maximum 3 dB(A) exceedance of the 85 dB(A) limit. The duration of the residual impact would be 5-10 seconds per event.

4.6.37 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 nighttime 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 nighttime casevac.

Geographic extent and likely size of community affected

4.6.38 Only the first tier buildings with facades directly facing the northern coast of Peng Chau would be subject to the residual helicopter noise impact. Whilst only the ‘Super Puma’ type helicopter will cause residual noise impacts, buildings that are within the distance of about 221 metres from the helicopter flight path and also have direct view to the airborne helicopter will be affected.

4.6.39 With reference to the Notes of the draft Peng Chau OZP No. S/I-PC/6 (dated April 15^th 2005), the planned population for Peng Chau of about 6,200 persons represents an insignificant increase in the current estimated population of about 6,130 persons. In addition, there is no planned residential development at the north coast of Peng Chau, and as such the affected area approximates to three buildings at Sea Crest Villa only.

4.6.40 The proposed situation compares favourably with the current situation under which over 100 residential buildings, principally in Shan Ting Tsuen, Kam Peng and Tung Wan Villa, are exposed to noise levels considerably greater than 85dB(A) from use of the existing helipad near Tai Lung Tsuen. Use of the proposed new helipad will therefore offer an improved noise environment compared with the existing flight path and landing site. The areas affected by the existing and proposed helipad are displayed in Figure 4.6.

4.6.41 The predicted residual helicopter noise impacts associated with the proposed helipad operation will only occur locally, i.e., northwest Peng Chau. There will be no spread of such noise impacts elsewhere.

Reversibility of Impact

4.6.42 The operational helicopter noise impact shall be reversible. The impact will occur less than daily, and each incident shall be of short duration only.

Other Considerations

4.6.43 Consideration had been given to eliminating this residual noise impact altogether such as relocating the proposed helipad a further 70 metres eastwards (section 4.6.15), however for the reasons outlined therein, such a proposal will not be acceptable on landscape and ecological grounds. Consideration has been given to constructing physical structures such as noise barriers / enclosures to provide effective noise shielding of the helicopter noise (section 0) however for the reasons outlined therein erection of such structures is not practicable. Taking into account the various other mitigation measures that have been considered/adopted as outlined in sections 4.6.13 to 4.6.31, it would appear that there would still be a residual noise impact of 3dB(A). Considering that this residual noise impact is of short duration lasting less than 10 seconds, as well as occurring only once about every 12 days, this will not cause long term noise nuisance to the affected residents at Sea Crest Villa.

4.6.44 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 has indicated that the noise from emergency medical helicopter services was exempted from the list of ‘Recommended Noise Reduction Approaches’ in the United States of America Federal Aviation Agency Hearings on [Non-military] Helicopter Noise, and that emergency helicopter service is a tolerable necessity. However consideration may be given to imposing some regulation on these operations to reduce noise impacts to NSRs such as the helicopters should use routes that take them as a matter of regulation over the least densely populated areas.

4.6.45 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.

4.6.46 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.

4.6.47 Section 4.5 of the EIAO-TM allows for approval of the EIA report even with residual environmental impact provided there is sound environmental justification and no long-term serious environmental implications. The only environmental impact in this case is the residual noise impact. To totally remove the residual noise impact will involve further relocating the proposed site eastwards which will not be environmentally acceptable as outlined above. Also since the residual noise impact being of short duration and infrequent will not have long term environmental implications, the proposed works would fall under this category of the EIAO for which approval seems to be in order.

4.7 Environmental Monitoring and Audit Requirements

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 residual 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 by the following means:

• Fax: 2815 2291
• Email: dois@had.gov.hk
• Address: Islands District Office, Harbour Building, 20th Floor, 38 Pier road, Central.

4.8 Conclusions and Recommendations

Construction Phase

4.8.1 The potential noise levels arising from daytime construction activities of the helipad during the period from December 2005 to November 2006 at nearby NSRs have been evaluated. Based on the construction schedule and plant inventory given, the unmitigated construction noise levels at Sea Crest Villa are found to exceed the daytime noise standards stated in Table 1B, Annex 5 of the EIA-TM. However, with implementation of appropriate mitigation measures, including use of silenced equipment and temporary noise barriers, the construction noise impacts can be reduced to the acceptable level in compliance with the noise standards.

4.8.2 The cumulative noise impacts arising from the construction of the proposed helipad and DSD’s proposed STW upgrade project at Tai Lei Island upon the common NSR have also been evaluated, and no adverse cumulative construction 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 L_max level. The L_max was calculated for two types of helicopter used for ‘casevac’ operations by GFS during a series of manoeuvring modes on and immediately over the helipad (i.e., without lateral movements) and during helipad approach / departure (i.e., with lateral movements).

4.8.4 The worst-case L_max noise level during helicopter manoeuvring over the helipad (without lateral movement) is predicted to comply with the 85 dB(A) limit for both ‘EC155 B1’ and ‘Super Puma AS332 L2’ type helicopters.

4.8.5 An initial assessment of helicopter noise levels with lateral movements predicted that the L_max 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 caused by the ‘EC155 B1’ type helicopter. There is, however, a predicted exceedance of 3 dB(A) at some residences at Sea Crest Villa from approach / departure flight of the ‘Super Puma AS332 L2’ type helicopter. Accordingly, mitigation options have been investigated in accordance with Annex 13 of the EIA-TM.

4.8.6 Of the applicable direct mitigation measures, consideration was given to relocating the proposed helipad site eastwards along the Pak Wan coastline. Helipad relocation beyond the noise impact zone was not recommended given the low magnitude, and the short duration and frequency of the predicted residual noise impact. Against this, it was also considered that relocation would introduce potentially significant landscape impacts, including impacts on a ‘Coastal Protection Area’ and the loss of a sandy beach, as well as increased dredging and associated water quality and marine / coastal ecology impacts.

4.8.7 After exhaustion of direct mitigation measures, the application of indirect mitigation measures was considered. Ultimately indirect mitigation was 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).

4.8.8 In summary, based on actual GFS flight data for Peng Chau, the residual helicopter noise impact from operation of the ‘Super Puma AS332 L2’ type helicopter would involve a 3 dB(A) exceedance of the 85 dB(A) limit approximately every 12 days, and would affect approximately three buildings at Sea Crest Villa only. 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 serious long-term environmental implications.

4.9 References

· 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 Waste MANAGEMENT aSSESSMENT

5.1 Introduction

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 minimize impacts to the surrounding environment and where possible to minimize generation in the first place.

5.2 Legislation & Standards

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;

· Works Bureau 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;

· Waste Disposal Plan for Hong Kong (December 1989), Planning Environment and Lands Branch, Hong Kong Government Secretariat.

5.3 Baseline Conditions & Sensitive Receivers

5.3.1 The only development in the immediate vicinity of the Project site is the existing Tai Lei road / bridge that was constructed around 1983 and the more recent development of a low-rise residential complex, Sea Crest Villa [Section 4, Figure 4.2 refers].

5.3.2 There is an existing footpath across the hill behind (south) of the site that is presently being upgraded by Home Affairs Department (HAD) (“Construction of a footpath along Pak Wan, Peng Chau” under HAD’s Rural Planning and Implementation Strategy).

Site Conditions

5.3.3 Review of previous literature revealed that the surface of the seabed around the proposed helipad site is predominantly sandy (51-75% cover) with scattered rocks and boulders (<30% cover) (Oceanway Corporation Limited, 2001).

5.3.4 More detailed sediment quality data was collected in November 1996 under the EIA Study for the Peng Chau Sewage Treatment Plant Development in 1996 by CES (Asia) Limited (1997). In the study, two of the five surface sediment samples were collected approximately 1 km west of the helipad Project site boundary. Based on the chemical analyses of the samples and assessment in accordance with the sediment quality evaluation criteria Environmental, Transport and Works Bureau Technical Circular (Works) (ETWB TCW) No. 34/2002, it was determined that the sediments are Category L type and thus are not contaminated.

5.3.5 Appendix 5.1 presents a plan indicating the historical sediment sampling locations and the sediment quality results of the two surface sediment samples taken compared against the sediment quality criteria as set out in ETWB TCW No. 34/2002, Management of Dredged/Excavated Sediments. A flow chart illustrating the categorization of sediments in accordance with ETWB TCW No. 34/2002 is presented in Appendix 5.2.

5.3.6 A Sediment Testing Proposal was prepared under this study and approved by the relevant Authority, including EPD, to carry out additional sediment sampling and analysis to reconfirm the findings of previous literature and studies. However, given the nature of the sediments within the helipad footprint (weak decomposed granite with coral and shell fragments), the number of samples taken was necessarily limited and complete sample cores could not be taken. As such, sampling was abandoned upon agreement with CEDD subsequent to the collection of two samples.

5.3.7 Based on the borehole logs, the geological description from the two cores are similar, with the upper 3-6 meters comprised of unconsolidated Hang Hau Formation sediments overlying a bedrock of highly / completely decomposed granite (Bachy, 2003). No evidence of silt or mud was recorded.

5.3.8 Given the characteristics of the sediments, undisturbed nature of the site area, lack of streams discharging into the area (therefore no sources of particulate matter) and presence of live coral communities nearby, there is little likelihood for marine contamination to be present. The analytical results further support the categorization of the sediment as Category L type. This information was presented to in a Tier 1 sediment quality proposal that was accepted by EPD under ETWB 34/2002. Allocation of dumping of 14,000m³ of marine sediment from the Project has also been obtained from EPD.

5.4 Assessment Methodology

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 that stipulates the assessment of waste management implications shall also cover an 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 minimizing 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 Waste Types

5.5.1 The key waste issues arising from the construction of the helipad will primarily be related to the handling and disposal of the uncontaminated dredged marine sediments and the import of fill materials.

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.

5.6 Impact Assessment and Evaluation

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

Marine Sediments

5.6.3 The preliminary design requires dredging to be undertaken to enable the construction of the foundation for the proposed helipad and EVA. The dredging profile varies slightly at different sections along the EVA and the helipad [Figures 5.1 to 5.3 refer]. In total, it is estimated that 14,000m³ of sediment will be dredged.

5.6.4 As referred previously, the core samples collected and analysed under this study were found to have little likelihood for marine contamination to be present and as such were considered to be Category L type sediment.

5.6.5 The potential for retaining the dredged sediments in place has been considered by CEDD. However, based on the results of the sediment physical characterization tests that show the marine sediment in the works area to be is too ‘fine’ and without the integrity to physically support reclamation / Project construction. As such, the options to leave the sediments in place or to reuse in the construction works have since been ruled out by CEDD and dredging of this material down to a suitable rock grade is necessary, and all dredged sediments will be required to be disposed of off-site.

5.6.6 Although the volume of dredged sediments is relatively small, 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 dredging permit from Territory Control Group (TCG) of EPD.

5.6.7 It is estimated that the number of barge movements required for the disposal of the marine sediments (for off-site marine disposal) will be 3 barges every 2 days. 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.

Imported Fill

5.6.8 The principle of avoidance in the waste management hierarchy has been adopted in the design of the helipad and EVA. As a means to reduce rock fill requirements, the helipad design has incorporated the use of rock armour around the perimeter of the helipad and the outer wall of the EVA. Furthermore, the elevation of the helipad and the EVA will be lowered as far as practicable in order to minimize the extent of the footprint and thereby reducing fill requirements. Nevertheless, even with these reductions in fill requirements, the delivery and handling of the imported fill materials will be a key issue given the presence of coral nearby and the potential visual impacts on residents at Sea Crest Villa.

5.6.9 Table 5.1 below presents the estimated volumes of rock fill, general fill, rock armour and concrete to be imported for the works. A total volume of 30,200m³ of imported material will be required over an estimated period of 7 months.

Table 5.1 Material Import Requirements

Imported Material Type	Quantity (m^3)
	Recycled Material	Virgin Material	Total
Rock fill	-	11,700	11,700
Sand fill	-	-	-
Sandy foreshore	-	-	-
Hardcore	-	-	-
General fill	4,500	-	4,500
Rock armour	-	13,000	11,500
Concrete	-	1,000	1,000
Total	4,500	25,700	30,200

5.6.10 Although the Works Programme [Appendix 2.2 refers] indicates a 2-week overlap in the dredging (final stage) and the reclamation (initial stage) works, there is considered to be no nuisance impacts arising during this period assuming that the works and material delivery do not coincide with the barge transport of dredged sediments.

5.6.11 It is envisaged that imported materials will not be stockpiled in any significant quantities at site at any one time. During the reclamation phase, it is envisaged that the imported fill material will be directly deposited from the barge and into place. While the frequency of material delivery will be dependent on the progress of the reclamation works, it is estimated that the material import rate will be on average 1 to 2 barges every day throughout the estimated 7-month reclamation/construction period (between February 2006 and September 2006). As a conservative estimate, this frequency is not considered to cause any significant increase in marine traffic or impacts to nearby sensitive receivers.

5.6.12 While in most cases the material will likely be used immediately upon delivery to site, where stockpiling of materials is necessary, the use of the site office area should be avoided as far as practicable to minimize any impacts to sensitive receivers from the stockpiling and removal activities. The reclaimed sections of the EVA and helipad can be made use of although stockpiling near the vegetated slopes should be avoided.

Construction Waste

5.6.13 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 including the following:

· Site clearance waste (vegetation, rocks);

· Waste metal (off cuts) from in-situ concrete casting work;

· Spent concrete (limited if pre-fabricated elements are largely used); and

· Material and equipment wrappings.

5.6.14 The wave deflector blocks around the perimeter of the helipad will be constructed of pre-cast elements. Given the location and size of the proposed site office area (south of Sea Crest Villa) it is envisaged that these works, if conducted on-site, will take place on the works areas. Alternatively, the Contractor may consider off-site pre-casting. Provisions shall be made in the Contractor’s Particular Specifications to ensure that the appropriate environmental legislation is adhered to if pre-casting works are carried out at an off-site location. Any storage of pre-cast elements is also assumed to be within the works area.

5.6.15 Overall, it is estimated that site clearance activities will result in the generation of 10m³ of C&D waste that should be disposed of to landfill while generation of another 40m³ of C&D materials is predicted during the remainder of the construction period. This will include any waste metal off-cuts and if in the event that pre-casting is carried out on site, excess spent concrete will also likely be generated although the volumes are considered to be small. 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 minimize the material volume for landfill disposal. Alternatively, outlets such as Public Fill Banks should be identified for the inert material if no on-site reuse opportunities exist.

5.6.16 Due to design restrictions (safety considerations) and the irregularity (in size) of the waste material, it is unlikely that these waste materials will be reused on site. However, the Contractor should identify recycling options for select materials (i.e. waste metal, plastic film wrap, etc.) prior to considering landfill disposal.

Chemical Waste

5.6.17 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 batteries maintenance).

5.6.18 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 450 litres / month. These wastes may pose environmental and safety hazards if not properly handled, stored and disposed of. As small waste quantities are anticipated, no impacts are predicted to arise with proper handling, storage and disposal.

General Refuse

5.6.19 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.

5.6.20 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 Peng Chau. However, as a worst case, it is estimated that a factor of 1.06kg/person/day of municipal solid waste (MSW) will be generated (EPD, 2000). The total quantity of waste generated will thus be dependent on the Contractor size of work force to be stationed on site. For estimation purposes, we have assumed that the size of the work force will be a maximum of 40 site workers. Based on these assumptions, the volume of MSW likely to be generated on site will be 254kg/week.

5.6.21 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 also arise. Given that the site is located along the shoreline, any windblown debris will cause water quality impacts if the debris lands in the water and result in visual impacts (if blown onto surrounding land areas as well). 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. With proper on-site handling storage and disposal of wastes to designated off-site waste facilities, no adverse impacts are predicted.

Sewage

5.6.22 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.

Operational Phase

5.6.23 Upon completion, 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.

5.6.24 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 helipads and thus is considered to have no adverse impact to the environment.

5.7 Summary of Waste Materials Generated

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 5.2. 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.

5.7.3 As the sediments to be dredged are classified as Category L type (as per EWTB TCW No. 34/2002), the DEP has indicated that it is acceptable to dispose of the sediments at the South Cheung Chau Spoil Disposal Area.

Table 5.2 Summary of Construction Phase Waste Generation

Activity	Material Type	Likely time of arising	Estimated total volumes	Disposal / Treatment Site
Ground preparatory works	Site clearance C&D waste	Pre-construction	10 m^3*	Landfill (via Outlying Islands Transfer Facility located on Pei Lei Island).
Dredge & Reclaim	Sediment	First 4 months of Construction	14,000 m^3	South Cheung Chau Spoil Disposal Area ^
General works	Construction waste	Throughout construction	40 m^3**	Public Fill Bank #
	Chemical waste	Throughout construction	450 litre/month**	Chemical Waste Treatment Centre
	General refuse (generated by site staff)	Throughout construction	254 kg/week (assumes max of 40 staff and a 6 day week)	Landfill (via Outlying Islands Transfer Facility located on Pei Lei Island).

Note: * Volume estimates will be based upon vegetation height and density of cover. ** Provisional estimate.

^ Disposal of slurry to South Cheung Chau Spoil Disposal Area has been approved by DEP (fax ref.: (19) in EP60/G1/12-397). However, this should be re-visited once generation volumes are confirmed.

# Tseung Kwan O Area 137 or Tuen Mun Area 38.

5.8 Impact Mitigation & Residual Impact Assessment

5.8.1 Significant impacts due to the generation of waste on site are not predicted. However, given the potential for environmental impacts to arise (dust, noise, water quality and visual impacts) mitigation measures are required to ensure that proper handling, storage, transportation and disposal of materials is implemented at the outset and throughout the construction phase of the helipad. In line with Government’s position on waste minimization, the practice of avoiding and minimizing waste generation and waste recycling should be adopted as far as practicable.

5.8.2 Recommended mitigation measures to be implemented through the course of the construction of the helipad include:

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) The reuse/recycling of all materials on site shall be investigated prior to treatment/disposal off site;

iii) Good site practices shall be adopted from the commencement of works to avoid the generation of waste and to promote waste minimization practices;

iv) 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 filling area or public fill bank after obtaining the appropriate licence;

v) With reference to WBTC No. 21/2002, 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;

vi) Dredged sediments shall be handled in accordance with the ETWB TCW No. 34/2002 on Management of Dredged/Excavated Sediment and where the sediments cannot be reused onsite, arrangements shall be made with the MFC for allocation of dumping space;

vii) Stockpiling is not envisaged, however if it becomes unavoidable, stockpiling in any vegetated areas shall be avoided (as far as possible) and shall be covered with tarpaulin and/or watered to prevent windblown dust and/or surface runoff;

viii) Under the Waste Disposal (Chemical Waste) (General) Regulation, 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 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;

ix) 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 on Tai Lei. Further to the issue of ETWBTC (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;

x) 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;

xi) Toolbox talks should be provided to workers about the concepts of site cleanliness and appropriate waste management procedures, including waste reduction, reuse and recycling; and

xii) A recording system for the amount of wastes generated, recycled and disposed (including the disposal sites) should be proposed, and the ET leader shall include a summary of such information in each of the monthly EM&A Reports.

