Proposed Comprehensive Development
at Wo Shang Wai, Yuen Long
Environmental Impact Assessment
March 2008
Mott Connell Ltd
7th Floor,
West Wing Office
Building
New World
Centre
20 Salisbury Road
Tsim Sha Tsui, Kowloon
Hong Kong
Tel: 2828 5757
Fax: 2827 1823
Anne.Kerr@mottconnell.com.hk
in association with
Urbis Limited
Master Plan Limited
Asia
Ecological Consultants Limited
Allied
Environmental Consultant Limited
"This
document has been prepared for the titled project or named part thereof and
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To the
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List of Contents Page
Chapters
Page
No.
1 INTRODUCTION 1-1
1.1 Background 1-1
1.2 The
Project 1-2
1.3 EIAO
and Designated Projects 1-5
1.4 Continuous
Public Involvement 1-5
1.5 Scope 1-6
1.6 Objectives
of the EIA Study 1-6
1.7 The
Assessment Area 1-7
1.8 Programme 1-8
1.9 Structure
of the EIA Report 1-8
2 CONSIDERATION OF ALTERNATIVES 2-1
2.1 Summary 2-1
2.2 The
Project Area 2-1
2.3 Site
Context 2-5
2.4 Consideration
of Alternatives 2-6
2.5 Working
Up the Initial Options 2-13
2.6 Construction
Methods and Sequences of Works 2-19
3 Air Quality 3-1
3.1 Summary 3-1
3.2 Legislation,
Standards, Guidelines and Criteria 3-2
3.3 Assessment
Methodology 3-3
3.4 Baseline
Conditions/ Sensitive Receivers 3-4
3.5 Air
Quality Impact Assessment 3-5
3.6 Mitigation
of Impacts 3-8
3.7 Residual
Impacts 3-9
3.8 Environmental
Monitoring and Audit 3-10
3.9 Conclusions
and Recommendations 3-10
4 NOISE IMPACT 4-1
4.1 Introduction 4-1
4.2 Government
Legislation and Standards 4-1
4.3 Background
Noise Climate 4-3
4.4 Identification
of Potential Noise Impacts 4-5
4.5 Determination
of Noise Sensitive Receivers 4-6
4.6 Assessment
Methodology 4-8
4.7 Prediction
and Evaluation of Noise Impacts 4-12
4.8 Mitigation
Measures 4-14
4.9 Conclusion 4-18
5 WATER QUALITY IMPACT 5-1
5.1 Summary 5-1
5.2 Environmental
Legislation, Standards, Guidelines and Criteria 5-1
5.3 Existing
Environment and Sensitive Receivers 5-5
5.4 Assessment
Methodology 5-14
5.5 Identification
of Impacts 5-14
5.6 Mitigation
Measures 5-17
5.7 Environmental
Monitoring and Audit 5-18
5.8 Conclusions 5-19
5.9 References 5-19
6 Sewerage and Sewage Treatment Implications 6-1
6.1 Summary 6-1
6.2 Introduction 6-1
6.3 Assessment
Approach and Methodology 6-1
6.4 Design
Assumptions, Parameters and Criteria 6-2
6.5 Existing
Sewerage Conditions 6-3
6.6 Estimated
Pollutant Loads to the Existing Water Body due to the Proposed Development 6-4
6.7 Proposed
Mitigation Measures 6-5
6.8 Short
Term Measures during Construction Stage 6-6
6.9 Conclusion
and Recommendations 6-6
7 WASTE MANAGEMENT 7-1
7.1 Summary 7-1
7.2 Environmental
Legislation and Standards 7-1
7.3 Assessment
Methodology 7-2
7.4 Construction
Waste Impact 7-2
7.5 Evaluation
of Impacts 7-4
7.6 Mitigation
Measures 7-6
7.7 Land
Contamination 7-9
7.8 Sediment
Quality and Potential Biogas 7-22
7.9 Environmental
Monitoring and Audit Requirements 7-40
7.10 Conclusions 7-40
8 Ecological Impact assessment 8-1
8.1 Summary 8-1
8.2 Introduction 8-1
8.3 Assessment
Area 8-2
8.4 Sites
of Conservation Importance in the Area 8-3
8.5 Survey
Methodologies 8-4
8.6 Results
of surveys 8-8
8.7 Ecological
Value of habitats in the Project Area and within the Assessment Area 8-27
8.8 Potential
Ecological Impacts 8-38
8.9 Mitigation
Measures Adopted to Avoid, Minimise and Compensate for Ecological Impacts 8-54
8.10 Post-mitigation
Acceptability of the Project 8-65
8.11 Conclusions 8-72
8.12 References 8-73
9 Fisheries Impacts ASSESSMENT 9-1
9.1 Summary 9-1
9.2 Legislation
and Standards 9-1
9.3 Assessment
Methodology 9-2
9.4 Baseline
Conditions 9-2
9.5 Prediction
of Impacts 9-4
9.6 Evaluation
of Impacts 9-6
9.7 Mitigation
Measures 9-7
9.8 Environmental
Monitoring and Audit Programme 9-8
9.9 Conclusion 9-8
9.10 References 9-8
10 CULTURAL HERITAGE 10-1
10.1 Summary 10-1
10.2 Relevant
Legislation & Guidelines 10-1
10.3 Assessment
Methodology 10-2
10.4 Baseline
Conditions and Sensitive Receivers 10-2
10.5 Impact
Assessment 10-3
10.6 Mitigation
Measures 10-4
10.7 Residual
Impacts 10-4
10.8 Conclusion 10-4
10.9 Reference 10-4
11 Landscape and Visual Impact 11-1
11.1 Summary 11-1
11.2 Environmental
Legislation and Guidelines 11-2
11.3 Scope
and Content of the Study 11-3
11.4 Planning
and Development Control Framework 11-7
11.5 Baseline
Study 11-9
11.6 Landscape
Impact Assessment 11-21
11.7 Visual
Impact Assessment 11-43
11.8 Conclusions 11-58
12 IMPACTS SUMMARY 12-1
12.1 Summary 12-1
13 SUMMARY OF ENVIRONMENTAL OUTCOMES 13-1
13.1 Overall 13-1
13.2 Air
Quality 13-1
13.3 Noise 13-1
13.4 Water
Quality 13-1
13.5 Sewerage
and Sewage Treatment 13-2
13.6 Waste
Management 13-2
13.7 Ecology 13-2
13.8 Fisheries 13-2
13.9 Cultural
Heritage 13-2
13.10 Landscape
and Visual Impact 13-2
14 ENVIRONMENTAL MONITORING AND AUDIT (EM&A) REQUIREMENTS 14-1
14.1 Overview 14-1
14.2 Air
Quality 14-1
14.3 Noise
Impact 14-1
14.4 Water
Quality 14-1
14.5 Sewerage
and Sewage Treatment Implications 14-2
14.6 Waste
Management 14-2
14.7 Ecology 14-2
14.8 Fisheries 14-2
14.9 Cultural
Heritage 14-2
14.10 Landscape
and Visual Impact 14-2
15 PROJECT IMPLEMENTATION SCHEDULE 15-1
16 SUMMARY AND CONCLUSIONS 16-1
16.1 Summary 16-1
16.2 Conclusions 16-1
List of Tables
Table 2‑1...... Development
Criteria. 2-13
Table 2‑2...... Summary
of Alternative Options Considered. 2-18
Table 3‑1...... Hong
Kong Air Quality Objectives (mg/m3)(i) 3-2
Table 3‑2...... Traffic
Forecast in Year 2027. 3-4
Table 3‑3...... Air
Quality at Yuen Long Monitoring Station in Past Five Years. 3-5
Table 3‑4...... Locations
of Representative Air Sensitive Receiver 3-5
Table 4‑1...... Relevant
Noise Standards for Planning Purposes. 4-2
Table 4‑2...... Noise
Standards for Daytime Construction Activities. 4-2
Table 4‑3...... Area
Sensitivity Ratings (ASRs) 4-3
Table 4‑4...... Acceptable
Noise Levels (ANLs) 4-3
Table 4‑5...... Measured
Noise Levels. 4-4
Table 4‑6...... Identified
Noise Sensitive Receivers within 300m from the Boundary of Project Area. 4-6
Table 4‑7...... Horizontal
Distances between the Assessment Points of Representative NSRs and the Notional
Centre of Each Phase for Construction Stage. 4-6
Table 4‑8...... Assessment
Points of the Representative NSRs for Operational Stage. 4-7
Table 4‑9...... Inventory
of Noise Sources at Each Phase – During Construction. 4-9
Table 4‑10.... Summary
of Open Storage Site Noise Measurement Results at Point F. 4-11
Table 4‑11.... Traffic
Flow Forecast of Existing and Future Road Networks (Year 2027) 4-11
Table 4‑12.... Maximum
Predicted Unmitigated Construction Noise Levels at Representative NSRs. 4-12
Table 4‑13.... Predicted
Noise Levels at Representative NSRs. 4-13
Table 4‑14.... QPME
to be used at the Construction Site. 4-14
Table 4‑15.... Maximum
Predicted Mitigated Construction Noise Levels at Representative NSRs with the
use of QPME 4-15
Table 4‑16.... Maximum
Predicted Mitigated Construction Noise Levels at Representative NSRs with the
uses of QPME, Noise Barriers and Site Hoardings. 4-16
Table 5‑1...... Standards
for effluents discharged into Group C inland waters (All units in mg/L unless
otherwise stated; all figures are upper limits unless otherwise indicated) 5-2
Table 5‑2...... Standards
for effluents discharged into Group D inland waters (All units in mg/L unless
otherwise stated; all figures are upper limits unless otherwise indicated) 5-3
Table 5‑3...... Key
Water Quality Objectives for inland waters in Deep Bay Water Control Zones. 5-4
Table 5‑4...... Summary
of River Water Quality at Nearby Fairview Park Nullah in the Deep Bay Water
Control Zones between 2002 and 2005 (Source: River Water Quality in Hong Kong
in 2002 – 2005 (EPD)) 5-6
Table 5‑5...... In-situ
Water Quality Testing Parameters. 5-8
Table 5‑6...... Water
Quality Testing Parameters in Laboratory. 5-9
Table 5‑7...... Summary
of Water and Sediment Quality Monitoring Results in Dry Season (For Monitoring
Stations WM1 to WM7) 5-9
Table 5‑8...... Summary
of Water Quality Monitoring Results in Wet Season (For Monitoring Stations WM1
to WM7 & WM11 to WM13) 5-10
Table 5‑9...... Summary
of In-situ Water Quality Monitoring Results in Dry Season (For Monitoring
Station WM8 to WM10) 5-12
Table 5‑10.... Summary
of In-situ Water Quality Monitoring Results in Wet Season (For Monitoring
Station WM8 to WM10) 5-12
Table 5‑11.... Summary
of Key Water Quality Objectives Compliance for the Water Quality Monitoring
Station WM1 to WM7 and WM11 to WM13. 5-12
Table 6‑1...... Design
Unit Load Factors. 6-3
Table 6‑2...... Pollutant
Loads arising from the Raw Sewage of the Proposed Development 6-5
Table 7‑1...... Potential
contaminants. 7-11
Table 7‑2...... General
hazardous effects of contaminants potentially present 7-12
Table 7‑3...... Ground
conditions encountered and depth of subsamples tested. 7-13
Table 7‑4...... Summary
of chemical test results on soil samples. 7-14
Table 7‑5...... Summary
of chemical test results on ground water samples. 7-17
Table 7‑6...... Summary
of additional TPH test results on ground water samples. 7-17
Table 7‑7...... Summary
of land contamination locations. 7-18
Table 7‑8...... Criteria
for the chemical screening of sediment (from ETWB(W)TC 34/2002) 7-23
Table 7‑9...... Criteria
for classification of sediment (from ETWB(W)TC 34/2002) 7-23
Table 7‑10.... Criteria
for disposal of sediment at sea. 7-23
Table 7‑11.... Depth
of marine sediment encountered and subsamples tested. 7-25
Table 7‑12.... Samples
for Tier III biological testing. 7-26
Table 7‑13.... Results
of Tier III Testing. 7-26
Table 7‑14.... Results
of Tier III Testing. 7-26
Table 7‑15.... Summary
of chemical screening results and sediment classification. 7-27
Table 7‑16.... Depth
of pond deposit encountered and tested for TOC.. 7-30
Table 7‑17.... Results
of Gas Spike Test Survey. 7-32
Table 7‑18.... Results
of TOC Testing on Pond Mud. 7-33
Table 7‑19.... Assessment
of Biogas potential using TOC results. 7-36
Table 7‑20.... Percentage
% of methane emitted after June 2006. 7-36
Table 7‑21.... Maximum
potential CH4
generation in June 2008. 7-37
Table 7‑22.... Estimated
volume and classification of excavated sediment 7-38
Table 8‑1...... Habitats
present in Project Area and Assessment Area. 8-13
Table 8‑2...... Mean
and
maximum number of individuals of bird species of conservation importance
and wetland-dependent bird species recorded on morning transect counts in
Project Area (PA) and in other parts of the Assessment Area (AA), April
2005-June 2006. (Level of Concern based on Fellowes et al. 2002) 8-14
Table 8‑3...... Wetland-dependent
bird species recorded in the Tam Kon Chau count area on monthly waterbird
counts conducted by the Hong Kong Bird Watching Society, April 2005-March 2006
(data from Anon 2005, Anon 2006a) 8-17
Table 8‑4...... Heights
of ardeids flying over the Project Area, June 2006. 8-19
