1. INTRODUCTION

1.1 Background Information

Mott Connell Limited (MCL) was commissioned by CLP Power Hong Kong Limited (CLP) in September 1999 to carry out the Route Options Assessment for 3 x 132kV electricity supply circuits leading from Pui O Substation at Lantau Island south to Cheung Chau Substations.

Due to the obsolescence, age and operational problems, CLP’s 33kV equipment has been gradually phased out and uprated to 132kV in order to maintain the integrity of the network in transmission and distribution. The 33kV phasing-out programme commenced in 1980 in Kowloon Peninsula and now extends to the New Territories and Outlying Islands.

Mott Connell Limited (MCL) was commissioned by CLP Power Hong Kong Limited (CLP) in September 1999 to carry out the Route Options Assessment for 3 x 132kV electricity supply circuits leading from Pui O Substation on Lantau Island south to Cheung Chau Substations.

Cheung Chau is situatedat the south-east of Lantau and has population of 24,000. The maximum demand in 1999 was 20MVA. Electricity supplies to Cheung Chau are provided by the Cheung Chau South and North Substations. These two substations are fed from the South Lantau / Pui O 33kV system via 3 overhead lines and submarine cable circuits (about 8km) and backup with a limited 11kV circuits. Due to the long sections of these 33kV overhead lines at onerous locations, they are susceptible to unfavourable weather conditions such as lighting/typhoon incidences and which may cause supply interruption.

To improve the supply reliability, transmission efficiency and system performance, all the 33kV equipment,equipment and overhead transmission lines in Lantau will be decommissioned and replaced with 132kV. The South Lantau / Pui O 33kV phasing out programme includes replacement of the existing 3 x 33kV and 11kV, 20MVA transformers at Cheung Chau South and North Substations. These will be replaced by 132kV and 11kV, 35 mVAMVA units via new 132kV underground and submarine cablecircuits.

Two sets of thecircuits. The proposed 132kV circuits will be connected to Cheung Chau South Substation and are scheduled to be commissioned inat the end of 2003. The remaining 1 x 132kV circuit will be connected to Cheung Chau North Substation and is to be commissioned in the end of 2004. At least two sets of the new 132kV circuits will need to be put 2004.

2004. After commissioning of the proposed 132kV circuits, the existing 33kV overhead lines will be removed while the 33kV submarine cables will be retained in place for possible future use. They may be used at 11kV to serve as inter-connectors when necessary.

into operation before 2 sets of the existing 33kV circuits can be decommissioned and demolished.

The objective of this assignment is to investigate the environmental impacts for the proposed 3 x 132kV circuits such that theextent of the potential impacts caused by the provision of 3 x 132kV circuits, and to identify any mitigation measures which may be needed to ensure the new circuits can be installed without causing significantadverse impacts on local residents and the receiving environment.

1.2 Objectives of the EIA Study

The objectives of the EIA study are as follows:

(i) to describe the proposed project and associated works together with the requirements for carrying out the proposed project;

(ii) to provide information on the need of the power line and the consideration of alternatives for avoiding the country park as power transmission corridor;

(iii) to compare the main environmental impacts of different options and alignments with the proposed project and with the likely future environmental conditions in the absence of the project;

(iv) to identify and describe the elements of the community and environment likely to be affected by the proposed project and/or likely to cause adverse impacts to the proposed projects, including both the natural and man-made environment;

(v) to identify and quantify any potential losses or damage to flora, fauna and natural habitats;

(vi) to identify any potential landscape and visual impacts and to propose measures to mitigate these impacts;

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

(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, assesses 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 to reduce them to acceptable levels;

(x) to investigate the extent of side effects of proposed mitigation measures that may lead to other forms of impacts;

(xi) to identify constraints associated with the mitigation measures recommended in the 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.

1.3 Description of the Assignment

In order to fulfill the objectives of the Study, the EIA has:

(i) determined the overall acceptability of any adverse environmental and health consequences that are likely to arise as a result of the proposed project;

(ii) identified the conditions and requirements for the detailed design, construction and operation of the proposed project to mitigate adverse environmental and health consequences wherever practicable; and

(iii) defined the acceptability of residual impacts after the proposed mitigation measures is implemented.

1.4 Structure of the Report

Following this introductory section, the EIA is organised as follows:

· Section 2 presents a brief description of the Project including the site selection, construction methodology and the time schedule;

· Section 3 describes the impacts which could arise during the construction of the project and provides mitigation measures to ensure compliance with relevant standards and guidelines;

· Section 4 describes the water quality assessment;

· Section 5 describes the impact assessment on fisheries;

· Section 6 describes the ecological impacts which focus on the terrestrial ecology and stream courses identified in the Study Area. An evaluation of the impacts is presented along with an assessment of the residual impacts following mitigation and recommendations for monitoring and auditing of the works are made;

· Section 7 presents the assessment of the impacts on cultural heritage;

· Section 8 describes the assessment of the landscape and visual impacts and includes descriptions of the significance of the landscape and visual impacts associated with the proposed works;

· Section 9 describes the wastes arising as a result of the construction of the project and recommends measures for the appropriate disposal of such wastes;

· Section 10 describes the health issues associated with the implementation of the project;

· Section 11 describes the assessment of marine archaeological impact associated with the proposed works;

· Section 12 describes the environmental monitoring and auditing of the works as identified from the preceding impact assessments;

· Section 13 reviews the findings and presents the overall conclusions of this Report; and

· Section 14 presents the schedule of recommended mitigation measures.