1.1.1
The
engineering feasibility study of the Anderson Road Quarry (ARQ) Development in
East Kowloon has been conducted under the Agreement No. CE18/2012 (CE) Development of Anderson Road Quarry -
Investigation (the FS) to ascertain the feasibility of implementing the
development proposal. The FS was
classified as a designated project under the Schedule 3 of the Environmental
Impact Assessment Ordinance (EIAO). Hence, as a part of the study, an
environmental impact assessment (EIA) report titled Development of Anderson
Road Quarry has been submitted and approved under the EIAO (Register:
AEIAR-183/2014) on 28 July 2014.
1.1.2
Community
engagement was conducted under the FS and public views were collected. There
was no strong view from the public on the cavern development and some of the
LegCo members recommended promoting business opportunity or educational
purposes in making use of the cavern. It was recommended in the FS to construct
and operate cavern development within the boundary of the ARQ Development.
1.1.3
The
FS had therefore covered the proposed cavern developments for (i) quarry
exhibition centre and (ii) commercial use which are identified as designated
projects (DPs) by virtue of item Q.2, Part I, Schedule 2 of the EIAO,
"Underground rock caverns. The approved Schedule 3 EIA Report of
the FS had already reviewed the potential environmental impacts of the proposed
cavern developments and concluded that no insurmountable environmental impacts
are expected from the cavern developments.
Nevertheless, detailed environmental implications of the proposed cavern
developments will be further investigated in a separate EIA under the EIAO.
1.1.4
Subsequently,
in accordance with the requirements of Section 5(1) of the EIAO, a project
profile (No. PP-501/2014) for the Development of Anderson Road Quarry Site
Rock Cavern Developments (the Project) was submitted to the Director of Environmental
Protection (the DEP) for application for an EIA Study Brief on 27 January
2014. Pursuant to Section 5(7)(a) of the EIAO, the DEP has issued a Study Brief
(No.: ESB-269/2014) dated 10 March 2014 for the EIA study.
1.1.5
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 associated works that will take place concurrently. This
information will contribute to decisions by the Director on:
·
the overall acceptability of any adverse
environmental consequences that are likely to arise as a result of the Project;
·
the conditions and requirements for the
detailed design, construction and operation of the Project to mitigate against
adverse environmental consequences wherever practicable; and
·
the acceptability of residual impacts after
the proposed mitigation measures are implemented.
1.1.6
This
Project comprises the construction of a cavern located on the rock slopes in
the north side of the ARQ Development.
1.2.1 The principal purpose of this EIA
Executive Summary (ES) is to present the summary of the findings, conclusions
and recommendations in the EIA report. This ES contains the following
information:
·
Section 2 presents purpose and nature of the
Project.
·
Section 3 outlines information over
consideration of alternatives.
·
Section 4 presents the key findings of
environmental impacts.
·
Section 5 describes environmental monitoring
and audit.
·
Section 6 presents the conclusions.
2.1.1
With
reference to the EIA SB, the original scope of the proposed cavern developments
under the Project comprises a cavern for quarry exhibition and caverns for
commercial use as shown in Figure 2.1 with the following details:
·
One cavern at +200mPD for quarry exhibition
area/resource centre. Its dimensions are about 25m(W) x 11m(H) and 35m(D);
·
One cavern at +310mPD for commercial use
(e.g. food and beverage). Its dimensions are about 25m(W) x 5m(H) and 10m (D);
·
Three caverns at +310mPD for commercial use
(e.g. food and beverage). Their dimensions are about 16m(W) x 4m(H) x 10m(D);
and
·
Three caverns at +190mPD for commercial use (e.g.
food and beverage). Their dimensions varies between 22-25m(W) x 11m(H) x
25-35m(D).
2.1.2
The
Project Proponent has conducted a Market
Study and Financial Analysis for Proposed Commercial Portion of ARQ Site
Development including the proposed caverns for commercial development,
which is still undergoing at the time when this EIA Report is prepared. Because decisive information on the
commercial caverns is not yet available,
the 7 nos. of proposed caverns for commercial use will not be
constructed and developed under the ARQ project or in the foreseeable
future, Hence, the proposed caverns for
commercial use is not covered in this EIA.