5.8.3 The Contractor shall comply with all relevant statutory requirements and guidelines and their updated versions that may be issued during the course of Project construction.

5.9 Environmental Monitoring and Audit Requirements

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 supervision 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 Conclusions and Recommendations

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.

5.11 References

· Bachy Soletanch (2003). Construction of Helipad at Peng Chau: Marine Ground Investigation and Reference Sediment Sampling. Ground Investigation Factual Fieldwork Report. Final report submitted to 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.

· EPD (2000). Monitoring of Municipal Solid Waste 1999. Environmental Protection Department, Hong Kong Government.

· Oceanway Corporation Ltd. (2001). Underwater Survey at Peng Chau and Neighbouring Islands.. Unpublished final report submitted to the Agriculture and Fisheries Department, HKSAR Government.

6 water quality impact assessment

6.1 Introduction

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 Assessment Approach

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) Characterize 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 analyze 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 analyze all existing, future and other project(s) related water and sediment pollution sources; and analyze 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., Peng Chau Sewage Treatment Works Upgrading);

(ix) Propose water pollution prevention and mitigation measures to be implemented during the construction and operational stages so as to minimize 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 Clauses 3.4.1.4(xii)(a) – (c) of the EIA Study Brief.

6.3 Regulations, Standards and Guidelines

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 Peng Chau helipad falls entirely within the Southern WCZ. The coastal waters around Peng Chau 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 6.1.

Table 6.1 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
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.

6.4 Baseline Conditions

Beneficial Uses Sensitive to Water Pollution – Water Sensitive Receivers (WSRs)

6.4.1 Beneficial uses sensitive to water pollution with a radius of 1 km from the Project site have been identified in accordance with Annex 14 of the EIA-TM. The coastal waters around Peng Chau are designated as a secondary contact recreation sub-zone for recreation uses.

6.4.2 While no water sports or leisure boating activities were been observed in the immediate vicinity of the Project area during this Study, small sailing boats from Discovery Bay were noted to utilise waters ~100m offshore on several occasions – particularly at weekends. The entrance to the Discovery Bay Marina is located approximately 1 km from the Project area.

6.4.3 There are no bathing beaches or seawater abstraction sites in the assessment area.

Ecology

6.4.4 Live coral communities have been identified around Tai Lei [Section 7; Figure 7.1 refers]. These coral communities are WSRs 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.

6.4.5 As regards fisheries, there are no recognised fish spawning grounds or fish culture zones in the assessment area, although casual (i.e., apparently not commercial) shellfish harvesting and recreational fishing activities have been observed in the assessment area. There is evidence of shore-based and boat-based fishing activity within the Project boundary, although such activities are on a very limited scale. The fisheries impact assessment is presented in Section 8.

Water Quality

6.4.6 Routine water quality monitoring is undertaken by EPD at fixed stations within WCZs. The closest monitoring station in the vicinity of proposed Project site, ‘SM10’, is located inside the Southern WCZ, approximately 1.7 km to the northwest of the site (coordinate: 22^o18.125’N, 114 ^o 1.919’E).

6.4.7 The water quality of SM10 for the past 5 years is extracted from Marine Water Quality in Hong Kong (1997-2001) and summarised in Table 6.2.

6.4.8 As it can be seen that the baseline water quality complies with the relevant WQOs except for Total Inorganic Nitrogen (TIN). The baseline TIN level exceeds the WQOs and has shown the tendency of increasing over the last 5 years.

Table 6.2 Summary of Water Quality at ‘SM10’ between 1997 and 2001

	1997	1998	1999	2000	2001
DO mg/L	6.9 (6.3-7.7)	5.9 (3.2-7.2)	6.1 (4.7-7.7)	6.5 (4.9-8.0)	6.0 (4.7-7.4)
DO mg/L (bottom)	6.8 (6.3-8.0)	5.9 (3.9-7.2)	6.3 (4.9-8.0)	6.5 (4.7-8.0)	6.2 (4.8-7.5)
DO % Saturation	94 (86-104)	90 (70-101)	85 (67-97)	90 (72-105)	84 (65-108)
DO % Saturation (bottom)	93 (86-100)	91 (83-98)	87 (69-101)	90 (68-104)	86 (70-106)
Suspended Solids (mg/L)	6.4 (3.3-14.5)	6.9 (4.1-9.9)	12.5 (4.3-45.0)	12.8 (1.7-36.0)	17.9 (6.4-50.5)
Unionised Ammonia (mg/L)	0.003 (0.001-0.008)	0.003 (0.001-0.009)	0.003 (0.001-0.005)	0.004 (0.001-0.014)	0.004 (<0.001-0.010)
Total Inorganic Nitrogen (mg/L)	0.28 (0.16-0.45)	0.27 (0.14-0.43)	0.25 (0.11-0.40)	0.30 (0.09-0.59)	0.33 (0.21-0.44)

Notes:

1. Unless otherwise specified, data presented are depth-average (A) values calculated by taking the means of three depths: Surface (S), Mid-depth (M) and Bottom (B).

2. Data in brackets indicate the ranges.

Sediment Quality

6.4.9 The closest EPD monitoring station for sediment quality within the Southern WCZ is SS5 which is located to the south of Hei Ling Chau, approximately 4 km from the Project site (coordinate: 22^o15.443’N, 114^o1.078’E).

6.4.10 The sediment quality of SS5 for the past 5 years as extracted from Marine Water Quality in Hong Kong (1997 - 2000) 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).

6.4.11 Previous ecology field investigation around the proposed helipad site indicated that the surface is predominantly comprised of sand (51-75% cover), with scattered rocks and boulders (Oceanway, 2001).

6.4.12 An approved Sediment Testing Proposal was implemented under this study to determine the chemical characteristics of the marine sediment in the proposed Project area. However, despite several attempts to collect samples from within the footprint of the proposed helipad and EVA link the sampling failed due to the coarse sediment nature, i.e., mainly dead coral and shell fragments on the seabed surface.

6.4.13 From consequent ground investigation works two sediment core samples were collected from within the proposed helipad footprint, from which they were characterised as comprising fine to coarse sand and gravel overlying a bedrock of highly / completely decomposed granite (Bachy, 2003). No evidence of silt or mud was recorded. Accordingly, as potential sediment contamination was considered highly unlikely, a Tier 1 sediment quality proposal for the Project was prepared and accepted by EPD under WBTC 34/2002 and allocation for the disposal of 14,000m³ marine sediment from the Project has been obtained.

Tidal Hydrodynamics

6.4.14 The tidal currents in the area change periodically. The peak velocity at mid ebb and mid flood tide is approximately 0.4 m/s and 0.6 m/s respectively.

Identification of Impacts

6.4.15 As presented in Section 5, the marine sediment around the Project site has been reasonably assumed to be 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 Impacts from SS may be caused by sediment plumes being transported to WSRs, in this case the corals and the Southern WCZ, leading to the elevation of the SS levels at the WSRs. 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 for bathing beaches and sites of ecological interest.

6.4.17 The 90^th percentile of SS at SM10 over the last 4 years (1997 – 2000) is 33.5 mg/l, which has been used as the background level. A 30% increase above the background level is thus 10.1 mg/l, giving a total SS limit of 43.6 mg/l. Due to the cumulative impacts from other Projects in 2001, the monitoring data of 2001 was not used in deriving the background SS level.

6.4.18 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. Given the ecological interest in the area, a limit on the sedimentation rate of 0.1kg/m²/day was applied to the Project, following the study for Sand Dredging at the West Po Toi Marine Borrow Area (ERM, 2001).

6.4.19 During the operation stage of the Helipads, the helipad footprint may alter the tidal flow regime of the region, thus affecting the water quality, in particular the area between the Helipad and the closest land point ‘The Discovery Bay Marina’. Models have been used to predict the alteration to the flow regime, thus the impacts on the water quality identified in Section 6.6.

6.4.20 The predicted maximum SS elevation resulting from the dredging has been compared to the SS tolerance value (i.e., 10.1 mg/l) to determine the acceptability of the WQ impacts.

6.5 Assessment Approach & Methodology

Gaussian equation

6.5.1 The following equations, based on the Gaussian theory (CIRIA), were used to estimate the resulting elevation of SS concentration:

c_t(x,t) = M_t exp{-(x-x)²/(4D_xt)-y²/(4D_yt)-W_st/h}/{4phtÖ(D_xD_y)} (1)

C (x,t₁) = S c_t (x,t) where t=0 to t₁ (2)

Where: c_t – SS concentration from one-off releasing source at time t

C – Cumulative SS concentration (kg/m³) resulting from the source released from the beginning to time t₁

M – Amount of sediment released (kg)

X – Distance from the releasing point along the flow direction (m)

Y – Distance from the releasing point normal to the flow direction (m)

t – Time after release (s)

W_s – Settling velocity (m/s)

h – Water depth (m)

D_x – Dispersion coefficient in X-direction (m²/s)

D_y – Dispersion coefficient in Y-direction (m²/s)

x = ut (m) and

u - Flow velocity (m/s)

6.5.2 The critical activity in the helipad construction is the dredging activities associated with the site formation, and thus the impact of this dredging activity on marine water quality has been assessed. The backfill material will have a minimum particle size of 20mm. As such, no fine sediment is expected to be released during the backfilling operation. It is reasonable to consider that the potential impact of other activities such as backfilling will be acceptable as long as the dredging impact is acceptable.

Model Input and Assumptions

6.5.3 To ensure that the assessment does not under-estimate potential water quality impacts, a series of worst-case assumptions have been made for input to the model. These relate to ‘S-factors’ (i.e., the sediment leakage rate from dredging), peak tidal velocity for extreme sediment plume formation and dispersal, and bathymetry (i.e., a shallow water depth scenario was assessed, as this will allow conservative estimation of suspended solids levels).

6.5.4 A single backhoe dredger with a grab capacity of 6 – 8 m³ per grab will be engaged for the dredging. The maximum volume of 8m³ per grab has been adopted to represent the worst-case scenario in the calculation on the assumption that the sediment leakage rate for either a 6m³ or an 8m³ grab would be the same, and assuming that the number of grab ‘events’ per unit time would be the same for these two different grab volumes.

6.5.5 The total dredging volume is 14,000 m³ over a period of 30 days with 8 working hours per day, giving a mean dredging rate of 58 m³/hr or 0.0162 m³/s. For the purpose of this impact assessment, a daily maximum dredging rate of 465 m³ has been assumed. The dredging shall be monitored and a daily record shall be kept to ensure the dredging rate would not exceed the assumed maximum daily rate of of 465 cubic metres as recommended in the EIA.

6.5.6 The typical sediment leakage rate (or S-factor) for a grab dredger is 12 to 25 kg/m³ (i.e. there will be 25 kg sediment leakage for every cubic metre of volume dredged). Using the S-factor of 25 kg/m³ as the worst-case scenario, the calculated leakage rate is 0.405 kg/s.

6.5.7 Based on borehole sampling data, on average 85% of the marine sediment is consisted of sand or coarser material (i.e., gravels), with 15% comprising finer sediment. As such, there will be 0.344 kg/s sand or coarser material and 0.061 kg/s silt or clay released into the water column during the dredging period.

6.5.8 The model was run separately to assess the SS elevation resulting from the sand and the fine sediments. The SS elevation resulting from the sand release is then superimposed to that from releasing the fine sediments. The total SS elevation is then compared to the tolerance value to determine the acceptability of the water quality impact. A typical particle size for sand, 200μm is conservatively adopted for assessing the impact of sand release. The settling velocity of the sand is estimated to be 0.02 m/s.

6.5.9 The water depth at the offshore end of the proposed works area is approximately 1 mCD, and reaches 5 mCD some 50m from the shoreline. For the purpose of this assessment, a constant total water depth of 2 m has been used for estimating the mixing zone (i.e., within which SS elevation is in excess of 30% above the baseline SS level). A constant total water depth of 5.8m has been used for estimating the SS elevation at the coral site around Tai Lei Island, based on the information from the site survey and the navigation chart.

6.5.10 The tidal currents in the area change periodically. The peak velocity at mid ebb and mid flood tide is approximately 0.4 m/s and 0.6 m/s respectively. The frequency distribution of current velocity at Peng Chau for the wet and dry seasons is displayed in Figure 6.1. As the coral sites are to the west of the dredging area, there will be no dredging impact on the coral communities during the flood tide as the dredging plume will be travelling eastwards, in the opposite direction.

6.5.11 The constant peak velocity at the ebb tide has been adopted for calculating the impact on the coral communities during the ebb tide. It is conservatively assumed that this peak constant velocity is for a continuous 6.5 hours during the entire ebb tide. The flood tide peak velocity, as it is bigger than the ebb tide velocity, is however conservatively adopted for estimating the extent of the mixing zone.

6.5.12 As the sediment will be released continuously during the dredging period, the resulting sediment concentration from the dredging within each time element as calculated using the Gaussian Equation (1) is superimposed to obtain the resultant sediment concentration of the continuous release.

6.5.13 A typical dispersion coefficient of 1 m²/s is used for both D_x and D_y.

Figure 6.1 Frequency and Direction of Current Velocity at Peng Chau

Source: Outlying Islands Sewerage Stage 1 Phase 1 EIA Study (CES (Asia), 1997) [in EIA Study Report for Peng Chau Sewage Treatment Works Upgrade (CDM, 2004)].

6.6 Impact Assessment & Evaluation

6.6.1 As discussed above, the background SS level based on the 90^th percentile over the 4-year period from 1997 to 2000 is 33.5 mg/l, and the tolerance of SS elevation is 10.1 mg/l.

6.6.2 Table 6.3 summarises the calculated SS elevation. It can be seen that the SS elevation will not exceed the tolerance level even in the very vicinity of the dredging location for the average water depth of 5.8m in the study area. However, the mixing zone where the SS elevation exceeds the tolerance level will be about 16m (along the flow direction) by 5m (normal to the flow direction) for a water depth of 3m.[§§§] The mixing zone will increase to 25m (along the flow direction) by 8m (normal to the flow direction) if the water depth is reduced to 2m. Figure 6.2 displays the cumulative spatial extent of the mixing zone in relation to the works area.

Table 6.3 Predicted SS Elevation

X (m)	Y (m)	Csand (mg/l)	Csilt (mg/l)	C= Csand+ Csilt (mg/l)
Depth = 5.8m
20	0	4.17	0.84	5.01
15	0	4.92	0.96	5.88
10	0	6.44	1.22	7.66
9	0	6.71	1.26	7.97
8	0	6.85	1.29	8.14
7	0	6.82	1.27	8.09
6	0	6.59	1.23	7.82
5	0	6.14	1.15	7.29
2	0	3.92	0.72	4.64
8	1	6.72	1.26	7.98
8	2	6.34	1.19	7.53
Depth = 3.0m
18	0	7.69	1.70	9.39
16	0	8.30	1.80	10.10
15	0	8.69	1.86	10.55
10	0	11.72	2.36	14.08
9	0	12.26	2.44	14.70
8	0	12.56	2.49	15.05
7	0	12.54	2.47	15.01
8	2	11.62	2.30	13.92
8	5	7.83	1.57	9.40
Depth = 2.0m
26	0	7.63	2.14	9.77
25	0	7.92	2.19	10.11
8	8	5.62	1.23	6.85
8	6	9.08	1.94	11.02

6.6.3 Only one dredger will be in operation during the dredging works. As such, the spatial extent of exceedance of the WQO for SS will be localised, and no significant adverse impacts are expected in the secondary contact recreation sub-zone.

6.6.4 The dredging at the helipad and the associated EVA will lead to some SS elevation at the coral sites identified. However, the maximum SS elevation at the identified coral sites around Tai Lei Island is at a negligible level of 0.002mg/l and the sedimentation rate is estimated to be considerably less than 0.1kg/m²/d.

6.6.5 As such, given the small scale of dredging, no adverse water quality-induced impacts are anticipated either at the coral community at east Tai Lei [Section 7 refers] or on fisheries resources within the Project boundary [Section 8 refers]. There will be no adverse water quality impacts on the WSRs at the Discovery Bay Marina.

6.6.6 During the operation stage, the flow cross-section to be affected by the helipad footprint is in the shallow water near the coast and is less than 50m in length. In view of a total cross-section length of ~ 1km between the proposed Project and the closest land point on Lantau (i.e., the Discovery Bay Marina), no significant impact on the tidal regime and therefore water quality around the Project area is anticipated during the operational phase.

6.6.7 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.

Cumulative Impacts

6.6.8 The marine works for the Peng Chau STW submarine outfall shall be developed by the open trench method from August 2005 for completion around April 2006. Marine works for the Peng Chau Helipad are scheduled between February and July 2006. Although the latest information from DSD indicates there may be around 2 months of concurrent works, the impact assessment using a standard calculation based on the Gaussian theory has indicated no overlap in the affected area. As such, no cumulative water quality impacts are anticipated.

6.7 Impact Mitigation & Residual Impact Assessment

6.7.1 An increase in the dredging rate without additional mitigation measures would lead to an increase in the sediment leakage rate and an increase in water quality impact, and should be avoided. If an increase in the dredging rate is unavoidable, the potential water quality impact on the WSRs should be re-assessed.

6.7.2 While no significant adverse water quality impacts are predicted, it is as a precautionary good practice measure recommended that a silt curtain(s) be placed in an arc on three sides (east, north and west) around the dredger to prevent sediment dispersal to open marine waters. This shall ensure the area of the mixing zone is minimised, and the silt curtain(s) should be installed prior to the commencement of dredging. The silt curtain(s) shall enclose the dredger while not interfering with its operation. The silt curtain(s) shall be progressively moved as the dredger moves through the dredging area, and shall be weighed down against the seabed prior to commencing dredging.

6.7.3 The following good site practices are recommended to further minimize potential water quality impacts:

· The daily dredging volume should be spread as evenly as possible over the working hours whenever practical to avoid sudden surge of pollution elevation during short spells;

· Special care should be taken during lowering and lifting grabs to minimize unnecessary disturbance to the seabed;

· To ensure vessels used have adequate clearance of the seabed in order to reduce undue turbidity generated by turbulence from vessel movement or propeller wash;

· Barges should be fitted with tight fitting seals to their bottom openings to prevent leakage of material;

· The contractor should ensure that grabs are tightly closed and the hoist speed is suitably low;

· Barges should not be filled to a level which will cause overflow of materials during loading and transportation; and

· Large objects should be removed from the grab to avoid losses from partially closed grabs.

6.8 Environmental Monitoring & Audit

As no significant adverse water quality impacts are anticipated, no water quality monitoring is required for the Project.

