Table of
Contents
15 Summary of Environmental Outcomes
and Conclusions
15.2 Considerations of Alternatives
15.6 Sewerage and Sewage Treatment
Implication
15.7 Waste Management Implication
15.8 Land Contamination Assessment
15.9 Ecological Impact (Terrestrial
and Aquatic)
15.11 Landscape & Visual Impacts
15.14 Environmental Outcomes and
Environmental Benefits of the Project
This section
summarises the key environmental outcomes arising from
the assessments completed in this EIA Report for the proposed Project in Tseung Kwan O Area 137.
For each of the environmental components assessed, a summary of key
environmental sensitive receivers is completed, together with an overview of
the key potential environmental impacts and key mitigation measures,
highlighting their benefits where necessary.
·
Consideration of Alternative Sites (Section
2.2);
·
Consideration of Alternative Development
Options (Section 2.3);
·
Consideration of Alternative Construction
Methods (Section 2.4); and,
·
Consideration of Alternative Works Sequences
(Section 2.5).
Based on the
review and consideration of project alternatives presented in the preceding
sections, the preferred alternative to be taken forward to this EIA study is
the provision of submarine pipelines for intake and outfall, desalination plant
by Reverse Osmosis, slope mitigation of 0.49 ha of the country park area by
soil nailing, flexible barriers and rock stabilization, and construction of a 9
km rising mains along Wan Po Road. Both
open-cut excavation method and trenchless construction method will be used for
the construction of desalination plant and the truck feed system. The proposed submarine intake and outfall
will be constructed by trenchless method with minor seabed dredging for the
installation of the diffusers. Within
the proposed Desalination Plant, bored piling and in situ concreting will be used for foundation and superstructure
construction, respectively.
The selection of
the preferred scenario and construction method has brought about a series of
environmental benefits to the Project, including:
·
The provision of alternative potable water source and alleviate the
shortage of freshwater resources due to climate change and subsequent adverse
weather;
·
The trunk feed system are proposed to be constructed underneath Wan Po
Road to minimize disturbance to sensitive receivers and natural habitats;
·
The mixed-use of localized soil nailing, localized flexible barrier and
localized rock slope stabilization for slope mitigation has minimized the
disturbance to the natural habitats at the Clear Water Bay Country Park;
·
The alignment and length of submarine utilities are at sufficient
distances from sensitive receivers to reduce potential impacts on water
quality, marine ecology and fisheries;
·
The use of micro-tunnel boring machine for construction of the proposed
submarine utilities reduces the extent of seabed dredging and dredging volume,
thereby reducing the marine footprint of this project and the potential impacts
on water quality, marine ecology and fisheries; and,
·
The recommended land-based construction methods are expected to avoid
prolonged construction duration and hence reduce potential disturbance to the
environment and the local public.
This summary
of environmental outcomes is completed upon completion of EIA Study. The summary of each of the components is
structured as follows:
·
List of sensitive receivers;
·
Protection of Environmentally Sensitive Areas;
·
Key Environmental Problems Avoided / Environmental Outcomes;
·
Assessment Methodology and Criteria;
·
Key Construction Impacts;
·
Key Operation Impacts;
·
Key Mitigation Measures;
·
Residual Impacts; and
·
Compliance with the guidelines and criteria of the Environmental Impact Assessment Ordinance -
Technical Memorandum (EIAO-TM).
Table
15.1 presents a
summary of findings of the assessment of impacts to air quality as a result of
the construction and operation of this Project.
Full details of the assessment and mitigation measures are presented in Section 4 of the EIA Report.