2.1.3
The
scope of the Project has now been revised and includes only the construction of
the cavern for the quarry exhibition centre. The proposed cavern for quarry
exhibition area/resource centre located at the northern rock slope of the ARQ
development, which is shown in Figure 2.2.
2.1.4
The
scope of the works of the proposed cavern for quarry exhibition will comprise
the following activities:
·
Mobilization of construction plant and site
clearance at portal area of the cavern;
·
Removal of existing vegetation at portal area
of the cavern;
·
Slope excavation and stabilization works,
e.g. rock dowel installation at cavern portal;
·
Rock excavation by drill and break method
(estimated volume of excavation is 14,820 m3 approximately) and temporary
installation for cavern;
·
Permanent lining of approximate 0.9m thick
and portal structure construction for cavern; and
·
Landscaping works.
2.2.1
The
quarry operation of the Anderson Road Quarry (ARQ) Site, currently under a Quarry Rehabilitation Contract, will be
terminated in mid-2016. The
rehabilitation of the ARQ Site will provide a
new landform consisting of benches and slopes on rock face, and a platform of
approximate 40 ha for development.
2.2.2
Planning
Department (PlanD) of the HKSAR Government conducted the Planning Study on Future Land Use at Anderson Road Quarry Feasibility
Study (the Planning Study) which was commenced and completed in 2011 and
2013 respectively. The overall objective of this Planning Study is to examine
the future land use of the ARQ Site and to explore the development potential
for residential and other uses.
2.2.3
According
to the findings and recommendations of the Planning Study, apart from housing
development, the ARQ Site also provides a solution space for accommodating
district-wide G/IC provision and the potential use of the man-made slopes at
the backdrop amounting over 45 ha of area should also be explored, which may
include using rock cavern to accommodate suitable land uses to serve this area
or to release land resources in other areas, and using the rock face for
recreational purposes.
2.2.4
After
reviewing the current available geotechnical data and site situation, it is
feasible to construct some rock caverns at ARQ Site for future development. In
view of the shortage of land supply for housing development in the Territory,
placing of some suitable land uses e.g. G/IC facilities and/or commercial
development into rock caverns to serve the ARQ area could release some of the
precious land resources in other areas for residential development.
2.2.5
In
addition, the ARQ has been in operation for more than 50 years, cavern could be
used for retaining some of the features of the past quarry operation to reflect
the history and for educational or tourism functions.
2.3
Project Programme
2.3.1 The works of rock cavern development
will be included in Phase 2 of the main contract of site formation and
infrastructures (SF&I Contract) of the ARQ Site Development. The anticipated commencement date of the
SF&I Contract will be in 2016 Q3 while its Phase 2 construction works is
expected to be carried out in early 2018. The anticipated construction time for
the quarry exhibition cavern will be around 24 months and the anticipated
completion date will be 2020.
2.4.1 During the period of construction for
the rock cavern development, the concurrent projects with construction works in
the vicinity (500m from the site of cavern construction) will include the
followings:
|
Project
Item
|
Works
Components
|
Time Line
|
|
1
|
Site
formation and infrastructure within ARQ Site
|
End 2016
end 2020
|
|
2
|
Flood
attenuation facilities (drainage retention tank and artificial lake, etc.) within
Quarry Park area
|
Early
2018 end 2020
|
|
3
|
Salt and
fresh water pumping stations at northern portion of ARQ Site
|
Mid 2018
end 2020
|
|
4
|
Service
reservoirs at +250mPD platform of rock slopes at the northern portion of ARQ
Site
|
Mid 2018
end 2020
|
|
5
|
Road
improvement works at junction of Clear Water Bay Road and On Sau Road
|
End 2016
- mid 2020
|
3.1.1
Under
the Planning Study on Future Land Use at
Anderson Road Quarry Feasibility Study conducted by Planning Department,
extensive community engagement exercise on the suggested land use options was
conducted. Rock cavern on existing rock
slopes was recommended for options of land supply.