6.9 Conclusions and Recommendations

6.9.1 There is some potential for water quality impacts associated with proposed construction phase dredging activities.

6.9.2 As only one dredger will be in operation during the dredging works, calculations predict that elevations in suspended solids at the identified sensitive receivers are negligible and well within the tolerance level. It is also predicted that the SS elevation will not exceed the tolerance level of 10.1 mg/l even in the very vicinity of the dredger, based on an average water depth of 5.8m in the study area. The mixing zone where the SS elevation will exceed the tolerance level is only 16m (along the main flow direction) by 5m (normal to the flow direction) at a water depth of 3m and 25m by 8m at a water depth of 2m, and will not affect water sensitive receivers.

6.9.3 The use of silt curtains will further limit the extent of the mixing zone, and will ensure compliance with the water quality criteria at the WSRs. As such, no significant adverse water quality impacts are anticipated during the construction phase and, accordingly, no adverse residual impacts are expected.

6.9.4 As regards cumulative effects, the construction method for the Peng Chau STW submarine outfall will involve the open trench method. These works will be commenced in August 2005 for tentative completion around April 2006. As there will be no overlap in the affected area, no cumulative impacts are anticipated.

6.9.5 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.

6.9.6 As the backfilling material will be rock armour and granular material with a minimum particle size of 20mm, no fine sediment is expected to be released into water column during the backfilling stage and this activity will have much less water quality impacts than the dredging activities.

6.9.7 It is concluded that the potential adverse water quality impacts of the proposed helipad are insignificant during both the construction and operation stages. The proposed good practice measures will further safeguard the compliance of the water quality with the water quality criteria during construction works.

6.10 References

· Bachy Soletanch (2003). Construction of Helipad at Peng Chau: Marine Ground Investigation and Reference Sediment Sampling – Ground Investigation Factual Fieldwork Report. Final report submitted to Civil Engineering Department, HKSAR Government.

· CDM (2004). EIA Study Report for Peng Chau Sewage Treatment Works Upgrade. Drainage Services Department, HKSAR Government.

· CES (Asia) Ltd. (1997). Outlying Islands Sewerage Stage 1, Phase 1. EIA Study – Final Assessment Report. Drainage Services Department, HKSAR Government.

· CIRIA (2000). Scoping the Assessment of Sediment Plumes from Dredging, CIRIA Publication C547.

· 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.

· 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.

7 Ecology

7.1 Introduction

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 For the terrestrial ecological impact assessment, the assessment area is defined in the EIA Study Brief as that area of terrestrial habitat likely to be impacted by the Project. Given the scale, nature and location of the works, this area has been defined as an area of 100 metres radius from the proposed Project. 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 Assessment Approach

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 3.4.2 and Clause 3.4.3 (for corals) of the EIA Study Brief. For ease of presentation, the objectives of these two EIA Study Brief clauses have been consolidated 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, minimize 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 Regulations, Standards and Guidelines

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’ – defined as any species and / or habitat regularly occurring in the assessment 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:

Town Planning Ordinance (Cap. 131)

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.

Forests and Countryside Ordinance (Cap. 96) and Forestry Regulations

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.

Animals & Plants Ordinance (Protection of Endangered Species) (Cap. 187)

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 Ecological Baseline

7.4.1 Clause 3.4.2.4 (iv) (a) – (f) of the EIA Study Brief provides guidelines for establishing a general ecological profile of the assessment 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).

· Underwater Survey of Peng Chau and Neighbouring Islands: September 2001. (Oceanway Corporation Limited, 2001a).

· Outlying Islands Sewerage Stage 1, Phase 1. EIA Study – Final Assessment Report. Drainage Services Department (CES (Asia) Limited, 1997).

· Construction of Footpath along Pak Wan, Peng Chau Rural Planning & Implementation Strategy (Home Affairs Department, 2002).

7.4.5 Discussion of fisheries resources is presented in Section 8.

Sub-tidal Ecology

7.4.6 A comprehensive survey of the HKSAR’s marine benthic community was undertaken on behalf of AFCD throughout 2001, and included sampling two stations in proximity to Peng Chau: one station located approximately 1 km due north of Tai Lei, and one located approximately 1 km due south of Tai Lei. Both survey stations are slightly outside the marine ecology assessment area, but survey data is broadly indicative of the marine benthic community within the assessment area.

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 7.1 below summarises these representative species and shows their presence / absence in the seabed community at north (N) and south (S) Peng Chau from summer and winter surveys.

Table 7.1 Representative Species in the Peng Chau Marine Benthic Community (CityU, 2002)

Family	Species	Summer Survey		Winter Survey
		N. Peng Chau	S. Peng Chau	N. Peng Chau	S. Peng Chau
Polychaete	Mediomastus spp.	-	Ö	Ö	Ö
	Sigambra hanaokai	Ö	-	-	Ö
	Agalaophamus dibranchis	Ö	Ö	Ö	-
	Cossurella dimorpha	-	Ö	-	-
	Ophiodromus angustifrons	-	-	-	Ö
	Paraprionospio pinnata	Ö	-	-	-
	Prinospio malmgreni	-	-	-	-
	Prinospio ehlersi	-	-	Ö	Ö
	Otopsis sp.	-	-	Ö	Ö
Crustaceae	Callianassa japonica	-	-	-	-
	Neoxenophthalamus obscuris	-	-	Ö	-
Echinoderm	Amphiodia obtecta	Ö	-	-	-
Sipunculan	Apionsoma trichocephalus	-	-	-	-
	Total Species Richness (0.5 m^2)	10	17	15	20
	Total Individuals (m^2)	44	56	50	130
	Total Wet Weight (g/m^2)	0.44	27.26	46.62	18.96

7.4.8 Table 7.1 shows that seasonal variation in total species richness is low, although there is some seasonal variation in abundance at South Peng Chau. The seasonal change in wet weight at North Peng Chau is of note given that the overall abundance changes little and that the species evenness at this survey station was relatively high in both summer (0.80) and winter (0.96).

7.4.9 To appreciate the ecological significance of the marine benthic community, a comparison was made of univariate indices (d, H’ and J) at South Peng Chau (the more diverse of the two Peng Chau survey areas) with the mean indices values from other comparable survey areas in western and southern (W & S) HKSAR waters [Table 7.2 refers].

Table 7.2 Univariate Statistics for S. Peng Chau & Similar HKSAR Survey Areas (CityU, 2002)

Index	Summer		Winter
	S. Peng Chau	W & S HKSAR	S. Peng Chau	W & S HKSAR
Species Richness index (d)	4.80	7.26	4.55	4.90
Species Diversity index (H’)	2.68	2.87	1.93	2.32
Species Evenness index (J)	0.95	0.82	0.64	0.73

7.4.10 Table 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 South Peng Chau. Compared to the mean value for other survey stations with similar characteristics (mainly in western and southern waters) the South Peng Chau community generally has lower species richness and lower diversity. Species evenness in the summer survey was high, indicating a relatively balanced benthic community, while this changed in the winter survey to a lower than average level, indicating increased dominance (abundance) by one or more species.

7.4.11 Overall, the community can be considered as having lower than average ecological value (compared to other surveyed areas with a similar character), while no marine benthic species of particular note were found in the Peng Chau area.

7.4.12 As regards corals, reconnaissance dives around the entire coastline of Peng Chau conducted in February 2001 recorded a total of 24 hard coral species and five octocorals species (Oceanway, 2001a). The percentage cover for both coral groups was less than 5%, and the most abundant coral taxa recorded was the common hard coral family, Faviidae.

7.4.13 Figure 7.1 shows the locations of several live coral communities in the assessment area. That closest to the Project area is a hard coral community at east Tai Lei (labelled community ‘A’), where the seabed comprises a mixture of sand and rocky outcrops at an average depth of -2.3m CD (ibid.). A total of 14 hard coral species were recorded here, with Favites spp., Leptastrea spp. and Platygyra sp. dominating the community. The coral community was described as having a low area of coral cover, but relatively high species richness. Other benthic species in the same area included anemones, sea cucumbers, hydroids and sea urchins.

7.4.14 This same location was re-surveyed in February 2003 under the Peng Chau Sewage Treatment Plant Upgrade project EIA for Drainage Services Department. A total of 13 species of hard coral were recorded and it was concluded that the community is essentially the same as that surveyed in February 2001 (CDM, 2004).

7.4.15 A summary of other communities as presented on Figure 7.1 is as follows:

· Community ‘B’: Four species of hard coral and two of soft coral have been recently recorded, all with very low cover. The green-lipped mussel P. viridis was abundant, and bryozoans, burrowing anemones and seapens were occasional (CDM, 2004).

· Community ‘C’: Oceanway (2001a) recorded one species of hard coral (Favites pentagona) and two species of soft coral (Euplexaura sp. and Dendronephytha sp.), and a fairly diverse invertebrate community comprising bryozoans, hydroids and particularly the green-lipped mussel, Perna viridis.

· Community ‘D’: No hard corals were found in this community. Encrusting bryozoans and the green-lipped mussel P. viridis were abundant (CDM, 2004).

· Community ‘E’: From three transects in this area Oceanway (2001a) recorded 15 species of hard coral from this predominantly bedrock habitat: Favites pentagona, Platygyra speciosa and Psammocora superficialus being most abundant. Other characteristic taxa are encrusting coraline algae and bryozoans, anemone beds and the black urchin Anthocidaris crassispina.

· Community ‘F’: Oceanway (2001a) survey reported that boulders and sand patches dominate the substrate, with 14 species of hard coral recorded: Cyphastrea sp. and Psammocora superficialus being most abundant. The remaining taxa were largely restricted to encrusting coraline algae and bryozoans.

7.4.16 No live coral was recorded from the shallow, sub littoral shoreline at Pak Wan. However, the remains of a dead coral community were noted off the small beach adjacent to Sea Crest Villa – parallel to the proposed EVA (Oceanway, 2001a). An unidentified anemone (most likely Haliplanella luciae, but potentially Spheractis cheungae) was recorded as highly abundant at this location, as was the encrusting coralline algae (Corallina sp.). The seabed composition at this point is primarily sand to an average depth of -2.1m C.D.

7.4.17 The profile was reportedly similar at the proposed helipad footprint where no live corals were recorded, and the seabed predominantly comprised of sand with scattered boulders (medium to large in size) to an average depth of -3.1m C.D. Typical benthic species by the proposed helipad footprint included hydroids, anemones, Perna viridis, and encrusting coralline algae (ibid.).

7.4.18 Regarding cetacean use of Peng Chau’s coastal waters, and with reference to accumulated records provided by AFCD, between October 1995 and April 2003 there have been several sightings of the Chinese White Dolphin Sousa chinensis around the island (AFCD, 2003). Four of these sightings were within 1 km of the island, with the closest observation to the Project area being some 500m west-southwest of Tai Lei. There have been several sightings off northeast Lantau, due north of Pak Wan, but all sightings were greater than 1.5 km from the Project area. There is no clear seasonal pattern to the distribution, although most observations have been made in the summer (June – August) and the winter (December – February) periods (ibid.).

7.4.19 The scenario is similar for the Finless Porpoise Neophocaena phocaenoides, with only two sighting recorded – both over 1.5 km off the southeast of Peng Chau (ibid.). The data suggests the coastal waters of Peng Chau (particularly north Peng Chau / Tai Lei) are infrequently visited by cetaceans, and do not appear to be an important part of the habitat range for these species.

Inter-tidal Ecology

7.4.20 As the Pak Wan coastal environment has not been subject to any past development there is no data for the area. There is, however, some historic data from August 1996 that was gathered from two transects for the then proposed development of a sewage treatment works at Peng Chau by CES (1997).

7.4.21 The data was collected from the rocky southwest shoreline of Tai Lei which has a similar shoreline character to that at Pak Wan: granite bedrock outcrop with crevices and pools, and with small boulders embedded in sand at the lower shore.

7.4.22 A total of 22 species of epifauna were recorded, and none of the species were uncommon on hard shores. Overall, gastropods were the dominant taxa, and limpets and periwinkles were the most abundant species. There were generally few species present at the mid and upper shore areas, with a more abundant and diverse community around the low water level. It was reported that “in general the fauna along the transect was sparse…” (ibid.).

Terrestrial Ecology

7.4.23 From the Tree Survey conducted on behalf of HAD (2002) for the Pak Wan footpath improvement works, 34 trees were recorded within the assessment area of the proposed helipad: Schefflera octophylla (14 no’s); Litsea rotundifolia (6 no’s); Cratoxylum ligustrimum (6 no’s); Macaranga tanarius (5 no’s); Ficus microcarpa (1 no.); Rhus succedanea (1 no.), and Sapium sebiferum (1 no.). None of the trees exists in the immediate vicinity of the helipad works area – all being generally upslope of the footpath improvement works area – and none will be affected by the works.

Field Survey Methodologies

7.4.24 The Ecological Baseline Survey was conducted between October 2002 and April 2003. Details of the mapping and survey methodologies and findings are presented under the following headings.

Habitat Mapping

7.4.25 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 during March and April 2003, which involves systematically surveying the assessment area to verify the accuracy of the initial interpretation of maps and photographs.

Sub-tidal Habitat

7.4.26 A Rapid Ecological Assessment (REA) survey was conducted at high water on the 27^th April 2003, with the objective of assessing the composition of the marine benthos of the shallow, sub-tidal community. The REA method was developed for the Indo-Pacific (DeVantier et al. 1998, 2000) and has been refined for use in Hong Kong SAR waters, and involves an assessment of the benthic cover (Tier I) and taxon abundance (Tier II). Data on various related environmental attributes were also collected (e.g., depth, substrate type, and visibility). Further details of the REA assessment categories (Tiers) are presented in Appendix 7.1.

7.4.27 The survey comprised five semi-quantitative dive surveys [Figure 7.2 refers]. Due to surveyor familiarity with the assessment area there was no need to conduct routine spot-check dives. From past coral dive survey in the area by the dive team the most promising areas for coral growth were selected.

7.4.28 A ‘P4’ survey vessel was moored over the selected dive area and the five transect locations positioned within a single ecological zone - habitat - depth range using GPS. At the desired survey location belt transect tapes 1-2 m wide and 50 metres long were laid across the seabed adjacent to the shoreline. Surface markers buoys were used to verify the survey area.

7.4.29 Prior to visual census work, due to the possibility of silt disturbance, the area 1m either side of each transect was first filmed using a mini-DV format camera. The REA field data were recorded on underwater data sheets by an experienced marine biologist, swimming ‘down-current’ along the identified section of coastline on SCUBA. Representative video footage and still images were taken on mini digital-video format, using a 3CCD camera system.

7.4.30 Incidental observations of fish were made during the ecological dive survey conducted on 27^th April.

Inter-tidal Habitat

7.4.31 A semi-quantitative survey of inter-tidal benthic fauna was conducted on 24^th October 2002 (wet-dry transitional period) and again on 30^th April 2003 (dry-wet transitional period). The survey covered the entire length of shoreline across which the proposed EVA is to be developed and ended on the larger of the two sandy beach areas off which the proposed helipad is to be constructed. On both days survey work was conducted at low water, and investigations were conducted at intervals of approximately every 10 metres along the shore. Figure 7.2 presents the survey alignment.

7.4.32 The October 2002 survey involved the random placement of a series of 0.25m² quadrats within the mid-lower shore zone. A more extensive survey was conducted in April 2003 when the same alignment as used for the October 2002 survey was followed, but which involved survey of upper shore fauna.

7.4.33 For both seasons the number and species name of all individual organisms was recorded. Infauna sampling was undertaken at the sandy beach areas for both seasons using a 10 cm diameter core to depths of 20 cm. Five core replicates were sampled at each sandy beach location.

Terrestrial Habitat

7.4.34 To complete an ecological profile for the area, a qualitative survey of vegetation was conducted on 24^th October 2002. Surveys of birds and butterflies present around inter-tidal and terrestrial habitat were conducted on 24^th October 2002, and 17^th and 27^th April 2003. Survey involved walking a line-transect along the shoreline of the Assessment area [Figure 7.2 refers].

Field Survey Results

Habitat Mapping

7.4.35 From the Habitat Mapping exercise, a total of six discreet habitat types were identified in the assessment area. Figure 7.2 presents the delineation of the habitats, and Table 7.3 summarises their respective areas.

Table 7.3 Habitat Types in the Assessment Area

Habitat Type	Approximate Area (hectares)
Sub-tidal	~ 235 ^
Sandy Shore	0.19 ^
Rocky / Boulder Shore	0.25 ^
Coastal Scrub	5.80
Secondary Woodland	0.15
Developed / Disturbed Area	0.90

Note: ^ Area of Sub-tidal habitat, Sandy Shore and Rocky / Boulder Shore calculated within the 1 km marine ecology assessment area (excluding Tung Wan which is > 1 km from the Project area).

7.4.36 A brief summary of these habitat categories 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 [Pak Wan has a shallow seabed, predominantly of sand widely overlain with scattered boulders. This mix of soft and hard substrates supports a community of benthic epifauna, while the overlying shallow water column supports a pelagic community].

2. Sandy Shore [there are two small sandy coves in the immediate vicinity of the works area. Both beaches are of medium / coarse grained sand from rock / boulder weathering. There are no streams along the north coast of Peng Chau, and hence no persistent natural sources of fine particulate material].

3. Rocky / Boulder Shore [This habitat type is present at exposed shoreline areas that are subject to wind / wave erosion, with a few areas of scattered cobbles and coarse sand, and with a few pools and gullies].

4. Coastal Scrub [Behind the shoreline and growing upslope from the coastal cliff is a coastal shrub community with occasional immature / semi-mature trees].

5. Secondary Woodland [There is a small area of secondary broad-leaved woodland behind some small shrines and a temple at the southwest of the assessment area].

6. Developed / Disturbed Area [This category includes the east of Tai Lei island (Refuse transfer station, Sewage treatment works and various storage areas), the Tai Lei road / bridge, Sea Crest Villa residential development and a small works area for HAD’s footpath improvement at the west and southwest of the assessment area – the ongoing (as of August 2003) footpath improvement works traverse the north coast of Peng Chau].

Sub-tidal Ecology

7.4.37 The sub-tidal survey was conducted in a semi-sheltered with some wave turbulence as a result of passing vessels. The five belt transects were surveyed at a depth of around -3m CD, and the entire sub-tidal zone was generally very shallow with depths no greater than around -4m CD approximately 50 metres from the coast. The underwater visibility on the day of survey was poor at 0.2 - 0.3 metres, although not unusual given the location, and so the transects were swum in a ‘S’-shape to gain full coverage of the seabed.

7.4.38 The substrate consisted of a thin veneer of extended bedrock and boulders (< -2 m depth) flattening out to a predominantly sandy seabed with scattered boulders at depths > -2 m CD. There was moderate sediment deposition with a noticeable layer of sandy sediment covering all hard substrate. Table 7.4 characterises the substrate in the assessment area.

