Agreement No. CE 13/2009 (WS)

In-situ Reprovisioning of Sha Tin Water Treatment Works – South Works

 

Environmental Impact Assessment Report

 

TABLE OF CONTENTS

 

1             INTRODUCTION

              1.1   Background

              1.2   Designated Project under the EIAO

              1.3   Objectives of the EIA Study

              1.4   Structure of the EIA Report

 

2             PROJECT DESCRIPTION

              2.1   Project Background

              2.2   Project Objectives and Need

              2.3   Benefits of the Development

              2.4   Project Location and Site History

              2.5   Scope of the Project

              2.6   Study Area

              2.7   Works Programme and Implementation

              2.8   Concurrent Projects Having Potential for Cumulative Effects

              2.9   Public Consultation

 

3             CONSIDERATION OF ALTERNATIVES

              3.1  “Without the Project” Scenario

              3.2   “With the Project” Scenario

              3.3   Alternative Reprovisioning Sites

 

4             AIR QUALITY

              4.1   Introduction

              4.2   Environmental Legislation, Plans, Standards and Guidelines

              4.3   Description of the Environment

              4.4   Identification of Environmental Impacts

              4.5   Assessment Methodology

              4.6   Prediction and Evaluation of Environmental Impacts

              4.7   Recommended Mitigation Measures

              4.8   Evaluation of Residual Environmental Impacts

              4.9   EM&A Requirements

              4.10 Conclusion

 

5             NOISE

              5.1  Introduction

              5.2  Description of the Environment

              5.3  Environmental Legislation, Plans, Standards, and Guidelines

              5.4  Identification of Environmental Impacts

              5.5  Assessment Methodologies

              5.6  Prediction and Evaluation of Environmental Impacts

              5.7  Evaluation of Residual Environmental Impacts

              5.8  EM&A Requirements

              5.9  Conclusion

 

6             WATER QUALITY

              6.1  Introduction

              6.2  Environmental Legislation, Plans, Standards and Guidelines

              6.3  Description of the Environment

              6.4  Assessment Methodologies

              6.5  Identification of Environmental Impacts

              6.6  Cumulative Impacts from Concurrent Project

              6.7  Prediction and Evaluation of Environmental Impacts

              6.8  Mitigation of Adverse Environmental Impacts

              6.9  Evaluation of Residual Environmental Impacts

              6.10 EM&A Requirements

              6.11 Conclusion

 

7             WASTE MANAGEMENT

              7.1  Introduction

              7.2  Environmental Legislation, Plans, Standards and Guidelines

              7.3  Assessment Methodologies

              7.4  Identification of Potential Environmental Impacts

              7.5  Prediction & Evaluation of Environmental Impacts

              7.6  Mitigation of Adverse Environmental Impacts

              7.7  Evaluation of Residual Environmental Impacts

              7.8  EM&A Requirements

              7.9  Conclusion

 

8             TERRESTRIAL ECOLOGY

              8.1  Introduction

              8.2  Environmental Legislation, Plans, Standards and Guidelines

              8.3  Assessment Methodology

              8.4  Description of the Environment

              8.5  Ecological Value

              8.6  Identification of Potential Ecological Impacts

              8.7  Prediction & Evaluation of Ecological Impacts

              8.8  Mitigation of Adverse Ecological Impacts

              8.9  Evaluation of Residual Ecological Impacts

              8.10 EM&A Requirements

              8.11 Conclusion

 

9             LANDSCAPE AND VISUAL IMPACT

              9.1  Introduction

              9.2  Legislation, Policies, Plans, Standards and Guidelines

              9.3  Assessment Methodology

              9.4  Review of Planning and Development Control Framework

              9.5  Baseline Study

              9.6  Landscape Impact Assessment

              9.7  Visual Impact Assessment

              9.8  Landscape & Visual Mitigation Measures

              9.9  Residual Impacts

              9.10 Cumulative Impacts

              9.11 EM&A Requirements

              9.12 Conclusion

 

10           CULTURAL HERITAGE

              10.1 Introduction

              10.2 Environmental Legislation, Plans, Standards and Guidelines

              10.3 Assessment Methodologies

              10.4 Baseline Review and Field Survey Result

              10.5 Evaluation of Cultural Heritage Impacts

              10.6 Mitigation of Cultural Heritage Impacts

              10.7 Evaluation of Residual Cultural Heritage Impacts

              10.8 EM&A Requirements

              10.9 Conclusion

 

11           LAND CONTAMINATION

              11.1 Introduction

              11.2 Environmental Legislation, Standards & Guidelines

              11.3 Assessment Methodologies

              11.4 Description of the Environment

              11.5 Identification of Sensitive Receptors

              11.6 Assessment of Environmental Impacts

              11.7 Mitigation of Environmental Impacts

              11.8 Evaluation of Residual Impacts

              11.9 EM&A Requirements

              11.10 Conclusion

 

