1.
Introduction
1.1.
PROJECT BACKGROUND
1.1.1. The Project is for construction of a new Annex Block, and
refurbishment of the existing Red House at Hong Kong Observatory (HKO)
Headquarters in Tsim Sha Tsui (hereinafter referred as
the “Project”). Site location plan of the Project is shown in Figure
1.1.
1.1.2. The Project is within a site of cultural heritage, and therefore is
classified as a Designated Project(DP) under Item Q.1 in Schedule 2 of the Environmental
Impact Assessment Ordinance (EIAO), the construction and operation of the
Project will require an Environmental Permit (EP).
1.1.3. The Project Proponent of the Project is HKO. Architectural
Services Department (ArchSD) is the works agent of the Project. Allied Environmental Consultants Limited (AEC) was commissioned by ArchSD
to undertake the Environmental Impact Assessment (EIA) study for the Project. A
separate architectural lead consultant will be engaged
by ArchSD to undertake investigation, planning, design and construction
supervision of the Project. Construction works under the Project will be
carried out by the Contractor engaged by ArchSD.
1.1.4. In accordance with the requirements of Section 5(1)(a) of the
EIAO, a Project Profile (No. PP-630/2021) for the Project was submitted to the
Director of Environmental Protection (DEP) for application for an EIA Study
Brief on 20 September 2021. Pursuant to Section 5(7)(a) of the EIAO, the
DEP issued a Study Brief (No.:ESB-347/2021) on 29 October 2021 for the EIA
study.
1.2.
OBJECTIVES OF THE EIA STUDY
1.2.1. The overall objectives of the EIA Study are to provide information
on the nature and extent of environmental impacts arising from the construction
and operation of the Project; to recommend appropriate mitigation measures to
control the potential environmental impacts arising
from the Project so as to comply with the requirements
of the Technical Memorandum on Environmental Impact Assessment Process
(EIAO-TM) of EIAO; and to confirm the environmental acceptability of the
Project. Key environmental issues identified include cultural heritage, air
quality, noise, water quality and sewerage, waste management, and landscape and
visual.
1.2.2. The potential environmental impacts arising from the construction
and operation of the Project have been assessed in accordance with the guidelines
and requirements stipulated in the EIAO-TM.
2.
Project Description
2.1.
location of the project
2.1.1. The Project Site is located at the southern side of HKO Headquarters
at 134A Nathan Road, Tsim Sha Tsui. It is a Declared Monument under the Antiquities
and Monuments Ordinance (Cap.53). An open car park, the Red House (being
used as an electronics laboratory at present) and an access road are found in
the Project Site as shown in Figure 1.1.
2.2.
Scope of The Project
2.2.1.
The Project aims to construct a new Annex Block
in the form of a four-storey building (plus a mezzanine floor above G/F and
U1/F above 1/F). Other associated and supporting
facilities such as rest rooms for shift duty officers, 7 open car parking
spaces for the Annex Block, etc. will be provided to meet HKO’s operation needs
and to support the round-the-clock uninterrupted operations of HKO’s mission-critical services. The proposed
building height is capped at +45 metres above Hong Kong Principal Datum (mPD)
as stipulated in the Tsim Sha Tsui Outline Zoning Plan (OZP) No. S/K1/28. Since
the existing car park is situated at around +24.4 mPD, the building height
measured from the car park level should not exceed about 20.6m.
2.2.2. The Project also covers refurbishment works to convert the existing
Red House into a History Room for showing the history of HKO to the public. In
addition, the Project includes road widening works for the Emergency Vehicular Assess
(EVA) at the existing access road and minor utility and maintenance works.
2.3.
Need of the Project
2.3.1. There is currently an acute shortfall of office space and functional
areas at the HKO Headquarters. HKO staff and the existing equipment are
accommodated in very congested environment hampering the effective operations
of existing essential services. The Project is to provide necessary space and
premises to (a) support and upgrade HKO’s essential operation and services to
strengthen HKO’s weather monitoring and forecasting capability to cope with
more extreme weather under the threat of climate change, and (b) organize more
public education and outreach activities for enhancing the community's
awareness of climate change and natural disaster prevention and response.
2.3.2. Without this Project, the HKO could not develop and render new
services to the government and the public for coping with the challenges of
climate change as there is no additional space to house the required
facilities, thereby causing negative impacts on the disaster risk reduction and
public safety which is undesirable to the society.
2.4.