Table 8‑5...... Summary
of birds using Flight paths 1, 2 and 3, May-June 2006. 8-20
Table 8‑6...... Relative
abundance of herpetofauna species recorded in the Project Area and in other
parts of the Assessment Area, April 2005 – June 2006. 8-22
Table 8‑7...... Relative
abundance of fish species recorded in Project Area and in the drainage channel
by Palm Springs, April 2005 – June 2006. 8-22
Table 8‑8...... Butterfly
species recorded in the Project Area (PA) and in other parts of the Assessment
Area (AA) during surveys, May 2005 – June 2006. 8-23
Table 8‑9...... Dragonfly
species recorded in the Project Area (PA) and in other parts of the Assessment
Area (AA) during surveys, May 2005 – June 2006. 8-25
Table 8‑10.... Number
of aquatic invertebrates recorded from sampling locations around the Project
Area, 2005-2006. 8-26
Table 8‑11.... Ecological
Evaluation of Grassland Habitats. 8-27
Table 8‑12.... Ecological
Evaluation of Seasonal Marsh. 8-28
Table 8‑13.... Ecological
Evaluation of Freshwater Marsh/Reedbed. 8-30
Table 8‑14.... Ecological
Evaluation of Fishponds. 8-31
Table 8‑15.... Ecological
Evaluation of Drainage Channels/ Ditches. 8-33
Table 8‑16.... Ecological
Evaluation of Woodland Habitats. 8-34
Table 8‑17.... Ecological
Evaluation of Plantation Habitats. 8-35
Table 8‑18.... Ecological
Evaluation of Active and Inactive Dry Agricultural Land. 8-36
Table 8‑19.... Ecological
Evaluation of Developed Area, Bare Ground and Wasteland. 8-37
Table 8‑20.... Potential
Direct Ecological Impacts to habitats in Project Area without mitigation
measures. 8-38
Table 8‑21.... Potential
Ecological Impacts to bird species of conservation importance in Project Area,
without mitigation measures. 8-41
Table 8‑22.... Potential
Ecological Impacts to Scarlet Basker and Danaid Egg-fly in Project Area,
without mitigation measures. 8-44
Table 8‑23.... Potential
Indirect Ecological Impacts to habitats in the Assessment Area without
mitigation measures. 8-45
Table 8‑24.... Potential
Ecological Impacts from pollution of watercourses and Deep Bay without
mitigation measures. 8-47
Table 8‑25.... Potential
Disturbance Impacts to waterbirds of conservation importance in Assessment Area
without mitigation measures. 8-49
Table 8‑26.... Potential
Ecological Impacts to egretries in Assessment Area without mitigation measures. 8-51
Table 8‑27.... Potential
Ecological Impacts to non-breeding bird flight paths without mitigation
measures. 8-53
Table 8‑28.... Summary
of Potential Ecological Impacts in the absence of Mitigation Measures. 8-55
Table 8‑29.... Summary
of Potential Ecological Impacts before and after adoption of Mitigation
Measures. 8-65
Table 9‑1...... AFCD
Figures on HKSAR Pond Culture Fisheries. 9-3
Table 9‑2...... Fishponds
Status and Area in the Project Area. 9-4
Table 9‑3...... Evaluation
of Fisheries Impact 9-6
Table 11‑1.... Relationship
between Receptor Sensitivity and Impact Magnitude in Defining Impact
Significance. 11-5
Table 11‑2.... Assessment
of Layout Options against Landscape / Visual Criteria. 11-25
Table 11‑3.... Proposed
Construction Phase Landscape and Visual Mitigation Measures. 11-27
Table 11‑4.... Proposed
Operation Phase Landscape and Visual Mitigation Measures. 11-28
Table 11‑5.... Significance
of Landscape Impacts in Construction and Operation Phases (Negative Impacts
unless otherwise stated) 11-34
Table 11‑6.... Significance
of Visual Impacts in the Construction and Operation Phases (Note: All impacts
negative unless otherwise noted) 11-56
Table 12‑1.... Impacts
Summary. 12-1
List of Plates
Plate 1.1 Aerial
Photo Showing the Proposed Development and the adjacent Environment
Plate 8.1 Grassland
Plate 8.2 Seasonal
Marsh
Plate 8.3 Freshwater
Marsh/ Reedbed
Plate 8.4 Active
Fishpond
Plate 8.5 Abandoned
Fishpond
Plate 8.6 Drainage
Channel/ Ditch
Plate 8.7 Secondary
Woodland
Plate 8.8 Plantation
Plate 8.9 Active
Dry Agricultural Land
Plate 8.10 Inactive
Dry Agricultural Land
Plate 8.11 Wasteland
Plate 8.12 Bare
Ground
Plate 8.13 Developed
Area
Plate 9.1 Fishpond
in maintenance stage (not in the site, refer to Figure 9.1 for location)
Plate 9.2 Abandoned
fishpond with reeds growing (refer to Figure 9.1 for location)
Plate 9.3 Recreational
fishing ground at Wo Shang Wai Village
Plate 9.4 Wetland
dependent birds foraging in partially drained fishpond
Plate 9.5 Release of fish fingerlings into fishpond after
maintenance
Plate 9.6 Capturing
freshwater shrimps and Mosquito Fish in Mai Po fishpond
Plate 9.7 Mosquito
Fish captured in the fishponds
Plate 9.8 Brackish
fishponds in Mai Po
Plate 9.9 Brackish
fishes cultured in Mai Po fishponds
Plate 10.1 Ancestral
Hall (Hin Hing Tong) in Mai Po Village
Plate 10.2 Ancestral
Hall in Wo Shang Wai Village
List of Figures
Figure 1.1 Locations and Assessment Area of the Proposed
Development Site
Figure 1.2 Location of Conservation Area and Buffer Area
Boundaries
Figure 1.3 Standing Water patches Observed
in Dry Season
Figure 1.4 Location of Gleyed Soil
Figure 1.5 Extract of Relevant OZP
Figure 2.1 Preliminary Development Concept
Figure 2.2 Generation of Options
Figure 2.3a Schematic “Rectangular”
Development
Figure 2.3b Concept Layout Rectangular
development (3 and 4 Storeys)
Figure 2.4a Schematic “Horse Shoe” Concept
Figure 2.4b Concept Layout Nucleated (Horse Shoe) (4 Storeys)
Figure 2.5 Sketch Master Layout Plan Option A – All 2.5/3-Storey
Houses
Figure 2.6 Sketch Master Layout Plan Option B – All 6-Storey
Apartments
Figure 2.7 Sketch Master Layout Plan Option C – Mixed Height
Scheme
Figure 2.8 Sketch Master Layout Plan Option D – 2.5/3-Storey
Houses with Duplex-on-Duplex
Figure 2.9 Sketch Master Layout Plan Option E – 2.5/3-Storey
Houses
Figure 2.10 Sketch Master Layout Plan Option F – 2.5/3-Storey
Houses with Duplex-on-Duplex
Figure 2.11 Phase Layout Plan for Construction
Figure 3.1 Location of the Air Sensitive Receivers
Figure 4.1 Assessment Area of the Proposed Development Site
Figure 4.2 Location of Representative Noise Sensitive Receivers
(NSRs) in Construction Phase
Figure 4.3 Locations of Representative Noise Sensitive Receivers
(NSRs) in Operational Phase
Figure 4.4 Alignment of Site Access Road and Haul Road
Figure 4.5 Location of Baseline Noise Measurement
Figure 4.6 Minimum Height Required for Proposed Noise Barriers
and Site Hoardings
Figure 4.7 Cross-section Diagram Showing Proposed Noise
Barriers
Figure 4.8 Cross–Sectional Diagrams of Four Types of Houses in
Residential Development
Figure 4.9 Computer Plot of Noise Model
Figure 5.1 Existing Drainage Pattern in Wo Shang Wai
Figure 5.2 Water Quality Sampling Locations
Figure 5.3 Tentative Drainage Discharge Arrangement
Figure 6.1 Planned Major Sewerage Works in Northwest New
Territories from DSD
Figure 6.2 Proposed Final Sewage Discharge Point
Figure 7.1 Current Land Use at the Project Area August 2006
Figure 7.2 Land Contamination Assessment Borehole Locations
Figure 7.3 Contaminated Land Excavation
Figure 7.4 Management Framework for Dredged/Excavated Sediment
Figure 7.5 Sediment Assessment Borehole Locations
Figure 7.6 Gas Spike Survey and Biogas Investigation Locations
Figure 7.7 Marine Sediment Excavation
Figure 8.1 Sites of known ecological value close to the Project
Area
Figure 8.2 Survey transects and sampling locations
Figure 8.3 Habitats present in Project Area and Assessment Area
Figure 8.4 Bird Flight Paths over the Project Area
Figure 9.1 Fishponds Status Around Wo Shang Wai on 18 November
2005
Figure 10.1 Potential Cultural Heritage
Resources
Figure 11.1A Extract of Relevant OZP
Figure 11.1B Plan of ZVI and VSRs
Figure 11.2 Landscape Resources (Plan)
Figure 11.3 Landscape Resources (Views)
(Sheet 1 of 12)
Figure 11.4 Landscape Resources (Views)
(Sheet 2 of 12)
Figure 11.5 Landscape Resources (Views)
(Sheet 3 of 12)
Figure 11.6 Landscape Resources (Views)
(Sheet 4 of 12)
Figure 11.7 Landscape Resources (Views)
(Sheet 5 of 12)
Figure 11.8 Landscape Resources (Views)
(Sheet 6 of 12)
Figure 11.9 Landscape Resources (Views)
(Sheet 7 of 12)
Figure 11.10 Landscape Resources (Views) (Sheet
8 of 12)
Figure 11.11 Landscape Resources (Views) (Sheet
9 of 12)
Figure 11.12 Landscape Resources (Views) (Sheet
10 of 12)
Figure 11.13 Landscape Resources (Views) (Sheet
11 of 12)
Figure 11.14 Landscape Resources (Views) (Sheet
12 of 12)
Figure 11.15 Landscape Character Areas (Plan)
Figure 11.16 Photo Views of Landscape Character
Areas (1 of 2)
Figure 11.17 Photo Views of Landscape Character
Areas (2 of 2)
Figure 11.18 Section Showing Derivation of ZVI
Figure 11.19 Photos of VSR Views (1 of 5)
Figure 11.20 Photos of VSR Views (2 of 5)
Figure 11.21 Photos of VSR Views (3 of 5)
Figure 11.22 Photos of VSR Views (4 of 5)
Figure 11.23 Photos of VSR Views (5 of 5)
Figure 11.24A Landscape and Visual Mitigation
Measures (1 of 7)
Figure 11.24B Landscape and Visual Mitigation
Measures (2 of 7)
Figure 11.25A Landscape and Visual Mitigation
Measures (3 of 7)
Figure 11.25B Landscape and Visual Mitigation
Measures (4 of 7)
Figure 11.25C Landscape and Visual Mitigation
Measures (5 of 7)
Figure 11.25D Landscape and Visual Mitigation Measures
(6 of 7)
Figure 11.26 Landscape and Visual Mitigation
Measures (7 of 7)
Figure 11.27 Landscape Resources Impacts in
Construction Phase
Figure 11.28 Residual Landscape Resources
Impacts in Operation Phase
Figure 11.29 Residual Landscape Character
Impacts in Construction Phase
Figure 11.30 Residual Landscape Character
Impacts in Operation Phase
Figure 11.31 Residual Visual Impacts in
Construction Phase
Figure 11.32 Residual Visual Impacts in Operation
Phase
Figure 11.33 Photomontage A – View from Palm
Springs Boulevard, Palm Springs
Figure 11.34 Photomontage B – View from Santa
Monica Avenue, Royal Palms
Figure 11.35 Photomontage C – View from Wo Shang
Wai Village
Figure 11.36 Photomontage D – View from Tam Kon
Chau Village
Figure 11.37 Photomontage E – View from Tam Kon
Chau Road
Figure 11.38
Photomontage F – View from Mai Po Lo Wai
Figure 11.39
Photomontage G – View from Mai Po Nature Reserve
List of Appendices
Appendix A EIA
Study Brief No. ESB - 131/2005
Appendix B-1 Application for Planning Permission at OU(CDWRA) Zoning
Appendix B-2 Construction Programme
Appendix
C Air Quality (Not used)
Appendix D Noise
Appendix E Water
Quality
Appendix F Sewage
Appendix G Ecology
Appendix H Wetland
Restoration Plan
PREFACE
Wo Shang Wai to the north of Royal Palms and Palm Springs is zoned
“OU(CDWRA)”. This area comprises formed
land, fish ponds filled prior to the publication of the Mai Po and Fairview Park Interim Development Permission Area
(IDPA) Plan, and fragmented and partially filled marshland. The western portion is currently mostly
vacant while the eastern portion is currently partly vacant and partly occupied
by a mix of uses including open storage uses, container yards and container
vehicle parks.