Table 15.1 Summary of
Environmental Assessment & Outcomes - Air Quality
Items |
Description |
Air Sensitive Receivers (ASRs) |
In accordance with
the EIA Study Brief Section 3.4.2.2
of the Project, the Study Area for the air quality impact assessment is
generally defined by a distance of 500m from the boundary of the Project
Site. A total of 20 ASRs were identified and illustrated in Figure 4.1 of the EIA Report. |
Protection of Environmentally Sensitive Areas |
With the implementation of the recommended dust control measures and adoption of good construction site practices, no adverse fugitive dust impact is anticipated within the assessment areas and associated ASRs. |
Key Environmental Issues Avoided/ Environmental Outcomes |
Potential impacts to the identified ASRs
are not anticipated by strictly following the dust control measures stipulated in the Air Pollution Control (Construction Dust) Regulations and good
site practices. |
Assessment Methodology and Criteria |
·
The
principal legislation for the management of air quality in Hong Kong is the Air Pollution Control Ordinance (APCO) (Cap 311). The APCO Amendment was passed in July 2013
and a set of new Air Quality Objectives (AQOs) has been effective from 1
January 2014. The new AQOs were used
as the evaluation criteria for this assessment. · A maximum hourly TSP level of 500 mg m-3 at ASRs is also stipulated in Annex 4 of the EIAO-TM to assess potential construction dust impacts. The measures stipulated in the Air Pollution Control (Construction Dust) Regulation should also be followed to ensure that any dust impacts are minimised. · Annex 4 of the EIAO-TM also stipulates that any predictive assessment of the odour impact should meet 5 odour units based on an averaging time of 5 seconds. |
Key Construction Impacts |
Soil excavation,
materials handling, truck movements on unpaved roads and wind erosion from
open stockpiling of dusty materials within the Project Site are identified to
be the potential dust generating activities. |
Key Operation Impacts |
Potential gaseous
emission from the standby generator and potential odour
nuisance may be resulted from the transportation, storage and handling of
sludge produced during the desalination process. |
Key Mitigation Measures |
Construction Phase: Dust control measures stipulated in the Air Pollution Control (Construction Dust) Regulation will be implemented during the construction of the desalination plant and freshwater rising main to reduce the potential fugitive dust emissions and also gaseous emission from construction plant. Operational Phase: No exceedance of the AQO criteria is anticipated at the ASRs and therefore no mitigation measures are required. |
Residual Impacts |
Construction Phase: With the implementation of the recommended dust control measures, no residual impacts are anticipated. Operational Phase: No adverse residual operational air quality impact is anticipated. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annexes 4 & 12 and applicable assessment standards/ criteria. |
Table
15.2 presents a
finding summary of the impact assessment to noise as a result of the
construction and operation of this Project. Full details of the assessment and mitigation
measures are presented in Section 5 of
the EIA Report.
Table 15.2 Summary of
Environmental Assessment & Outcomes - Noise
Items |
Description |
Noise Sensitive Receivers (NSRs) |
In accordance with
the EIA Study Brief Section 3.4.3.2
of the Project, the Study Area for the noise assessment includes all areas
within 300 m from the Project Boundary.
A total of 36 NSRs were identified and illustrated in Figure 5.3 of the EIA Report. |
Protection of Environmentally Sensitive Areas |
The environmentally
sensitive areas where the identified NSRs along Wan Po Road, Po Hong Road and
Tsui Lam Road are protected as a result of adoption
of the environmentally friendly options and designs. Adverse noise impacts on noise sensitive
receivers within the assessment areas have been minimized with the
practicable mitigation measures implemented. |
Key Environmental Issues Avoided/ Environmental Outcomes |
The maximum number of workfronts and working duration has been optimized to minimize the exceedances of daytime construction noise criteria.
|
Assessment Methodology and Criteria |
· The methodology for the noise impact assessment is in accordance with the procedures outlined in the GW-TM, which is issued under the NCO and the EIAO-TM. · Using a conservative approach, each work activity has been assumed to operate simultaneously. Based on the construction programme, cumulative noise impact throughout the construction phase has been assessed. |
Key Construction Impacts |
Potential sources of
noise impacts during the construction phase of the Project will mainly arise from
powered mechanical equipment (PME) operating at the land-based construction
work sites. No NSR was identified
within 300 m from the marine-based works area, hence the potential
construction noise impacts are expected to be minimal. |
Key Operation Impacts |
No noise sensitive
receivers were identified within 300m of the operational site area of the
proposed desalination plant at Tseung Kwan O, thus
no noise impact is anticipated in operation phase. |
Key Mitigation Measures |
In view of the predicted noise
exceedances at some of the NSRs along Wan Po Road during the construction of
the Project, the following mitigation measures have been considered: · Good construction site practice; · Use of quite PME; · Adoption of movable noise barriers and noise enclosures; · Use of noise insulation sheet; and · Scheduling of PME / construction activities. · The construction work in the influence areas near educational institutions shall be scheduled during long school holidays (eg summer holiday, Easter holiday or Christmas holiday, etc) as far as practicable. |
Residual Impacts |
Construction Phase: ·
With the implementation of
all practical mitigation measures and works scheduling , no residual impacts
are anticipated and predicted noise levels at all NSRs are predicted to
comply with the EIAO requirement. Operational Phase: · No adverse residual operational noise impact is anticipated. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annexes 5 & 13 and applicable assessment standards/ criteria. |
Table 15.3 presents the summary findings of the impact assessment on water quality as a result of the construction and operation of this Project. Full details of the assessment and mitigation measures are presented in Section 6 of the EIA Report.
