ES1 INTRODUCTION 1
ES1.1 Background Information 1
ES1.2 Objectives of the EIA Study 1
ES1.3 Description of the Assignment 2
ES1.4 Site Location 2
ES2 EVALUATION OF IMPACTS 3
ES2.1 Construction Impacts 3
ES2.1.1 Air Quality 3
ES2.1.2 Noise 3
ES2.2 Water Quality 3
ES2.3 Fisheries 4
ES2.4 Ecology 5
ES2.5 Cultural Heritage 5
ES2.6 Landscape and Visual Impact 6
ES2.7 Waste Management 6
ES2.8 Health Assessment 6
ES2.9 Marine Archaeological Impact Assessment 7
ES3 ENVIRONMENTAL MONITORING AND AUDIT 7
ES4 CONCLUSIONS AND RECOMMENDATIONS 7
LIST OF FIGURES
ES.1 Proposed Route Alignment
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.
To improve the supply reliability, transmission efficiency
and system performance, all the 33kV equipment, 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, 35MVA units via new 132kV underground and submarine cable circuits. The objective of this assignment
is to investigate the environmental impacts for the proposed 3 x 132kV circuits
such that the circuits can be installed without causing significant impacts on
local residents and the environment. This project is a Designated Project under Schedule 2, Q.1, of the Environmental
Impact Assessment Ordinance (EIAO) as a portion of the underground tunnel falls
within the “Country Park” zone. Therefore, CLP was instructed by the
Environmental Protection Department (EPD) to undertake an Environmental Impact Assessment (EIA) Study to
provide information on the nature and extent of environmental impacts arising
from the construction and operation of the proposed designed project and
related activities taking place concurrently. The alignment of the proposed 3 x 132 kV supply circuit from
the existing Pui O Substation on south Lantau Island, via Chi Ma Wan Peninsula
via Adamasta Channel towards Cheung Chau North and Cheung Chau South
Substations is shown in Figure ES.1.
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.
In order to fulfill the objectives of the Study,
this EIA has:
(i) determined the overall acceptability of any adverse environmental 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 consequences wherever practicable; and
(iii) defined the acceptability of residual impacts after the proposed mitigation measures is implemented.
The Study Area
covers Pui O, Chi Ma Wan Peninsula, Cheung Chau and Adamasta Channel. Outline
Zoning Plan (OZP) No. S/SLC/8 for the South Lantau Coast shows the different
zonings of the Study Area on Lantau Island (Part print of the OZP is
shown in Figure ES.2).
Encroachments of the potential cable routes on the Lantau South Country Park,
coastal protection area, green belt, village type development are expected.
Particular concerns are in Pui O area, Cheung Chau, Shap Long Kau Tsuen, Yim
Tin Kong Tsuen, Ham Tin Tsuen and Tai Long Wan where residential developments
In Cheung Chau, the 3 x 132kV circuits will be connected to the substations located in Cheung Chau north and south. The potential cable routes will impinge on the following areas.
· Cheung Chau Sai Tai Road, Tai Hing Tai Road, Praya Street and Pak She Praya Street in Cheung Chau central; and
· Sai Wan Promenade and Cheung Chau Typhoon Shelter in Cheung Chau south.
A qualitative assessment on
the construction dust impacts has identified that fugitive dust is the primary
potential air pollutant during the proposed works and t he dust impact will be minimal . E stablished dust suppression
techniques such as regular watering, covering/dampening any stockpiles and dampening
dusty materials before transportation.
Through the proper implementation of the recommended mitigation
measures, dust generation will be further controlled and exceedance of the
acceptable criteria will not be
expected. As a result, no routine air
quality monitoring will be required .
This EIA has concluded that the
predicted construction noise levels without mitigation at all the
affected NSRs except for SR3 will exceed
the acceptable noise criteria. With the implementation of good site practice
and practical noise mitigation measures, the construction noise impacts will be
reduced. After the implementation of
noise mitigation measures, residual construction noise impact will only occur
at SR5, the Buddhist Wai Yan Memorial College. However, it is anticipated that
the exposure to high noise level is only a short duration (2 to 3 days). In
addition, the road breaking activity in front of the school is recommended to
be carried out during the non-teaching period of the school (i.e. Saturday
afternoon and school holidays). This residual impact can be alleviated.
As noise exceedances during the construction phase are not predicted and the laying underground land cable is a trade practice well established by CLP, routine environmental noise monitoring is not required during construction. However regular site audits are recommended to be conducted to ensure the implementation of good site practices and appropriate mitigation measures.
The potential impact on the spawning and nursery ground is anticipated to be insignificant.
The predicted results of the water quality
modelling show that no exceedances of the WQO for suspended solids occur at the
selected water sensitive receivers by using the direct burying method.
Therefore, the water quality impacts caused by direct burying is acceptable. For dredging, the predicted elevated suspended
solids levels at all selected monitoring locations are well below the WQO
requirements when one trench is dredged at a time. However, exceedances of
suspended solids levels are predicted at Cheung Chau typhoon shelter, Po Yue
Wan and Adamasta Channel when dredging three trenches simultaneously. With the
implementation of the general mitigation measures and pollution prevention
measures, the water quality impacts at the water sensitive receivers are not
environmental monitoring and audit will be implemented to ensure the general
mitigation measures are effective and that the actual water quality impacts are
within the acceptable levels during the installation of submarine cables and
the reclamation works at Pui O Beach. A
review of existing information indicates that the Study Area supports fisheries
resources . As impacts resulting from the
project will be confined to dredging and reclamation, no adverse impacts to
fisheries resources are expected. The size of impact due
to dredging and reclamation is predicted to minor. Generally the mitigation
measures which are recommended to control water quality impacts to within
acceptable levels, are also expected to control impacts to fisheries resources.