The planning intention of this location is to provide
incentive for the restoration of degraded wetlands adjoining existing fish
ponds and to encourage the phasing out of sporadic open storage and port
back-up uses on degraded wetland. This
can be achieved through comprehensive residential and/or recreational
development to include wetland restoration area. Development or redevelopment schemes on the
degraded wetlands directly adjoining the existing continuous and contiguous
fish ponds should include wetland restoration and buffer proposals to separate
the development from and minimize its impact on the fish pond areas. Any new building should be located farthest
away from Deep Bay. (Approved Mai Po and Fairview Park OZP No. S/YL
- MP/6).
1.1.1.
In March 2005 the Project
Proponent, Profit Point Enterprises Limited (Ltd), acquired a
development site in Yuen Long at Wo Shang Wai, as shown on Figure 1.1. The site has evolved from tidal flats for
fishponds to infilled fishponds during the 1980’s until 1991 almost 15 years
before the Project Proponent obtained the site.
1.1.2.
The statutory planning intent
of the site at Wo Shang Wai is to provide an incentive for the restoration of
degraded land through comprehensive residential and/or recreational development
to include a wetland restoration area. It is also the intention of the zoning
plan to encourage the removal of existing sporadic open storage uses on
degraded land in the New
Territories. The overarching objective of this Project is
thus to formulate a land use system with creative layout design which will
simultaneously benefit both the planned residential community and the created
wetland and be sustainable in the long term.
The Project will allow wetland restoration to be realised in harmony
with residential development. It allows
an opportunity for innovative ideas to be showcased to demonstrate that it is
possible to achieve the planned intent to upgrade degraded areas in the New Territories
in a sustainable manner with ecological enhancement to the Wetland Buffer Area
within which the development site lies.
1.1.3.
The Project, and thus the EIA
has also sought ways to minimise impacts to acceptable levels and to harmonise
the apparently conflicting concepts of providing residential developments and
the adjacent sensitive ecology in the Deep Bay Buffer Zone. In order to put the proposed development into
context it is important to note that the site is bounded on three sides by
existing residential development and is in an area which has already been
disturbed by development as illustrated in Plate
1.1.
1.1.4.
In April 2005 Mott Connell
Ltd (MCL) was commissioned to undertake an EIA for this project. A Project Profile was prepared and submitted
to the Director of Environmental Protection (EPD), and in September 2005 a
Study Brief No. ESB – 131/2005 for the “Proposed Comprehensive Development at
Wo Shang Wai, Yuen Long” was issued. The
EIA has been conducted by MCL with Urbis providing the urban
planning and design, landscape and visual impact assessments. Masterplan and Allied Environmental
Consultant Limited were also engaged to provide statutory planning inputs
and noise impact assessment respectively to the EIA. In addition to the foregoing the Project has
also benefited from ecological inputs from Asia Ecological Consultants (AEC)
and Ecology and Environment, Inc. (E&E). AEC has principally been responsible for
input to the Ecological Assessments and developed the wetland restoration plans
as well as providing suggestions on the management and maintenance aspects. In addition to which, the Wetland Management arrangement have been reviewed by one of Hong Kong’s most experienced wetland
lawyers, John Davison. The Project has also benefited from the
adoption of the Continuous Public Involvement (CPI) process in which members of
the public and interested bodies have been consulted at various stages of the
Project development. The feedback
received has been considered and used as appropriate in the development and
refinement of the planned layout for this development project.
History and
Existing Condition of the Site
1.2.1
As revealed in the Study on the
Ecological Value of Fishponds prepared for Government in 1997, the Project
Area was filled by 1991. Since then, the northeastern side of the Project
Area has been used as open storage while the remaining
area has remained vacant.
1.2.2
The existing habitat types
within the proposed comprehensive development include developed area in active
use (open storage for containers and lorry parking), bare ground (site access),
grassland, seasonal marsh, freshwater marsh/reedbed and drainage
ditches. The Project Area is surrounded by residential developments, Wo Shang Wai village,
fishponds and an open storage area. The
site context is shown on Figure
1.1 whilst Figure 1.2
illustrates the Project Area in relation to
the Deep Bay Conservation Area and Wetland Buffer Area boundaries.
1.2.3
As the proposed project
includes wetland restoration it is important to define the site using accepted
terminology.
Definition of Wetland under the
“Ramsar Convention” is:
1.2.4
“Wetlands are areas of marsh,
fen, peatland or water, whether natural or artificial, permanent or temporary,
with water that is static or flowing, fresh, brackish or salt, including areas
of marine water, the depth of which at low tide does not exceed six metres.”
1.2.5
The Working Definition of Wetland as per the “Corps of Engineers,
Wetlands Delineation Manual” Wetlands Research
Program Technical Report Y-87-1, 1987, which is more specific in terms of
characterisation of a particular site, is as follows:
1.2.6
Wetland is defined as a site
containing the following features:
·
presence of wetland hydrology;
·
presence of hydric soil; and/or
·
presence of predominantly wetland
vegetation.
1.2.7
At Wo Shang Wai the ecological
surveys which were conducted between April 2005 and June 2006 recorded 66 plant
species within the site itself. The
vegetation observed on site is typically freshwater marsh/reedbed, seasonal
marsh and grassland, with reed grass Phragmites australis and common grasses
/ herbs such as Brachiaria mutica, Panicum spp., Paspalum spp. respectively. Riparian
vegetation along the drainage ditches within the site boundary is typical of
those found in the northwest New
Territories fishpond
areas including Brachiaria mutica,
Panicum spp., Paspalum spp., Eleusine indica and Bidens alba. No rare or
protected plant species of conservation importance were identified under the
Study. More details on the ecology of
the site are given in Chapter 8 of this EIA.
1.2.8
From on-site observations,
there are patches of standing water on site during the dry season as
illustrated on Figure 1.3.
As described later in this EIA the soils
have been tested to determine their characteristics from, inter alia, a hydric
soil perspective. No evidence of hydric
soils exists except in five locations on the former fish pond bunds there is
some indication of gleyed soil; refer to Figure 1.4. This
suggests some wetland function, which is not unexpected considering the
historical land use of the Project Area as
bunded fishponds. The extent of the
patches of standing water and the distribution of freshwater marsh vegetation
is around 23% of the total Project Area. In
summary the Project Area displays some
wetland characteristics which have been considered when developing the design
of the Project and the restored wetland in terms of both extent and component
features.
Rationale of a
Wetland Restoration Scheme with Residential Development
1.2.9
The rationale for the wetland
restoration scheme with residential development is to restore part of the
previously filled fishpond area to wetland with proper management in the
operation stage. The Study on Ecological
Value of Fishponds in Deep Bay Area (Aspinwall, 1997) showed that the area of
scattered open storage along the boundary of the Conservation Area (CA) caused
significant decreases in ardeid numbers using the fishponds, while the
residential areas at the southern boundary were identified as significantly
less intrusive than the open storage. The
proposed residential development with wetland creation will eradicate the open
storage uses that impact on bird numbers and restore the function of the
wetland, thereby enhancing the ecological value of the Deep Bay Wetland
Ecosystem. The restored wetland will:
·
compensate for the loss of
habitat as a result of proposed development;
·
provide flood protection to the
surrounding developed area;
·
provide life support by
increasing habitat heterogeneity and thus increasing the biodiversity of the
area;
·
provide ecological linkages
between the site and the CA; set a buffer between the residential development (set-back)
and the existing fishponds area to the north of the Project Area; and
·
increase the biodiversity of
the site and encourage various forms of wildlife.
Statutory Planning
Intention of the Site
1.2.10
According to the Approved Mai
Po and Fairview
Park OZP No. S/YL-MP/6, the Other Specified Uses (Comprehensive Development and
Wetland Restoration Area) [OU(CDWRA)] zone is intended to provide an incentive
for the restoration of degraded wetlands through comprehensive residential
and/or recreational development to include a wetland restoration area. It is also intended to phase out existing
sporadic open storage and port back-up uses on degraded wetlands. However, new buildings should be located as
far as practical away from Deep
Bay to minimise
disturbance to the CA. The maximum plot
ratio of 0.4 and maximum building height of 6 storeys including car park is
allowed under the statutory plans, with ancillary facilities to the domestic
development disregarded in the plot ratio calculation.
Purpose and
Objectives of the Proposed Project
1.2.11
The purpose of the Project is
to develop the site in accordance with the
Planning Objectives and permitted conditions stated in the Outline Zoning Plan
(OZP). This permits comprehensive residential development with wetland restoration.
The Project Proponents’ objective is to
provide high quality residential development which is in harmony with nature
and its surroundings, while complying with the planning intention of the site.
1.2.12
The findings of the
Environmental Impact Assessment (EIA) and in particular the ecological surveys
and assessments have provided the basis for the development assumptions. For example, the bird flight paths and use of
the site by different species groups gives an indication of the functions of
the site. This information was then used
in the analysis of the type of restored wetland to be developed. This information was also used in the
development of the layout of the whole site, as well as in the layout of the
proposed residential developments and in the building form, disposition and
height.
Significance of
the Proposed Project
1.2.13
The Project Area is adjacent to existing developed areas, where the building form and
landscaping provide few opportunities for biodiversity. The adjacent developments have also been
created from infilled fishponds and thus have a similar basis for development.
The difference between the adjacent developments and the proposed development
relates to the fact that the planning intent for the Project Area combines the comprehensive development with wetland restoration. In essence, the intent is that the proposed
development should be in harmony with its surroundings including the
residential developments which are close to the boundaries of the Project
Area. The
wetland restoration proposals conform to the requirements of the Town Planning
Board Guideline for Application for Developments within Deep Bay Area under
Section 16 of the Town Planning Ordinance, TPB PG-No. 12B, (TPB 12B) and are in
close proximity to the existing fishponds, thereby providing continuity and
connectivity with the Conservation Area.
1.2.14
This development presumption is
based on a series of guiding principles which were translated into development
objectives and illustrated on the “bubble diagram” (see Figure 2.1). The “bubble diagram” was drawn up using sound
wetland design and management principles and has been reviewed and developed as
the information and data became available from the ecological and other
baseline surveys, as well as the planning guidelines including those defined in
TPB PG-No. 12B.
Scenario without
the Proposed Project
1.2.15
The scenario without the
project would essentially be further environmental degradation and more
ecological harm.
The existing temporary uses of the site may prevail, grassland and low
shrubs would develop through natural succession, developing into tall grassland
and low scrub. Active vegetation
management would be required on a regular basis to maintain the grassland at a
low height otherwise there is the potential for unwelcome users of the site
(rats, mice, illegal immigrants etc. who might hide in tall grass). This is undesirable from a “good neighbour
perspective”, and on the basis that in order to reduce the risk of grass fires,
clearing of the site would need to take place frequently, which would reduce
the ecological value of the site. This
scenario is described in more detail in Section 2 under consideration of the
alternatives for development.
1.3.1
As the Project Area is 21.36
hectares (ha) including two zones (Other Specified Uses (OU) and
Village Type Development (V)), the Project has the
status of a Designated Project under Item 1 of Schedule 3 of the EIA Ordinance
(EIAO) (engineering feasibility study of urban development projects within an
Assessment Area covering more than 20 hectares).
1.3.2
In addition to the above, the
proposed residential development lies within the Deep Bay Buffer Zone 2 and is
not “New Territories exempted houses”. Thus item P1 of Schedule 2 of the EIAO also
applies to this Project.
1.3.3
In the early stages of the
Project it was identified that as there is no public sewerage system in the
area for the discharge of the domestic effluent, the “No Net Increase” (of pollution)
to Deep Bay also applies. At the time of preparing the Project Profile
the initial thinking was to provide a dedicated sewage treatment plant on-site
with the possibility of reusing treated effluent within the development. Reuse
of treated effluent from a treatment plant falls under item F4 of Part 1 of
Schedule 2 of the EIAO and thus such an activity becomes a Designated Project
in its own right. However during the
planning and assessment stage of the Project the Government committed to the
provision of a sewerage system which will include the catchment from this
development site. Government has
confirmed that the domestic effluent generated from this site can be discharged
via the public sewer (on Castle
Peak Road) and thus the timing of this development
project has been phased to accord with the provision of the Government sewer. Hence item F4 is no longer a relevant
component of this Project.
1.4.1
From the outset, the Project
Proponent has been committed to the Continuous Public Involvement (CPI) process
in recognition of the fact that such an approach can assist in the smooth
implementation of the Project. The CPI programme for this Project has included,
but not been limited to, the involvement of community and conservation interest
groups. The inputs and feedback on the development concepts and suggestions,
particularly on the development and management issues associated with the
wetland restoration, have been of particular value. Informal discussions with
Government Departments such as the Environmental Protection Department (EPD),
Agriculture, Fisheries and Conservation Department (AFCD), Drainage Services
Department (DSD), Planning Department (PlanD), Transport
Development (TD) and discussions with local interest groups,
Nature and Conservation Groups including Conservancy Association, Hong Kong
Bird Watching Society, World Wide Fund for Nature, Kadoorie Farm and Botanic
Garden, Green Power, residents of Palm Springs and Royal Palms and
international wetland experts have been fruitful and the feedback received has
resulted in a more robust conservation component to the development plan.