Table 15.3 Summary of
Environmental Assessment & Outcomes – Water Quality
Items |
Description |
Sensitive Receivers (SRs) |
The following SRs have been identified: · Fisheries Sensitive Receivers Fish Culture Zones at Tung Lung Chau and Po Toi O · Ecological Sensitive Receivers Coral Communities: Junk Bay, Fat Tong Chau, Tai Miu Wan, Cape Collinson, Tung Lung Chau, Tai Long Pai, Kwun Tsai, Tit Cham Chau, Joss House Bay · Water Quality Sensitive Receivers Gazetted Bathing Beaches: Big Wave Bay, Clear Water Bay, Shek O, Rocky Bay Coastal Protection Areas: Clear Water Bay Po Toi O Tai Miu Wan Cape Collinson Big Wave Bay Tai Tam · Seawater Intakes: Tseung Kwan O New Town, Siu Sai Wan, Heng Fa Chuen |
Protection of Environmentally Sensitive Areas |
With the
implementation of the suggested mitigation measures, full WQO compliance is
predicted at identified WSRs that does not show exceedance in WQO criteria
within the environmentally sensitive areas for all parameters in both dry and
wet seasons. For Tung Lung Chau Fish
Culture Zone, exceedance in WQO DO criteria is observed in baseline condition. The predicted level of DO depletion brought
by the Project would be very minimal and would not result in unacceptable
adverse impact to the receiver. |
Key Environmental Issues Avoided/ Environmental Outcomes |
· Disturbance to sensitive receivers has been avoided as a result of the site/ route selection process of the pipelines. · Impacts to water quality have been reduced by the adoption of trenchless techniques for most sections of the pipelines. · The amount of material to be dredged and hence disposed of has been reduced by optimising project design and phasing, thereby reducing impacts to water quality during dredging and disposal operations.
|
Assessment Methodology and Criteria |
· The potential impacts due to the construction and operation of the Project and associated developments were assessed following the EIAO-TM Annex 6 guidelines and the impacts evaluated based on the criteria in EIAO-TM Annex 14. · Impacts due to the dispersion of fine sediment in suspension during the construction of the submarine pipelines have been assessed using computational modelling (Delft3D and CORMIX models). · The simulation of operation impacts on water quality has also been studied by means of computational modelling. The models have been used to simulate the effects of the physical presence of hydrodynamic regime, flushing and sedimentation patterns, and water quality changes. |
Key Construction Impacts |
The water quality modelling works have indicated that the construction works (i.e. dredging and backfilling) can proceed at the recommended working rates without causing unacceptable impacts to water quality sensitive receivers. · Suspended Solids (SS): The majority of SS elevations in water have been predicted to remain within relatively close proximity to the dredging works and, as such, the majority of sediment has been predicted to settle within relatively close proximity to the works areas. Thus, no unacceptable impacts are expected to be posed by the works. · Water Quality (Dissolved Oxygen, Nutrients, and Heavy Metals): The dispersion of sediment due to dredging is not expected to impact the general water quality of the receiving waters. Effects will be transient, localised in extent, of small magnitude and compliant with applicable standards. Thus, no unacceptable impacts are expected to be posed by the works. · Other Discharges: Land based construction activities, vessel discharges and contaminants are not predicted to cause unacceptable impacts to the water quality sensitive receivers. |
Key Operation Impacts |
The discharge of RO
concentrate from the desalination process is the main environmental concern
for the Project operation. Results of
the modelling works indicate that no observable mixing zone is predicted for
most discharge scenarios for most chemical constituents and thus potential
impacts on water quality and hydrodynamics are predicted to be within
acceptable levels. |
Key Mitigation Measures |
Appropriate preventive and mitigation measures are recommended, for example deployment of silt curtain around grab dredger, reduce the dredging rate at intake, to minimize the potential water quality impact from these works. Environmental monitoring and audit is recommended to ensure the proper implementation of these measures. |
Residual Impacts |
Construction Phase: · No adverse residual construction impact on water quality is anticipated. Operational Phase: · Modelling assessment for operation phase effluent discharge indicated that no unacceptable adverse water quality impact from the RO concentrate discharge and other relevant discharge. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annexes 6 & 14 and applicable assessment standards/ criteria. |
Table
15.4 presents a
summary of findings of the assessment of impacts to sewage treatment as a
result of the construction and operation of this Project. Full details of the assessment and mitigation
measures are presented in Section 7
of the EIA Report.