Table 7.4 Categorisation of Benthic Cover and Substrate

	Ecological attributes						Substratum
Transect	Hard Coral	Dead Coral	Soft Coral	Black Coral	Macro-algae	Turf algae	Large Boulders	Small Boulders	Rubble	Sand	Silt
A1	0	1	0	0	0	0	0	3	0	6	0
A2	0	1	0	0	0	0	1	2	0	6	0
A3	0	1	0	0	0	0	2	3	0	5	0
A4	0	1	0	0	0	0	2	3	0	5	0
A5	0	0	0	0	0	0	2	3	0	5	0

Cover rank: 0 = 0%; 1 = 1-5 %; 2 = 6-10 %; 3 = 11-30%; 4 = 31-50%; 5 = 51-75% and 6 = 76-100%.

7.4.39 With reference to Table 7.4, there was no live coral in the survey area, although there was evidence of the past presence of hard corals with isolated patches of dead coral observed. The dead skeletal sections of coral indicated that the coral Goniopora sp. previously existed along this section of coastline. It could not be determined when or why this generally sediment-tolerant species had died.

7.4.40 The benthic taxa were generally restricted to hard substrate in permanent sub-tidal waters. Table 7.5 presents the survey dataset.

Table 7.5 Rank Abundance of Pak Wan Sub-tidal Benthic Community

Benthic Taxa			A1	A2	A3	A4	A5	Mean
Porifera	Callyspongia	sp.	1	0	0	0	0	0.2
	Encrusting sponge	Unidentified	0	2	2	0	0	0.8
	Cliona	sp.	0	2	0	2	0	0.8
Cnidaria	Haliplanella	luciae	4	3	3	3	3	3.2
	Hydroid	Unidentified	2	2	2	2	2	2.0
Bryozoa	Schizoporella	errata	2	1	1	2	1	1.4
Echinodermata	Holothuria	leucospilota	1	0	2	2	0	1.0
	Colochirus	crassus	0	1	0	0	0	0.2
	Astropecten	sp.	0	0	0	0	1	0.2
Crustacea	Portunus	pelagicus	0	1	0	1	0	0.4
	Balanus	sp.	3	0	2	0	0	1.0
Bivalve	Saccostrea	sp.	3	2	2	3	3	2.6
	Perna	viridis	2	2	2	3	3	2.4
Algae	Turf algae	Unidentified	4	3	3	3	3	3.2

Abundance Rank: 0=Absent; 1=Rare*; 2=Uncommon; 3=Common; 4=Abundant; 5=Dominant

[Appendix 7.1, Table 3 refers]

7.4.41 The benthic community predominantly comprises a dense covering of the anemone Haliplanella luciae, turf algae, and a range of calcareous fouling organisms: particularly the bivalves, rock oyster Saccostrea sp., and the green-lipped mussel Perna viridis. Other species present throughout the surveyed area were the bryozoan Schizoporella errata and hydroids, whilst holothurians (sea cucumbers), sponges (encrusting and ball forms), the barnacle Balanus sp., and the swimming crab Portunus pelagicus were locally present. A typical view of sub-tidal habitat dominated by anemones is presented on Figure 7.3.

7.4.42 Sightings of fishes during the course of the ecological survey were limited to just two species seen at very close quarters: Terapon jarbua (tiger fish) and Sebasticus marmoratus (rock fish).

7.4.43 From field investigations (i.e., interview / observations) conducted for the ‘Fisheries’ assessment, a fairly diverse fish community is evident in the Project vicinity. Common species include Diagramma pictum (painted sweetlip), Monacanthus chinensis (filefish); Acanthopagrus latus (yellow-finned seabream); Pagrus major (red seabream); Mylio macrocephalus (black bream) and Lateolabrax japonicus (common sea bass).

7.4.44 Further details of fisheries resources around Peng Chau are presented in Section 8.

Inter-tidal Ecology

7.4.45 Table 7.6 presents the type and relative abundance of the Pak Wan inter-tidal benthic community as surveyed in October 2002.

Table 7.6 Inter-tidal Survey Data for Pak Wan (BMT, October 2002)

Quadrat Number	1	2	3	4	5	6	7	8		9		10	11
Shoreline Character *	S	B/S	S	R/B	B/Co	Co	B/Co	Co		R/B		R/B	S
Infauna (present?)	N	N	N	N	N	N	N	N		N		N	N
Epifauna (present?)	N	Y	N	Y	Y	Y	Y	Y		Y		Y	N
Species	Abundance ^†
Capitulum mitella		4		3							4	9
Haliplanella luciae		2		VA	A		6		3			A
Patelloida saccharina				A	VA		VA				A	3
Thais clavigera				3			3		1		8
Tetraclita squamosa				2								2
Monodonta labio							4				4	2
Patelloida pygmea		7										4
Hermit crab					A		1		A
Nerita albicilla		A		6		6	A					A
Perna viridis											6	8
Porcelain crab				1							3
Hemigrapsus penicillatus						3			1
Acanthopleura japonica				4			1				8	3
Ligia exotica		2		1		A			1
Total Epifauna species	0	5	0	9	3	3	7		5		7	9	0
Seaweed (% cover)
Enteromorpha sp.											5
Ulva lactuca											30

Notes: * R = Rocky; B = Boulder; Co = Cobbles; S = Sandy

^† A = Abundant (11 – 20 individuals); VA = Very Abundant (21+ individuals)

7.4.46 The data shows that in terms of coastal habitat type, the sandy shore locations surveyed held neither epifauna nor infauna. As would be expected, there was also no infauna at any of the hard shore locations. The rocky / boulder shore habitat supported the greatest species diversity, with the limpet Patelloida saccharina typically abundant on stable hard substrate and the anemone Haliplanella luciae abundant in shallow pools with small boulders / cobbles at the lower shore. The neritid shell Nerita albicilla was also represented in a range of hard shore habitats, whilst the hermit crab was present in all quadrats with a pool – often occupying a shell of Chlorostoma rustica.

7.4.47 None of the epifauna species encountered in the October 2002 survey were uncommon, and all are characteristic of hard shore environments.

7.4.48 The May 2003 inter-tidal survey recorded similar species richness, despite more survey effort on inter-shore zonation. There was generally a decline in species richness from lower to upper shore zones, with an average richness for the lower, middle and upper shore zones of 4.1, 3.4 and 2.9, respectively. The full inter-tidal survey data are presented in Appendix 7.2, and can be summarised as follows.

7.4.49 At the upper shore the periwinkle Nodolittorina trochoides that was able to take advantage of nooks in the rough granite was generally very dominant. The barnacle Capitulum mitella was locally dominant in this zone, while the limpet Patelloida saccharina was locally common. The algae Ulva sp. was locally abundant, and particularly at quadrat #2 where flat rocks and boulders provided a good substrate for growth.

7.4.50 The most widespread and abundant species in the mid-shore zone by far was the barnacle Terraclita squamosa. The only exception to this was at quadrat #9 where a rock pool was located dominated by hermit crabs (most often inside shells of Chlorostoma rustica). The limpets Cellana toreuma and Patelloida saccharina and the top shell Monodonta labio being locally common in this zone. The whelk Thais clavigera and the chiton Acanathopleura japonica were very locally common in this zone.

7.4.51 As with the upper shore, Ulva sp. was the dominant algae on the mid-shore zone, although there was generally more algal diversity in this zone than the upper shore with both coralline algae and Ralfsia spp. being locally common. Enteromopha sp. was also present in two mid-shore quadrats.

7.4.52 The lower shore zone was characterised by a number of small pools on rocky shore (e.g., quadrat #4) and pools amongst cobbles (e.g., quadrat #5 and #6). These niches were colonised by the green anemone Haliplanella luciae that was the most abundant and widespread species at the lower shore. The barnacle Terraclita squamosa was locally abundant where there were boulders present (e.g., quadrat #9 and #10), while hermit crabs, Monodonta labio, Patelloida saccharina, Cellana toreuma and Capitulum mitella were all very locally common. The dominant algae in the low-shore zone were coralline algae that was locally abundant, and Ralfsia spp. that was locally common. Each of these species was present in six of the 11 survey areas.

7.4.53 As with the October 2002 survey, no epifauna nor infauna were found on the three surveyed areas of sandy shore, although it is of note that a significant volume of dead coral and various bivalves – particularly Ruditapes philippinarum – were present at the backshore of the main sandy beach in the assessment area, close to quadrat #11.

7.4.54 Overall, none of the epifauna and algal species encountered in the May 2003 survey was uncommon, and all are characteristic of hard shore environments.

Terrestrial Ecology

7.4.55 As regards vegetation, the coastal scrub community above Pak Wan is the largest and the most contiguous with adjacent land outside the assessment area. The inland coastal community was characterized by mixed low and tall shrub species, with an area of woodland situated opposite Sea Crest Villa. There are also pockets of backshore vegetation at sandy beach areas that are characterized by species such as Pandanus tectorius, Clerodendrum inerme and Macaranga tanarius. None of the coastal vegetation species are of conservation value, all being common and widespread in similar habitats.

7.4.56 Abundant species in the inland coastal community include the common grasses Apluda mutica, Melinis repens, Chloris barbata and Miscanthus sinensis; common herbs such as Bidens alba, the widespread fern Dicranopteris pedata, and the common shrubs Lantana camara and Melastoma candidum. There are also a number of native trees (generally immature, but with a few semi-mature specimens) upslope of the Pak Wan footpath, with the common native tree Schefflera octophylla dominant.

7.4.57 A survey of the butterfly community was conducted along the Pak Wan shoreline in October 2002 and May 2003 [Figure 7.2 refers]. A total of 14 butterfly species were recorded: originally 8 species in October 2002, with an additional 6 species recorded in May 2003, as presented in Table 7.7.

Table 7.7 Butterfly Survey Data for Pak Wan, Peng Chau (BMT, 2002 & 2003)

Species	Status	October 2002	May 2003
Eurema hecabe	VC	1	2
Lampides boeticus	C	2	/
Chilades lajus	VC	3	2
Pelopidas assamensis	U	1	/
Ypithima lisandra	VC	1	/
Ypithima baldus	C	2	/
Euploea core	VC	1	/
Abisara echerius	VC	5	3
Catopsilia pomona	C	/	1
Papilio demoleus	C	/	1
Papilio polytes	VC	/	1
Papilio (cf. Chilasa) clytia	C	/	1
Faunis eumeus	C	/	2
Graphium sarpendon	VC	/	1

Note: VC = Very Common; C = Common; U = Uncommon (Young & Chung, 2001).

7.4.58 According to Young & Chung (2001), almost all species recorded are either very common or common. The only exception was an individual of the uncommon Great Swift Pelopidas assamensis that was found in the coastal scrub habitat upslope of HAD’s footpath improvement area, approximately 12m above the shoreline. The most abundant butterfly species was Plum Judy, Abisara echerius.

7.4.59 The Great Swift P. assamensis is a medium-sized member of the Hesperiidae and can be found in densely vegetated habitat. As reported in Bascombe et al (1999), prominent adult nectar sources include Buddleja davidii and Vitex negundo – the latter being a common plant species that was noted during the ecological baseline survey. While the coastal scrub habitat in the assessment area is of some importance to P. assamensis, this habitat type is widespread across north Peng Chau.

7.4.60 Bird survey was conducted in October 2002 and May 2003. The survey route is displayed on Figure 7.2. A total of 16 bird species were recorded: originally 11 species in October 2002 and an additional 5 species in May 2003, as presented in Table 7.8.

Table 7.8 Bird Survey Data for Northwest Peng Chau (BMT, 2002 & 2003)

Species	HKSAR Status ^	HKSAR Abundance ^+	Site Abundance #
			October 2002	May 2003
Milvus migrans *	R / WV	C / W	4	2
Corvus marcorhynchos *	R	C / W	4	/
Pycnonotus sinensis	R	C / W	A	A
Pycnonotus aurigaster	R	C / W	/	6
Garrulax perspicillatus	R	C / W	4	A
Acridotheres cristatellus *	R	C / W	6	A
Egretta sacra *	R	U / L	4	/
Dicaeum cruentatum	R	LC / W	1	2
Motacilla alba ocularis *	R / WV	C / W	2	/
Streptopelia chinensis *	R	C / W	2	/
Myiphoneus caerulus *	R	C / W	2	/
Passer montana	R	C / W	A	6
Actitis hypoleucos	PM / WV	C / W	/	1
Tringa brevipes	PM	L	/	2
Lanius schach	R	C / W	/	1
Zosterops japonica	R	C / W	/	3

Notes: * Species observed flying between Tai Lei / Pei Lei and Pak Wan

^ R = Resident; WV = Winter Visitor; PM = Passage Migrant

+ C = Common; LC = Locally Common; U = Uncommon; W = Widespread; L = Localised

# A = Abundant (>10 individuals); / = Not Observed

7.4.61 Of the bird species observed, according to Viney et al (1994), all species recorded are common and widespread with the exception of the localised Reef Egret Egretta sacra observed on the hard shore within the Project boundary in October 2002, and the Grey Tailed Tattler Tringa brevipes that is a passage migrant with localised distribution – also observed on the Pak Wan hard shore, but in a more isolated area approximately 100 metres east of the Project boundary. The Reef Egret E. sacra prefers rocky coastal areas and is a typically solitary, while T. brevipes is often observed in small parties in similar habitat (ibid.). Accordingly, as these species are dependent on undeveloped shores, the hard shore habitat in the assessment area is likely to be of some importance. However, there is similar undisturbed habitat around the north, northwest and southwest coastlines of Peng Chau that these species can use.

7.4.62 The Scarlet-backed Flower Pecker Dicaeum cruentatum was observed during October 2002 and May 2003 in coastal scrub habitat upslope of the ongoing footpath improvement works area, approximately 30 metres from the closest section of the Project boundary. This species is locally common in the HKSAR, and requires pockets of trees for nest building. The three observations of this species were found in such an area, although no signs of a nest were observed.

7.4.63 Several bird species were observed flying between the generally disturbed Tai Lei and Pak Wan. This indicates that the Pak Wan area, where coastal vegetation is more expansive and undisturbed, affords local refuge to these birds.

Recognised Sites of Conservation Importance

7.4.64 With reference to Appendix A (Note 1) of Annex 16 of the EIAO TM, there are no recognised sites of conservation importance at or in the vicinity of the Project site.

Habitat Evaluation

7.4.65 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 EIAO TM, as follows.

Sub-tidal

7.4.66 The evaluation of the ecological value of the sub-tidal habitat waters is presented in Table 7.9 below.

Table 7.9 Ecological Evaluation of the Sub-tidal Habitat

Criteria	Evaluation
Naturalness	Largely natural, but localised degradation close to the proposed helipad footprint from historic coral-deposits (from lime burning) and some abandoned fishing gear.
Size	Approximately 0.57 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 – Low diversity, dominated by anemones and other species typical of a ‘fouling’ community.
Rarity	No rare species or live corals in the survey area. Adjacent coral community at east Tai Lei comprises a number of resilient common hard corals (Oceanway, 2001b).
Re-creatability	Loss of pelagic habitat, but potential for recreation of benthic habitat.
Fragmentation	Continuous with seabed to the west, north and east.
Linkage	Linkage with adjacent hard shore and sandy shore habitats, but none are of particular ecological value. Contiguous with surrounding waters.
Potential Value	Limited by water quality and baseline levels of suspended solids.
Nursery / Breeding Ground	Of local significance to benthic organisms, but no special value. Not a nursery ground for fish of ecological significance.
Age	N/A
Wildlife Abundance / Richness	Comprises a fouling benthic community typical of inshore western HKSAR waters. High abundance of anemones, but moderate species richness.
Ecological Value	Low / moderate value compared with benthic (hard coral) communities surveyed in inshore waters in the eastern waters. Similar to other inshore benthic communities surveyed in western waters (Oceanway, 2002).

Sandy Shore

7.4.67 The evaluation of the ecological value of the sandy shore habitat is presented in Table 7.10 below.

Table 7.10 Ecological Evaluation of the Sandy Shore (Beach) habitat

Criteria	Evaluation
Naturalness	The sandy shore closest to Sea Crest villa adjoins an artificial rock / boulder seawall. The furthest beach area is relatively natural, but is affected by flotsam (mainly fishing gear) that has accumulated at the backshore.
Size	There are two small sandy coves in the immediate Project area that cover approximately 0.05 hectares and have a combined length of ~120m. In total there is ~480 metres of sandy shore in the marine ecology assessment area that covers an area of around 0.2 hectares.
Diversity	A homogenous habitat comprising medium-coarse sand. No inflowing streams, and generally limited backshore vegetation due to the presence of rocks and cliff-face. Ecological survey recorded no epifauna / infauna.
Rarity	The sandy shore habitat is not rare and there were no rare species present.
Re-creatability	Can be easily recreated (e.g., artificial sandy beaches nearby at Discovery Bay and Ma Wan).
Fragmentation	The closer of the two sandy shores is partly fragmented with rock / boulder seawall. The further of the sandy shores is not fragmented.
Linkage	Linkage with adjacent hard shore and coastal waters, but none are of particular ecological value.
Potential Value	Limited by human fishing activities (hand-lining, netting and shellfish collection). Presumably limited by natural environmental conditions given the absence of infauna.
Nursery / Breeding Ground	None identified.
Age	N/A
Wildlife Abundance / Richness	Very low. No fauna species recorded from field survey. Backshore vegetation community has low abundance and low species richness.
Ecological Value	Low value due to small size, absence of fauna, ease of re-creatability and constrained potential value.

Hard Shore

7.4.68 The evaluation of the ecological value of the hard shore habitat is presented in Table 7.11 below.

Table 7.11 Ecological Evaluation of the Hard Shore habitat

Criteria	Evaluation
Naturalness	Hard shore in the assessment area is physically intact, but is locally affected by human fishing activities (abandoned fishing gear).
Size	Approximately 0.25 hectares, and a combined length of ~630m in the marine ecology assessment area. There are around 160m of hard shore along the affected Pak Wan shoreline west of the proposed Helipad.
Diversity	Low diversity epifauna community, supporting a range of common species –mainly gastropods. Most habitat / species diversity at the lower shore zone. Supports a few bird species, most notably the localised Reef Egret and Grey Tailed Tattler that may feed off rocky shores, although these birds are not of any particular conservation value.
Rarity	The hard shore habitat is not rare and there were no rare species present.
Re-creatability	Can be easily recreated.
Fragmentation	No artificial fragmentation, but naturally fragmented by areas of sandy shore.
Linkage	Contiguous with hard shore habitat that extends eastwards along the north Peng Chau coastline for approximately 180m (including 100m within the boundary of the ecological assessment area).
Potential Value	Potential value limited by factors including water quality, shore depth (narrow due to granite coastal cliff), and natural wave action that limits species richness / community diversity.
Nursery / Breeding Ground	Of local significance to hard shore organisms, but no special value.
Age	N/A
Wildlife Abundance / Richness	High abundance of typical ‘fouling’ organisms and species richness.
Ecological Value	Low / Moderate value by virtue of the area and length of habitat.