1.5.1
The scope of this EIA study
covers the potential impacts arising from this Project during the construction
and operation phases. The EIA study has
addressed the key issues identified in the aforementioned Study Brief as
outline below:
·
noise
impacts arising from construction and operation of the Project to the nearby
village and residential areas;
·
dust
impact arising from construction of the Project to the nearby air sensitive
receivers (ASRs), as there is no on-site sewage treatment plant there is no
sewage odour emanating from this development
·
landscape
and visual impacts during construction and operation of the Project;
·
the
potential water quality impacts caused by site formation, pond draining and
filling, drainage diversion, and any other works activities during
construction; the potential water quality impacts caused by the operation of
the Project;
·
potential
impacts on historical buildings/architectures and monuments;
·
terrestrial
and aquatic ecological impacts, in particular the potential impacts disturbance
and fragmentation to the adjacent recognized sites of conservation importance
including, for example, the Mai Po Nature Reserve, Mai Po Inner Deep Bay Ramsar
Site, Mai Po Village Site of Special Scientific Interest (SSSI), Mai Po Marshes
SSSI, Inner Deep Bay SSSI, Wetland Conservation Area and Wetland Buffer Area
(both were defined under Town Planning Board Guideline TPB PG-No. 12B) and
important habitats such as fishponds and egretries, due to the construction and
operation of the Project;
·
fisheries
impacts during construction and operation of the Project;
·
collection
and disposal of potentially contaminated dredged spoil arising from the
Project; and
·
the
short term and long term management of the proposed wetland restoration within
the site including trust and financial arrangement.
1.6.1
Under the Study Brief
(ESB-131/2005), the objectives of the Environmental Impact Assessment (EIA)
Study are:
(i)
to
describe the Project and associated works together with the requirements for
carrying out the Project;
(ii)
to
identify and describe elements of community and environment likely to be
affected by the Project and/or likely to cause adverse impacts to the Project,
including both the natural and man-made environment;
(iii)
to
identify and quantify all environmental sensitive receivers, emission sources
and determine the significance of impacts on sensitive receivers and potential
affected uses;
(iv)
to
identify and quantify any potential losses or damage to flora, fauna and
wildlife habitats;
(v)
to
identify any negative impacts on sites of cultural heritage and to propose
measures to mitigate these impacts;
(vi)
to
identify and quantify any potential landscape and visual impacts and to propose
measures to mitigate these impacts;
(vii)
to
propose the provision of infrastructure or mitigation measures so as to
minimise pollution, environmental disturbance and nuisance during construction
and operation of the site;
(viii)
to
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 Project in relation to the sensitive
receivers and potential affected uses;
(ix)
to
identify, assess and specify methods, measures and standards, to be included in
the detailed design, construction and operation of the Project which are
necessary to mitigate these environmental impacts and reducing them to
acceptable levels;
(x)
to
investigate the extent of secondary environmental impacts that may arise from
the proposed mitigation measures and to identify constraints associated with
the mitigation measures recommended in the EIA study, as well as the provision
of any necessary modification;
(xi)
to
identity, within the Assessment Area, any individual project(s) that fall under
Schedule 2 and/or Schedule 3 of the EIA Ordinance; to ascertain whether the
findings of this EIA study have adequately addressed the environmental impacts
of those projects; and where necessary, to identify the outstanding issues that
need to be addressed in any further detailed EIA study; and
(xii)
to
design and specify the environmental monitoring and audit requirements, if
required, to ensure the implementation and the effectiveness of the
environmental protection and pollution control measures adopted.
1.6.2
The Technical Requirements of
the EIA Study comply with those specified in the Study Brief No. ESB - 131/2005
(which is appended as Appendix A
for ease of reference).
1.7.1
The Assessment Area encompasses
all areas within 500m of the Project Area, comprising mostly residential uses (Palm Springs, Wo Shang Wai Village Houses, Royal Palms,
Mai Po Lo Wai, Mai Po San Tsuen and Maple
Gardens) and fishponds
adjoining the Project Area. Ecological
assessments also take into consideration sites of ecological importance
identified during the CPI process, including the egretries at Mai Po Village ‘satellite’, Tam Kon Chau and
Mai Po Lung, which are located outside the 500m Assessment Area boundary but
are within the foraging distance of breeding egrets. The Assessment Area
defined for this project is illustrated in Figure 1.1.
1.7.2
The development of the Project
has considered the adjacent recognized sites of conservation importance,
including but not limited to the Mai Po Nature Reserve, Mai Po Inner Deep Bay
Ramsar Site, Mai Po Village Site of Special Scientific Interest (SSSI), Mai Po
Marshes SSSI, Inner Deep Bay SSSI, Wetland Conservation Area and Wetland Buffer
Area and important habitats such as fishponds and egretries. It has also recognised that the ecological
sensitivity of the surrounding area is crucial to the successful implementation
of the Project.
1.7.3
Particular consideration has
been given to the adoption of workable solutions and methods of work within the
Deep Bay area while upholding the principles
of conservation and ecological protection. To this end the Deep Bay Guidelines have been
followed and the construction programme has taken account of these guidelines
which are fundamental to the assessment of noise impacts as detailed in
Sections 4 and 8 of this EIA. Development
of short term and long term management for the proposed wetland restoration
within the Project Area including financial arrangements is documented in a
standalone document in Appendix
H in accordance with the requirements of the
Study Brief (item 3.9.2.4 (xv)).
1.8.1
The overall programme for
implementation of the Project is given in Appendix B-2. The construction works are anticipated to
commence in 2008 and to be completed in 2012, with population intake timed to
accord with the availability of new regional infrastructure such as public
sewers on Castle Peak Road. As with any development project, the
implementation of the works will be staged via a series of work packages. Essentially the advance works which are being
undertaken at present include site and ground investigation contracts,
investigation for potential land contamination contracts, a Section 16 planning
application for the proposed comprehensive development at Wo Shang Wai (which
is in progress) as well as this EIA.
1.9.1
The EIA has been prepared to
contain all the findings of the Study as follows:
·
Section 2 presents the
consideration of alternative layout options and building height profiles as
required under the Study Brief, construction methods and sequence works and
describes selection of preferred scenario for the Project;
·
Section 3 describes the Air
Quality Impact Assessment;
·
Section 4 describes the issues
associated with Noise during and following construction, quantifies the impacts
and recommends mitigation measures;
·
Section 5 presents the Water
Quality Impact Assessment which include the potential problem of biogas on
reclamation (pond filling);
·
Section 6 describes the
Sewerage and Sewage Treatment Implications
·
Section 7 presents the Waste
Management Implications;
·
Section 8 describes the
Ecological Impact Assessment which is a combined report using the findings of
the baseline survey and describing the development of the mitigation measures
for the protection of the ecological resources and habitats. The management package for the wetland
restoration in the Project Area is appended to this EIA report;
·
Section 9 presents the
Fisheries Impact Assessment;
·
Section 10 describes the Impact
on Cultural Heritage;
·
Section 11 presents the
Landscape and Visual Impact Assessment (LVIA) which is one of the components of
the EIA;
·
Section 12 describes the Impact
Summary;
·
Section 13 provides a summary
of the Environmental Outcomes;
·
Section 14 presents the
Environmental Monitoring and Audit (EM&A) Requirements;
·
Section 15 presents an
Implementation Schedule; and
·
Section 16 presents a summary
of the Conclusions of the EIA.
PREFACE
Wo Shang Wai to the north of Royal Palms and Palm Springs is zoned
“OU(CDWRA)”. This area comprises formed
land, fish ponds filled prior to the publication of the Mai Po and Fairview Park Interim Development Permission Area
(IDPA) Plan, and fragmented and partially filled marshland. The western portion is currently mostly
vacant while the eastern portion is currently partly vacant and partly occupied
by a mix of uses including open storage uses, container yards and container
vehicle parks.
The planning intention of this location is to provide
incentive for the restoration of degraded wetlands adjoining existing fish
ponds and to encourage the phasing out of sporadic open storage and port
back-up uses on degraded wetland. This
can be achieved through comprehensive residential and/or recreational
development to include wetland restoration area. Development or redevelopment schemes on the
degraded wetlands directly adjoining the existing continuous and contiguous
fish ponds should include wetland restoration and buffer proposals to separate
the development from and minimize its impact on the fish pond areas. Any new building should be located farthest
away from Deep Bay. (Approved Mai Po and Fairview Park OZP No. S/YL
- MP/6).
2.1.1
This section of the EIA Report
provides a description on the need for the Project and narrative on the
alternatives considered, both of the conceptual layout of the whole site and of
the building forms, building heights and possible detailed layouts. The need for the Project is explained at the beginning
of the Section and addresses the implications of the further degradation of the
environment versus development. The
Section describes the development concept building process and the process for
the consideration of development alternatives of the Project Area. The Continuous Public Involvement (CPI)
process is described herein and has been an important component of the process
of developing and evaluating the alternatives. This section responds directly to Sections 3.3
through 3.6 inclusive of the Study Brief.
Background
2.2.1
The Project Area lies within an
area designated for “Other Specified Uses” “Comprehensive Development to
include Wetland Restoration Area” (OU(CDWRA)). The notes to the OZP make it
clear that the planning intent for OU(CDWRA) is :
“this zone is intended to
provide incentive for the restoration of degraded wetlands adjoining existing
fishponds through comprehensive residential and/or recreational development to
include wetland restoration area. It is also intended to phase out existing
sporadic open storage and port back up uses on degraded wetlands. Any new
buildings should be located farthest away from Deep Bay.”
2.2.2
The Project Area also falls
within an area which is designated as Wetland Buffer Area (WBA) in the Town
Planning Board Guidelines for Application for Developments within Deep Bay
under Section 16 of the Town Planning Ordinance. While the Guidelines are provided for general
reference and are not binding on the Town Planning Board, they do however imply
the underlying philosophy which is to encourage the restoration of lost
fishponds and to provide a desirable wetland habitat around Deep Bay
and the Mai Po Area. Specifically :
“6.4 the intention of the
WBA is to protect the ecological integrity of the fishponds and wetlands within
the Wetland Conservation Area (WCA) and to prevent development that would have
a negative off-site disturbance impact on the ecological value of fishponds…….
As a substantial number of fishponds with the WBA have already been lost over
time through filling and certain areas have been degraded by the presence of
open storage use, these degraded areas may be considered as target areas to
allow an appropriate level of residential/recreational development so as to
provide an incentive to remove open storage use and/or to restore some of the
fishponds lost.
6.5 Within the WBA, for
development or redevelopment which requires planning permission from the Board,
an ecological impact assessment would also need to be submitted.
Development/redevelopment which may have negative impacts on the ecological
value of the WCA would not be supported by the Board, unless the ecological
impact assessment can demonstrate that the negative impacts could be mitigated
through positive measures. The assessment study should also demonstrate that
the development will not cause net increase in pollution load to Deep Bay.”
2.2.3
With the foregoing as the
guiding principles, the assessment of the implications of development at Wo
Shang Wai commenced. In the first
instance, prior to the issue of a Study Brief under the Environmental Impact
Assessment Ordinance (EIAO), the following activities were undertaken:
·
Visits to the Project Area and
adjacent areas to characterize the site and the Assessment Area. This included the definition of the Project
Area, its relationship with its nearest neighbours including the adjacent Royal
Palms and Palm Springs
and the WCA to the north. The land uses
in the off-site areas were identified and categorized in terms of their
sensitivity to development, such as the egretries at Mai Po San Tsuen.
·
The history of the site was
ascertained through examination of site records and aerial photographs.
·
The planning status was
confirmed.
·
The constraints and
opportunities for development were considered and compiled as a set of planning
principles as illustrated in the “bubble diagram” (see Figure 2.1).
·
Initial ecological baseline
surveys were carried out.
·
Initial environmental
appraisals were conducted.
2.2.4
The next step in the assessment
of the Project Area and its development potential was to undertake a
preliminary environmental review such that an application for a Study Brief
could be made. This was affected by the
preparation of a Project Profile which contained the development parameters and
constraints which were illustrated in a “bubble diagram” (see Figure 2.1).
2.2.5
Upon receipt of the Study Brief
the ecological impact and other impact assessments were undertaken to determine
the existing conditions of the Project Area, the potential impacts associated
with permitted development and the associated mitigation measures needed to
ensure acceptability in terms of the requirements of the EIAO, its Technical
Memorandum and the Study Brief.
History
2.2.6
In the 1940’s and 1950’s the Project
Area comprised brackish rice paddies, and it was during the 1960s when fresh
water fish farming prospered in the New Territories that the rice paddies were
converted into fishponds. With increased
pressure for open storage activities in the North West New Territories (NWNT),
the ponds were progressively filled from around 1987. From the aerial photo taken on 18th August,
1990, it is evident that about 90% of the ponds in the site were filled with
the remainder filled by 1991. Part of
the Project Area has been continuously used from that date as open storage and
the parking of new vehicles.
2.2.7
The introduction of statutory
planning control in the area to prevent infilling of ponds and proliferation of
open storage uses commenced on 17 August 1990 with the gazettal of the Interim
Development Permission Area (DPA) Plan.
In August 1991, with the publishing of the Mai Po and Fairview Park
Development Permission Area Plan, the Project Area was zoned “Unspecified Use
Area”. Under both plans the existing
open storage uses on the Project Area were permitted to continue as they had
“existing use” status.