Table 15.4 Summary of
Environmental Assessment & Outcomes – Sewerage
Items |
Description |
Key Environmental Issues Avoided/ Environmental Outcomes |
The proposed strategy is considered feasible in terms of regional sewerage strategy, land, environmental impact and construction considerations. The proposed plant is considered sustainable in terms of sewerage. |
Assessment Methodology and Criteria |
The sewage flow
discharge from the proposed Desalination Plant is based on the following
standards, guidelines and reference for the sewerage and sewage treatment
design: ·
Technical Memorandum on Effluent Standards
(Water Pollution Control Ordinance, Cap. 358 section 21); ·
Sewerage Manual published by Drainage Services Department
(DSD); ·
EPD Report No. EPD/TP 1/05 Guidelines for
Estimating Sewage Flows for Sewerage Infrastructure Planning Version 1.0 |
Key Construction Impacts |
Construction of the
section of gravity sewer from the plant to connect with the existing public
sewer would mainly involve conventional technology such as cut-and-cover
excavation techniques. There is no significant constraint in terms of
complexity by general civil contractors. |
Key Operation Impacts |
The sewerage facilities provided as part of the proposed plant will be maintained by the government after completion. No specific maintenance operations are envisaged but it is considered desirable that the facilities will be inspected regularly to ensure that these sewers can function properly. The maintenance responsibility of those proposed sewerage facilities will be confirmed with relevant authorities in the detailed design stage of this project. |
Key Mitigation Measures |
The detailed design of the proposed sewerage system should be circulated to DSD, EPD and other relevant parties for comment during planning and detailed design stage to ensure acceptance by relevant parties. Access for sewers, equipment and personnel for maintenance of the works should be adequately provided. The maintenance responsibility of those proposed sewerage facilities will be confirmed with relevant authorities in the detailed design stage of this project. |
Residual Impacts |
Construction Phase: · No adverse residual construction impact on sewage treatment is anticipated. Operational Phase: · No adverse residual construction impact on sewage treatment is anticipated. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annex 14 and applicable assessment standards/ criteria. |
Table
15.5 presents a summary
of findings of the assessment of impacts to waste management as a result of the
construction and operation of this Project.
Full details of the assessment and mitigation measures are presented in Section 8 of the EIA Report.
Table 15.5 Summary of
Environmental Assessment & Outcomes – Waste Management
Items |
Description |
Key Environmental Issues Avoided/ Environmental Outcomes |
Potential project layouts,
construction design and methods, use of trenchless method and phasing of
dredging and reuse of excavated materials, were examined on the basis of
their potential environmental impacts. The preferred alternatives have led to
the reduction in the amount of dredged material expected to be produced and,
therefore, have brought about an overall reduction in waste management
impacts.
|
Assessment Methodology and Criteria |
The potential environmental impacts associated with the handling and disposal of waste arising from the construction and operation of this Project are assessed in accordance with the criteria presented in Annexes 7 and 15 of the EIAO-TM: · Estimation of the types and quantities of the wastes to be generated; · Assessment of the secondary environmental impacts due to the management of waste with respect to potential hazards, air and odour emissions, noise, wastewater discharges and traffic; and, · Assessment of the potential impacts on the capacity of waste collection, transfer and disposal facilities. |
Key Construction Impacts |
The key potential impacts during the construction phase are related to wastes generated from dredging, and land-based construction works. All the wastes produced during the construction phase are of small to moderate quantity and will be disposed of accordingly to their nature and relevant regulations, avoiding any potential adverse impact. |
Key Operation Impacts |
General refuse,
dewatered sludge and chemical waste will be produced during the operation
phase. The potential environmental impacts associated with waste storage,
handling, collection, transport and disposal will meet the criteria specified
in the EIAO-TM, thus no
unacceptable operational waste management impact is anticipated. |
Key Mitigation Measures |
A Waste Management
Plan, which will form as part of the Environmental Management Plan, will be
devised which incorporates mitigation measures that have been proposed to avoid
or reduce potential adverse environmental impacts associated with handling,
collection and disposal of waste arising from the construction and operation
of this Project. |
Residual Impacts |
With the implementation of the recommended mitigation measures, in particular the establishment and implementation of the Waste Management Plan, no adverse residual impacts are anticipated from the construction and operation of this Project. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annexes 7 & 15 and applicable assessment standards/ criteria. |
Table
15.6 presents a
summary of findings of the assessment of impacts to land contamination as a
result of the construction and operation of this Project. Full details of the assessment and mitigation
measures are presented in Section 8A
of the EIA Report.