12           HAZARD TO LIFE

              Introduction

              12.1 Background

              12.2.Hong Kong Risk Guidelines and Other Relevant Legislation

              12.3 Sha Tin Water Treatment Works: Location and Operations

              12.4 South Works Reprovisioning

              12.5 Scenarios Considered in the QRA

              QRA for the On-site Transport, Storage and Use of Chlorine at Sha Tin WTW

              12.6 Previous Hazard Assessments for Sha Tin WTW

              12.7 Meteorological Data

              12.8 Population Data

              12.9 Hazard Identification

              12.10 Consequence Analysis

              12.11 Rationalization of Chlorine Release Scenarios and Estimation of Scenario Frequencies

              12.12 Quantitative Risk Assessment

              12.13 Risk Mitigation

              12.14 Risk Conclusions

              QRA for Off-site Transport of Chlorine

              12.15 Introduction

              12.16 Previous Hazard Assessments for Chlorine Transport in Hong Kong

              12.17 Methodology Overview

              12.18 Chlorine Transport Route

              12.19 Hazard Identification

              12.20 Release Scenarios

              12.21 Consequence Analysis

              12.22 Frequency Analysis

              12.23 Population Data

              12.24 Meteorological Data

              12.25 Off-site Transport Risk Results

              12.26 Risk Mitigation and ALARP Assessment

              12.27 Conclusions and Recommendations

              Total Chlorine Risk

              12.28 Societal Risk

              12.29 Individual Risk

              Cumulative Risk within the Consultation Zone

              12.30 Cumulative Risk Assessment

              Uncertainty Analysis

              12.31 STWTW Chlorine

              12.32 BHN Offtake Station and Pipelines in the Old Beacon Hill Tunnel

              Conclusion

              12.33 Summary

              12.34 Recommendations

              References

             

13           IMPLEMENTATION SCHEDULE OF MITIGATION MEASURES

 

14           CONCLUSIONS

 

 

 

List of Tables

 

Table 1.1          Schedule 2 Designated Project in this EIA Study

Table 2.1          Comparison of the Existing and the Reprovisioning Treatment Processes

Table 3.1          Summary of Environmental Appraisal for In-situ Reprovisioning

Table 4.1          Hong Kong Air Quality Objectives

Table 4.2          Annual Average Pollutant Concentration in the Latest Five Years (Year 2009-2013) at Shatin Air Quality Monitoring Station

Table 4.3          Representative Air Sensitive Receivers

Table 5.1          Details of Representative Noise Sensitive Receivers (NSRs)

Table 5.2          Area Sensitivity Ratings (ASRs)

Table 5.3          Acceptable Noise Levels for Fixed Noise Sources

Table 5.4          Noise Criteria for Fixed Noise Sources

Table 5.5          Unmitigated Construction Noise Levels due to the Project at Representative NSRs During Normal Daytime Working Hours

Table 5.6          Quiet PME Recommended for Adoption during Construction Phase

Table 5.7          Cumulative Mitigated Construction Noise Levels at Representative NSRs During Normal Daytime Working Hours

Table 5.8          Predicted Fixed Plant Noise Levels at Representative NSRs

Table 6.1          Summary of Water Quality objectives for the Tolo Harbour & Channel WCZ

Table 6.2          WSD’s Water Quality Criteria for Flushing Water at Sea Water Intakes

Table 6.3          EPD Marine Water Quality Monitoring Data in 2010

Table 6.4          EPD River Water Quality Monitoring Data in 2010

Table 7.1          Summary of Inert C&D Material Quantities Generated

Table 7.2          Summary of Inert and non-inert C&D Material Volumes Generated from Construction Activities (In Bulk volumes)

Table 7.3          Anticipated Timing of Wastes Arising/ Generation from Construction Activities

Table 7.4          Waste Arising, Waste Handling Procedures and Disposal Routes

Table 8.1          Ecological Survey Programme

Table 8.2          Habitats Recorded within the Study Area

Table 8.3          Avifauna of Conservation Importance Previously Recorded within the Study Area

Table 8.4          Avifauna of Conservation Importance Recorded within the Study Area

Table 8.5          Terrestrial Mammals Previously Recorded within the Study Area

Table 8.6          Terrestrial Mammals of Conservation Importance Previously Recorded within the Study Area

Table 8.7          Butterfly Species of Conservation Importance Recorded within the Study Area

Table 8.8          Odonates Previously Recorded within the Study Area

Table 8.9          Odonate Species of Conservation Importance Recorded within the Study Area

Table 8.10         Herpetofauna Species of Conservation Importance Previously Recorded within the Study Area