Consideration of Alternative Options
2.4.1. To provide functional areas and necessary facilities for supporting
and upgrading HKO’s essential operation, a medium sized Annex Block that can
house adequate office space and functional areas have to be provided. Different
locations and design options have been identified and examined, in order to
optimize the operational benefits while minimizing environmental impacts.
Location of the New Annex Block
2.4.2. The location, size and arrangement on the new Annex Block is bounded
by operation needs of HKO. The suitable location within the HKO Headquarters
should be away from (1) the meteorological equipment/instruments in operation
at the grasslands in front of the 1883 Building; and (2) historic
buildings/structures as far as practicable.
2.4.3. Two alternative locations within HKO Headquarters have been proposed
for the new Annex Block (see Plate 2-1):
·
Location A – Existing open car park and its vicinity
area located at the southern side of the HKO Headquarters; and
·
Location B – Green area situated on a slope. Located at the northern
side of the HKO Headquarters.
2.4.4. Location A is considered more preferrable given
the following benefits:
·
Impact to the existing trees would be minimized
as it is an open car park and access road, with more paved area and less
vegetation;
·
The green area at Location B is known as one of
the remainings in urban Kowloon, so it should be preserved; and
·
As the green area at Location B is situated on a
slope, it is technically more complicated and of a higher cost for constructing
a building on a slope.
2.4.5. Location A has therefore been selected as the preferred location for
the new Annex Block that could best minimize the adverse environmental impacts
associated with the Project while achieving the needs of HKO.
Design of the New Annex Block
2.4.6. Two design options have been identified:
·
Option A – One block scheme; and
·
Option B – One block scheme with a wide atrium
at 1/F.
2.4.7. Option A consists of one block with building height capped at+45
mPD. The new Annex Block with no atrium in Option A may cause obstruction to
visual context of the building users and visitors.
2.4.8. Option B consists of one block with the building height capped at
+45mPD with a wide east to west aligned atrium at 1/F
which is beneficial to the visual context of the visitors. The atrium will act as air path and enhance the
natural ventilation, thereby reducing the electricity demand of mechanical
ventilation system and air conditioning. Also, Option B
will provide footpaths and encourage pedestrian movement within the HKO Headquarters.
2.4.9. Moreover, the central void above the atrium within the 2/F to R/F in
Option B would allow natural daylight entering the rooms on lower floors and
hence reduce the energy consumption in interior lighting.
2.4.10. From
cultural heritage perspective, Option B can provide a more articulated and
dynamic form with reduced building mass to minimise visual intrusion and
preserve sight lines to the existing historic buildings within HKO
Headquarters.
2.4.11. In
view of the above, Option B is considered to be the preferred design option for
the Project.
Construction Methodology
2.4.12. For
the construction of the Project, the major construction activities comprise the
following:
·
Site preparation and road works;
·
Excavation and Foundation; and
·
Construction of Annex Block and Refurbishment of
Red House.
Foundation works
2.4.13. Feasibility
of various foundation methods have been reviewed and studied. Driven H-pile and
socketed H-piles are being considered for the Project. For driven H-piles, it
will not be adopted as it would induce a relatively high disturbance in terms
of noise level and vibration. Silent hydraulic press-in method is also studied
and will not be used for the Project, as it is to be used for sheet piling
while no such works will be carried out. In view of the above, socketed H-piles
is considered most suitable for the Project as it could generate less noise and
vibration with minimal soil disturbance.
Main Building Construction
2.4.14. In
general, the suitable main building construction
options will not present significant differences in terms of the
environmental impacts to the nearby sensitive receivers. Conventional cast in‐situ reinforced beam‐slab
system will be adopted based on the latest design.
2.4.15. Innovative
construction methods are encouraged in this Project. Reinforced concrete Modular
Integrated Construction (MiC) by fully making use of Building Information
Modelling (BIM) tool, will be adopted where applicable for staff offices, rest
rooms, lavatories and panties at 2/F and 3/F. It will be sub-divided into
pre-finished modules with building services provisions by means of off-site
prefabrication.
Preferred Option
2.4.16.
The preferred options should introduce minimal
environmental impacts and present environmental benefits when compared to other
options and alternatives. Based
on the above considerations, the preferred options in respect of the location,
building, design and construction method are summarized below for detailed
design of the Project and adopted for this EIA study.