Table 15.6 Summary of
Environmental Assessment & Outcomes – Land Contamination
Items |
Description |
Key Environmental Issues Avoided/ Environmental Outcomes |
Potential project
layouts, construction design and methods, use of trenchless method and
phasing of excavation, were examined on the basis of their potential
environmental impacts. The preferred alternatives have led to the avoidance
of contaminated land and, therefore, have brought about an overall reduction
in land contamination risk.
|
Assessment Methodology and Criteria |
The following legislation covers the handling, treatment and disposal of wastes in Hong Kong, and has been considered in the assessment. · Annex 19 of the Technical Memorandum on Environmental Impact Assessment (Annex 19 of EIAO-TM); · Guidance Manual for Use of Risk-based Remediation Goals for Contaminated Land Management (The RBRGs Guidance Manual); · Guidance Note for Contaminated Land Assessment and Remediation (The Guidance Note); and · The Practice Guide for Investigation and Remediation of Contaminated Land (The Practice Guide). Apart from the abovementioned, the following legislation, documents and guidelines may cover or have some bearing upon the assessment of contamination and the handling, treatment and disposal of contaminated materials for the Project: · Water Pollution Control Ordinance (WPCO) (Cap 358); · Waste Disposal Ordinance (WDO) (Cap 354); · Waste Disposal (Chemical Waste) (General) Regulation (Cap 354C); and · Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes. |
Key Construction Impacts |
Based on the review
of historical aerial photographs, the TMS Site was once part of the sea prior
to reclamation finished in 2000. After
the completion of the reclamation work, the TMS Site was left vacant until
the magazine storages and other associated facilities were constructed in
2012. Therefore the risk of potential
land contamination due to land use prior to the 2012 is anticipated to be
low. |
Key Operation Impacts |
Same as above. |
Key Mitigation Measures |
In order to minimize the potential adverse impact to the environment due to the handling of contaminated materials, the following environmental mitigation measures are proposed during the course of site remediation. · Excavation profiles shall be properly designed and executed; · An impermeable surfacing shall be placed under the stockpile and a cover should be employed to prevent dust emission and possible cross contamination. If not applicable, regular watering shall be applied; and · Trucks carrying contaminated materials shall be enforced with speed control. |
Residual Impacts |
With the implementation of the recommended mitigation measures, in particular the establishment and implementation of the Contamination Assessment Plan (CAP), no adverse residual impacts are anticipated from the construction and operation of this Project. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annex 19 and applicable assessment standards/ criteria. |
Table
15.7 presents a
summary of findings of the assessment of impacts to ecological resources as a
result of the construction and operation of this Project. Full details of the assessment and mitigation
measures are presented in Section 9
of the EIA Report.
Table 15.7 Summary of
Environmental Assessment & Outcomes – Ecological Impact
Items |
Description |
Sensitive Receivers (SRs) |
In accordance with the
EIA Study Brief Section 3.4.7 of
the Project, the ecological sensitive receivers were identified and detailed
in Section 9. |
Protection of Environmentally Sensitive Areas |
The Clear Water Bay Country
Park is the recognized ecologically important /sensitive sites located within
the Study Area. Only one flora species of conservation interest Marsdenia lachnostoma
was recorded along the alignment for flexible barriers of slope mitigation
works. The other flora species of
conservation interest were recorded outside of the works areas for natural
slope mitigation works, hence the impacts on these species are avoided. |
Key Environmental Issues Avoided/ Environmental Outcomes |
· Disturbance to the Country Park Area has been minimized as a result of the selection of slope mitigation method. · Potential project layouts, construction design and methods were examined on the basis of their potential environmental impacts. The adopted layout has reduced the works extent to natural habitats in the Clear Water Bay Country Park. · Impacts to marine ecology have been reduced through the adoption of trenchless installation technique for the pipelines. This results in less adverse effect on water quality of surrounding areas and thus to the marine ecosystems. |
Assessment Methodology and Criteria |
· A literature review was supplemented by a programme of field surveys that covered terrestrial and aquatic assemblages and habitats. · The potential impacts due to the construction and operation of the proposed Project were assessed following the EIAO-TM Annex 16 guidelines and the impacts evaluated based on criteria in EIAO-TM Annex 8 and Guidance Notes. |
Key Construction Impacts |
· Potential construction phase impacts to ecological resources, as well as impacts to flora and fauna, may arise from the permanent loss of habitats for desalination plant development and permanent loss of naturalness of habitat (0.49 ha) due to slope mitigation works and disturbances to benthic habitats within the dredging footprint. · Water quality impacts arising from the proposed dredging works will be compliant with assessment criteria, transient and confined to the works areas and, therefore will not give rise to adverse impacts to marine ecological resources. |