2.2.8
In June 1994 the Town Planning
Board gazetted the new Outline Zoning Plan to replace the DPA plan, and on that
plan the Project Area was zoned as “Conservation Area”. An objection was lodged to that zoning and
the Board accepted the argument that the Project Area in its form at that time
had limited conservation value because of the existing land use. On 27 October 2000 the Board gazetted an
amendment to the Outline Zoning Plan under Section 6(7) of the Town Planning
Ordinance to rezone the Project Area to the OU(CDWRA) zoning which exists at
present (see Figure 1.5). In doing so, the Board recognized the
“existing use” rights of the Project Area for open storage and provided an
incentive for the redevelopment of the site to provide residential development
in conjunction with the creation of a new wetland conservation area.
2.2.9
The existing use rights for the
Project Area therefore go back to 1990 and also relate to the situation when
the zoning was changed in 2000. These
important dates must therefore be used when establishing the base case against
which any wetland creation should be measured. The applicant purchased the land in 2005, well
after the present zoning of the Project Area was introduced.
Statutory
Planning Intention for the Project Area
2.2.10
The Project Area is zoned ‘OU(CDWRA)’
with a small portion at site entrance zoned as ‘V’. Accordingly, the proposed residential
development shall follow these parameters:
|
Plot Ratio
|
0.4
|
|
Maximum Building Height
|
6 storey including car park
|
|
Layout Arrangement
|
Building farthest away from Deep Bay
|
|
Maximum GFA
|
82,800m2
|
2.2.11
According to the Approved Mai
Po and Fairview
Park OZP No. S/YL-MP/6, the OU(CDWRA) zone is intended to provide incentive for
the restoration of degraded wetlands through comprehensive residential and/or
recreational development to include wetland restoration area. It is also intended to phase out existing
sporadic open storage and port back-up uses on degraded wetlands. However, new buildings should be located
farthest away from Deep
Bay. A maximum plot ratio of 0.4 and maximum
building height of 6 storeys including car park is allowed. The ‘V’ zone does
not include density calculation and is merely proposed as access and amenity in
terms of the proposed development.
Ancillary facilities to the domestic development may be disregarded in
the plot ratio calculation.
The Need for the
Project
2.2.12
The need for the project is
derived directly from the statutory zoning of the Project Area by the Town
Planning Board (TPB) as OU(CDWRA) with the expressed purpose of encouraging new
residential development in degraded sites such as this. The implementation of
the project provides a means to achieve the TPB’s intention of safeguarding the
ecological integrity of Wetland Conservation Area (WCA) to the North and
providing new wetland areas with compatible residential development. Determining whether or not any proposed
residential development with wetland restoration area will create ecological
impacts to the Project Area or its surroundings needs to be considered in a
rational manner with the ecological impact assessment being a key component of
the assessment process.
2.2.13
The need for the Project has
thus been considered taking full cognisance of the Town Planning Board
Guidelines (TPB PG-No. 12B):
“to allow an appropriate
level of residential/recreational development so as to provide an incentive to
remove the open storage use and/or to restore some of the fishponds lost.”
2.2.14
Reference has also been made to
the Study on Ecological Value of Fishponds in Deep Bay Area (Aspinwall, 1997)
which showed that the area of scattered open storage along the boundary of the
Wetland Conservation Area (WCA) caused significant decreases in ardeid numbers
using the fishponds, while the residential areas at the southern boundary were
identified as significantly less intrusive than the open storage. The proposed
residential development with wetland creation will eradicate the open storage
uses that have potential negative impact on bird life.
Purpose and
Objectives for the Proposed Project
2.2.15
The purpose of the project is
to implement the Planning Intention for the site as stated in the planning
notes of the OU(CDWRA) zone on the Outline Zoning Plan quoted above. Furthermore TPB PG-No.12B states that:
“Development proposals to
restore lost fishponds or to replace existing undesirable uses by wetland
habitats are encouraged.”
2.2.16
The objectives established for
the project so as to achieve this purpose are:-
(a)
To determine the function of the existing habitats,
assess the ecological impact of development and provide a comprehensive
proposal which will enhance the ecological function of the site and contribute
to the overall value of the Wetland Buffer Area and the Wetland Conservation
Area.
(b)
To provide a viable high quality residential
development in harmony with the conservation objectives of the zoning.
(c)
To provide for an increase in the wetland function
provided by the site over the existing degraded situation.
(d)
To provide a comprehensive residential development
with a plot ratio of 0.4 so as to provide support for the creation of a
sustainable managed wetland.
(e)
To ensure that the form and height of the residential
development is compatible with the general character of the area within the
flexibility provided by the 6 storey height limit.
(f)
To establish clear conservation objectives which are
compatible with the function that this wetland will provide in the Deep Bay
context taking account of the locational constraints and the form of the
development proposed on the site.
(g)
To provide an effective wetland and visual buffer to
separate the residential part of the development from the “CA” zone to the
north.
The Existing
Site Conditions
2.3.1
The proposed Project is
significant in that the Project Area is recognised by the TPB to be degraded
and that action should be taken by the private sector to arrest further
environmental degradation and ecological harm. The existing temporary uses are
incompatible with the adjacent Conservation Area zoning and would benefit from
being removed. The continued degraded
nature of the site is difficult to manage and creates a fire risk and community
safety concerns. An appropriate form of
residential development with newly created wetland will add positively to the
biological system of the Deep Bay Area and the broader regional ecological
functions of Mai Po in a sustainable manner.
2.3.2
The adjacent developed areas
have a building form and landscaping which provides few opportunities for
diverse wildlife. The adjacent
developments were also created from infilled fishponds and thus have a similar
basis for development.
The Surrounding
Conditions
2.3.3
The Project Area is located on
the northern edge of the low-rise residential development at Palm Springs and Royal Palms. In this respect it forms a transition between
a development area and the fishponds to the north which are zoned as
“Conservation Area” on the Outline Zoning Plan.
A part of the existing Palm
Springs, residential development area is also located
outside the western-most edge of the site and is between the site and the Mai
Po Nature Reserve located a further 700 metres to the west.
2.3.4
The adjacent existing
development is predominantly three storeys in height in accordance with the
planning restrictions for the R(C) zone.
Along the north eastern boundary is the scattered village development of
Mai Po San Tsuen and Mai Po Lo Wai villages interspersed with areas of open
storage and other temporary uses. Other
than the existing commercial fishponds to the north of the Project Area, there
is no feature which is of particular ecological or environmental sensitivity
immediately adjacent to the site.
2.3.5
The existing habitat types
within the proposed comprehensive development include developed area in active
use (open storage for containers and lorry parking), bare ground (site access),
grassland, seasonal marsh, freshwater marsh/reedbed and water ditches. It is surrounded by a residential area,
village development, fishponds and open storage.
2.3.6
The freshwater marsh/reedbed, seasonal
marsh and grassland are secondary habitats developed on land filled over 15
years ago. Vegetation is typical to
those similar habitats located in the surrounding NWNT areas. No rare or protected or species of
conservation interest of flora were identified. Fauna species recorded within the Project Area
are common and widespread throughout the Deep Bay Area.
Introduction
2.4.1
The EIA Study Brief requires
that consideration be given to alternative layout options and building profiles
for the Project in arriving at the preferred option. A description of the environmental factors
taken into consideration is required and a comparison between the options is to
be provided. The preferred option should
avoid or minimize adverse environmental effects to the maximum practicable
extent. In particular, consideration
must be given to avoiding disturbance to the adjacent recognized sites of
conservation importance and important habitats during the construction and
operation of the project. Where avoidance
is not possible then minimisation and mitigation of potential impacts to
acceptable levels is required. The
process outlined in Figure
2.1 and Figure 2.2,
“Generation of Options”, illustrates how the principles of the “bubble diagram”
were transposed into options or alternatives.
Working Up the
Alternatives from Development Principles
2.4.2
At this juncture it is
important to summarise the development principles which have been considered in
the development of options or alternative development proposals. It is also important to note that some of the
development principles apply to all options and do not provide differentiation
between options/alternatives/layouts.
Wetland Restoration
2.4.3
Wetland restoration is one of
the statutory requirements laid down in the OZP No. S/YL-MP/6. TPB PG-No. 12B “Application for Developments
within Deep Bay Area under Section 16 of the Town Planning Ordinance” (April,
1999) defines Wetland Restoration as:
“Development proposals to
restore lost fishponds or to replace existing undesirable uses by wetland
habitats…”
and the
definition of wetland habitat adopted by the TPB from Ramsar is :
“any area of marsh, fen, peatland or water whether natural or
artificial, permanent or temporary, with water that is static or flowing,
fresh, brackish or salt, including any area of marine water the depth of which
at low tide does not exceed 6 metres, in which plants and/or animals live.”
2.4.4
Wetland Restoration is a term
used to describe activities that return wetland from a disturbed or totally
altered state to a previously natural condition. The converted wetland not only restore the
physical state but also the functional values, by the re-establishment of flora
and fauna to enhance life support, flood control, recreational, educational, or
other functional uses (Hammer, 1996). From
the analysis carried out as a result of the ecological assessments the wetland
restoration area (WRA) will be 4.74 hectares (details provided in Section
8). The functions of the proposed WRA
are given in detail in Appendix H.
Buffering from Existing Ponds in the North
2.4.5
The Project Area is located in
the Wetland Buffer Area (WBA) and adjacent to the Wetland Conservation Area
(WCA) as identified in TPB PG-No. 12B. According to the Guideline, development
in the WBA should provide a wetland and visual buffer to separate the
development from the WCA, to minimise its impact on the wetland and to restore
some of the lost fishponds to an appropriate form of wetland adjoining the WCA.
Building Form and Location
2.4.6
The OZP permits buildings up to
six storeys in height. However,
consideration needs to be given to the form of other development in the area
which is mainly of three storeys in height, such as at Royal Palms, Palm Springs, Fairview
Park, Mai Po San Tsuen and Maple Garden. The form of development proposed on the site
should therefore be compatible with the general character of the neighbourhood
in terms of height and also in visual impact terms.
2.4.7
The OZP zoning also requires
that any buildings be located as far as possible from the Mai Po Nature
Reserve, and consideration should be given to the open nature of the general
area between the Project Area and the Nature Reserve. Consideration also needs to be given to the
relationship to the residential development on the adjacent site, with regard
to building height variation; building height; spacing between units and
distance between building and Visually Sensitive Receivers (VSRs).
2.4.8
Adequate open space provision
must be provided in the development such that it fulfils HKSAR Government
Planning Standards and Guidelines but also conforms to what are currently
regarded as basic sustainable development principles including green space
corridors, areas for groundwater recharge and opportunities for sustainable
community interaction.
2.4.9
Building form and layout are
key factors which have been examined when considering the different
alternatives.
Access
to the Project Area
2.4.10
The only vehicle access to the Project
Area is via the Castle Peak Road
– Mai Po section. The access passes
through the Village zone before entering the OU(CDWRA) zone. This access shall also serve as the future
access to the site after appropriate upgrading works. All options will use this access, therefore
there are no differentiating factors for this consideration.
Parking Provision for Residential Development
2.4.11
As the Project Area is remote from
mass transit and due to the large unit size, car usage is expected to be
high. According to the HKPSG
requirement, the minimum parking varies according to the flat size and the
distance from a railway station. The
development is likely to have mainly large units and the parking standard is
stipulated as a minimum with possible greater provision being subject to
Transport Department’s approval. The
parking standard calculation results in a minimum requirement of approximately
1.5 car parking spaces for each dwelling unit.
However, it is considered that a higher parking provision than 1.5
spaces per unit may be appropriate and this will be subject to further
discussion with Transport Department. This
is not a factor which will differentiate between the options.
No Community Facility Needed
2.4.12
Given the small anticipated
population of the development, no particular community facilities are
required. However, the normal provision
of a Club House will be provided for the residents’ use for all options.
Site Formation Level Relative to Water Level
2.4.13
The minimal site formation
level for buildings in Hong Kong in general is
+5.5m to prevent flooding. The
difference between building level, water level and level of existing channels
and ponds shall be taken into account when designing the area for building
works and when forming the waterscape design.
This is not a factor which will differentiate between the options
considered.
Adjacent Site within the same OU(CDWRA)
2.4.14
Part of the OU(CDWRA) zone
falls outside the proposed site boundary and is in separate ownership. That portion of the OU(CDWRA) zone may
therefore be developed independent of the current proposal. The existing vehicular access to that Project
Area will be suitable for future up-grading to serve permanent development of
the site. It also fronts onto an
adjacent area of fishponds zoned as ‘Conservation Area’ and there is scope for
a wetland area to be created adjacent to the existing ponds. The implementation of the current proposal
will therefore not adversely affect the long-term achievement of the desired
form of development within the whole zone.
Paragraph 9.9.4 of the Explanatory Statement recognises that the zoning
may be implemented in parts. The Project
Area has incorporated a buffer between this area and the residential and
wetland area in the form of the Clubhouse and open areas.
No
Net Increase in Pollution Load to Deep
Bay
2.4.15
To protect water quality and
ecosystems in and around Deep Bay, this Project within the WBA should not cause a
net increase in the pollution load to Deep Bay
(i.e. no net increase requirement) as specified in the Town Planning Board
Guidelines No. 12B. The government has a
confirmed program for the construction of public sewers along Castle Peak Road. It is therefore intended that the development
should not be completed and occupied before the availability of the public
sewer. It is understood that the current
program is for the public sewer to be completed in 2012 and that is compatible
with the development program for this Project.
