1 Introduction

1.1 Background

1.1.1.1 Serious flooding occurred at Po Lin Monastery, Ngong Ping Bus Terminus, Ngong Ping Village and areas in the vicinity of the Ngong Ping 360 Terminal during a heavy rainstorm on 7 June 2008. The observed flooding depths at various locations were between 0.5m to 1m.

1.1.1.2 After the flooding incident, Drainage Services Department (DSD) commissioned a “Drainage Study for Ngong Ping” to identify and quantify the flood hazard and formulate cost-effective drainage improvement plans in order to set out a comprehensive strategy and programme for safeguarding the Ngong Ping area from future flood risks. The drainage study identified that the flood protection level of the existing watercourses at the north of Po Lin Monastery as well as the upstream and downstream of Ngong Ping 360 Terminal is less than 1 in 10 years design return period. The bottleneck of the natural stream near Lin Ping Drive also induces flooding problem.

1.1.1.3 Short-term drainage improvement measures were implemented in 2009. However, long-term drainage improvement schemes have, also, been recommended for implementation under the “Drainage Improvement Works at Ngong Ping” to enhance the capacity of the trunk drainage system so as to reduce the flood risk in Ngong Ping. The proposed long-term drainage improvement measures would include constructing an upstream interception drain, a loop system and a downstream flood relief drain to divert the storm-water away from the existing drainage system. All these recommendations make up the current Project. Upon completion of the Project, the trunk storm-water drainage system in Ngong Ping will have sufficient capacity to cater for a rainstorm with a 50-year return period.

1.1.1.4 The scope of drainage improvement works under the Project is illustrated in Figure 1.1.

1.1.1.5 The Project involves drainage works which constitute the following designated projects under Part I, Schedule 2 of the Environmental Impact Assessment Ordinance (EIAO) and, therefore, requires an Environmental Impact Assessment (EIA) to be undertaken and an Environmental Permit (EP) to be obtained prior to construction commencement:

(a) Item I.1(b)(i) - A drainage channel which discharges into an area which is less than 300m from the nearest boundary of an existing site of special scientific interest;

(b) Item I.1(b)(vii) - A drainage channel which discharges into an area which is less than 300m from the nearest boundary of an existing conservation area; and

1.1.1.6 A Project Profile was submitted in April 2011 under the EIAO and the Director of Environmental Protection (DEP) issued the EIA Study Brief No. ESB-227/2011 in May 2011, accordingly. The purpose of the EIA Study is to provide information on the nature and extent of environmental impacts arising from the construction and operation of the Project and associated works that take place concurrently. This information will contribute to decisions by the DEP on:

(a) the acceptability of any adverse environmental consequences that are likely to arise as a result of the Project;

(b) the conditions and requirements for the design, construction and operation of the Project to mitigate against adverse environmental consequences; and

1.1.1.7 Meinhardt Environment Limited (MEL) was appointed by DSD in September 2011 to undertake the EIA Study.

1.2 Objectives of the EIA Study

1.2.1.1 The objectives of the EIA study are as follows:

(a) to describe the Project and associated works together with the requirements and environmental benefits for carrying out the Project and the types of designated projects to be covered by the Project;

(b) 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 natural and man-made environment and the associated environmental constraints;

(d) to provide information on the consideration of alternative design options of the Project including scale, extent, layout, configuration, design and type of design orientation and the construction methods with a view to avoiding or minimizing potential environmental impacts to environmentally sensitive areas and sensitive uses; to compare the environmental benefits and disbenefits of different options; to provide reasons for selecting the preferred option(s) and to describe the part environmental factors played in the selection of preferred option(s);

(e) to identify and quantify emission sources (including air quality, noise, water quality and waste, etc. as appropriate) and determine the significance of impacts on sensitive receivers and potential affected uses;

(f) to identify and quantify any potential loss or damage and other potential impacts to ecology, flora, fauna and natural habitats and to propose measures to mitigate these impacts;

(g) to identify any potential landscape and visual impacts and to propose measures to mitigate adverse impacts;

(h) to identify any negative impacts on sites of cultural heritage and to propose measures to mitigate these impacts;

(i) to investigate any impacts on people and communities;

(j) to investigate any impacts on agricultural activities;

(k) to propose provision of mitigation measures so as to minimize pollution, environmental disturbance and nuisance during construction and operation of the Project;

(l) to investigate the feasibility, practicability, effectiveness and implications of the proposed mitigation measures;

(m) to identify, predict and evaluate the residual environmental impacts (i.e. after practicable mitigation) 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;

(n) 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 cumulative effects and reduce them to acceptable levels;

(o) to investigate the extent of the 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; and

(p) to design and specify environmental monitoring and audit requirements to check the effective implementation of the recommended environmental protection and pollution control measures.

1.3 Approach to EIA Study

1.3.1 Baseline Conditions

1.3.1.1 The relevant aspects of the existing environment have been identified and described to provide a baseline for the identification and prediction of potential impacts which are likely to arise from implementing the Project. Baseline environmental surveys were undertaken and relevant reports / documents have been reviewed (and information incorporated where appropriate) to determine the existing environmental conditions at the Project site and all surrounding areas likely to be affected by the Project.

1.3.2 Impact Modelling

1.3.2.1 Individual aspect assessments have been undertaken in accordance with the relevant guideline on assessment methodology from the EIAO-TM. Computer modelling has been used to quantitatively predict environmental impacts for air quality during the construction phase. The modelling predictions have been based on approved / recognised local and international methods as described in the relevant sections of this report.