·
Optimum location: at the
existing open car park and its vicinity area located at the southern side of
the HKO Headquarters;
·
Optimum design: One
block scheme with a wide atrium at 1/F at the existing carpark within the HKO
Headquarters; and
·
Optimum construction method: socketed H-piling and conventional cast in‐situ
reinforced beam‐slab system, with MiC method where applicable.
2.4.17. The elevation
drawing and rendering diagrams for the preliminary building design are shown in
Plate 2-2 to
Plate 2-5 .
_20231225_files/image004.jpg)
Plate 2-2 Elevation Drawing of the New Annex Block
_20231225_files/image005.jpg)
Plate 2-3 Preliminary Design of the New Annex Block
(1)
_20231225_files/image006.jpg)
Plate 2-4 Preliminary Design
of the New Annex Block (2)
_20231225_files/image007.jpg)
Plate 2-5 Preliminary Design of the New Annex
Block(3)
2.5.
Project Implementation Programme
2.5.1. Subject to the design process, the availability of fundings and
other constraints, the construction of the Project is tentatively scheduled to
commence in 2025 Q3 and completed in 2029 Q1.
2.6.
Public Consultation
2.6.1.
The
Food, Environmental Hygiene and Public Works Committee of Yau Tsim Mong
District Council (YTMDC) was consulted on the scope of the Project on 2 March
2021 and Members attended the meeting expressed their general support to the
Project. The Project Profile for EIA study was exhibited to the public for
comments on 21 September 2021 for 14 days. Comments received from the public
mainly focused on the potential impacts of Project on air ventilation, natural
daylight, air quality, noise, landscape, visual, building separation and tree
management which have been assessed in this EIA study. Key concerns and
comments have also been incorporated into the design of the Project as far as
practicable.
3.
Environmental impact assessment
3.1.1. The EIA Study was conducted in accordance with the EIA Study Brief
No. ESB-347/2021, following the guidelines on assessment methodologies in the EIAO-TM. 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 the Project. Individual aspect assessments have
been undertaken to qualitatively/quantitatively predict environmental impacts
during the construction and operation phases. Mitigation measures have been
identified and evaluated to avoid, control, minimise or remedy the potential
impacts.
3.2.
Air Quality Impact
3.2.1. Potential air quality impacts associated with the construction and
operation phases of the Project have been assessed in accordance with the
criteria and guidelines as stated in the requirements given in Section 3.4.4
and Appendix B of the EIA Study Brief, as well as Annexes 4 and 12 of EIAO-TM.
The assessment area for air quality impact assessment is within 500m from the
boundary of the Project Site.
3.2.2. The potential dust emission sources would be mainly from the
construction work activities of the excavation and wind erosion at the Project Site.
As the size of the Project Site is limited and the excavation is minor such
that the amount of excavated materials generated would be small, no adverse
dust impact would be anticipated at the representative air sensitive receivers
(ASRs) with the implementation of sufficient dust suppression measures as
stipulated under the Air Pollution Control (Construction Dust) Regulation
and guidelines stipulated in EPD’s Recommended Pollution Control Clauses
for Construction Contracts as well as following the
requirements under Air Pollution Control (Non-road
Mobile Machinery) (Emission) Regulation.
Operation Phase
3.2.3. During operation of the Project, the Annex Block will be equipped
with central air condition for daily operation and will not rely on opened
window for ventilation. Also, the location of fresh air intake will be
carefully designed with sufficient separation distance from nearby roads. No
chimney is identified within 500m assessment area from the Project Site. There
would be limited vehicular emissions from parking activities of the Project. No
gaseous industrial emission from the Project is expected. Therefore, the
Project would not be considered a pollution source during the operation phase.
With the low induced traffic and use of non-polluting energy sources, adverse
air quality impact due to the operation of the Project is not anticipated.
3.3.
Noise Impact
3.3.1. Potential noise impacts associated with the construction and
operation phases of the Project have been assessed in accordance with the
criteria and guidelines as stated in the requirements given in Section 3.4.5
and Appendix C of the EIA Study Brief, as well as Annexes 5 and 13 of the
EIAO-TM. The assessment area for noise impact assessment is defined by a
distance of 300m from the boundary of the Project Site.