A sewer will therefore be laid from the site to connect to the new
public sewer, thus there is no difference between any of the alternatives
considered for this element.
Avoidance of Key Ecological Impact
2.4.16
The existing conditions within
the Project Area are such that any development would have unavoidable negative
impacts to existing wetland habitats, especially through fragmentation of this
habitat from nearby existing wetlands.
Thus it is considered that retention of existing wetlands within the
Project Area is not feasible. The only feasible and desirable option is to
compensate for the loss of these wetlands by creation of a Wetland Restoration
Area which would be located to the immediate south of the existing offsite fishpond
habitats. This will permit enhancement
of the wetland habitats within the Project Area, through habitat management and
through integration with contiguous wetland habitats in the Deep Bay
ecosystem. This will have the additional
benefit of creating a buffer area between the residential development of the
Project Area and fishpond habitats to the north of the Project Area, minimizing
potential disturbance impacts to wetland-dependent birds using these fishponds.
The type, nature, size, dimension, functions and other design parameters of the
habitats to be created will be carefully considered to achieve a robust
eco-system. To minimize impacts on the
ecology, existing ecological resources including the reeds and some native
vegetation within and surrounding the Project Area will be reused as far as
possible. Suitable areas of topsoil on the site will also be retained for the
use in landscape planting as far as possible. To minimize the disturbances to
both on-site habitats and to provide maximum linkage to surrounding fishponds,
the wetland restoration area will be constructed at the earliest stage, to form
a buffer between the construction site and the Conservation Area. This is a key element in considering the
alternatives.
Adjacent Ponds Wo Shang Wai Village
2.4.17
There is an existing pond
located to the south of the Project Area in Wo Shang Wai Village. There are also ponds within the Palm Springs
development. The latter ponds are zoned
‘CA’ while the one in the village is zoned for residential development in the
long term. While there may be relatively
little ecological value in these two adjacent water bodies, it is considered
that their existence should be taken into account when preparing the layout for
the site. While there is no intention of
establishing a physical link with them, it may be advantageous to consider ways
of trying to improve the visual corridor of these water bodies to the fishponds
located to the north of the Project Area.
Water Supply to Wetland Features
2.4.18
Wetland features need water to
perform ecological and landscaping functions.
Rain water will be the source of water and historic data indicates that
the normal rainfall expected in the area should provide adequate water in all
but exceptionally dry years. In the dry
months of the year there will be some natural draw-down of water by
evaporation. This is a natural process
of the wetland which facilitates feeding by some species. The design of the wetland will include four
compartments separated by bunds. Short
periods of flooding or drain down of water in these compartments could be
controlled by the uPVC pipes located within each internal bund and sluice gates
at the discharge point. This will permit
the rapid discharge of water when the compartments are full or following heavy
rainfall events for water level control. The area will be designed such that water can
be pumped between each compartment for maintenance using pumps.
Flight Path of Birds
2.4.19
Wetland birds fly over the
northern part of the Project Area (Figure 8.4 summarises the
bird flight path survey analyses), but there appear to be no regularly used
flight paths which would be significantly impacted, provided careful
consideration is given to the building heights, the building profile and the
effects of lighting/glare effect at night of the proposed developments.
2.4.20
Six storey buildings could
affect the use of any existing fishponds, or those wetland habitats created on
site, by foraging egrets from nearby egretries and by other species of
conservation concern, particularly during winter migratory bird season. Parts of the Project Area adjacent to
off-site wetlands to the north would be unsuitable for any 6 storey buildings.
Existing and Proposed Hydrology
2.4.21
The development will not
extinguish any existing flow path (including streams and channels) and the
existing ditch on the perimeter of the site will be filled in order to
facilitate the construction of the site formation for the proposed Development.
However, an internal drainage network underneath the
future road system within the proposed development will be provided to collect
the surface runoff generated within the site area.
Careful consideration will be given to ensuring the overall drainage provisions
and systems on site will not reduce the drainage performance of the area.
Nuisance from Existing Open Storage in the Northeast
2.4.22
The development has also taken
into account the potential industrial/residential interface problem arising
from the existing open storage use within the OU(CDWRA) zone which is
located immediately next to the Project
Area. Industrial noise arising from the
nearby open storage operations may impose noise nuisance and other
impacts.
Sustainable Development
2.4.23
The design and construction of
a development of this nature provides an ideal opportunity for the introduction
of sustainable development measures.
These will be incorporated, where appropriate, into the design of the
site formation works, construction process, building materials and also in the
design and management of the residential and wetland areas. The need to ensure the long term
sustainability of the wetland restoration area will be a major influencing
factor in this respect.
Continuous Public Involvement (CPI)
2.4.24
Wetland restoration in
conjunction with development is a relatively new concept to Hong
Kong. A CPI exercise has
been carried out in parallel with the EIA preparation. This process has assisted in soliciting
community and professional views, comments and suggestions at various stages in
the design and data collection process.
Green groups and residents of the developments surrounding the Project
Area have been
consulted during the preparation of the layout options and comments have been
taken into account in arriving at the preferred option. The CPI process has been extremely useful in
clarifying concerns and providing a sharing of experiences with others before
selection of the preferred option. The
CPI process undertaken for this Project is described in Section 1.
Consideration of
‘No-development’ Option
2.4.25
Various factors need to be
considered when contemplating the ‘No-development’ option as described in the
following paragraphs.
2.4.26
Agricultural use is permitted
as of right under the OZP, and does not require government’s approval for such
use on the subject area. This implies
that the whole site could in theory be used for agricultural purposes. This
would neither be ecologically sustainable, nor is it compatible with the
adjacent fishponds. Agricultural use would eventually reduce the ecological
value of the site and damage the ecology in the wider context of the WBA and
WCA.
2.4.27
According to information from
the Town Planning Board (TPB) records, 64 applications have been submitted to
the TPB since 2001 for permission for uses including open storage, parking
area, workshop, etc. on various OU(CDWRA) zones within Yuen Long; of which 16
applications have been approved (up to June 2007). Most of the planning applications were
approved on a temporary basis for up to 3 years (Appendix B-1). It should be noted that the existing open
storage and lorry parking uses were on the Project Area before the gazettal of
the OZP and are permitted to continue without a time limitation, as they have
“existing use” status.
2.4.28
Under the statutory OZP,
submission of a Wetland Restoration Area or Layout Plan is not necessarily
required for applications for temporary uses.
There is no guarantee that the Project Area would be restored to its
original condition or that any negative impacts would be mitigated after the
interim uses are completed. In theory
the potential for such interim uses therefore presents serious environmental
risks. If the subject site remains
undeveloped, similar kinds of interim uses could be present on site and their
associated environmental impacts would reduce the ecological value and further
degrade the ecology of the habitats.
2.4.29
According to the management
offices of Palm Springs
and Royal Palms, concerns on crime, grass fire and security of the subject site
have been reported by residents of these neighbouring residential
developments. The Project Area is
covered with grassland and in some parts, high grass with potential fire risk
and mosquito breeding issues. If the
subject site remains in the current condition, worries about crime and
trespassers through this undeveloped/vacant land to the adjacent low-rise
residential buildings would continue.
Active land stewardship and regular maintenance of the Project Area is
possible to reduce the risks. However,
it would and has at the same time unavoidably as a consequence, reduced the
ecological value of the site by destabilising the ecological habitats.
2.4.30
The above paragraphs indicate
that if the Project Area remains in its current condition not only would the
planning intention not be achieved but the permitted uses and possible
short-term uses on site might offer potential to further degrade its ecological
value and continue to pose nuisance to neighbouring developments. The proposed residential development, with
the provision of wetlands, is considered to be a desirable use of the Project
Area. It would maintain the ecological
value of the Project Area on a sustainable basis, as well as providing proper
site management and security measures to avoid nuisance to the surrounding
areas.
2.4.31
The ‘no action’ alternative
could therefore result in long term degradation of the Project Area and is not
therefore favoured.
Compatible
Development
2.4.32
Another alternative considered
was to develop the Project Area in a manner similar to the adjacent development
at Palm Springs
and Royal Springs to the south and west of the application site. These developments are of a form which could
be described as typical for the North
West New Territories. They are typically
low-rise, characterised by predominantly 3 storey houses and a dense network of
roads. There is little or no variation
in height profile. The arrangement of
units is typically low-rise with terraced units sitting alongside free-standing
units.
2.4.33
This form of development has no
design element which gives consideration to the ecology of the location, even
though they are usually accompanied by areas of landscaping, trees planted
along roads and vegetation within the private gardens. These features are usually for ornamental and
decorative landscape purposes and generally are of little ecological
value. The adjacent residential
development at Palm Springs
and Royal Palms was approved prior to the “Fish Pond Study” and the
implementation of the Buffer Zone concept to protect and enhance the wetlands
and the Mai Po Marshes.
2.4.34
This form of residential
development therefore is not in line with the current requirements for
development in the Buffer Zones and offers very little urban design/landscape
and visual benefits in terms of variation of profile, permeability and
landscape provision.
2.4.35
It has no mitigation measures
to help restore or enhance the ecology of the area. During consultation with the Green Groups it
became clear that this form of development was no longer considered acceptable
within the Buffer Zone areas as there were no mitigation measures
included.
2.4.36
The lack of any buffer areas
between the residential development and the adjacent fishponds was considered
unacceptable and allowed for intrusion of human activities onto the fishpond
areas. Most fundamental was the lack of
provision of any form of wetland within the Project Area. Without any attempt to restore wetland and to
encourage the use of the area by suitably selected species of birds, the
traditional form of residential development did not achieve any of the
ecological objectives that have now been established for the Buffer Zone
areas.
2.4.37
For these reasons a form of
development similar to the adjacent Palm
Springs and Royal Palms is considered unacceptable and
this alternative was discarded.
2.5.1
It is important to note that
one objective relating to the permitted development on site is “an appropriate
level of residential/recreational development”.
The proposed development must also fulfil the requirements of TPB No.
12B and moreover provide ecological mitigation for the functions which will be
lost as a result of the proposed development.
Therefore the ecological survey data and analyses contained within the
Ecological Impact Assessment (refer to Section 8) were drivers in the layout of
the development.
Development
Criteria for Option Consideration
2.5.2
The statutory zoning allows
flexibility in the design and layout of the buildings on the site. The amount of development permitted is the
same as the traditional form at a plot ratio of 0.4. However, the height limit is lifted to permit
up to 6 storeys and this therefore allows some scope to provide taller
buildings with smaller site coverage.
This in turn allows for more of the Project Area to not be built on and
scope for part of the un-built area to be used for ecological mitigation
purposes.
2.5.3
By considering the statutory
zoning a number of options or forms of development layouts were generated for
consideration. Some of the initial forms
of development included a generic ‘rectangular’ form illustrated on Figure 2.3a and a
generic ‘horseshoe’ form illustrated on Figure 2.4a of residential
development with associated areas of wetland.
The ‘rectangular’ form provided little relief or edge effects and
basically gave only a strip of wetland to separate the residential and CA zones
(Figure 2.3b).
2.5.4
The concept of providing the
buffer was acceptable in terms of the general concept set out in the TPB PG-No.
12B although it needed to be refined and developed to provide other component
features of a well designed WRA.
2.5.5
The horseshoe style of
development had advantages in that it gave a longer water/residential interface
(Figure 2.4b), but
the concept did present some challenges in terms of providing a buffer between
residential developments and the CA. It
was evident early on that the form of development needed to be refined and
elaborated to accommodate the various “development criteria” which were used to
develop alternatives and differentiate between options. The Development Criteria which allow
differentiation between the options are summarized in Table 2–1.
Table 2‑1 Development Criteria
|
Alternative Factors Considered
|
Reason for
Consideration
|
|
Wetland Restoration
Area (WRA)
|
The size, layout, form of the compensation differs between the
options (refer to Section 8).
|
|
Buffering between
Development and Existing Ponds to the North
|
Minimum distance between residential developments and CA vary (refer to Section 8)
|
|
Building Form and
Location
|
Different building heights or mixes or layouts vary and affect
performance of options (refer to Section 11)
|
|
Continuous Public
Involvement (CPI)
|
CPI was used in the development of layouts, or in the modification
of layouts following input from CPI
(refer to Section 1and 11)
|
|
Avoidance of Key
Ecological Impacts
|
Extent and variety of compensation is a key feature as is
mitigation during construction (refer to Section 8)
|
|
Adjacent Ponds
|
Factors include the continuity of water features
|
|
Water Supply to
Wetland Features
|
Source of water varies
|
|
Flight Path of
Birds
|
Use of flight path data to ascertain impacts of development on
avifauna (refer to Section 8 and Figure 8.4)
|
|
Nuisance from
Existing Open Storage in the Northeast
|
Interface issues
|
|
Sustainable
Development
|
Opportunities for sustainable development or green building designs
|
Integrated
Wetland Concept Option
2.5.6
Developing the theme
illustrated in the “bubble diagram” and taking cognisance of the buffer zone
between residential and CA, the limitations and ecological impacts arising from
retention of existing wetland habitats within the Project Area, and the
opportunities of a simple, sustainable yet ecologically diverse WRA, various
broad ecologically sensitive layout options were considered. Firstly, an integrated design (Option A)
was derived which provided a series of residential development areas
interspersed with water/wetland areas.