Coastal Scrub

7.4.69 The evaluation of the ecological value of the coastal scrub habitat is presented in Table 7.12 below.

Table 7.12 Ecological Evaluation of the Coastal Scrub habitat

Criteria	Evaluation
Naturalness	Appears to be natural and is physically intact. Likely subject to localised fire damage.
Size	Coastal scrub habitat in the assessment area covers approximately 5.80 ha.
Diversity	Moderately diverse with a range of short shrub, grasses and ferns present. The Dichotomy Forked Fern Dicranopteris pedata is dominant. Birds and butterflies are moderately diverse, although the only uncommon species of note was the Great Swift butterfly.
Rarity	Habitat type is widespread in upland areas of Peng Chau. No rare species encountered.
Re-creatability	Some possibility to recreate, although several years would likely be required to return the habitat to one of similar structure and diversity.
Fragmentation	There is a sizable grave area and various isolated gravesites in and adjacent to this habitat, but it is generally not fragmented.
Linkage	Good linkage with similar habitat type across north and east Peng Chau.
Potential Value	Potential that if left undisturbed, through ecological succession the scrub community may develop into tall shrub habitat and ultimately woodland.
Nursery / Breeding Ground	No breeding grounds were noted during survey, but this habitat type will likely have some such role for insects, reptiles and possibly resident birds.
Age	Likely to be around 10-15 years old in places, although the likelihood of localised fire damage from grave areas means some areas will be younger.
Wildlife Abundance / Richness	Moderate. The low shrub community offers a range of flowering and fruiting plant species that are particularly attractive to birds and butterflies.
Ecological Value	Moderate value due to size, linkage and value to wildlife.

Secondary Woodland

7.4.70 The evaluation of the ecological value of the secondary woodland habitat is presented in Table 7.13 below.

Table 7.13 Ecological Evaluation of the Secondary Woodland habitat

Criteria	Evaluation
Naturalness	Appears to be natural and is physically intact, but is close to existing sources of disturbance from adjacent development. No evidence of recent fire damage, but adjacent to a sizable area of graves.
Size	Secondary woodland in the assessment area covers approximately 0.15 ha.
Diversity	Moderately diverse habitat, mainly comprising immature and semi-mature native broadleaved tree and shrub species, but also with occasional mature tree specimens. Various common herb, grass and creepers are present.
Rarity	Habitat locally uncommon, but similar habitat type but of far greater ecological value is widespread on nearby Lantau Island and other parts of the HKSAR. No rare species encountered.
Re-creatability	Difficult to recreate given age and size of the habitat.
Fragmentation	Unfragmented.
Linkage	A single isolated stand of woodland, but with linkage to the east with partly undisturbed coastal scrub habitat.
Potential Value	Potential to develop into mature broadleaved woodland provided there is no fire damage to the habitat. Potential for lateral extension of the woodland through ecological succession of adjacent coastal scrub habitat.
Nursery / Breeding Ground	Potential for bird and other wildlife breeding is limited due to the small size of the woodland stand. Natural vegetation growth and regeneration likely limited due to vegetation density (light limiting).
Age	Most vegetation is immature / semi-mature trees. Age ~20 years. Isolated pockets of more mature trees likely to be 40+ years old.
Wildlife Abundance / Richness	Limited due to small habitat area.
Ecological Value	Moderate value due to combined naturalness, linkage, potential and age.

Developed / Disturbed Area

7.4.71 The evaluation of the ecological value of the developed / disturbed area is presented in Table 7.14 below.

Table 7.14 Ecological Evaluation of the Developed / Disturbed Area

Criteria	Evaluation
Naturalness	Completely artificial habitat.
Size	The developed / disturbed area in the assessment area covers approximately 0.90 hectares.
Diversity	Very low – only weed and ornamental flora species and common birds / butterfly species present.
Rarity	Habitat is artificial. No rare species.
Re-creatability	N/A
Fragmentation	N/A
Linkage	N/A
Potential Value	Limited – only by planting with native vegetation and / or increasing coverage of vegetation.
Nursery / Breeding Ground	None identified.
Age	N/A
Wildlife Abundance / Richness	Minimal. Restricted to common and opportunistic bird species.
Ecological Value	Very Low value as an artificial and continuously disturbed area.

7.5 Impact Assessment & Evaluation

Methodology

7.5.1 The assessment of ecological impacts has been conducted with reference to Annex 16 of the EIAO 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.

7.5.2 For sub-tidal ecology – particularly coral impacts – the assessment makes use of calculations for suspended solids levels at the closest coral community to the Project area. The area of habitat directly affected by dredging and / or reclamation activities has also been calculated and the impact significance has been evaluated with reference to the criteria listed in Table 1, Annex 8 of the EIAO TM. These criteria are: Habitat Quality (Table 7.9 – Table 7.14 refer); Species (protection status, distribution and rarity); Size / Abundance of affected area / species; Duration and Reversibility of impact; and Magnitude of environmental change.

Construction Phase

Sub-tidal Ecology

7.5.3 The Project requires the dredging of approximately 14,000m³ of seabed material from an area of approximately 0.57 hectares (ha). Of this area, approximately 0.33 ha will be permanently lost under the reclamation. The remaining 0.24 ha will be temporarily affected by the dredging. Calculation of these areas is presented in Appendix 7.3.

7.5.4 The marine benthic community in the assessment area is characterised by a range of common species that are not of any particular conservation significance. The 0.57 ha of shallow sub-tidal habitat to be directly impacted (i.e., dredged) does not support any live corals. Of this area, the 0.24 ha that will be temporarily affected by dredging activities only will be available for natural recolonisation by marine benthic species once the construction works are complete.

7.5.5 The recolonisation process will likely take in the order of weeks to months for most marine benthic species. On completion of the marine works the sloping seawall will also be available for colonisation by a range of species (particularly gastropods), and potentially mobile coral larvae from the nearby coral community east of Tai Lei.[****]

7.5.6 Overall the ecological impact of the reclamation, without mitigation, is considered to be low by virtue of the low ecological value of the habitat and the availability of similar undisturbed coastal marine habitat along the north and northeast coastline of Peng Chau.

7.5.7 In summary, without mitigation there will be a net permanent loss of approximately 0.33 ha of marine benthic habitat. Some artificial marine benthic habitat will, however, be created through construction of the sloping seawall along the seaward-edge of the EVA link and around the helipad. The significance of this mitigation is discussed under the sub-section 7.6.

7.5.8 As regards water quality-induced impacts from dredging activities, dredging at the helipad and the associated EVA will lead to some SS elevation at the coral sites identified. However, the maximum SS elevation at the identified coral sites around Tai Lei Island is at a negligible level of 0.002mg/l and the sedimentation rate is estimated to be considerably less than 0.1kg/m²/d. As such, no significant adverse impacts on any of the coral communities in the assessment area are anticipated from dredging activities [Figure 7.1 refers].

7.5.9 The other species in the marine benthic community in the assessment area are typical fouling species that are widespread in coastal waters of the HKSAR, and which are not of conservation significance. The low predicted sedimentation rate (i.e., the small scale and duration of the dredging) combined with the natural flushing of the Project area means that no significant adverse water quality-induced ecological impacts on the marine benthic community are anticipated.

Inter-tidal Ecology

7.5.10 The Project will lead to the permanent loss of most of the inter-tidal habitat within the Project area through reclamation. This amounts to approximately 0.10 ha of mixed sandy and rocky / boulder habitat, as follows:

· Sandy shore: approximately 0.01 hectares (~80m length).

· Rocky / Boulder shore: approximately 0.09 hectares (~ 160m length).

7.5.11 The only inter-tidal habitat within the Project area not to be entirely lost is the most easterly and larger of the two sandy beaches, where neither infauna nor infauna was recorded through the ecological baseline survey. Most (~ 80%) of this sandy beach would not be reclaimed for the Project.

7.5.12 The inter-tidal habitats are characterised by a community of generally low species diversity, with no infauna recorded through the ecological baseline survey due to the lack of suitable substrate. All epifauna species recorded were common and typical of hard shores in the western HKSAR. No species of conservation significance were recorded.

7.5.13 Overall the ecological impact of the reclamation on the inter-tidal habitat is considered to be low by virtue of the low ecological value of the habitat and the availability of similar undisturbed inter-tidal habitats along the north and northeast coasts of Peng Chau.

7.5.14 There will be some replacement of the permanently lost inter-tidal habitats through the construction of the sloping seawall along the seaward-edge of the EVA link and the helipad, as discussed under sub-section 7.6.

Terrestrial Ecology

7.5.15 The construction works will be primarily along the Pak Wan shoreline that is generally characterised by rock and boulder habitat. There is some terrestrial vegetation growing in some areas of the backshore, but such areas are generally restricted to locations on the rocky cliff-face above the splash zone. There will be no construction works at the backshore or cliff-face where vegetation exists. Butterfly use of the shoreline area is limited due to the general absence of vegetation, compounded by seawater spray and a general wind climate (i.e., turbulence) that is not conducive to butterfly activity.

7.5.16 Given that the works are restricted to the shoreline area, and as there is a steep cliff-face separating the shore from the inland terrestrial habitats, there will be no direct or indirect impacts on the coastal scrub or secondary woodland habitats from the construction of the Project.

7.5.17 There is one area of disturbed land situated between Sea Crest Villa and the small sandy beach area at the western side of the Project area that will be directly affected by the Project. This area of land is presently (as of April 2005) occupied by the works area for HAD’s ongoing Pak Wan footpath improvement works. As such, this area is largely disturbed. The baseline ecological survey did not record any species of ecological significance from this disturbed area, from which approximately 10m² of vegetation will be cleared – predominantly the grasses Chloris barbata and Miscanthus sinensis that are of low ecological significance. The impact is thus negligible and no impact mitigation is considered necessary.

Operation Phase

Sub-tidal Ecology

7.5.18 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.

7.5.19 As concluded in the water quality impact assessment, the small scale of the Project and the coastal works involved, and the absence of any other physical constraints to water flow in the Project area, mean that no hydrodynamic and / or associated water quality impacts are anticipated during the operational phase of the Project.

Inter-tidal Ecology

7.5.20 As with sub-tidal ecology, no waste / materials will be generated and no water quality impacts are anticipated that could affect adjacent areas of shoreline.

7.5.21 As with sub-tidal ecology, no hydrodynamic and / or associated water quality impacts are anticipated during the operational phase of the Project.

Terrestrial Ecology

7.5.22 The operational helipad will be a source of noise when in use that has the potential to disturb birds in the Project area. There may also be some localised air turbulence that could disturb birds and butterflies in the coastal areas and at the backshore behind the proposed helipad. There may also be some visual disturbance to certain shorebirds, such as the reef egret Egretta sacra and the Grey Tailed Tattler Tringa brevipes – both of which are localised species that are sensitive to human intrusion.

7.5.23 As the helipad is to be situated approximately 50 metres from the coastal scrub habitat, no significant impacts on birds or butterflies in this habitat are anticipated. This coastal scrub habitat is extensive along the northern end of Peng Chau and species that inhabit it have a large contiguous area for refuge. Furthermore, no nesting areas or breeding birds were noted during the course of the baseline ecological survey.

7.5.24 As regards the two species of shorebirds of some conservation note observed within the assessment area (i.e., E. sacra and T. brevipes), with the construction of the Project it is possible that these species would prefer more natural rocky shoreline and would vacate the immediate Project area. This is particularly the case with Tringa brevipes that was observed approximately 100m east of the proposed Project area in a very sheltered / protected part of the rocky coastline. For both of these species, there is sufficient available undisturbed coastal habitat for refuge along the north and northeast of Peng Chau in the event of noise or visual disturbance, while when the helipad is not in use the Project area would be available for use by these species. As such, no significant impacts are anticipated.

Cumulative Impacts

7.5.25 The marine works for the Peng Chau STW submarine outfall shall be developed by the open trench method in August 2005 for completion around April 2006. Marine works for the Peng Chau Helipad are scheduled between February and September 2006. Although there is a period of around 2 months concurrent works, the impact assessment has indicated no overlap in affected area. As such, no cumulative water quality-induced ecological impacts are anticipated.

Summary of Ecological Impacts

7.5.26 Table 7.15 below summarises the predicted ecological impacts and their significance.

Table 7.15 Summary of Ecological Impacts

	Construction Phase	Operational Phase	Cumulative Effects
Sub-tidal Ecology	· Permanent loss of ~0.33 ha of marine benthic habitat. Mitigation proposed. · Temporary loss of ~0.24 ha of marine benthic habitat. Natural recolonisation predicted, and no mitigation proposed. · Localised water quality impacts. No coral impacts predicted, but precautionary measures proposed. · Overall, no adverse direct or indirect impact on species of conservation significance.	No significant impacts predicted. No mitigation proposed.	No significant impacts predicted. No mitigation proposed.
Inter-tidal Ecology	· Permanent loss of ~0.10 ha of mixed sandy and rocky / boulder shore habitat. Mitigation proposed. · Overall, no adverse direct or indirect impact on species of conservation significance.	No significant impacts predicted. No mitigation proposed.	No significant impacts predicted. No mitigation proposed.
Terrestrial Ecology	· Clearance of ~10m^2 of weedy vegetation. Natural recolonisation predicted, and no mitigation proposed.	No significant impacts predicted. No mitigation proposed.	No significant impacts predicted. No mitigation proposed.

7.6 Impact Mitigation & Residual Impact Assessment

Construction Phase

Sub-tidal Ecology

7.6.1 Permanent Habitat Loss: There will be some mitigation for the permanent loss of 0.33 ha of marine benthic habitat through the creation of artificial seawall habitat. The marine area of sloping seawall to be constructed will cover approximately 0.08 ha, based on an estimated average width (seawall foot and lower slope) of 4 metres and a total seawall length of approximately 200 metres. However, after mitigation there would still be a net loss of approximately 0.25 ha of marine benthic habitat.

7.6.2 The substrate of the artificial habitat will be granite boulder, similar to the substrate along the existing rocky and boulder shoreline and as occasionally present in the shallow coastal waters. It is anticipated that the marine seawall section will be naturally colonised by the same taxa as exist in the baseline marine benthic community.

7.6.3 It is anticipated that the rough texture of the artificial boulder seawall may be conducive to colonisation by hard corals from established communities nearby. Such an occurrence has been observed on the seawall constructed under the Yung Shue Wan Phase 1 Reclamation project, with hard corals having become well established in a period of approximately 3-4 years from completion of construction (BMT, 2003). Furthermore, the nearest pre-construction coral community to the Yung Shue Wan Phase 1 Reclamation seawall was approximately 400 metres, compared with a distance of approximately 110 metres between the east Tai Lei coral community and the nearest section of seawall proposed under the Peng Chau helipad project.

7.6.4 Should corals colonise the seawall then this would give the Project area a significantly higher marine ecological value than under baseline conditions. It could also be expected that should corals colonise the proposed seawall that a generally more diverse and ecologically valuable marine community would develop. For example, increased fish diversity. Thus, although the Project would lead to a net loss in the area of marine benthic habitat, it is considered that the adverse residual impact is of low significance given the low baseline ecological value and increased potential ecological value from seawall development.

7.6.5 Water Quality: While the water quality calculations do not predict any adverse impact on the live coral community at east Tai Lei, as this community (and other coral communities in the vicinity) is of some local conservation significance, it is proposed that a silt curtain be used for the duration of dredging works as a precautionary measure to ensure no adverse impacts.

Intertidal Ecology

7.6.6 Permanent Habitat Loss: The proposed seawall would provide mitigation for the permanent loss of approximately 0.10 ha of inter-tidal habitat; most of which would be all rocky / boulder shore habitat in the Project area. This sum includes approximately 0.01 ha of sandy beach, although most of the sandy beach habitat in the Project area will not be affected.

7.6.7 The inter-tidal area of sloping seawall to be constructed will cover approximately 0.12 ha, based on an estimated average width of 5 metres and a total seawall length of approximately 200 metres – an overall net increase of 0.02 ha of inter-tidal habitat area. This is a balance of the net loss of 0.01 ha of low ecological value sandy beach habitat and the net gain of 0.03 ha of higher ecological value rocky / boulder shore habitat. Overall, there would be no significant adverse residual ecological impacts.

7.7 Environmental Monitoring & Audit Requirements

7.7.1 Construction phase monitoring is not proposed as the suspended sediment impact zone is not predicted to reach closer than 75m from the east Tai Lei coral community, and since a silt curtain(s) is to be used around the dredger as a precautionary measure.

7.7.2 No operational phase monitoring is required as there is no coral in the Project area that could be affected to by localised hydrodynamic change or increased shading, while it is universally accepted that intertidal and sub-tidal sessile invertebrates would colonise the proposed artificial sloping seawall.

7.8 Conclusions & Recommendations

7.8.1 The Project requires approximately 14,000m³ of dredging covering a seabed area of approximately 0.57 ha. Of this area, approximately 0.33 ha of marine benthic habitat will be permanently lost under the reclamation, with the remaining 0.24 ha temporarily affected and available for recolonisation on completion of marine works. There will also be the permanent loss of approximately 0.1 ha of mixed sandy, rocky and boulder habitat.

7.8.2 As regards impact mitigation, a length of approximately 200m of artificial sloping boulder seawall is to be constructed that will provide some level of mitigation for the permanent loss of natural habitat. Approximately 0.08 ha of marine benthic habitat and 0.12 ha of inter-tidal habitat can be created, resulting in a net loss of some 0.25 ha of marine benthic habitat and a net gain of some 0.02 ha of inter-tidal habitat. Given the low baseline ecological value of the marine and inter-tidal habitat at Pak Wan, the adverse residual impact is not considered significant.

7.8.3 The small scale and short duration of the marine works will not cause any adverse water quality-induced impacts on the nearest coral community at east Tai Lei. No significant terrestrial ecology impacts are anticipated.

7.8.4 No significant ecological impacts are anticipated during the operational phase of the Project.

7.8.5 There are no monitoring requirements for the Project.

7.9 References

· AFCD (2003). Sightings of Chinese White Dolphin and Finless Porpoise around Waters of Peng Chau. Marine Conservation Division, AFCD.

· Bascombe, M.J., Johnston, G. and Bascombe, E.S. (1999). The Butterflies of Hong Kong.

· Binnie Consultants Ltd. (1995). Fill Management Study, Phase IV – Marine Ecology of Hong Kong: Report on Underwater Dive Surveys. Volume I, January 1995.

· BMT Asia Pacific Limited (2003). Agreement No 18/2002 (EP): EIA Study for Construction of Helipads at Peng Chau and Lamma Island – Investigation. Key Issues Report. Unpublished final report submitted to Civil Engineering Department, HKSAR Government.

· CDM (2004). Agreement No. CE 83/2001 (DS) Peng Chau Sewage Treatment Works Upgrade – Investigation, Design and Construction. Environmental Impact Assessment Report. Report submitted to Drainage Services 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 of the HKSAR Government. Centre for Coastal Pollution and Conservation, City University of Hong Kong.

· DeVantier, L.M., De’Ath, G., Done, T.J. and Turak, E. (1998). Ecological Assessment of a complex natural system: A case study from the Great Barrier Reef. Ecological Applications 8: 480-496.