Construction Phase
3.3.2. Potential noise emission would be generated from construction work
activities. Powered mechanical equipment (PME) would be the major noise
sources. Construction noise assessment was conducted in accordance with the
EIAO-TM and the Technical Memorandum (TM) on Noise from Construction Work other
than Percussive Piling. The unmitigated scenario showed that the construction
noise impact at 7 noise sensitive receivers (NSRs) near the Project Site ranges
from 65 dB(A) to 86 dB(A), resulting in exceedances at 6 NSRs. The exceedances
can be mitigated by optimisation of construction programme, using quieter PME
and quiet working methods and movable noise barrier. Mitigated scenario showed
the construction noise impact at the NSRs would be reduced to 56 dB(A) from 75
dB(A) and comply with construction noise standards. As such, no adverse impact
would be anticipated at the NSRs during the construction phase of the Project.
Operation Phase
3.3.3. During the operation phase, assessment was conducted in accordance
to the TM for the Assessment of Noise from Places Other Than Domestic
Premises, Public Places or Construction Sites. Noise from fixed plant
including mechanical ventilation and air conditioning system (MVAC) equipment
and other fixed noise sources have been assessed, and will be properly selected and implemented with mitigation measures where necessary in order to reduce the
noise generated by the fixed plant not to exceed the maximum allowable sound power
levels (SWLs). As such, adverse fixed noise impact on the NSRs is not
anticipated during the operation phase.
3.4.
Water Quality and Sewerage Impact
Construction Phase
3.4.1. Potential water pollution sources during construction
phase have been identified as wastewater generated from
general construction activities, construction site runoff, sewage from
construction workforce and accidental spillage of chemicals. Measures including
the implementation of good site practices in accordance with the EPD’s ProPECC
PN1/94 Construction Site Drainage, provision and management of
portable chemical toilets on-site as well as preventive measures for avoiding
accidental chemical spillages are recommended to mitigate any adverse water
quality impacts. With the implementation of these measures, adverse residual
impacts would not be anticipated.
Operation Phase
3.4.2. The potential sources of water quality impacts during operation phase
would be related to increased surface runoff. Adequate drainage system with
silt traps and oil interceptors will be incorporated to collect the surface
runoff. With proper design of drainage system and implementation of the
recommended pollution control measures, no adverse water quality impact from
surface runoff would be expected.
3.4.3. Furthermore, there would be insignificant sewerage and sewage
treatment implications during the operation of the Project. Additional sewerage
generated from the operation of the Project is estimated taking surrounding
catchment areas into consideration. It is expected that the public sewers and
pumping station at downstream would have sufficient capacity to cater for the
additional flow from the Project. No upgrading works is required and adverse
water quality impact would not be anticipated with the implementation of the
recommended mitigation measures.
3.5.
Waste Management Implications
3.5.1. The major waste types generated from construction activities will
include construction and demolition (C&D) materials from site preparation
and road works, excavation and foundation works, construction of Annex Block
and refurbishment of Red House; chemical waste from maintenance of construction
plant and equipment and general refuse from the workforce. Provided that all
these identified wastes are handled, stored, collected, transported and
disposed of in strict accordance with the relevant legislative and recommended
requirements and that the recommended good site practices are properly
implemented, adverse environmental impact is not anticipated during construction
phase of the Project.
3.5.2. During the operation phase, waste generated will be primarily from
typical office activities. No chemical waste or waste lead-acid batteries is
anticipated from laboratory workshops and battery rooms provided at the new
Annex Block. Provided that waste will be stored and handled properly and
disposed of at regular interval, environmental impacts associated with the
waste management is not expected.
3.6.
Cultural Heritage Impact
3.6.1. Cultural heritage resources have been identified and reviewed
through literature review and field surveys. The study area for the cultural
heritage impact is defined by a distance of 150 m from the boundary of the
Project Site. Visual impact to the major heritage resources is not anticipated
during construction and operation phases. The
underground utilities diversion works will be localised, the refurbishment
works will only be within the Red House area, and mitigation measures will be
taken to reduce the impact on the key historic buildings. Indirect
vibration/settlement/tilting
impact on historic buildings during construction phase will be monitored with
monitoring measures.
3.6.2.
No Site of Archaeological Interest is found
within the cultural heritage assessment area.
3.6.3. The excavation of the Project is mainly located in the developed area undergone construction works
with high level of ground disturbance, and area unfavourable to cultural deposit
accumulation which has no archaeological
potential, therefore no adverse archaeological impact due to the Project is
anticipated. The Project Proponent is required to inform AMO immediately when
any antiquities or supposed antiquities under the Antiquities and Monuments
Ordinance (Cap. 53) are discovered during the course of works.