Table 8.11         Herpetofauna of Conservation Importance Recorded within the Study Area

Table 8.12         Freshwater Species of Conservation Importance Previously Recorded within the Study Area

Table 8.13         Ecological Evaluation of the Secondary Woodland Habitat within the Study Area

Table 8.14         Ecological Evaluation of the Plantation Habitat within the Study Area

Table 8.15         Ecological Evaluation of the Watercourse Habitat within the Study Area

Table 8.16         Ecological Evaluation of the Developed Area Habitat within the Study Area

Table 8.17         Direct Habitat Loss

Table 8.18         Overall Impact Evaluation of Secondary Woodland

Table 8.19         Overall Impact Evaluation of Plantation

Table 8.20         Overall Impact Evaluation of Watercourse

Table 8.21         Overall Impact Evaluation of Developed Area

Table 8.22         Summary of Potential Impacts to Species of Conservation Importance

Table 8.23         Flora Species Proposed for Woodland Compensation

Table 9.1          Relationship between Landscape Sensitivity and Impact Magnitude in Defining Impact Significance

Table 9.2          Relationship between Visually Sensitive Receivers (VSRs) Sensitivity and Impact Magnitude in Defining Impact Significance

Table 9.3          Baseline Landscape Resources (LRs) and Their Sensitivity

Table 9.4          Baseline Landscape Character Areas (LCAs) and Their Sensitivity

Table 9.5          Visually Sensitive Receivers (VSRs) and Their Sensitivity

Table 9.6          Magnitude of Landscape Impacts during Construction and Operation Phases

Table 9.7          Locations and Development Details of Major Permanent Aboveground Structures

Table 9.8          Visually Sensitive Receivers (VSRs) and Their Magnitude of Impacts

Table 9.9          Proposed Landscape and Visual Mitigation Measures for Construction Phase

Table 9.10         Proposed Landscape and Visual Mitigation Measures for Operation Phase

Table 9.11         Significance of Landscape Impacts during Construction and Operation Phases

Table 9.12         Significance of Visual Impacts in Construction and Operation Phases (Adverse Impacts unless otherwise stated)

Table 11.1         Details of Chemical Storage and Usage Areas within the Project site

Table 11.2         Potentially Contaminated Hotspots Identified

Table 11.3         Potential Remediation Techniques

Table 12.1         Scenarios Considered in the QRA

Table 12.2         Meteorological Data for Sha Tin Water Treatment Works

Table 12.3         Detailed Population Data

Table 12.4         Physiological Effects of Chlorine

Table 12.5         Characterisation of Chlorine Release Scenarios

Table 12.6         Summary of Source Term Modelling Results for Sha Tin WTW

Table 12.7         Chlorine Toxicity Relationship

Table 12.8         Summary of Wind Tunnel Tests Results for Sha Tin WTW

Table 12.9         Summary of CFD Modelling Results

Table 12.10       Summary of DRIFT Results

Table 12.11       Comparison of Wind Tunnel, CFD and DRIFT Results (Neutral stability, 2m/s wind speed)

Table 12.12       Chlorine Cloud Heights

Table 12.13       Effective Outdoors Probability of Fatality

Table 12.14       Rationalisation of Chlorine Release Scenarios

Table 12.15       Release Scenarios Included in QRA

Table 12.16       Base Failure Rate Data

Table 12.17       Event Frequencies

Table 12.18       Maximum N Value within the FN Chart

Table 12.19       Breakdown of PLL by Release Scenario

Table 12.20       Breakdown of PLL by Population

Table 12.21       Calculation of ICAF for Candidate Mitigation Measures (Construction Phase Scenario)

Table 12.22       Summary of Good Practice Measures to Protect Reprovisioning Workers

Table 12.23       Chlorine Truck Transport Route

Table 12.24       Details of Route Sections

Table 12.25       Representative Release Cases Considered

Table 12.26       Consequence Distances (m)

Table 12.27       Predicted Chlorine Cloud Heights

Table 12.28       Predicted Affected Floor Levels

Table 12.29       Chlorine Toxicity

Table 12.30       Summary of Release Frequencies

Table 12.31       Event Outcome Frequencies

Table 12.32       Plot Ratio Data and Indoor/ Outdoor Population Ratio

Table 12.33       Wind Direction Probabilities

Table 12.34       PLL for Off-site Chlorine Transport

Table 12.35       Risk Mitigation Measures from Atkins (2006) Study

Table 12.36       Potential Risk Mitigation Measures

Table 12.37       Cost Benefit Analysis

Table 12.38       Selected Risk Mitigation Measures and Implementation Schedule

Table 12.39       Detailed Implementation Plan for Selected Risk Mitigation Measures