This layout is illustrated in Figure 2.5 and is a
combination of water, roads and buildings providing for 276 houses. Each house is large having an average floor
area of 300 square metres. This layout
is relatively land intensive and shows that the areas of water are relatively
narrow and that the areas of buffer between the residential development and the
fishponds to the north are relatively small.
There is limited height profile variation and interest, as well as
relatively limited areas of landscape reprovisioning. The area of restored wetland is around 3.4ha
for the core wetland and 1.0ha for the linear wetland areas between the
development areas.
2.5.7
While the shoreline between water
and land is relatively long, the close proximity of the residential uses to the
water would likely have a negative impact on how the wetland would operate in
relation to the target bird species and would not alleviate the issues of
fragmentation of wetland highlighted in Section 2.4.16. The main disadvantage is the creation of a
high site coverage and need for a large area for roads, limiting space for
wetland restoration and landscaping, and the interface between residential
developments, wetland restoration area and the existing fishponds adjoining the
Project Area within the CA.
2.5.8
Furthermore, the layout does
not accord with the TPB PG-No. 12B requirement to locate the residential
developments as far as possible from the adjacent WCA and on that reason alone
was considered to be not acceptable for further consideration.
Transitional
Wetland Concept Options
2.5.9
A layout based on the
conceptual design framework as established in the statutory OZP was considered
as this is more likely to meet the ecological objectives. This approach can be seen in Figure 2.2 where the
concept was developed from a bubble diagram to a conceptual zoning of the Project
Area and then refined to a number of options.
2.5.10
Figure 2.6 illustrates the concept (Option B) of introducing wetland
areas into the residential zone. The
intention was to provide compensatory habitats for species using the site such
as dragonflies and butterflies and amphibians.
The concept was to provide a large area of core wetland area located to
the north of the Project Area with linear wetland areas between “fingers of
housing land” flowing south and protruding into the residential
development. While a priority was given
to achieving a high quality of wetland mitigation, consideration was also given
to achieving a high quality residential environment based upon a respectful
relationship between the residential development and the wetland area.
2.5.11
Option B represents the medium rise form of development and has all 6
storey blocks. 36 blocks 6 storeys
high are proposed. This form of
development provides the largest population with smaller units with average
size of 95.8 square metres although it could also reduce population intake by
having 3x duplex or 2x triplex blocks.
However, the analysis of flight paths of birds indicates that there was
likely to be an adverse impact because of the height of the buildings. These would be the only buildings of this
height in the whole of the Mai Po area and in this respect visually
significant. The development has around
28% of the Project Area for wetland areas with 3.4 ha for core wetland and 2.5
ha for linear wetland areas. Although
the option offers relatively high areas of landscape reprovisioning and visual
permeability, it also offers no variation in height profile and results in
visual effects from relatively tall 6-storey structures on visual receivers
(especially on residents in Royal Palms and Palm Springs, and on the landscape
character of the Tsing Lung Tsuen Plain.
2.5.12
Figure 2.7 has a similar medium rise layout with streams of wetland extending
within the residential area (Option C).
The width of wetland between the fingers is narrower and this may result
in greater negative impact from human activities on the use of the wetland by
the target species. There is 21% of the Project
Area as core wetland (around 4.3 ha), around 2.1 ha of linear wetland areas and
around 44% as landscape area. The layout
has 2.5/3 storey houses along the fingers which would reduce the light
glare and have less impact on the bird flight paths. There are 4 storey buildings
introduced along the boundary and some 6 storey blocks are retained in
the central area away from the wetland.
This results in a gentle built-form profile consisting of 44 detached
houses, 116 semi-detached houses, 164 units as four storey duplex blocks and
144 flats in 6 storey apartment bocks.
There is concern however that the location of 4 storey buildings along
the boundary will have a negative impact in relation to the adjoining
residential developments.
2.5.13
The medium rise options which
included 6 storey buildings were not selected due to their visual impact on the
regional landscape and the potential effect on ecology.
2.5.14
Figure 2.8 shows an alternative low rise option which removes all of the 6
storey buildings and has 28 2.5/3 storey detached houses, 132
semi-detached houses and 188 duplex units in 4 storey buildings (Option
D). About 19% of the Project Area is
core wetland area of approximately 4.0 ha and around 10% or 2 ha are linear
wetland areas. The longer waters edge
also means that more of the wetland will likely be subject to intrusion by
human activities. This option achieves
some limited variation in profile and its relatively less dense layout may
offer slightly reduced effects on landscape character whilst offering greater
area for landscape mitigation. The possible negative impact of 4-storey
development along the boundary of the adjacent residential developments also
remains.
2.5.15
Another low rise option (Option
E) shown on Figure 2.9
has the same area of wetland as Option D.
Some buildings are now only 2.5/3 storeys high along the
boundaries of the Project Area adjacent to the existing residential properties
with backyards directly fronting onto the proposed development in Wo Shang Wai. The low-rise structures conform closely to
the existing scale of structures in the landscape, but provide limited height
profile variation and interest. The same
relationship exists between the residential buildings proposed on the Project
Area to the wetland area as for Option D.
However, there is less communal open space than in Option D.
2.5.16
From an ecological perspective,
the low rise options (Option D and E) with 2.5/3 storey houses
at the centre of the Project Area are likely to have similar environmental/ecological
performance. In both options, the proposed residential areas are located away
from the ecological sensitive receivers i.e. fishponds in the WCA and kept
close to the existing residential estates of Palm Springs and Royal Palms,
leaving the proposed wetland restoration area (WRA) to encourage direct
ecological linkage with the fishponds in the WCA. The reduction in building
height and the reduction in number of residential units by approximately 60%
and 25% respectively from the medium rise options would reduce the population
of the whole development and thus reduce human activities in vicinity to the
WRA. This minimization measure aims to prevent future human disturbance from
the proposed residential area on the sensitive habitats offsite and also
enhance the performance of the proposed wetland onsite as far as possible.
2.5.17
The proposed wetland of both Option
D and E would contain a core area and several stream features. As a
result of the discussion between different interest groups (Nature Conservation
Groups, relevant Government Departments and Wetland Specialists) during
Continuous Public Involvement (CPI), a further refined scheme was generated.
Refined
Preferred Option
2.5.18
This option was developed after
a thorough assessment of the ecological impacts and evaluation of the findings
of the ecological baseline undertaken for this Project. In addition to which several rounds of
consultation with Green Groups, residents of Palm Springs and Royal Palms and
discussions with Government Departments.
The modified option presented here as Option F, is the Preferred
Option, and is included in Figure 2.10.
2.5.19
This option has discarded the
“streams of water” (wetland area in between the residential houses protruding
in the form of fingers) as being wetland habitat and turns them into landscaped
areas. As the interface between the
residential area and wetland area has been designed out, the negative edge effect
from human activities should also be minimized. The further enlargement of the
WRA, the distance between the proposed residential area and the fishponds in
WCA, is increased. The potential
off-site impacts could be further reduced by this design, and provide
opportunity for ecological enhancement of the fishpond area.
2.5.20
As a result of further CPI, the
length of the fingers of land has been shortened and the form of the design has
been amended to create a loop in the road network and to pull the land back
from the northern edge of the Project Area.
This also improves traffic circulation so that visitors who lose their
way will be able to use the loop rather than having to turn in a
cul-de-sac. The effect of pulling the
land back has been to increase the area of wetland to the north to 22%
of the Project Area (around 4.74ha).
The landscaped area provide a visual softening and greening effect to
the Project as a whole and physically link with the WRA proposed at the
northern portion of the Project Area and fishponds at the north to provide aesthetical
view. The 4.74ha of WRA under Option F will be in the form of freshwater
marshes with reeds, freshwater ponds, trees and shrubs that provide habitats
for the target species and provide a visual buffer to separate the residential
development from the WCA to meet the planning intention of OU(CDWRA). A buffer
planting area with trees, shrubs and groundcovers and garden fence will be
included along the edge of the wetland restoration area to functionally and
visually separate the residential areas and amenity areas from the wetland
restoration area.
2.5.21
It was considered to be equally
important to address the concerns of the residents in the neighbouring
developments. Other than providing a
landscape buffer, greater setback of buildings and the staggered arrangement of
building facades, the 4 storey blocks which are directly facing the backyard
space of the adjoining 3 storey structures in Palm Springs and Royal Palms have
been changed into 2.5/3 storeys buildings to minimize the “over-looking”
effect. The evolution of the various
layout options were ecologically driven and environmentally oriented for
improvement. It is anticipated that the
“over-looking” concerns from both the Palm
Springs will be further investigated in the detailed
design for the planning application submission.
2.5.22
The preferred option (Option
F) has 127 nos. of 2.5/3 storey detached houses, 44 semi-detached
houses and 180 duplex units in 4 storey buildings. It offers a balanced alternative with regard to
ecology/landscape/visual criteria as well as a number of advantages over other
options, namely: its reduced visual effects on adjoining residents in Palm Springs and Royal
Palms as well as some variation in building profile. The 4-storey development previously located
along the southern boundary has been moved to the centre of the Project Area in
this option. The fingers of water
(wetland streams) between the areas of housing have been removed and are
replaced by landscape areas, resulting in an overall increase in the available
area for landscape mitigation.
Summary of
Alternatives Considered
2.5.23
The CPI process has therefore
resulted in achieving a design and layout which maximizes the effectiveness and
functionality of the wetland habitat area that is to be created on the site, by
limiting adverse human interference. It
also allows for minimal impact on existing bird flight paths and results in a
compatible form of residential development along the boundaries with the
neighbouring sites.
2.5.24
The consequences of
implementing the Preferred Option would therefore be the creation of an area of
enhanced managed wetland in excess of the compensation required for the
ecological value of the existing wetland on the site, and with a much improved
carrying capacity for wildlife, and particularly for birds. The design clearly demarcates the landscape
water elements from the wetland habitat that is created. It also creates an effective system of buffers
between the residential development and the wetland habitat, and between the
residential developments and the fishponds to the north.
2.5.25
The approach taken in reaching
this design option has been to avoid any impact on the surrounding areas if at
all possible and if this could not be achieved, then the impact has been
minimized. An example of this is illustrated by the location of the different
house types along the boundary of the Project Area. Any residual impact that may remain will be
further offset by mitigation, such as by detailed design of the buffer space
and earth bunds between the waters edge and the residential development.
2.5.26
The Preferred Option has
therefore provided a residential development created in the context of an
ecological design. This has included a
strategy for the long term management of a newly created wetland system which
will enhance the overall integrity of the Mai Po Marshes.
Summary of
Alternative Options Considered
2.5.27
To summarise the discussions in
the foregoing Sections
Table 2–2 has included
salient points which illustrate the consideration of alternatives.
Table 2‑2 Summary of Alternative Options Considered
|
Development Criteria
|
Integrated Option
|
Medium Rise Option
|
Low Rise Option
|
|
A
|
B
|
C
|
D
|
E
|
F
|
|
Wetland
Restoration Area (WRA) (ha)
|
3.4
|
3.4
|
4.3
|
4.0
|
4.0
|
4.7
|
|
Buffering
between Development and Existing Ponds to the North (m)
|
little
buffer distance between residential developments and the CA.
|
provided
by discrete WRA
|
increased
buffer zone especially in the northwest of the Site
|
|
Building
Form and Location
|
all
2.5/3 storeys
|
all 6 storeys
|
hybrid
up to 6 storeys
|
hybrid 2 and 4 storeys
|
all
2.5/3 storeys
|
hybrid 2.5/3 and 4 storeys
|
|
Continuous
Public Involvement (CPI)
|
discussed
as part of CPI, not forward option
|
discussed
as part of CPI
|
discussed
as part of CPI
|
discussed
as part of CPI used to develop option F
|
discussed
as part of CPI
|
discussed
as part of CPI process and
subsequently
further refined following further CPI
process
|
|
Avoidance
of Key Ecological Impact
|
extensive
mitigation required during formation of wetland restoration area
|
minimisation
and mitigation measures adopted
|
avoidance,
minimisation and mitigation principles adopted
|
|
Adjacent
Pond
|
fragmented
development
|
continuity
provided especially with the adjacent fishponds
|
|
Water
Supply to Waterscape
|
initially
rainwater plus supplies of “top up” water such as tap water using fixed pumps
and a network of pipes
|
rainwater
only with no fixed pumps
|
|
Flight
Path of Birds
|
consideration
of birds with medium flight height but no buffer provided at the northern
portion
|
some of
the frequent flight paths may be affected by the building heights and
increase disturbance
|
buffer
zone provided but limited width at the northwest of the Site where there are
records of frequent flight paths
|
consideration
of frequent birds flight path at low height with appropriate buffer width
especially increased at northwest part of the Site
|
|
Nuisance
from Existing Open Storage in the Northeast
|
reduced,
but interface with low-rise residential units
|
impacts further
minimized by locating non-noisy private facilities in this area.
|
|
Sustainable
Development
|
All have
opportunities to incorporate sustainable development and green building
design. However F has most sustainable
solution as the WRA is wholly sustained by rainwater and not fed by
alternative sources and requires no energy to maintain its functions.
|
Forms of
construction
2.6.1
There are fundamentally 3 forms
of construction under the development project, namely site formation, building
construction and wetland restoration. In
this case, it is important to consider the types of building structures that
would be suitable in the context of the statutory planning requirement and from
a geotechnical perspective.