3.6.4. To conclude, the construction and operation of the Project would not
cause unacceptable impact on cultural heritage resources.
3.7.
Landscape and Visual Impact
3.7.1. A landscape and visual impact associated with the construction and
operation phases of the Project has been assessed in accordance with the
relevant requirements as specified in Section 3.4.9 and Appendix G of
the EIA Study Brief, as well as Annexes 10 and 18 of the EIAO-TM. The
assessment area for landscape assessment is within 500 m from the boundary of
the Project Site while that of visual impact is based on the Project’s Visual
Envelope(VE) or Zone of Visual Influence (ZVI) within which the Project is
pronouncedly visible from key sensitive viewers.
3.7.2. Landscape and visual impact on Landscape Character Areas (LCAs),
Landscape Resources (LRs) and Visually Sensitive Receivers (VSRs) of the
Project have been assessed.
3.7.3. The Project will generate some unavoidable landscape and visual
impacts which are identified and addressed in the Landscape and Visual Impact
Assessment. The impacts include the removal of some existing trees, site
formation works and the construction of a new building within the Project Site.
3.7.4. Mitigation measures have been incorporated to reduce the impacts,
which include minimizing the development footprint, retention of existing
vegetation, careful design and positioning of the building footprint to avoid impact
to sensitive LRs, planting of new compensatory trees, greening on-site for the loss of trees and
vegetation, and designing and implementing the new buildings and structures
which are integrated into the existing environment.
3.7.5. 136 nos. of existing trees (188 nos. in total) within the Project site
will be potentially affected. Tree preservation and compensatory tree planting
will be carried out in accordance with DEVB TC(W) NO. 4/2020. These
trees are mainly common woodland or cultivated tree species, and not in the
Register of Old and Valuable Tree promulgated under DEVB TC (W) 5/2020.
The affected trees depending on their conditions will either be transplanted or
compensated with planting ratio of a minimum 1:1 by number as far as
practicable within the HKO Headquarters.
3.7.6. Of the 8 LRs identified within the assessment area, only LR1(S) (Semi-Natural Woodland within Site) will
experience Substantial residual impact due to the limited ability
to compensate for the loss of woodland within the Project Site. However, LR1
and LR1(S) Combined (Semi-Natural Woodland within HKO Headquarters) will
experience Moderate residual impact. All the other LR will
experience no residual impacts in the construction and operation phases of the
Project.
3.7.7. Of the 9 LCAs identified, only LCA6(S) (Urban Forest Landscape within the Site) will experience Moderate
residual impact due to limited ability to compensate for the loss of woodland
within the Project Site. LCA1(S) (Institutional Landscape within Site) will
experience Insubstantial residual impacts and all the others will
experience no residual impacts.
3.7.8. Of the 19 VSRs, the adverse residual visual impact with mitigations
ranges from None to Moderate.
3.7.9. The overall residual landscape and visual impacts of the Project are
Acceptable with Mitigation Measures during the construction
and operation phases.
4.
Environmental Monitoring and Audit Requirements
4.1.
Environmental Monitoring and Audit (EM&A)
represents for air quality, noise, water quality and sewerage, waste
management, cultural heritage as well as landscape and visual input have been
recommended, with proper site inspection and audit during construction and
operation phases, to check the effectiveness of the recommended mitigation
measures and compliance of relevant statutory criteria. The EM&A
requirements are divided into environmental monitoring and/ or project auditing
in the form of site inspection and supervision.
Table 4.1 Summary of EM&A Requirements
|
Environmental Aspect
|
Construction Phase
|
Operation Phase
|
Monitoring Parameter
|
|
Air
Quality
|
Site
Audit
|
/
|
/
|
|
Noise
|
Site
Audit + Monitoring
|
Site
Audit
|
Leq(30mins)
|
|
Water
Quality and Sewerage
|
Site
Audit
|
/
|
/
|
|
Waste
|
Site
Audit
|
/
|
/
|
|
Cultural
Heritage
|
Site
Audit + Monitoring
|
/
|
3A
levels monitoring
|
|
Landscape
and Visual
|
Site
Audit
|
Site
Audit
|
/
|
5.
Conclusion
5.1.
The environmental impact assessment has concluded
that with the implementation of the recommended mitigation measures, the
Project would comply with the requirements of the EIA Study Brief and EIAO-TM,
and would not give rise to unacceptable environmental impacts during both
construction and operation phases.
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