Table 12.40       PLL for On-site Chlorine and Off-site Chlorine Transport

Table 12.41       Summary of Uncertainty Analysis

Table 12.42       Fraction of Outdoor Working Hours

Table 13.1         Implementation Schedule of Mitigation Measures

Table 14.1         Summary of Key Environmental Outcomes and Benefits

 

 

 

Abbreviation

 

Abbreviation

ACM

ACABAS

Asbestos Containing Materials

Advisory Committee on the Appearance of  Bridges and Associated Structure

Aecom

Aecom Asia Company Limited

AFCD

Agricultural, Fisheries and Conservation Department

AHM

Artificial hard material

A&MO

Antiquities and Monuments Ordinance

AMO

Antiquities and Monuments Office

ANL        

Acceptable Noise Levels

APCO       

Air Pollution Control Ordinance

AQOS

Air Quality Objectives

ASARs

Air Sensitive Receivers

 

 

BOD

Biochemical Oxygen Demand

 

 

CAP

Contamination Assessment plan

CBA

Cost-benefit analysis

CEDD

Civil Engineering and Development Department

C&D

Construction and Demolition

C&DMMP

Construction and Demolition Material Management Plan

Chemical house

Water Treatment Works Logistics Centre

CNP

Construction Noise Permit

COCs

Contaminants of concern

COD

Chemical Oxygen Demand

 

 

DA-TM

Technical Memorandum on Noise from Construction Work in Designated Areas

DAF

Dissolved Air Flotation

DC

Distance Attenuation

DEP

Director of Environmental Protection

DGs

Dangerous Goods

D&HC

Development and Housing Committee

DO

Dissolved Oxygen

DP

Designated Project

 

 

EIA

Environmental Impact Assessment

EIAO      

Environmental Impact Assessment Ordinance

EIAO-TM

Technical Memorandum on Environmental Impact Assessment Process

EM&A

Environmental Monitoring and Audit

EPA

Environmental Protection Agency

EPD

Environmental Protection Department

ER

Environmental Review

 

 

FSD

Fire Services Department

 

 

GW-TM

Technical Memorandum on Noise from Construction Work other than Percussive Piling

 

 

HKPSG

Hong Kong planning Standards and Guidelines

ICOMOS

International Council on Monuments and Sites

IND-TM

Technical Memorandum on Noise from Places other than Domestic Premises, Public Places or Construction Sites

 

 

KCR

Kowloon-Canton Railway

 

 

LC

Local Concern

LCAs

Landscape Character Areas

LCSD

Leisure and Cultural Services Department

LRs

Landscape Resources

 

 

Max. SWL

Maximum Permissible Sound Power Level

MLD

Million litres per day

MTRC

Mass Transit Railway Corporation

 

 

NCO

Noise Control Ordinance

NGIs

Notifiable Gas Installations

NSR

Noise Sensitive Receivers

 

 

OSHO

Occupation Safety and Health Ordinance

OU

Other Specified Uses

OZP

Outline Zoning Plan

 

 

PER

Preliminary Environmental Review

PFC

Public Filling Committee

PGC

Potential Global Concern

PHIs

Potentially Hazardous Installations

PME

Powered Mechanical Equipment

PP-TM

Technical Memorandum on Noise from Percussive Piling

PPE

Potential Hazardous Installation

PPFS

Preliminary Project Feasibility Study

PRC

Potential Regional Concern

ProPECC

Practice Note for Professional Persons

 

 

RAP

Remediation Action Plan

RBRGS

Risk-based Remediation Goals

RC

Regional Concern

RR

Remediation Report

RSE

Registered Structural Engineers

RSLs

Regional Screening Levels

RSS

Resident Site Staff

 

 

SCL

Shatin to Central Link

SI

Site Investigation

South Works

The Project

SPL

Sound Pressure Level

SS

Suspended Solids

SSSIs

Sites of Special Scientific Interest

STSTW

Sha Tin Sewage Treatment Works

STW

Sewage Treatment Works

SWLs

Sound Power Levels

 

 

TM-DSS

Technical Memorandum on Standards for Effluents discharged into Drainage and Sewerage Systems

TM-EIA

Technical memorandum on Environmental Impact Assessment Process

TMs

Technical Memoranda

TSP

Total Suspended Particulates

 

 

UNESCO

United Nations Educational, Scientific and Cultural Organization

 

 

Waste Disposal

Chemical Waste

WBTC

Works Branch Technical Circular

WCP

Woodland Compensation Plan

WCZs

Water Control Zones

WDO

Waste Disposal Ordinance

WHO

World Health Organization

WMP

Waste Management Plan

WPCO

Water Pollution Control Ordinance

WQOs

Water Quality Objectives

WRL

West Rail Line

WSD

Water Supplies Department

WSP

Water Safety Plan

WSR

Water Sensitive Receivers