Therefore, no fisheries-specific mitigation
measures are required.
reviews of existing information supplemented with the results of recently
undertaken field surveys on marine ecological resources indicate that the
intertidal rocky shores within the Study Area are of medium ecological value
whereas for the sandy habitats, low ecological value was assigned. Soft bottom subtidal habitats identified in
the review were regarded as of low ecological value. A few isolated colonies of hard and soft corals were recorded on
the subtidal hard surface habitats and were considered as of low ecological
value. The waters near the
and submarine cable laying site s do not appear to be highly utilised by marine mammals and it is
considered that this area does not contain critical habitat for the
Indo-pacific Hump-backed dolphins and Finless Porpoises.
impacts to marine ecological resources from the proposed construction works may
arise either indirectly, e.g. through perturbations of the surrounding water
quality, or directly as a result of habitat loss
. A total
of 0.055 ha intertidal sandy shore habitat, small areas of rocky
shore and 0.5 ha of subtidal soft bottom assemblages will be permanently lost as a
result of the construction activities associated with the Project. However, the assemblages to be lost are of
low-medium ecological value and given the small area to be directly affected,
the impacts are unlikely to be severe.
Indirect impacts during the construction process, such as an increase in
SS levels and decrease in DO in the water column may impact intertidal and
subtidal filter feeders and other marine organisms. However, the effects are not expected to be severe and no
unacceptable impacts are predicted to occur.
Operational impacts to marine ecological resources are not predicted to occur through disturbances to water quality due to changes in the hydrodynamic regime of the area or an increase in marine traffic for cable maintenance and repair.
Literature reviews of existing information supplemented with the results of field surveys on cultural heritage resources indicate that 31 historical buildings and features and two known archaeological sites are located within the Study Area. The proposed development has tried to avoid the heritage sites as far as possible but concerns have been raised regarding the potential impact on some of the identified sites.
measures have been recommended to avoid impacts to cultural heritage resources;
control of the construction work schedule during peak visiting hour at Pui O
Tin Hau Temple; detail design of the underground cable construction to avoid
and minimise the potential impact to the archaeological deposit at Bui O Public
School (Site A) and inner raised beach at Pui O (Site B). The future road level of the proposed Chi Ma
Wan Road widening shall be raised to allow adequate cover requirement for the
cables which shall be laid above the concerned zone. If the avoidance of
reaching the `no dig’ zone below existing ground level at both Site A and Site
B is not possible, archaeological monitoring should be undertaken in this
section during construction to preserve the archaeological deposit, if any, by
record and take environmental samples for future study if necessary.
and Visual Impact Assessment highlights that the significant adverse impacts
will occur during the construction phase. Significant impacts are also
restricted to particular locations, namely Pui O tunnel and Tai Long Wan tunnel
Cheng Chau landfall area. With mitigation measures the long term adverse impacts will be
negligible. The alignment of the circuit is significantly constrained by the
technical engineering requirements.
However, the nature of the proposed works and construction methodology
means that much of the cable can be constructed with minimal disturbance to the
existing landscape owing to the limited working boundary along existing roads,
footpaths. In conclusion therefore, the
proposed works will have limited adverse impacts or negligible impacts on
baseline condition with appropriate mitigation measures. In conclusion, the
landscape and visual impacts are considered acceptable with mitigation
In order to suitably manage the potential environmental effects associated with construction related wastes, full consideration must be given of the re-use of surplus clean material on site (where practicable), or within other development projects, once material balances are finalised. All mitigation measures and waste management procedures outlined within the EIA must be implemented in order to control or eliminate the potential impacts to the environment from waste generation and disposal.
The predicted EMFs for the proposed underground cables, cables in tunnel and submarine cables will be well under the stipulated guideline limits issued by the ICNIRP. As such, the existence of EMF associated with the proposed project is not anticipated to pose any adverse impact on public health.
Based on the findings of the baseline review, geophysical survey and diver inspection, it was confirmed that no archaeological significant material was identified in the study area. Therefore any further archaeological investigation or mitigation measures are not required.
A comprehensive Environmental Monitoring and Audit (EM&A) programme has been recommended during construction and operation of the 132kV supply circuit from Pui O Substation to Cheung Chau Substations. The EM&A requirements cover air quality, noise, water quality, waste management, ecology, cultural heritage and landscape and visual assessment issues and are a full reflection of the recommendations made within the EIA Report. With the inclusion of the recommended EM&A requirements into the works programme it is anticipated that the works can be carried out with full compliance of the standards set by the EIA-TM.
The overall conclusion is that the installation of the proposed 132kV supply circuit from Pui O Substation to Cheung Chau Substations would comply with all environmental standards and legislation, provided that the recommended environmental control measures are implemented. There is no residual impact on the environment except for construction noise. However, the residual noise impact can be alleviated by rescheduling the noisy construction activities and the duration being affected will be very short. Therefore, this residual impact is considered to be acceptable.
Recommendations are made for monitoring and auditing during the construction phase of the work to ensure compliance with the findings of the EIA Report.