· DeVantier, L.M., Turak, E., Al-Shaikh, K.A. and De’Ath, G. (2000). Coral communities of the central-northern Saudi Arabian Red Sea. Fauna of Arabia 18: 23-66.

· ERM (1998). Fisheries Resources and Fishing Operations in Hong Kong Waters. Final report for the Agriculture & Fisheries Department of the HKSAR Government.

· Fabricius, K.E. (2001). Identification and documentation of octocorals from Hong Kong waters. Unpublished final report for the Agriculture, Fisheries and Conservation Department, HKSAR Government.

· HAD (2002). Construction of Footpath along Pak Wan, Peng Chau Rural Planning & Implementation Strategy. Home Affairs 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.

· Oceanway Corporation Ltd. (2001a). Underwater Survey at Peng Chau and Neighbouring Islands. Unpublished final report submitted to the Agriculture, Fisheries and Conservation Department, HKSAR Government.

· Oceanway Corporation Ltd. (2001b). Reconnaissance Dive Survey: Tai Lei Island, Peng Chau. Unpublished final report submitted to the Agriculture, Fisheries and Conservation Department, HKSAR Government.

· Oceanway Corporation Ltd. (2002). Corals and coral communities of Hong Kong: Ecological values and status 2001-02. Underwater Survey in Coastal Waters of Hong Kong. Unpublished final report submitted to the Agriculture, Fisheries and Conservation Department, HKSAR Government.

· Viney, C., Phillipps, K. and Lam, C.Y. (1994). Birds of Hong Kong and South China. Government Printer, Hong Kong.

· Young, J.J. and Chung, L.P. (2001). Butterflies of Tai Po Kau Nature Reserve: A Checklist of Butterflies [recorded in Tai Po Kau Nature Reserve and Hong Kong]. Commercial Press, Hong Kong.

8 fisheries

8.1 Introduction

8.1.1 This section presents the approach to and the findings of the fisheries impact assessment. The aim of the assessment is to examine all fisheries resources within the assessment area to ensure their protection.

8.1.2 For the purpose of this assessment the ‘assessment area’ is the same as that for the marine ecology assessment, i.e., a 1 km radius around the Project site.

8.2 Assessment Approach

8.2.1 The fisheries assessment has been undertaken in accordance with the criteria and guidelines in Annexes 9 and 17 respectively of the EIA-TM, and with reference to the requirements of Clause 3.4.4 of the EIA Study Brief as follows:

(i) Description of the physical environmental background;

(ii) Description and quantification as far as possible existing capture fisheries activities;

(iii) Description and quantification as far as possible the existing fisheries resources;

(iv) Identification of parameters and areas that will be affected;

(v) Identification and quantification as far as possible any direct/ indirect and onsite/ offsite impacts of fisheries;

(vi) Evaluation of impacts and make proposals for any environmental mitigation measures as per Clause 3.4.4.3(vi) of the EIA Study Brief; and

(vii) Review the need for monitoring and, if necessary, propose a monitoring and auditing programme.

8.3 Applicable Regulations, Standards and Guidelines

8.3.1 In addition to the requirements of the EIAO (Cap. 499), the Fisheries Protection Ordinance and Regulations (Cap. 171) are applicable. This Ordinance exists “to promote the conservation of fish and other forms of aquatic life within the waters of Hong Kong and … to prevent activities detrimental to the fishing industry”.

8.3.2 The Marine Fish Culture Ordinance (Cap. 353) is generally not applicable to this Project as there are no fish culture zones within 1 km of the site (the nearest zones are Ma Wan and Cheung Sha Wan – both ~7km away).

8.3.3 A maximum suspended solids concentration of 50 mg/l has been used as a guideline for fisheries impact assessment. The guideline was derived by CityU (2001) using local chronic toxicity data.

8.4 Assessment Methodology

8.4.1 The assessment methodology for fisheries comprised two parts: literature review, and interview / site observations.

8.4.2 The literature review relied upon the AFCD Port Survey 2001/02 (AFCD, 2003) and the AFCD Port Survey 1996/97 (AFCD, 1998). These surveys characterise the fisheries resources and fisheries value in Peng Chau waters.

8.4.3 The field survey element involved informal interviews with fishermen on the Tai Lei bridge – a popular fishing location – conducted on 30^th April 2003. The fishermen interviewed could be considered as ‘recreational’, although the fish catch was for personal consumption. The interviews were supplemented with direct and indirect observations of fishing activity around the coastline of Tai Lei and north Peng Chau during April and May 2003.

8.4.4 Incidental observations of fish were made during the ecological dive survey conducted at high water on 27^th April 2003 [Section 7 also refers].

8.5 Fisheries Baseline

Literature Review

8.5.1 The Port Survey 2001/02 (AFCD, 2003) provides a range of fisheries data, including the following that has been used to generate some of the tables that follow:

· Distribution of fishing operations (number of vessels)

- Overall

- By vessel type

· Major species of fish catch (adult fish & fish fry)

· Distribution of fisheries production (adult fish) in terms of kg / hectare

- Overall

- By vessel type

- By Top 10 families

· Distribution of fisheries production (fish fry) in terms of tails / hectare

· Distribution of fisheries production in terms of dollar value (adult fish & fish fry)

8.5.2 Accordingly, catch data for the top ten HKSAR families in waters (i) the north of Peng Chau, and (ii) to the east, south and west of Peng Chau, provide an indication of fish / crustacean family abundance. Figure 8.1 displays the delineation of these two areas.

8.5.3 To represent the worst-case scenario for impact assessment, the peak adult fish productivity data (kg/ha) for each of the top 10 families for the two Peng Chau fishing areas has been ranked against the top 10 major species of fish catch for the entire HKSAR.[††††] This comparison is presented in Table 8.1.

Table 8.1 Top Ten Ranked Adult Fish / Crustacean Families (from AFCD, 2003)

Family	Rank
	HKSAR	Peng Chau
Rabbitfish (SIGANIDAE)	1	=1
Sardines / Shad (CLUPEIDAE)	2	=6
Croakers (SCIAENIDAE)	3	3
Scad (CARANGIDAE)	4	=6
Squid	5	9
Shrimp	6	=4
Anchovy (ENGRAULIDAE)	7	10
Crab	8	=1
Seabreams / Breams (SPARIDAE)	9	=4
Threadfin bream (NEMIPTERIDAE)	10	8

Note: The top ranking category, “Mixed Species”, has been excluded from Table 8.1, as it comprises juvenile fishes only.

8.5.4 Of note from the above Table 8.1 the top ranked Family in both HKSAR and Peng Chau waters is the Siganidae. Other locally important taxa are crabs (mixed species), croakers Sciaenidae, seabream Sparidae, and shrimp (mixed species).

8.5.5 It is noted that the top ten families at Peng Chau presented in Table 8.1 are relative to the overall ranking for all HKSAR waters, and so it is possible that other families not included in the HKSAR top ten are locally important around Peng Chau. No specific data for the Peng Chau area were presented in the Port Survey 2001/02, although area-specific data does exist from the Port Survey 1996/97. Accordingly, the top adult species caught (by weight) specifically in the Peng Chau fishing zone based on AFCD (1998) data are presented in Table 8.2.

Table 8.2 Top Adult Fish / Crustacean Species by Weight from Peng Chau (AFCD, 1998)

Species	Common Name	Family
Acetes spp.	Silver Shrimp	N/A
Siganus oramin	Rabbitfish	SIGANIDAE
Charybrids cruciata	Red Crab	N/A
Johnius belengeri	Croaker	SCIAENIDAE
Pseudosciaena crocea	Yellow Croaker	SCIAENIDAE
Ilisha elongata	White Herring	PRISTIGASTERIDAE *
Apogon spp.	Cardinal Fish	APOGONIDAE *
Eleutheronema tetradactylum	Threadfin	POLYNEMIDAE *
Clupanodon punctatus	Gizzard Shad	CLUPEIDAE

Notes: The top ranking category, “Mixed Species”, has been excluded from Table 8.2, as it comprises juvenile fishes.

* Family not in top ten as shown in Table 8.1.

8.5.6 Of the above species, three belong to families not listed in Table 8.1: Ilisha elongata (Pristigasteridae), Apogon spp. (Apogonidae) and Eleutheronema tetradactylum (Polynemidae). Thus, these species / families are of some fisheries importance at Peng Chau.

8.5.7 The Port Survey 2001/02 also provides data on fisheries production (fish fry) in terms of tails / hectare. Fry production in the waters around Peng Chau was in the lowest of six assessment categories: 0 – 50 tails / hectare. The scenario was the same for all southern and western HKSAR waters, with the exception of fishing areas to the east of Peng Chau (around Kau Yi Chau) and southwest of Peng Chau (around Mui Wo / west Hei Ling Chau) where fry production was in the second lowest category of 50 – 100 tails / hectare.

8.5.8 For comparison, fry production in eastern waters (i.e., Port Shelter, Tai Long Wan and Tolo Harbour) was generally in the category 100 – 500 tails / ha, while fry productivity in far northeast waters (i.e., Double Haven / Yan Chau Tong Marine Park) was between 1,000 – 3,000 tails / ha.

8.5.9 Despite the low fish fry productivity, the overall value of fisheries production (adult fish and fish fry) around Peng Chau is high, at HK$ 5,000 – 10,000 / ha. This places the waters immediately around Peng Chau is the second highest of six value categories for the HKSAR, and indicates that while the fish fry productivity is low, the adult fishery is of high value.

8.5.10 In terms of overall productivity and fisheries value (HK$ value and ranking), the results of the Port Survey 2001/02 correspond with the results of the first Port Survey 1996/97, as summarised in Table 8.3 below.

Table 8.3 Production of Peng Chau Fisheries Areas (AFCD, 1998)

		Production (Catch / ha –1)			Rank Production / HKSAR Total
Name (Code)	Area (ha)	Adult Fish (Kg)	Fry (Tails)	Value (HK$)	Adult Fish	Fry	Value
Peng Chau (0027)	542	441	N/A	9,451	17 / 210	N/A	22 / 210

Note: Peng Chau fishing zone from AFCD (1998) covers all waters up to 1 km around Peng Chau.

8.5.11 For comparison, the overall value of fisheries production around Peng Chau based on AFCD (2003) data is the same as that at the Double Haven / Yan Chau Tong Marine Park. Other smaller outlying islands in the western HKSAR have a similar overall production value to Peng Chau (e.g., Lamma Island, Soko Islands and Shek Kwu Chau), while out of all southern and western HKSAR waters only Cheung Chau, Kau Yi Chau and the Po Toi Island have a higher valued total productivity.

8.5.12 The Port Survey 2001/02 presents data for fisheries productivity for a range of fishing methods. Based on a total of between 400 and 700 fishing vessels of all types, Table 8.4 presents the peak production by each method from the two Peng Chau fishing areas.

Table 8.4 Production Range for Fishing Methods at Peng Chau (AFCD, 2003)

Fishing Operation	Peak Production (kg / ha)
Stern Trawler	0
Pair Trawler	0
Shrimp Trawler	100
Hang Trawler	200
Gill Netter	50
Long Liner	50
Hand Liner	50
Purse Seiner	200
Sampan (P4’s)	100
Miscellaneous Craft	50
All Methods	800

8.5.13 For each of the four most productive fishing methods presented in Table 8.4 for Peng Chau waters, the percentage contribution of each method to overall HKSAR productivity is as follows: Shrimp Trawler [20%], Hang Trawler [5%], Purse Seiner [7%] and Sampan [40%] (AFCD, 2003).

8.5.14 As regards the commercial value of individual taxa in Peng Chau waters, no such data was presented in the Port Survey 2001/02. However, an estimate can be made with reference to data on the top adult species caught (by weight) in the Peng Chau fishing zone from the Port Survey 1996/97 (AFCD, 1998).

8.5.15 Table 8.5 below presents an estimate of commercial value for these top adult species based on averaged real commercial data (wholesale price / kg) released by the Fish Marketing Organization (FMO) for various dates in August 2003. A ranking method has been devised based on FMO prices, as follows:

· Very Low Value (up to HK$ 10 / kg).

· Low Value (HK$ 11 – 30 / kg).

· Moderate (HK$ 31 – 60 / kg).

· High (HK$ 61 – 90 / kg).

· Very High (HK$ 91+ / kg).

Table 8.5 Commercial Value of Top Adult Fish Species around Peng Chau (AFCD, 1998; BMT, 2003).

Species	Common Name	Commercial Value
Acetes spp.	Silver Shrimp	Moderate / High *
Siganus oramin	Rabbitfish	Very Low
Charybrids cruciata	Red Crab	Unavailable
Johnius belengeri	Croaker	Very Low
Pseudosciaena crocea	Yellow Croaker	Moderate
Ilisha elongata	White Herring	Unavailable
Apogon /Apogonichthys spp	Cardinal Fish	Very Low
Eleutheronema tetradactylum	Threadfin	Moderate
Clupanodon punctatus	Gizzard Shad	Very Low / Low *

Notes: The top ranking category, “Mixed Species”, has been excluded from Table 8.4, as it comprises juvenile fishes.

* Estimated value based on various past records and professional judgement.

Field Survey

8.5.16 The survey was undertaken through direct and indirect observations of fishing activities within and adjacent to the assessment area.

8.5.17 Within the assessment area, along the Pak Wan shoreline, evidence of fishing activity includes:

· Direct and indirect observations of shellfish harvesting on the rocky shore (and along much of the north coast of Peng Chau) as indicated by rock scars. As the number of oysters removed was significant within the study area (i.e., complete removal), it is possible that the oysters have some commercial value and may have been sold into the local market (as opposed to only personal consumption). It should be noted that no rock oysters were observed during the ecological inter-tidal survey.

· Remnants of hand-lines, fishing weights and nets along the Pak Wan shoreline. Some fishing gear would be used for fishing from the rocky shore, while others would be deployed from small boats (P4’s) slightly offshore. For example, 2 - 3 P4’s were observed fishing with hand-lines and nets in the assessment area in May 2003.

· Dead fish, apparently cast-aside due to small size and / or unsuitability for consumption – particularly the Hong Kong puffer-fish Takifugu alboplumbeus, of which several were found on the rocky promontory beside the proposed helipad footprint.

8.5.18 The Tai Lei bridge is a popular fishing area for hand-liners, with approximately ten individuals fishing off the bridge – most with 2-3 hand-lines each. From interviews and supporting observations, fishing is predominantly for self-consumption.

8.5.19 Table 8.6 summarises the common catch species based on site interviews and observations. As with the data in Table, commercial value is generally based on averaged market prices from the FMO.

Table 8.6 Common Fish Catch species at Northwest Peng Chau (BMT, 2003)

Species	Common Name	Commercial Value
Diagramma pictum	Painted sweetlip	Unavailable
Monacanthus chinensis	Filefish	Low
Acanthopagrus latus	Yellow-finned seabream	Moderate
Pagrus major	Red seabream	Moderate *
Mylio macrocephalus	Black bream	Unavailable
Lateolabrax japonicus	Sea perch	Moderate
Apogon fasciatus	Broadbanded cardinalfish	Very Low

Note: * Estimated value based on various past records and professional judgement.

8.5.20 Of some note during the fisheries survey were observations of schools of adult Apogon fasciatus (broadbanded cardinalfish) in the shallows under the Tai Lei bridge, and beside the vertical seawall approximately 50m south of the bridge, indicating that this species is locally abundant in inshore waters of west / northwest Peng Chau. Based on data from the Port Survey 1996/97, A. fasciatus was ranked 8^th in terms of common adult fish catch in the Peng Chau area.

8.5.21 A number of jellyfish were also observed off the Tai Lei bridge, although it is not known if locally they have a commercial value. From interviews it was also determined there are occasional catches of sea cucumber from the bridge.

8.5.22 Other observations of fishing activity in the broader area include five trawlers and two sampans seen fishing with nets on the western side of Peng Chau. There is a small fleet of ~ 20 sampans (P4’s) moored at the south side of Tai Lei. A few of these boats were observed fishing the waters off Pak Wan using nets and hand-lines. However, fishing activity by this method in the immediate vicinity of the Project area would appear to be limited.

8.5.23 The waters further off the north coast of Peng Chau form part of the ferry route between Discovery Bay and Central. Evidence of fishing activity in these waters was limited to a small number of Hang Trawlers – typically only one vessel operating at any one time – observed throughout the period April – August 2003. The most popular area for Hang Trawlers in the general vicinity of the Project is the northern part of Tai Pak Wan (Discovery Bay) where there is no ferry traffic.

8.5.24 Only two species of fish were observed during the sub-tidal ecological survey were limited to just two species seen at very close quarters due to poor visibility: Therapon jarbua (tiger fish) and Sebasticus marmoratus (rock fish). Based on FMO (2003) data, both of these species have low commercial value.

8.6 Impact Assessment & Evaluation

8.6.1 The impact assessment shall draw upon the findings of the above literature review and field survey results, and the results of the water quality impact assessment.

8.6.2 Impact evaluated shall be conducted according to the criteria provided in Annex 9 of the EIA-TM, as follows:

· Nature of impact

· Size of affected area (permanent loss and water quality impact)

· Loss of fisheries resources / production

· Destruction of nursery and spawning grounds

· Impact on fishing activity

· Impact on aquaculture

8.6.3 Evaluation of fisheries impacts based on water quality (elevated suspended sediment levels) shall refer to guideline of 50 mg/l determined by CityU (2001).

Construction Phase

8.6.4 The Project will involve dredging over a marine area of some 0.57 hectares, and will result in the permanent loss of approximately 0.33 hectares of shallow coastal environment. As fish are highly mobile species, and as there are undisturbed coastal waters around the Project area, no significant adverse fisheries impacts are anticipated from the reclamation.

8.6.5 The potential for fisheries impacts through deteriorating water quality (i.e., the effects of increased suspended sediment and / or decreased dissolved oxygen levels from dredging activities) has been determined with use of the water quality calculations, as referred to in Section 6. The maximum elevation in suspended solids above baseline levels adjacent to the Project area were predicted for each of two dredging scenarios: (1) dredging at the proposed helipad footprint; and (2) dredging at the closest point of the proposed EVA link to the popular Tai Lei bridge fishing area – a distance of approximately 90 metres to the centre of the bridge.[‡‡‡‡]

8.6.6 Calculations prepared for the water quality impact assessment [Section 6] predict a maximum suspended solids elevation of approximately 0.002mg/l above baseline levels in waters below Tai Lei bridge for scenario (1) – a negligible increase as regards fisheries impacts. Suspended sediment levels would be more elevated within the immediate vicinity of dredging, although as only one dredger will be used during the works, suspended sediment levels greater than the 50 mg/l guideline would be highly localised around the immediate dredging location. In this case, adult fish would be able to avoid these areas, and no adverse fisheries impacts are anticipated.