Key Operation Impacts |
Unacceptable
operation phase impacts to ecological resources are not expected to arise
from the change in hydrodynamic regime, RO concentrate discharge, and water
quality changes. |
Key Mitigation Measures |
· Avoid direct and reduce indirect Impacts to ecologically sensitive habitats. · For slope mitigation works within the Clear Water Bay Country Park, no trees will be felled and vegetation clearance to enable the slope works will be kept to a minimum. · The alignment for flexible barriers of slope mitigation works would be at a sufficient distance from the recorded flora species of conservation interest Marsdenia lachnostoma. · The alignment chosen for the submarine facilities is away from key ecological sensitive habitats · The use of trenchless techniques during the installation of the submarine facilities will reduce the severity of perturbations to water quality and hence allow compliance with the impact assessment criteria at sensitive receivers. · The modelling work has demonstrated that the selected working rates for dredging works will not cause unacceptable impacts to the receiving water quality. The mitigation measures designed to mitigate impacts to water quality to acceptable levels (compliance with assessment criteria) are also expected to mitigate impacts to marine ecological resources. |
Residual Impacts |
No adverse residual construction and operational ecological impact is anticipated. |
Compensation Areas Included |
Since habitat loss/ disturbance due to other land-based construction and marine dredging works for laying the submarine intake and outfall of the Project only occurs on the habitats of low or low to moderate ecological value where species of conservation interest will be avoided, ecological compensation is not required. |
Compliance with EIAO-TM |
The assessment and the residual impacts are acceptable and in compliance with the EIAO-TM Annexes 8 and 16 and applicable assessment standards/criteria. |
Table
15.8 presents a summary of findings of
the assessment of impacts to fisheries resources as a result of the
construction and operation of this Project.
Full details of the assessment and mitigation measures are presented in Section 10 of the EIA Report.
Table 15.8 Summary of
Environmental Assessment & Outcomes – Fisheries Impact
Items |
Description |
Sensitive Receivers (SRs) |
The identified fisheries sensitive receivers are: · Recognized spawning and nursery ground of commercial fisheries resources at Port Shelter (located at least 2 km east from the proposed Project); · Artificial reefs at Outer Port Shelter area (located at least 5 km east from the proposed Project); and, · Fish Culture Zone at Tung Lung Chau (south to the proposed Project at a distance of about 1 km). |
Protection of Environmentally Sensitive Areas |
Environmentally
sensitive areas including spawning and nursery ground of commercial fisheries
resources at Port Shelter, artificial reefs at Outer Port Shelter area and
Fish Culture Zone at Tung Lung Chau have been identified; however, the
assessment of water quality impacts demonstrated that these areas will not be
affected. |
Key Environmental Issues Avoided/ Environmental Outcomes |
· Potential project layouts, construction and operation design and methods were examined on the basis of their potential environmental impacts. |
Assessment Methodology and Criteria |
· A literature review was conducted to establish the fisheries importance of the area surrounding the proposed Project. · The potential impacts due to the construction and operation of the Project and associated developments were assessed following the EIAO-TM Annex 17 guidelines and the impacts evaluated based on the criteria in EIAO-TM Annex 9. |
Key Construction Impacts |
· Direct disturbances of fisheries habitat and fishing ground; and, · Perturbations to key water quality parameters. |
Key Operation Impacts |
· Loss of seabed habitat within the small footprint of the submarine facilities; · Impingement and entrainment of fisheries resources · Change in water quality |
Key Mitigation Measures |
· The mitigation measures designed to mitigate impacts to water quality to acceptable levels (compliance with assessment criteria) are expected to mitigate impacts to fisheries resources. · Construction impacts to fisheries resources and fishing operations have largely been avoided through the planning and design of the marine works; in particular those associated with the dredging. No fisheries-specific mitigation measures are required during construction. · Unacceptable operation phase impacts are not expected and so no additional fisheries-specific mitigation measures are required during operation. |
Residual Impacts |
Impacts to fisheries
resources, habitats and fishing operations during construction and operation
phase are considered to be within acceptable level. The permanent loss of 0.11 ha of seabed
fisheries habitat for the installation of submarine utilities is considered
to be of negligible significance and within acceptable level. |
Compensation Areas Included |
No additional
fisheries-specific compensation are required during operation. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annexes 9 & 17 and applicable assessment standards/ criteria. |
Table
15.9 presents a
summary of findings of the assessment of impacts to landscape and visual as a
result of the construction and operation of this Project. Full details of the assessment and mitigation
measures are presented in Section 11
of the EIA Report.