Site
Characteristics
2.6.2
The Project Area is located
immediately west of the Scheduled Area No.2 as delineated by Environmental,
Transport and Works Bureau (ETWB) Technical Circular (Works) No. 4/2004.
2.6.3
Based on available ground
investigation findings, marble has been found in the western portion of the Project
Area. About 2m thick fill layer is
underlain by layers of marine and alluvial deposit which are mainly clay in
nature. Deep weathered metasiltstone or
meta-sandstone has been envisaged in the eastern portion of the Project Area.
Site Formation
Work
2.6.4
Owing to the compressible
nature of the top marine and alluvial clay, the Project Area is subject to
settlement which requires some engineering works to resolve the problem.
2.6.5
In order to accelerate the
settlement process preloading in collaboration with vertical band drains may be
adopted at the Project Area. The extent
of the excavation or surcharging for the sites to be selected for residential
building will be subject to further engineering appraisals.
2.6.6
Excavated material will be
utilized on site where possible for wetland restoration preloading and
eventually for landscaping or disposal to a suitable facility. Contamination testing of existing fill will be
conducted to confirm, or otherwise, that the fill is inert and can be reused. Similarly, sedimentation testing will be
carried out in accordance with ETWB Technical Circular (Works) No. 34/2002. This will identify an appropriate disposal
strategy for any excavated sediment.
Building
Construction Work
2.6.7
Ground investigation work has
been carried out to confirm the classification of existing marble quality. Non-percussive piling, if any is to be carried
out, will need to take heed of the additional loading imposed on the marble.
2.6.8
On the other hand, due to the
long term settlement anticipated, because of the existence of superficial
marine and alluvial clay, conventional raft footing alone, resting on top of
these compressible layers may impose excessive settlement to the building
structures, which is not desirable.
2.6.9
In order to control effect on underlying
marble as well as settlement consideration, box footing or pile raft supported
by short piles could be the foundation schemes for some 2.5 to 3 stories
houses. For the non-marble zone,
conventional Continuous Flight Augar (CFA) piles could be another foundation
option for houses up to 4 stories high which include the clubhouse situated in
eastern corner of the site.
2.6.10
The statutory zoning plan
permits 6 storey dwelling. However, it
is envisaged there will be a range of 2.5/3 to 4 storey residential properties of
maximum GFA 82,800m² and plot ratio 0.4. These will be constructed in conventional cast
in-situ method. The feasibility of using
pre-cast construction will be subject to further engineering appraisals.
Wetland
Restoration
2.6.11
In terms of creating the
wetland, it is envisaged that the wetland restoration could be formed using a
clay perimeter and existing marine mud.
This would avoid exporting this material from site. A liner is expected to be required to prevent
water loss; this could be natural or artificial, the final decision will be
made at the detailed design stage. In
any case a layer of soil will be laid on the bottom and sides of the wetland in
order to provide suitable conditions for the establishment of the wetland. The edges of the wetland restoration works
will be formed at suitably shallow gradients to ensure they remain stable.
Sequence of
Works
2.6.12
The Project Area covers
approximately 21.36ha and construction is planned to be undertaken in phases as
shown in Figure 2.11.
2.6.13
In order to protect the nearby
residents and the ecological resources utilizing the adjacent fishponds as well
as the Project Area per se from the disturbance of construction works (noise,
movement, visual nuisance) noise barriers are proposed as shown in Figure 4.6. The establishment of barriers/hoardings is the
initial task on site and is scheduled to take place sequentially over a 6 month
period.
2.6.14
The Wetland Restoration Area
will be constructed and established under Phases A and B, shown on Appendix B-2, taking around 8
months for the excavation of the Wetland Restoration Area and profiling of the
ground (refer to Appendix H
for details of the shape and form of this area), with an establishment period of at least 12
months. This establishment period will permit the wetland to be rain fed and
filled, and vegetation to be planted. The hoarding between the WCA fishponds
and the Wetland Restoration Area will be removed only upon completion of the
site works. However the hoarding between
the Wetland Restoration Area and the construction site will remain until
construction works has been completed. This
is to protect the newly created ecological resource from the effects of
construction of the residential area, as described in Section 8. The noise barriers around the perimeter of the
site (for the protection of the noise sensitive human resources) will be of
varying height (as described in Section 4). This barrier may be removed in stages once the
first layer of houses and protection is provided to the Project Area.
2.6.15
Site formation and preloading
will start in Phases C and D in advance of the excavation for the wetland. Site formation works will include excavation,
filling, installation of vertical band drains and preloading works. Once preloading works have been completed the
materials will be moved from phase to phase around the site to minimize off
site export or import of materials, thereby minimizing truck movements and
waste of onsite resources.
2.6.16
Around eight months after
Phases C and D commence site formation works, Phases E and F will start and
follow the same construction sequencing.
2.6.17
Construction of substructure
and superstructure work will be carried out immediately after the preloading
activity for each Phase. Overlapping of
different forms of construction is expected during the whole construction
period.
2.6.18
Raft footing supported by short
piles (Pile Raft System) or box foundation is preferred for supporting the 2.5
to 3-storey houses for both marble and non-marble zone, while Continuous Flight
Augar (CFA) piles will be an option to be considered for duplex-on-duplex
properties.
2.6.19
Superstructure construction
will be carried out using conventional cast-in-situ method instead of using
pre-cast construction. The feasibility
of using pre-cast construction will be subject to further engineering appraisals.
PREFACE
Wo Shang Wai to the north of Royal Palms and Palm Springs is zoned “OU(CDWRA)”. This area comprises formed land, fish ponds
filled prior to the publication of the Mai Po and Fairview Park
Interim Development Permission Area (IDPA) Plan, and fragmented and partially
filled marshland. The western portion is
currently mostly vacant while the eastern portion is currently partly vacant
and partly occupied by a mix of uses including open storage uses, container
yards and container vehicle parks.
The planning intention of this location is to provide incentive for
the restoration of degraded wetlands adjoining existing fish ponds and to
encourage the phasing out of sporadic open storage and port back-up uses on
degraded wetland. This can be achieved
through comprehensive residential and/or recreational development to include
wetland restoration area. Development or
redevelopment schemes on the degraded wetlands directly adjoining the existing
continuous and contiguous fish ponds should include wetland restoration and
buffer proposals to separate the development from and minimize its impact on
the fish pond areas. Any new building
should be located farthest away from Deep
Bay. (Approved Mai Po and
Fairview Park
OZP No. S/YL - MP/6).
3.1.1
An air quality impact
assessment has been undertaken in accordance with Section 3.9.1 of the EIA Study
Brief to define the nature and scale of potential air quality impacts
associated with the Project. For this
Project, major air sensitive receivers are essentially residents in nearby
developments including the Mai Po San Tsuen, Royal Palms, Palm Springs and the Wo Shang Wai village.
3.1.2
Potential impacts associated
with the construction phase have been assessed. Major sources of air quality
impact include fugitive dust emissions during the excavation of pond deposits
and infill materials during the foundation works, and construction of the Project
and the associated infrastructure works. (i.e. roads, drains, pavements etc.).
Other minor sources include emissions from vehicles using the Project Area.
3.1.3
However, the Study Brief states
that quantitative assessments are only required if construction dust is likely
to cause exceedance. As fugitive dust impacts are expected to be minor and
could be controlled by standard mitigation measures, no quantitative modelling has
been undertaken to predict the fugitive dust impacts. Details of the mitigation
measures and audit requirements are contained in this section.
3.1.4
During the operational phase, air
quality impacts associated with vehicular emissions on- and off-site are considered
insignificant. Major roads like the San Tin Highway and
the Castle Peak Road
are some 230m away from the nearest air sensitive receivers of the Project Area,
and the traffic flow on-site along access roads is also expected to be low and mainly
dominated by private cars.
3.1.5
As a result, vehicular emission
impacts on air sensitive receivers within the proposed development should be insignificant. There is no on-site sewage treatment plant
proposed or any other sources that will contribute to odour emissions and hence
no odour modelling has been undertaken.
3.1.6
The conclusion is that there should
be no unacceptable air quality impacts associated with the implementation of
this project, both during the construction and operational phases.
3.2
Legislation, Standards,
Guidelines and Criteria
3.2.1
Legislation, Standards,
Guidelines and Criteria relevant to the consideration of air quality impacts
under this study include the following:
·
Hong Kong Air Pollution Control
Ordinance;
·
Air Pollution Control
(Construction Dust) Regulation; and
·
Environmental Impact Assessment
Ordinance and Technical Memorandum on Environmental Impact Assessment Process.
Hong Kong Air Pollution Control Ordinance
3.2.2
Hong Kong’s air quality is regulated through the Air Pollution Control
Ordinance (Cap. 311) (“APCO”). The APCO specifies Air Quality Objectives
(“AQOs”), which are the statutory limits for a number of pollutants and the
maximum allowable number of times that these may be exceeded over specified
periods – these pollutants are defined as Criteria Pollutants (“CP”). The Air
Quality Objectives (AQOs) that have been defined for these pollutants (CP) are
given in the following table
Table 3‑1 Hong Kong Air Quality Objectives (mg/m3)(i)
|
Pollutant
|
1 Hour (ii)
|
8 Hours (iii)
|
24 Hours (iii)
|
3 Months (iv)
|
1 Year (iv)
|
|
Sulphur Dioxide
|
800
|
|
350
|
|
80
|
|
Total Suspended Particulates
|
500(vii)
|
|
260
|
|
80
|
|
Respirable Suspended Particulates (v)
|
|
|
180
|
|
55
|
|
Carbon Monoxide
|
30,000
|
10,000
|
|
|
|
|
Nitrogen Dioxide
|
300
|
|
150
|
|
80
|
|
Photochemical Oxidants (as ozone) (vi)
|
240
|
|
|
|
|
|
Lead
|
|
|
|
1.5
|
|
|
|
|
|
|
|
|
Air Pollution Control (Construction Dust) Regulation
3.2.3
Air Pollution Control
(Construction Dust) Regulation stipulates the
construction dust control requirements for both notifiable (e.g. site
formation) and regulatory (e.g. road opening) works to be carried out by the
Contractor. The requirements for various
notifiable and regulatory works are given in Parts 1 and 2 of the Regulation
respectively. Part 3 of the Regulation
stipulates the general control requirements (e.g. site boundary and entrance)
for construction dust. The control
requirements for individual activities (e.g. stockpiling of dusty material) are
given in Part 4 of the Regulation.
Environmental Impact Assessment Ordinance and Technical Memorandum
on Environmental Impact Assessment Process
3.2.4
The criteria for evaluating air
quality impacts are stated in Annexes 4 and 12 of the Technical Memorandum
on Environmental Impact Assessment Process (EIAO-TM). The EIAO-TM states that the hourly Total
Suspended Particulate (TSP) level should not exceed 500mg/m3
(measured at 25oC and one atmosphere) for construction dust impact
assessment There is also a criterion
for odour to meet 5 odour units based on an averaging time of 5 seconds for
odour prediction assessment.
Construction Phase
3.3.1
Activities anticipated during
the construction phase that could potentially give rise to fugitive dust
emissions include site formation and construction of on-site infrastructure
(roads/drains) and residential units. Other potential sources of air quality
impacts may include exhaust emissions from construction vehicles and odour
generated from the excavation of pond deposits. Para 3.9.1.4 (iii) of the EIA
Study Brief states that a quantitative assessment is needed if the potential
construction dust impact is likely to cause exceedance of the criteria despite
incorporation of dust construction measures.
Operational Phase
3.3.2
Potential air quality impacts could
attribute to vehicular emissions from both on-site and off-site sources as well
as odour sources in the vicinity. However, there will be no need for on-site
sewage treatment plant as public sewer will be available shortly after
completion of the development.
3.3.3
During the operational phase, sources
of air quality impact include vehicular emissions from road traffic and on-site
vehicular movements. Para
3.9.1.4 (iv) of the EIA Study Brief states that if the assessment indicates
likely exceedance of the recommended limits in the TM at the development and
the nearby ASRs, a quantitative impact evaluation following the methodology in para.
3.9.1.4 (v) shall be carried out.
3.3.4
As the minimum separation distance
between the major roads, San Tin Highway and Castle Peak Road, and the nearest
air sensitive receivers within the proposed development is more than 230m, vehicular
emissions from the major roads should unlikely to affect the residential
development and hence a qualitative assessment has been adopted in this Study.
Traffic Forecast
3.3.5
The traffic forecast for the
year 2027 (15 years after the originally planned occupation year of 2012) (both
AM and PM peak hour flow) has been summarised in Table
3–2 below. Although
the occupation of the proposed residential development is now been postponed to
2013, the effect on air quality due to a further 1.95% annual increase in the
flow is considered insignificant.
Table 3‑2 Traffic Forecast in Year 2027
|
Peak
Hour Vehicle flows (veh/hr)
|
San Tin Highway
|
Castle Peak Road
|
Project
Access Road
|
San Tam Road
|
|
AM
|
PM
|
AM
|
PM
|
AM
|
PM
|
AM
|
PM
|
|
Motor
cycles
|
51
|
82
|
6
|
8
|
2
|
3
|
4
|
6
|
|
Private
Car
|
2533
|
2631
|
226
|
240
|
88
|
89
|
162
|
213
|
|
Taxi
|
243
|
212
|
20
|
18
|
|