8.6.7 As the scale and duration of the dredging works for the proposed EVA link are substantially smaller than the helipad dredging works, the extent of the mixing zone under scenario (2) is correspondingly smaller – estimated to be no greater than 25m either side of the dredging point at a water depth of 2m. The main fishing area of the Tai Lei bridge is approximately 90m from the closest EVA link dredging point and is some distance from the mixing zone. However, even at the edge of the mixing zone it can be expected that sediment levels would be within the 50 mg/l guideline. As with the helipad footprint dredging, adult fish can avoid areas of elevated sediment levels around the immediate dredging location, and no adverse fisheries impacts are anticipated.

8.6.8 While there will be greater elevations of suspended solids within the scenario (2) mixing zone close to the Tai Lei bridge, these coastal waters do not support any fisheries nursery area and do not appear to be important as a spawning ground. The adult fish that dominate the fish community are sufficiently mobile to avoid any area of localised water quality deterioration (given the small scale and short duration of dredging at this location). As such, no adverse fisheries impacts are anticipated from the Project.

8.6.9 As determined from Sub-section 8.5, based on the adult fish catch the waters around Peng Chau fall into the second highest of six production (HK$ value) categories for the HKSAR. Despite this, there are no aquaculture production areas in the area that would be affected by the Project. The area around the Tai Lei bridge where recreational fishing is popular can be considered as a kind of capture fishery. Despite this, no adverse fisheries impacts are anticipated at this location.

8.6.10 No fish nursery or spawning grounds have been identified in the Project area from the literature review and field surveys. The Port Survey 2001/02 concluded that fish fry production in waters around Peng Chau was low, at 0 – 50 tails / hectare. Accordingly, no destruction or disturbance of nursery or spawning grounds is anticipated from the Project.

8.6.11 While there is some fishing activity from the actual Pak Wan shoreline, as is evident from fishing debris, this is generally limited due to the narrowness, and hence inaccessibility, of the shore. Most fishing in the immediate vicinity is restricted to ‘hand-lining’ from the Tai Lei bridge, although the Project would not cause permanent loss of fisheries habitat (or general fishing opportunity) in this area.

8.6.12 Shore-based fishing activity at Pak Wan and from the Tai Lei bridge would appear to be recreational, rather than commercial.

8.6.13 Due to very shallow water depth, vessel-based fishing activity in the Project area at Pak Wan is limited to P4’s. It would also appear that this is not a popular fishing area as it is exposed and the waters are relatively rough compared to the leeward side of the Island. For the same reason, better vessel-based fishing opportunities exist in waters to south, east and west Peng Chau, and particularly towards the productive waters around Kau Yi Chau.

8.6.14 Given the scale of the Project and the distance from any areas of aquaculture activity, there will be no impacts on aquaculture resources. Accordingly, given the limited use of waters in the Project area for fishing, and the scale of the Project and duration of marine works, no significant impacts on fishing activity are anticipated.

Operation Phase

8.6.15 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.

8.6.16 The small scale of the Project and the coastal works involved, and the absence of any other physical constraints to water flow in the Project area, mean that no hydrodynamic and / or associated water quality and hence fisheries impacts are anticipated during the operational phase of the Project.

8.6.17 It is most likely that as the Project will improve access, opportunities for shore-based fishing in the area will increase. It is also possible that upon construction of the artificial boulder seawall along the seaward edge of the EVA and helipad, a range of benthic and fish species may be attracted to the area. Such a scenario has been observed at the seawall constructed under the Yung Shue Wan Phase I Reclamation project, and whereat signs of the development of a fairly diverse fish community were observed (BMT, 2003).

Cumulative Impacts

8.6.18 The marine works for the Peng Chau STW submarine outfall shall be developed by the open trench method in August 2005 for completion around April 2006. Marine works for the Peng Chau Helipad are scheduled between February and September 2006. Although there is a period of around 2 months concurrent works, the impact assessment has indicated no overlap in affected area. As such, no cumulative water quality-induced fisheries impacts are anticipated.

8.7 Impact Mitigation & Residual Impact Assessment

8.7.1 No adverse impacts are anticipated and no specific mitigation measures are required. However, the various good site practices that have been recommended to minimize water quality impact potential are also applicable for fisheries [Section 6.7 refers].

8.8 Environmental Monitoring & Audit Requirements

8.8.1 There are no EM&A requirements for fisheries.

8.9 Conclusions & Recommendations

8.9.1 While the Project will lead to the permanent loss of approximately 0.33 hectares of shallow coastal environment, the permanently affected area is not of any particular fisheries value being situated in very shallow coastal waters. There is unrestricted fisheries habitat in adjacent waters contiguous with the Project area, including undeveloped / undisturbed shallow coastal water habitat east of the Project area.

8.9.2 No significant water quality-induced impacts are predicted in the popular fishing area off Tai Lei bridge given the small scale of the dredging activities for the EVA link, while there are no impacts on the waters of this popular fishing area form the larger dredging activity scheduled for the helipad footprint due to the greater distance separation.

8.9.3 The operational Project will not give rise to any fisheries impacts, while there may be some fisheries benefits from the construction of approximately 200m length of artificial seawall habitat. No fisheries monitoring is necessary.

8.10 References

· AFCD (1998). Port Survey 1996/97. Fisheries Management Division, Agriculture, Fisheries & Conservation Department, HKSAR.

· AFCD (2003). Port Survey 2001/02. Fisheries Management Division, Agriculture, Fisheries & Conservation Department, HKSAR.

· BMT Asia Pacific Limited (2003). Agreement No 18/2002 (EP): EIA Study for Construction of Helipads at Peng Chau and Lamma Island – Investigation. Key Issues Report. Unpublished final report submitted to Civil Engineering Department, HKSAR Government.

· City University (2001). Agreement No. CE 62/98: Consultancy Study on Fisheries and marine Ecological Criteria for Impact Assessment. City University of Hong Kong. Final Report submitted to Agriculture, Fisheries & Conservation Department, HKSAR.

· FMO (2003). Wholesale Prices of Fresh Marine Fish on 13/08/2003: Fish Price Information for Castle Peak Wholesale Market. Fish Marketing Organisation.

9 CULTURAL HERITAGE IMPACT ASSESSMENT

9.1 Introduction

9.1.1 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 Peng Chau on cultural heritage and marine archaeology.

9.1.2 For the purpose of the marine archaeology assessment the ‘assessment area’ occupies an area offshore of about 300m² that includes the proposed helipad site and EVA link. The assessment area for the marine archaeology investigation is provided on Figure 9.1.

9.1.3 There is no specific requirement for terrestrial cultural heritage assessment in the EIA Study Brief. However, Clause 3.4.7.2 of the EIA Study Brief states that the cultural heritage assessment shall try to identify “other unknown items of archaeological and historical interests at or close to the proposed Project”. As such, the coastline and adjoining slopes above the helipad and EVA link were included in the terrestrial cultural heritage assessment area – a radius of approximately 100 metres from the Project location.

9.2 Assessment Approach

9.2.1 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 3.4.7 and 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 9.4 below.

9.3 Regulations, Standards and Guideline

9.3.1 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.

9.3.2 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.

9.3.3 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.

9.3.4 Other legislation that supplements the work of heritage preservation includes the Lord Wilson Heritage Trust Ordinance (Cap. 425) that came into operation in 1992.

9.4 Assessment Methodology

Marine Archaeology

9.4.1 As detailed in Appendix A of the EIA Study Brief, marine archaeology assessment involves four stages, as follows:

Baseline Study

9.4.2 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.

9.4.3 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.

9.4.4 Throughout the course of the assessment meetings and discussions were held with representatives of the Antiquities and Monuments Office (AMO).

Geophysical Survey

9.4.5 In accordance with marine archaeological investigation (MAI) guidelines a marine geophysical survey was carried out in the assessment area in October and 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.

9.4.6 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 9.6.

9.4.7 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 coordinated 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

9.4.8 The data examined during the desktop review and geophysical survey will be analyzed to provide an indication of the likely character and extent of archaeological resources with the assessment area. This would facilitate formulation of a strategy for investigation.

Remote Operated Vehicle (ROV) / Visual Diver Survey / Watching Brief

9.4.9 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 Peng Chau 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

9.4.10 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 study initially involves compiling details of geology and geomorphology in the assessment area through reference to geological maps; available bore hole data, early maps of the area and aerial photographs.

9.4.11 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

9.4.12 Verification of historical buildings and structures as well as existing and potential archaeological sites has been carried out in and around the assessment area.

9.5 Baseline Conditions

Geological and Topographical Setting

9.5.1 The geology of the area is of the medium grained tertiary intrusive igneous rhyolitic bedrock. Shallow colluvial deposits are also common along gentle swales along the northern coastline at Peng Chau. There is also large fine-grained acidic dyke which runs parallel to the coastline adjacent the development area. The coastline is moderately sloping with a small beach adjacent the area of the helipad footprint

Land use history: Historic background

9.5.2 Peng Chau has a recorded onshore archaeological site of the Neolithic period as well as an archaeological site where kiln remains of the historic period were discovered.

9.5.3 It is unlikely that there was any shore-based settlement at Peng Chau before 1725-1750, and doubtful that even the anchorage was much used before about 1700. The first shore-based settlement consisted of sheds and workshops on the landward side of a footpath that ran around the head of the bay that formed the anchorage (Sayer, 1975).

9.5.4 The northern edge of the original town is marked by the existing Tin Hau Temple that has been dated back to the 57^th year of Emperor Qianlong of the Qing Dynasty (i.e., the year of 1792). The town was a success, and even as early as 1834 there were enough fishing junks using the bay as their home anchorage to petition the Viceroy against abuses by the naval authorities. By 1857 there were 200 junks in the anchorage and an association was founded to protect their interests. Most of these 200 vessels were deep-sea trawlers engaged in the Yellow Croaker fisheries, but there were also a large number of inshore sampan fishermen, mostly Hoklos, who fished particularly for shrimps (ibid.).

9.5.5 The original settlement was extended in the middle nineteenth century by reclamation over the beach to provide a second row of shops on the seaward side of Wing On Street. Further large areas of reclamation north and south of the town were completed at the very end of the nineteenth century to support the lime-burning trade that, along with fishing, was the main industry of the town. Sayer (1975) reports that there were corals across the seabed between Peng Chau and East Lantau that could be dredged for stone to be burnt into lime – a resource much in demand by the building trade throughout the Pearl River Delta. There were regular ferries before 1900 running between Peng Chau and the cities of the Delta: it is likely that lime was a major part of the cargo they carried.

9.5.6 Before the late nineteenth century reclamations, the limekilns had been located mostly on the shore of East Lantau, although they continued to be operated by Peng Chau people. Early in the twentieth century reports state that nearby some 80 Peng Chau-based boats were actively dredging corals, and by which time 12 limekilns were in operation on the island. Some of the boats engaged in dredging were Hoklo sampans that collected coral part of the year, and fished for shrimps in the summer.

9.5.7 In the last few decades there has been considerable additional reclamation at Peng Chau, and the original shoreline is now well inland. It is likely that reclamation and new buildings disturbed much of the marine archaeological deposits.

Land use history: Prehistoric background

9.5.8 While the area surrounding the entire Hong Kong archipelago was dry land some 8, 000 – 10,000 years ago with sea-level stability being reached at 6,000 B.P – preservation of habitation sites of this period (now submerged) is likely to be rare.

Historical Building and Structures

9.5.9 Verification of historic buildings and structures was conducted in June 2003. The area covered the shoreline, slopes above (including graves sites) and various built structures adjacent to Sea Crest Villa.

9.6 Impact Assessment and Evaluation

Marine Archaeology

9.6.1 The geophysical survey recorded seabed levels in the assessment area range from -0.0 to -4.1 mPD (Cosine Ltd., 2003). The shallowest part of the study area is closest to shore, and the seafloor gently dips away to the north and northwest with few irregularities.

9.6.2 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.

9.6.3 The seabed for the most part is composed of rock rubble and cobbles. There appears to be a distinct edge of rubble and cobbles in the northern part of the site, which runs parallel to the shoreline. This may possibly be a rock terrace.

9.6.4 The northwest of the study area is composed of sand with boulders protruding from, or resting on, the seabed. There is a small depression in the seabed approximately 60 m to the north west of the high water mark. With reference to Figure 9.1, this depression is labelled item ‘A’. The feature is 0.5 m deep with a weakly elevated rim and irregular outline. It has been interpreted as possibly being coral rather than a rock outcrop. However, given its irregularity it is also possible that it could be a cultural feature.

9.6.5 Taking the difficulties of obtaining good quality data into consideration, some sense of the stratigraphy of the study area can be ascertained. Generally, the thickness of the coarse sand stratum increases with distance from shore. At approximately 10 to 15 m from shore there is little or no sand coverage. At approximately 70 m from shore the sediment thickness reaches 15 m. Areas of larger pebbles and small rock boulders were more obvious closer to the shoreline.

9.6.6 The sediments rest on bedrock, the gradient of the bedrock suggesting that prior to sea level rise in the early Holocene, the study area was once an exposed hillside. It was not possible to distinguish weathered rock, Grade IV to VI.

9.6.7 As regards step 2 of the MAI guidelines, establishing archaeological potential involved consideration of the potential for the following: shipwrecks; anchors; artefacts associated with submerged terrestrial sites; and / or artefacts from adjacent terrestrial sites.

9.6.8 Of these categories, the potential for encountering shipwreck remains was a possibility given the absence of any land reclamation in the study area, although the distance of the Pak Wan area from the main town would diminish the likelihood. The casting off of anchors from a vessel may be a response to trying to avoid getting shipwrecked, although the likelihood of finding such remains in the study area is considered very low. There is also some potential that the objects identified from the geophysical survey could be associated with past activity on the shoreline.

9.6.9 Task 3 of the MAI guidelines, dive survey, was enacted as a precautionary measure given: (i) the anomalies recorded during the geophysical survey; and (ii) the presence of ‘dead zones’ close to the shore that the geophysical survey was unable to survey due to shallow water depth constraints.

9.6.10 A dive survey of the helipad site was conducted on the 24^th June. A total of six separate dives were undertaken: three to examine the anomalies recorded during the geophysical survey and three long transects parallel to the coastline, in the rocky areas close to shore.

9.6.11 The visual diver survey at the Peng Chau study area found two possible distinct forms of cultural activity: (i) Artefacts (mostly ceramics) deposited on the seabed from shore; and (ii) Deposits of coral rubble offshore forming mounds. The coral mound is item ‘A’ as indicated on Figure 9.1. Item ‘B’ was confirmed to be a boulder.

9.6.12 As regards artefacts being deposited from shore, it would appear that these were mostly thrown from the cliff overlooking the study area. That this activity was partly linked with visitation to the graves located on the upper slope above the cliff as evidenced by the recovery of a fragment of a grave bowl. On initial examination the ceramics appear to be mostly that of ‘village ware’ of indistinct date and provenance, although likely to be less than 200 years old and of low archaeological significance.

9.6.13 The coral rubble mounds appear to have been deposited as a temporary dump for the lime burning activities on shore. Their possible association with early 20^th century industry on Peng Chau is notable although this material is also of low cultural significance.

Historical Buildings and Structures

9.6.14 Field investigation at the western edge of the proposed helipad site, at the backshore area, revealed a large deposit of kiln residue – presumably the refuse from an early 20^th century limekiln. It is likely that a large kiln was located immediately upslope from this deposit and has since been removed.

9.6.15 Several graves within 40-50m of the proposed development - above the beach - were noted although these will not be impacted by Helipad development. A small temple and sister shrines located about 50m south of Sea Crest Villa will also not be impacted by the Project.

9.7 Impact Mitigation & Residual Impact Assessment

No potential impacts on resources of cultural heritage or archaeological value will arise from the proposed Project. As such, there is no mitigation requirement.

9.8 Environmental Monitoring & Audit

9.8.1 There are no archaeological / cultural heritage monitoring and audit requirements for the Project.

9.9 Conclusions & Recommendations

9.9.1 Given that two items / objects were recorded during the geophysical survey at Pak Wan, and the limitations of the geophysical survey in accessing shallow coastal waters due to insufficient water depth, it was decided to conduct a precautionary dive survey to cover these areas.

9.9.2 The two items / objects were recorded by the marine geophysical survey were an area of coral rubble that was deposited from the shoreline, and a boulder. Various small items were recorded form the dive survey in waters too shallow for the geophysical survey boat, and these have been assessed to be of minimal to low cultural heritage significance. No further field investigation is recommended for the Peng Chau study area.

9.9.3 Desktop and field evaluation of terrestrial cultural heritage in and around the study area at Peng Chau revealed no archaeological sites, historic buildings or structures which are likely to be impacted by the helipad development.

9.10 References

· Cosine Ltd. (2003). Island Helipads EIA Study: Yung Shue Wan, Lamma Island and Peng Chau – Geophysical Investigation

· EPD (2002). Environmental Impact Assessment Ordinance (Cap. 499). Guidance Notes: Assessment of Impact on Sites of Cultural Heritage in Environmental Impact Assessment Studies. Environmental Protection Department / Antiquities and Monuments Office.

· Hase, P. H. (2002). Notes on the history of Peng Chau (unpublished).

· Sayer, G.R. (1975). Hong Kong 1862-1919. Hong Kong University Press.

10 Implementation Schedule of Recommended Mitigation Measures

10.1 Introduction

10.1.1 The implementation schedules of the recommended mitigation measures for each environmental aspect assessed in this EIA are given in the following Tables 10.1 - 10.6, as appropriate.