Table 15.9 Summary of
Environmental Assessment & Outcomes – Landscape & Visual
Items |
Description |
Visually Sensitive
Receivers (VSRs), Landscape Resources (LRs) and Landscape Character Areas
(LCAs) |
A total of 31 VSRs, 11 LRs and 4 LCAs were identified. |
Key Environmental Issues Avoided/ Environmental Outcomes |
· Sensitive VSRs have been avoided by choosing an appropriate plant layout. · Slope mitigation works haven carefully considered to ensure there is minimal disturbance to the landscape. · No tree fell as a result of the slope mitigation works. |
Protection of Environmentally Sensitive Areas |
The landscape impact
assessment confirms that the majority of project site is currently with
landscape of low quality with little valuable vegetation or amenity value and
thus in general the Project at construction and operation is considered to
have little landscape impact. For visual impact,
the Project includes buildings up to a maximum of 20 m height and is
situated in an area that is naturally shielded by topography to the north
east and separated by at least 2 km from viewers across the Tathong Channel on Hong Kong Island to the south east,
and thus the represents a low number of viewers. |
Assessment Methodology and Criteria |
· The methodology of the LVIA was based on Annexes 10 and 18 in the EIAO-TM under the EIA Ordinance and associated Guidance Notes. · The landscape assessment considered the impact of the proposed development on the existing landscape and particularly on the landscape character units within 500 m of the development site. · The visual assessment examined the impact of the proposed development on the existing views and the visual amenity, particularly from the VSRs within the viewshed. · In order to illustrate the visual impacts of the proposed desalination plant, photomontages prepared from selected viewpoints compare the existing conditions with the view after construction. The residual impacts are evaluated qualitatively, in accordance with the requirements of Annex 10 of the EIAO-TM. |
Key Construction Impacts |
During the construction phase of the Project, potential impacts could result from the following: · Site clearance for the civil works, including removal of vegetation and tree felling where necessary (e.g. of weedy species); · Open-cut excavation and re-provision of surfaces within the reclamation area; · Clearance for temporary access to construction site; · Landscaping works; · Presence and operation of construction vehicles and machinery; · Temporary works area; · Stockpiling areas; · Construction of the new facilities; · Trenchless technologies for construction of the proposed submarine outfall; and · Seabed dredging for the installation of the intake structures and outfall diffuser. In addition, there is the potential for slope mitigation works, including: · Passive/ flexible debris barriers typically 4-5 m high, some soil nailing at the lower section of the natural slope and stabilization of boulders and rocks using local concrete infills dowelling. |
Key Operation Impacts |
During the operation phase of the Project, potential impacts could result from the following: · Operation of new buildings, machinery and plant and new access road; and · Landscaping works. |
Key Mitigation Measures |
Mitigation measures are proposed to be considered during planning, detailed design, construction and operation and often one measure can be relevant to both construction and operation phases of the proposed development. For example detailed design measures will be implemented during construction but will aim to reduce both construction and operation impacts. Equally soft landscape mitigation measures such as compensatory planting may be implemented during construction, but their full effect will often not be appreciated for up to 10 years. Tree felling and preservation will be undertaken in accordance with DEVB TCW No. 10/2013, in which on-site compensatory area has been provided. All measures should be implemented at the earliest stage possible i.e. at or before construction, particularly for soft landscaping. |
Residual Impacts |
No significant
adverse residual impacts have been identified. The Landscape and Visual
Mitigation Measures proposed will help to mitigate the impacts on the LCAs,
LRs and VSRs. Overall the residual impacts are assessed as slight to
insignificant. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annexes 10 & 18 and applicable assessment standards/ criteria. |
Table
15.10 presents a
summary of findings of the assessment of impacts to land contamination as a
result of the construction and operation of this Project. Full details of the assessment and mitigation
measures are presented in Section 12
of the EIA Report.
