1.
INTRODUCTION
1.1.1
The project is entitled “Improvement of Fresh Water Supply
to Cheung Chau” (hereinafter referred to as “the Project”). Figure 1.1
shows the location of the proposed Project. Figure 1.2
shows the aerial view of the Project.
1.1.2
Cheung Chau, with a population of
around 23,000, is currently supplied with treated water from Silver Mine Bay
Water Treatment Works on Lantau via two submarine water mains, 10” (about 250
mm) and 500 mm in diameter, across Adamasta Channel. Treated water is normally
provided by the 500 mm diameter main, with the 10” main serving as emergency
backup.
1.1.3
Laid
in 1963, the existing 10” submarine water main providing partial emergency back
up fresh water supply to Cheung Chau is approaching the end of its design life
of 50 years. Repairs would be
uneconomical and take a long time given the difficulty of the task and the
condition of the main. To improve the reliability of water supply to Cheung
Chau, it is necessary to strengthen the emergency back up by replacing the
existing 10” submarine water main with a new 500 mm diameter submarine water
main.
1.1.4
Black & Veatch Hong Kong Limited
was commissioned by Water Supplies Department (WSD) to study the feasibility of
laying the proposed submarine pipeline and associated land mains, identify alternative
sites and alignments if necessary.
1.1.5
The
Project is to construct and operate a new submarine water main across Adamasta
Channel from Lantau to Cheung Chau to replace the existing submarine water main,
which is serving as emergency back up, to improve the reliability of water
supply to Cheung Chau.
1.2
Requirements under the
Environmental Impact Assessment Ordinance
1.2.1
The Project is a Designated Project (DP) under the
Environmental Impact Assessment Ordinance (EIAO) (Cap.499) by virtue of:
(i)
Item Q.1, Part 1, Schedule 2 of the
EIAO : All projects including new access roads, railways, sewers, sewage
treatment facilities, earthworks, dredging works and other building works
partly or wholly in an existing or gazetted proposed country park or ….(The landfall at Lantau falls within the
existing Lantau South Country Park.)
1.2.2
In accordance with the EIAO, an environmental Impact
Assessment (EIA) report is required to be prepared to meet the requirements
under the EIAO and for an Environmental Permit to be obtained for the
construction and operation of the Project.
1.2.3
An application (No. ESB-187/2008) for an EIA study brief
under section 5(1)(a) of the EIAO was submitted on 24 April 2008 with a Project
Profile (No. PP-351/2008).
1.2.4
Pursuant to section 5(7)(a) of the EIAO based on
the project information given in the Project Profile, the Director of
Environmental Protection (the Director) issues an EIA study brief
(ESB-187/2008) in May 2008 to the Applicant to carry out an EIA study.
1.3
Purpose and Objective of the
Environmental Impact Assessment (EIA) Study
1.3.1
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 related activities taking place concurrently. This
information will contribute to decisions by the Director of Environmental
Protection on:
(i)
the
acceptability of adverse environmental consequences that are likely to arise as
a result of the Project;
(ii)
the
conditions and requirements for the design, construction and operation of the
Project to mitigate against adverse environmental consequences; and
(iii)
the
acceptability of residual impacts after the proposed mitigation measures are implemented.
1.3.2
The objectives of the EIA study are as follows:
(i)
to
describe the Project and associated works together with the requirements for
carrying out the proposed Project and the types of designated project(s) to be
covered by the Project;
(ii)
to
identify and describe the elements of the 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 and the associated
environmental constraints;
(iii)
to provide information on the consideration of
alternative options of water main alignment, landfalls locations and
construction method with a view to avoiding or minimizing the potential
environmental impacts to environmentally sensitive areas and other sensitive
uses; to compare the environmental benefits and disbenefits of each of the
different options; to provide reasons for selecting the preferred option(s) and
to describe the part environmental factors played in the selection;
(iv)
to identify and quantify
emission sources and determine the significance of impacts on sensitive
receivers and potential affected uses;
(v)
to identify and quantify any
potential loss or damage and other potential impacts to ecology and fisheries
resources, flora, fauna and natural habitats and to propose measures to
mitigate these impacts;
(vi)
to identify any negative
impacts on archaeological resources and to propose measures to mitigate these
impacts;
(vii)
to propose the provision of
mitigation measures so as to minimize pollution, environmental disturbance and
nuisance during construction and operation of the Project;
(viii)
to investigate the feasibility,
practicability, effectiveness and implications of the proposed mitigation
measures;
(ix)
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 of
the Project in relation to the sensitive receivers and potential affected uses;
(x)
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;
(xi)
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
(xii)
to design and specify environmental monitoring and
audit requirements to check the effective implementation of the recommended
environmental protection and pollution control measures.
1.4.1
The EIA study is conducted in accordance with the
requirements set out in the EIA study brief and the Technical Memorandum on
Environmental Impact Assessment Process (EIAO-TM).
1.5
Structure of the EIA Report
1.5.1
The backgrounds, descriptions and justifications of this
Project are provided in Chapter 2.
The preliminary design proposal and the landscaping design measures of the
Project as required in the EIA study brief is also provided in Chapter 2. For each of the
environmental parameters that have been identified, assessment results and
mitigation measures are presented in the following sections.
·
Chapter 3 – Water Quality Impact Assessment
·
Chapter 4 – Ecological Impact Assessment
·
Chapter 5 – Fisheries Impact Assessment
·
Chapter 6 – Cultural Heritage Impact Assessment
·
Chapter 7 – Construction Waste Management
·
Chapter 8 – Construction Noise Impact Assessment
·
Chapter 9 – Environmental Monitoring and Audit Requirements
·
Chapter 10 – Environmental Outcomes
·
Chapter 11 – Conclusion
1.5.2
The Implementation Schedule of the mitigation measures
recommended in this EIA report and details pertaining to the impact assessment
are attached in the Appendices.