Table 10.1 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 measures?	Location / Timing of implementation of Measures	What requirements or standards for the measures to achieve?
S.3.5.1	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.3.5.1	S.4.2.2	Typical dust control measures include: The working area for site clearance adjacent to Sea Crest Villa shall be sprayed with water or a dust suppression chemical immediately before, during and immediately after the operation so as to maintain the entire surface wet.	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.3.5.1	S.4.2.2	For reclamation works, if a stockpile of dusty materials is more than 1.2 m high and within 50m of Peng Lei Road or the Pak Wan footpath, the stockpile shall be properly treated and sealed with latex, vinyl, bitumen or other suitable surface stabilizer.	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.3.5.1	S.4.2.2	Immediately before leaving a construction site, every vehicle shall be washed to remove any dusty materials from its body and wheels.	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.3.5.1	S.4.2.2	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.	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.3.5.1	S.4.2.2	Erection of hoarding of not less than 2.4 m 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
S.3.5.1	S.4.2.2	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.	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.3.5.1	S.4.2.2	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.	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 10.2 Noise – 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 measures?	Location / Timing of implementation of Measures	What requirements or standards for the measures to achieve?
S.4.5.7	-	Use of silenced plant, or plant equipped with mufflers or dampers in substitute of ordinary plant.	Noise During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period.	Annex 5 of EIA-TM
S.4.5.8	-	Movable noise barriers positioned as close as possible to PMEs such that none of the PMEs will be visible when viewed from any noise sensitive facades.	Noise During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period.	Annex 5 of EIA-TM
S.4.5.10	S.5.9.3	Adopt good working practices in order to minimise construction noise as far as possible: Noisy equipment and noisy activities should be located as far away from the NSRs as is practical;	Noise During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period	Annex 5 of EIA-TM
S.4.5.10	S.5.9.3	Unused equipment should be turned off;	Noise During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period	Annex 5 of EIA-TM
S.4.5.10	S.5.9.3	Number of powered mechanical equipment (PME) should be kept to minimum and the parallel use of noisy equipment / machinery should be avoided;	Noise During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period	Annex 5 of EIA-TM
S.4.5.10	S.5.9.3	Regular maintenance of all plant and equipment; and;	Noise During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period	Annex 5 of EIA-TM
S.4.5.10	S.5.9.4	Observe and comply with the statutory requirements and guidelines.	Noise During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period	Annex 5 of EIA-TM

Table 10.3 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 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	-	In line with Government’s position on waste minimization, the practice of avoiding and minimizing 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 in accordance with the requirements as set out in the Environmental, Transport and Works Bureau Technical Circular (ETWBTC) No. 15/2003;	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	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	Environment, Transport and Works Bureau Technical Circular (Works) (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 minimization 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 (at Tai Lei) 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 shall be established	Monitor the disposal of C&D and solid wastes from the site	Contractors	At the outset of the construction of the helipad	(WBTC No. 21/2002
S.5.8.2	S.6.2.2	Dredged sediments shall be handled in accordance with the Environment, Transport and Works Bureau Technical Circular (ETWBTC) No. 34/2002 on Management of Dredged/Excavated Sediment and where the sediments cannot be reused onsite, arrangements shall be made with the MFC for allocation of dumping space;	Waste Management During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period	ETWBTC No. 34/2002
S.5.8.2	S.6.2.2	Stockpiling is not envisaged, however if it becomes unavoidable, stockpiling in any vegetated areas shall be avoided (as far as possible) and shall be covered with tarpaulin and/or watered to prevent windblown dust and/or surface runoff;	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	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 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;	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 on Tai Lei. Further to the issue of ETWBTC (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; and	Waste Management During Construction	Contractors	At all construction work sites, throughout the whole duration of the construction period	ETWB TCW No. 6/2002A, ETWBTC No. 15/2003
S.5.8.2	S.6.2.2	All chemical toilets shall be regularly cleaned and the nightsoil 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
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.5.8.2	S.6.2.2	A recording system for the amount of wastes generated, recycled and disposed (including the disposal sites) should be proposed	Waste Management During Construction	Contractors	Throughout construction period	EIAO - TM
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	Throughout construction period	EIAO - TM

Table 10.4 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 measures?	Location / Timing of implementation of Measures	What requirements or standards for the measures to achieve?
S.6.5.4	-	A single backhoe dredger with a grab capacity of 6 – 8 m^3 per grab will be engaged for the dredging.	Water Quality During Construction	Contractors	At all dredging areas, prior to the commencement of dredging.	Water Pollution Control Ordinance (Cap. 358), WQOs for Southern WCZ
S.6.5.5	-	Dredging rate not to exceed the daily maximum rate of 465 m^3.	Water Quality During Construction	Contractors	At all dredging areas, prior to the commencement of dredging.	Water Pollution Control Ordinance (Cap. 358), WQOs for Southern WCZ
S.6.7.2	S.7.2.3	Silt curtains to be installed at all dredging areas prior to the commencement of dredging. The silt curtains should be extended to the seabed level as far as possible.	Water Quality During Construction	Contractors	At all dredging areas, prior to the commencement of dredging.	Water Pollution Control Ordinance (Cap. 358), WQOs for Southern WCZ
S.6.7.3	S.7.2.4	The following good site practices are also recommended to further minimize the potential water quality impact: The daily dredging volume should be spread as evenly as possible over the working hours whenever practical to avoid sudden surge of pollution elevation during short spells;	Water Quality During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	Special care should be taken during lowering and lifting grabs to minimize unnecessary disturbance to the seabed;	Water Quality During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	To ensure vessels used have adequate clearance of the seabed in order to reduce undue turbidity generated by turbulence from vessel movement or propeller wash;	Water Quality During Construction	Contractors	At all marine construction areas, throughout the whole duration of the construction period	Not applicable (good practice only)
S.6.7.3	S.7.2.4	Barges should be fitted with tight fitting seals to their bottom openings to prevent leakage of material;	Water Quality During Construction	Contractors	At all marine construction areas, throughout the whole duration of the construction period	Not applicable (good practice only)
S.6.7.3	S.7.2.4	The contractor should ensure that grabs are tightly closed and the hoist speed is suitably low;	Water Quality During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	Barges should not be filled to a level which will cause overflow of materials during loading and transportation;	Water Quality During Construction	Contractors	At all marine construction areas, 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 grab to avoid losses from partially closed grabs.	Water Quality During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)

Table 10.5 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 measures?	Location / Timing of implementation of Measures	What requirements or standards for the measures to achieve?
S.7.6.1	-	Sub-tidal Ecology · The marine area of sloping seawall to be constructed will cover approximately 0.08 ha, based on an estimated average width (seawall foot and lower slope) of 4 metres and a total seawall length of approximately 200 metres.	Ecology During Construction	Contractors	At the marine area of sloping seawall, during the construction period.	Annex 16, EIA-TM
S.7.6.2	-	· The substrate of the artificial habitat will be granite boulder, similar to the substrate along the existing rocky and boulder shoreline and as occasionally present in the shallow coastal waters.	Ecology During Construction	Contractors	At the marine area of sloping seawall, during the construction period.	Annex 16, EIA-TM
S.7.6.7	-	Intertidal Ecology · Inter-tidal area of sloping seawall to be constructed will cover approximately 0.12 ha, based on an estimated average width of 5 metres and a total seawall length of approximately 200 metres – an overall net increase of 0.02 ha of inter-tidal habitat area. This is a balance of the net loss of 0.01 ha of low ecological value sandy beach habitat and the net gain of 0.03 ha of higher ecological value rocky / boulder shore habitat.	Ecology During Construction	Contractors	At the inter-tidal area of sloping seawall, during the construction period.	Annex 16, EIA-TM
S.7.6.2	-	· The substrate of the artificial habitat will be granite boulder, similar to the substrate along the existing rocky and boulder shoreline and as occasionally present in the shallow coastal waters.	Ecology During Construction	Contractors	At the inter-tidal area of sloping seawall along the existing rocky and boulder shoreline, during the construction period.	Annex 16, EIA-TM
S.7.6.5	S.8.2.3	Water Quality induced Ecology Impacts · Silt curtains to be installed at all dredging areas prior to the commencement of dredging	Ecology During Construction	Contractors	At all dredging areas, prior to the commencement of dredging.	Animals & Plants Ordinance (Protection of Endangered Species) (Cap. 187)
S.6.7.3	S.7.2.4	· The daily dredging volume should be spread as evenly as possible over the working hours whenever practical to avoid sudden surge of pollution elevation during short spells;	Water Quality During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· Special care should be taken during lowering and lifting grabs to minimize unnecessary disturbance to the seabed;	Water Quality During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· To ensure vessels used have adequate clearance of the seabed in order to reduce undue turbidity generated by turbulence from vessel movement or propeller wash;	Water Quality During Construction	Contractors	At all marine construction areas, throughout the whole duration of the construction period	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· Barges should be fitted with tight fitting seals to their bottom openings to prevent leakage of material;	Water Quality During Construction	Contractors	At all marine construction areas, throughout the whole duration of the construction period	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· The contractor should ensure that grabs are tightly closed and the hoist speed is suitably low;	Water Quality During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· Barges should not be filled to a level which will cause overflow of materials during loading and transportation;	Water Quality During Construction	Contractors	At all marine construction areas, 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 grab to avoid losses from partially closed grabs.	Water Quality During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)

Table 10.6 Fisheries – 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.8.2.3	Water Quality induced Fisheries Impacts · Silt curtains to be installed at all dredging areas prior to the commencement of dredging	Fisheries During Construction	Contractors	At all dredging areas, prior to the commencement of dredging.	Animals & Plants Ordinance (Protection of Endangered Species) (Cap. 187)
S.6.7.3	S.7.2.4	· The daily dredging volume should be spread as evenly as possible over the working hours whenever practical to avoid sudden surge of pollution elevation during short spells;	Fisheries During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· Special care should be taken during lowering and lifting grabs to minimize unnecessary disturbance to the seabed;	Fisheries During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· To ensure vessels used have adequate clearance of the seabed in order to reduce undue turbidity generated by turbulence from vessel movement or propeller wash;	Fisheries During Construction	Contractors	At all marine construction areas, throughout the whole duration of the construction period	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· Barges should be fitted with tight fitting seals to their bottom openings to prevent leakage of material;	Fisheries During Construction	Contractors	At all marine construction areas, throughout the whole duration of the construction period	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· The contractor should ensure that grabs are tightly closed and the hoist speed is suitably low;	Fisheries During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)
S.6.7.3	S.7.2.4	· Barges should not be filled to a level which will cause overflow of materials during loading and transportation;	Fisheries During Construction	Contractors	At all marine construction areas, 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 grab to avoid losses from partially closed grabs.	Fisheries During Construction	Contractors	At all dredging areas, throughout the whole duration of the dredging period.	Not applicable (good practice only)

11 summary Conclusion & recommendations

11.1 Summary Conclusion of Technical Assessments

11.1.1 The Project will involve the construction of a permanent helipad at Pak Wan on the northwest coast of Peng Chau to serve the local community in the absence of an existing permanent facility. The helipad is required mainly for emergency use. The Pak Wan site was one of eleven site options for the Helipad considered in detail, and was selected as the optimal location for the Project due to its remoteness from the built environment, while it is still easily accessible from the Peng Chau medical clinic.

11.1.2 Based on the construction schedule and plant inventory given, the unmitigated construction noise levels at Sea Crest Villa are found to exceed the daytime noise standards stated in Table 1B, Annex 5 of EIA-TM. However, through implementation of appropriate mitigation measures, including use of silenced equipment and temporary noise barriers, the construction noise impacts can be reduced to an acceptable level. The cumulative noise level with the construction of the Peng Chau STW Upgrade at Tai Lei Island was evaluated and no adverse impacts are anticipated.

11.1.3 Through liaison with the Government Flying Service (GFS) the helicopter flight path angle has been reduced to eliminate residual noise impacts from the EC155 B1 during helicopter approach, while an existing natural rocky cliff-face will effectively screen the Sea Crest Villa residential development from helicopter manoeuvring noise impacts. There is a predicted residual helicopter noise impact of 3dB(A) from flight of the Super Puma AS332 L2 type helicopter (worst-case scenario), although it has been calculated that the helicopter noise levels at Sea Crest Villa from the currently used flight path range between 89dB(A) for the ‘EC 155B21’ type helicopter to 92 dB(A) for the ‘Super Puma’ type helicopter.

11.1.4 It is also noted that the predicted impact duration for the proposed helipad will be very short (less than 10 seconds) as the impact zone only arises when the Super Puma is approximately 30m from helipad landing. Eliminating the residual noise impact from the ‘Super Puma’ would require moving the proposed helipad another 70m to the east, resulting in more construction work and greater landscape and environmental impact potential. The frequency of the residual helicopter noise impact is predicted to be once every 12 days.

11.1.5 Consideration was given to helicopter noise mitigation. However it was found that there are no options for direct mitigation of helicopter noise without creating potentially significant landscape and ecological impacts; while indirect measures such as use of increased window glazing and installation of air conditioners were considered impracticable due to the intermittent / unpredictable helipad use and the short helicopter noise impact duration.

11.1.6 Provided that the proposed controls on waste management are implemented, no potential environmental impacts from the construction and operational phases of the Project are anticipated. As regards water quality, only one dredger will be used for the works and predictions are that elevations in suspended solids levels at sensitive receivers will be negligible, and will not exceed the tolerance level of 10.1mg/l even in the very vicinity of the dredger, based on an average water depth of 5.8m in the study area. As such, no significant adverse water quality impacts are anticipated from Project construction. Likewise, there will be no adverse water quality-induced ecological impacts on the nearest coral community at east Tai Lei.

11.1.7 There will be a net loss (residual impact) of approximately 0.25 ha of marine benthic habitat and a net gain of some 0.02 ha of inter-tidal habitat, although given the low baseline ecological value of the marine and inter-tidal habitat at Pak Wan, the adverse residual impact is not considered significant. No significant terrestrial ecology impacts are anticipated. No significant ecological impacts are anticipated during the operational phase of the Project and there are no monitoring requirements for the Project. Likewise, no adverse fisheries impacts are anticipated and no fisheries monitoring is required.

11.1.8 Two objects were recorded during the marine geophysical survey conducted at Pak Wan to support the marine archaeological / cultural heritage assessment. A dive survey confirmed the objects to be rock and dead coral of no archaeological interest. There were no terrestrial archaeological sites, historic buildings or structures that will be impacted by the Project.

11.2 Key Recommendations

11.2.1 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 the unpredictability of helipad use makes EM&A impracticable, it is not recommended. However, should the need arise, the local community may lodge noise complaints with the Islands District Office.

11.2.2 No specific EM&A requirements have been identified for waste management, although it is recommended that regular construction phase site inspections and the supervision of waste management procedures be included as part of the WMP to be prepared by the Contractor. The implementation of additional good practice measures proposed in Section 3 will ensure there are no construction dust impacts.

11.2.3 No adverse water quality impacts are anticipated from Project construction. However, it has been recommended that silt curtains be used around the dredging area as a good practice measure to ensure compliance with water quality criteria. This measure will also ensure no adverse water quality induced ecological impacts on the coral community at east Tai Lei, or on the fisheries area off the Tai Lei bridge that is a popular recreational fishing area.

11.3 Summary of Environmental Outcomes

11.3.1 The key environmental outcomes of the Project may be summarised as follows:

11.3.2 Population and environmentally sensitive area protected: An optimum Project site has been selected that that is relatively distant from the built environs of Peng Chau, but which is also readily accessible from the Peng Chau Clinic. The chosen helipad site offers the local community a significant time saving compared with the existing helipad at Tai Lung Tsuen, while the existing helipad is predicted to generate significant helicopter noise impacts (i.e., > 85 dB(A)) on residents of over 100 village type and medium rise residential buildings, principally in Shan Ting Tsuen, Kam Peng and Tung Wan Villa. In addition, it is predicted that the existing flight path across Sea Crest Villa currently exposes residents to greater noise levels than will be experienced once the prposed new helipad is operational.

11.3.3 Environmentally friendly designs recommended: Other measures incorporated into the Project design to avoid / minimise environmental impacts include reducing the Project footprint by (i) reducing the elevation of the helipad and EVA as far as practicable, and (ii) reducing the gradient of the sloping boulder seawall from standard design. The construction sequence has been optimised to minimise cumulative construction noise effects with works for the proposed Peng Chau Sewage Treatment Works Upgrade.

11.3.4 Key environmental problems avoided: As referred under 11.3.2 above, the proposed permanent helipad will significantly improve the accessibility to / from the helipad and greatly reduce the travel time in emergency situations. There will also be a significant reduction in the number of buildings that are adversely affected by helicopter noise. The helipad location makes use of the natural rocky cliff-face between the helipad surface and Sea Crest Villa that will effectively shield the residential development from helicopter manoeuvring noise.

11.3.5 Compensation areas included: There will be a net loss of approximately 0.25 ha of marine benthic habitat and a net gain of some 0.02 ha of artificial inter-tidal habitat from seawall construction, although given the low baseline ecological value of the marine and inter-tidal habitat at Pak Wan, the adverse residual impact is not considered significant. The seawall will also benefit local fisheries that favour shallow coastal waters.

11.3.6 Environmental benefits of environmental protection measures recommended: Residual helicopter noise impacts associated with helicopter approach / departure of the ‘EC 155B1’ type helicopter that will be used in most cases have been effectively eliminated through realignment of the helicopter flight path. While there will be a residual helicopter noise impact when the noisier ‘Super Puma AS L2’ type helicopter) is in use, although GFS will aim to use the quieter ‘EC 155B1’ type wherever possible.

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[*] The development of a Floating Pontoon was investigated but was not considered feasible for ‘casevac’ operations due to questions over operability and accessibility under adverse weather conditions.

[†] EPD (2000). EIAO Guidance Note No. 1/2002: Basic Principles of the EIA Process. January 2002.

[‡] Technical Memorandum on Environmental Impact Assessment Process (EIA-TM)

[§] Environmental Protection Department Air Service Group, Air Quality in Hong Kong 2002, (2002), Table C3 and Table C4.

[**] http://aee.faa.gov/noise/Section_747_FAA_Study_Process_Issues_Expressed.htm

[††] Location as advised by CEDD and with confirmation of District Land Office (DLO) of Lands Department.

[‡‡] Contract No. CV/2000/09: Infrastructure for Penny's Bay Development - Environmental Monitoring. [http://www.pennysbaycontract1.com/noise1.html]

[§§] Notional Source Position - the location of all the PME to be grouped at the position mid-way between the approximate geographical centre of the construction activity and its boundary nearest to the NSR.

[***] Predicted noise level extracted from Appendix 4E of the EIA Report for Agreement No. CE 83/2001 (DS) Peng Chau Sewage Treatment Works Upgrade -- Investigation, Design and Construction.

[†††] With reference to the GFS Helipad Specification Guidelines, a ‘FATO’ is an area over which a helicopter completes the approach manoeuvre to a hover or landing, or commences into forward flight during take-off. All final approaches shall terminate at the FATO and all take-off movements shall start there.

[‡‡‡] Existing slant distance calculated based on horizontal distance separation of 340m between Sea Crest Villa and the landing site at Tai Lung Tsuen, and a vertical distance separation of 88m between Sea Crest Villa (top floor: +11.6mPD) and the existing flight path (+99.6mPD) that is located approximately 55m from Sea Crest Villa. Based on GFS Guidelines, it has been assumed that the approaching helicopter will maintain a descending angle of 12.5 degrees down the flight path to the landing site at Tai Lung Tsuen over the entire 340m horizontal distance (i.e., max. elevation over NSR assumed).

[§§§] The mixing zone is the region of a water body where initial dilution of a pollution input takes place and where water quality criteria can be exceeded (EIA-TM, Annex 6).

[****] Recent observations by BMT (2003) of hard corals on the artificial sloping seawall constructed under the Yung Shue Wan Phase 1 Reclamation indicate there is also potential that the Pak Wan seawall may be similarly colonised by corals.

[††††] This assumes the ranking of “Major species of fish catch (adult fish & fish fry)” has been generated from overall productivity data, and that the contribution to the overall ranking by fish fry is not significant (i.e., the combined adult and fry productivity is broadly indicative of adult fish only, since the weight (kg/ha) contribution of fish fry can be reasonable expected to be small).

[‡‡‡‡] Most fishing activity off Tai Lei bridge is from the centre or the Tai Lei side where there is a rocky shoreline that is a natural and relatively sheltered (and hence attractive) habitat for fish.