Table 15.10 Summary of
Environmental Assessment & Outcomes – Landfill Gas Hazard
Items |
Description |
Key Environmental Issues Avoided/ Environmental Outcomes |
A
qualitative assessment of the hazard associated with the construction and
operation of desalination plant, and construction of freshwater mains (i.e.
the targets) was conducted based on the catergorisation
of the Source, Pathway and Target terms and the EPD assessment
framework. The qualitative hazard to
the proposed desalination plant and fresh water mains from landfill gas has
assessed as being from low to medium for various targets.
|
Assessment Methodology and Criteria |
In accordance with the Guidance Note, the risk due to landfill gas may be evaluated based upon the following three criteria: · Source – the rate and concentration of gas generation by the landfill; · Pathway – the nature of and length of potential pathways through which landfill gas can migrate and leachate flow, such as geological strata, utility services; and · Target – the level of vulnerability of various elements of the development to landfill gas. Following the determination of the categories of source, pathway and target, a qualitative assessment of the overall risk was made by reference to the Guidance Note EPD/TR8/97. |
Key Construction Impacts |
The
qualitative hazard to the proposed desalination plant and fresh water mains
from landfill gas has assessed as being from low to medium for various
targets. |
Key Operation Impacts |
Same as above. |
Key Mitigation Measures |
In general, the restoration
and aftercare of the TKO Stage II/III Restored Landfill and TKO Stage I
Restored Landfill, and the control of landfill gas and leachate of the SENT
Landfill and SENT Landfill Extension should not be relied upon to ensure the
safety of adjoining developments; however, it must also be acknowledged that
the restoration works and landfill gas control measures undertaken will have
the effect of lowering the potential for an incident to occur off-site. Allowance for this has been made in the
qualitative assessment undertaken. All
recommended mitigation measures were detailed in Section 12.7. |
Residual Impacts |
With the implementation of the recommended mitigation/precautionary measures, no adverse residual impacts are anticipated from the construction and operation of this Project. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annexes 7 & 19 and applicable assessment standards/ criteria. |
Table
15.11 presents a summary
of findings of the assessment of hazard to life as a result of the construction
and operation of this Project. Full
details of the assessment and mitigation measures are presented in Section 13 of the EIA Report.
Table 15.11 Summary of
Environmental Assessment & Outcomes – Hazard to Life
Items |
Description |
Key Environmental Issues Avoided/ Environmental Outcomes |
The
location of chlorine storage has been considered to stay away from the
surrounding populated areas.
|
Assessment Methodology and Criteria |
The hazard assessment has been conducted with reference to the EIAO-TM Criteria with particular focus of the followings: ·
Potentially
Hazardous Installations (PHI) QRA: Storage, Use and On-site Road Transport of
Chlorine (from TKO Area 137 Pier to Chlorination Store of the Desalination
Plant)1; ·
Off-site
Marine Transport of Chlorine (from Sham Shui Kok
Dock to TKO Area 137 Pier); ·
Storage,
Use and Transport of Sodium Hypochlorite associated with the Desalination
Plant Operation; ·
Transport
(On-site and off-site), Storage, Handling of Cryogenic and Pressurised Liquid Carbon Dioxide; and ·
Other
Risk Associated Issues, including: ·
Storage,
Use and Transport of other DGs associated with the Desalination Plant
Operation; ·
Explosive
Transport in TKO Area 137 (Existing, Committed and Planned Projects Requiring
Explosive Transport from TKO 137 Pier); and ·
Explosive
Offloading Operation at TKO Area 137 Pier. |
Key Construction Impacts |
Not
anticipated. |
Key Operation Impacts |
In all cases, the
Individual Risk complies with the Hong Kong Risk Guidelines and the Societal
Risk lies in the acceptable region. The societal risk expressed in the form
of FN curves, lies in the acceptable region of the HKRG for the use,
transport and storage of chlorine at the Desalination Plant. |
Key Mitigation Measures |
With the
implementation of safeguard measures as described in the assessment, no
unacceptable risks are foreseen as a result of the operation of the
Project. No mitigation measures are
thus deemed necessary. |
Residual Impacts |
No residual impact is expected. |
Compliance with EIAO-TM |
The assessment and the impacts are acceptable and in compliance with the EIAO-TM Annexes 4 and applicable assessment standards/ criteria. |