1.3.2.2 The methodologies used in the assessments have previously been applied in similar EIA studies in Hong Kong which have been accepted for use in assessing environmental impacts and for the comparison of predicted results with the EIAO-TM standards. While there are some limitations in the methodologies, for example the accuracy of the predictive base data for future conditions such as weather conditions, such uncertainties have been considered during the formulation of assessment conclusions. These have been addressed by the adoption of realistic but worst case assumptions to provide a conservative assessment of environmental impacts. Where worst case assumptions have been used, it has been stated in the assessment methodologies.

1.3.3 Impact Evaluation

1.3.3.1 The predicted changes and effects resulting from the proposed Project have been evaluated in accordance with the criteria given in the EIAO-TM, including beneficial or adverse; direct or indirect; short term or long term; reversible or irreversible and cumulative. It is noted that, as the project is localised and confined to a relatively small study area in the Ngong Ping area, transboundary issues would not be relevant and have not been considered further. In addition, as no fisheries activities are undertaken in the study area, the impacts on fisheries activities are, also, not considered further. Wherever practicable and appropriate, quantitative assessments have been undertaken.

1.3.3.2 With the exception of local and regional ecological policies for ecological protection, no other regional or national plans and policies are relevant in this EIA.

1.3.4 Impact Mitigation

1.3.4.1 Mitigation measures have been identified and evaluated to avoid the impacts in the first instance. Thereafter the mitigation has sought to control, reduce and minimise or remedy the impacts. The effectiveness of the proposed mitigation has been assessed and any residual environmental impacts have been identified and considered for their acceptability.

1.3.4.2 An implementation schedule for the mitigation measures has been prepared, which for each mitigation measure, identifies when and where it is required, the parties responsible for its implementation and where necessary, for its maintenance.

1.4 EIA Study Scope

1.4.1.1 The environmental issues covered in this EIA study and assessment areas, as specified in the EIA Study Brief (No. ESB-227/2011), are presented below:

· Potential noise and air quality impacts from the construction of the Project to sensitive receivers near the Project;

· Potential water quality from the construction and operation of the Project;

· Potential waste management implications arising from the construction and operation of the Project;

· Potential ecological impacts arising from the construction and operation of the project;

· Potential landscape and visual impacts during the construction and operation of the Project;

· Potential impacts to cultural heritage resources; and

· Potential cumulative environmental impacts of the Project and associated works, through interaction or in combination with other existing, committed and planned projects in their vicinity, and that those impacts may have a bearing on the environmental acceptability of the Project.

1.4.1.2 The Drainage Services Department has undertaken some advanced consultation with the local residents, Po Lin Monastery representatives, Ngong Ping 360 and Green Groups to identify key concerns and issues. In 2009, overall support for the project was expressed by the Po Lin Monastery / Ngong Ping Village / Ngong Ping 360 to avoid future flooding and green groups (including Kadoorie Farm and Botanic Garden, Green Lantau Association and World Wide Fund for Nature), also, expressed no objections. Subsequently in 2012, major views were, also, sought from the local villagers and the key issues raised, together with how these have been addressed in this EIA Report, are detailed below:

1. Affected crops at government land (Stockpiling Area 3): Financial compensation to be arranged with DLO and the area will be reinstated and hydroseeded after the construction works have been completed (Section 6).

2. Request to reduce the works area affected: As indicated in Section 2, the pipeline alignment and location and size of the works areas, has been carefully reviewed to minimise the areas affected.

3. Request to avoid works at night time: While any night-time works would be controlled under the Noise Control Ordinance and not covered by this EIA Report, night-time works are not proposed.

4. Request to protect the health of existing trees due to trench excavation: The pipeline alignment and location of the works areas have been located so as to minimize the number of trees to be affected. Also, in situations where trees are close to the alignment, an approach to retain and protect or prune the trees has been adopted as opposed to felling (see Section 6.12).

1.5 Structure of the EIA Report

1.5.1.1 The report is divided into the following sections:

(a) Section 2 provides detailed description of the project including the need for the project, alternatives considered in the selection of the preferred drainage alignment and alternative construction methods;

(b) Section 3 provides a description of the construction air quality impacts for the drainage system and highlights mitigation requirements;

(d) Section 5 describes the water quality impacts during the construction and operational phases;

(e) Section 6 provides details of the ecological impact assessment;

(f) Section 7 presents the landscape and visual impact assessment;

(g) Section 8 comprises the cultural heritage impact assessment of the drainage alignment including terrestrial archaeology and built heritage;

(h) Section 9 details the waste management assessment;

(i) Section 10 outlines the recommended environmental monitoring and audit requirements;

(j) Section 11 outlines the Implementation Schedule and Recommended Mitigation measures;

(k) Section 12 presents the summary of environmental outcomes; and

(l) Section 13 presents a summary and conclusions.

1.6 Common Abbreviations

1.6.1.1 The more commonly used abbreviations are summarised below.

ASR	Air Quality Sensitive Receiver
C&C	Cut-and-cover
DO	Dissolved Oxygen
DSD	Drainage Services Department
EIA	Environmental Impact Assessment
EIAO	Environmental Impact Assessment Ordinance
EIAO-TM	Technical Memorandum on Environmental Impact Assessment Process
EM&A	Environmental Monitoring and Audit
EP	Environmental Permit
EPD	Environmental Protection Department
MEL	Meinhardt Environment Limited
NSR	Noise Sensitive Receiver
NWWCZ	North Western Water Control Zone
PLM	Po Lin Monastery
PME	Powered Mechanical Equipment
SS	Total Suspended Solids
SSSI	Site of Special Scientific Interest
SSWCZ	Southern Supplementary Water Control Zone
WCZ	Water Control Zone
WQ	Water Quality
WQO	Water Quality Objectives