3.1.2
The
proposed rock cavern development is located at the north side of the ARQ
Development. Due to its use as a quarry site, ARQ is a highly disturbed environment
where ecological value is considered to be minimal. Under the rehabilitation
contract (No. GE/96/10), the landscape of the quarry will be rehabilitated
through extensive tree and shrub planting on exposed rock face.
3.1.3
Without
the proposed rock cavern development, the planting established under the
rehabilitation contract will, though gradually, begin to mature. Some habitats
may be expected to increase in ecological value in future as a result of
ecological succession, such as the maturation of shrubland into woodland.
3.1.4
However,
without the proposed rock cavern development, the area will be left as a vacant
rock face. The opportunity to fulfil the social needs of using the rock cavern
as the alternative land supply will be lost. It will also be difficult to find
space within ARQ development unless other land areas e.g. with
residential/recreation uses are consumed.
3.2
Consideration of Alternative Development Options
3.2.1
The
prime objectives of proposing cavern development are to fully utilize the
available rock feature available and to explore the alternative way for land
supply.
3.2.2
Since
the ARQ has been in operation for more than 50 years in the Territory, it is
considered worth to make efforts for retaining some of the features of quarry
operation to reflect the history. An
exhibition centre or a resource centre is reckoned to be a suitable way of
showing the history of past quarry operation to the public.
Size of the exhibition centre
3.2.3
The
proposed cavern for exhibition centre with an exhibition area of 1,000 m2,
based on a usable floor area of 2.6 m2 per visitor and a
staff/visitor ratio of 1:13, is considered appropriate and sufficient for
exhibition centre of similar nature.
3.2.4
Alternative
footprint area of the proposed quarry exhibition cavern has been considered for
accommodating larger scale of exhibition centre. After coordination with relevant government
departments and with consideration of the geography of the ARQ Development and
the nature / content of possible exhibition, the proposed quarry exhibition
centre is considered sufficient with reference to some of the existing museums
with similar nature and scale such as Police Museum (570m2) and Dr
Sun Yat-sen Museum (2,560 m2) in Hong Kong. The sizes of the
proposed quarry exhibition centre is approx. 1,000m2, which is in
between the Police Museum and Dr Sun Yat-sen Museum. Furthermore, the
added environmental benefit of the compact design is the reduction of
construction and demolition materials/wastes quantity arising from the
construction stage. Thus, the recommended exhibition area of approximate 1,000m2
is considered appropriate.
Location of the exhibition centre
3.2.5
The
location of the proposed quarry exhibition centre cavern is currently at the
northern rock slope of the ARQ Site Development as shown in Figure 3.1,
it is adjacent to the proposed public transport terminus and within the future
Quarry Park area. Other possible
locations as indicated in Figure 3.1 at the existing rock slopes and
within the boundary of the ARQ Site Development for situating the proposed
cavern for quarry exhibition centre have been examined. These locations include
·
Alternative 1 - Rock slopes at platform of
+200mPD along and adjacent to the proposed carriageway of Road L1 (middle
portion of existing rock slopes);
·
Alternative 2 - Rock slopes at platform of
+200mPD adjacent to future development sites (south-eastern portion of existing
rock slopes); and
·
Alternative 3 - Rock slopes at platforms of
other level higher than +200mPD.
3.2.6
These
other possible locations were considered not as suitable as the current
location. Since the existing rock
slopes of Alternative 1 and Alternative 2 are mainly contiguous to proposed
public carriageway and residential developments, size of the cavern should be
further enlarged (i.e. the environmental dis-benefit would be increasing the
quantities of construction and demolition materials/wastes in the construction
stage as well as the construction air quality and noise impacts) to allow
assembly area for visitors and vehicular loading and unloading area for the
museum cavern development if the cavern is adjacent to carriageways. In addition, there is no public access, both
pedestrian and vehicular accesses to the proposed cavern under Alternative 2 if
it is located adjacent to future residential developments. Nuisance will be created to the nearby future
residential areas and school sites by the visitors of the quarry exhibition /
museum cavern in case it is situated in the close proximity to the nearby development
sites.
3.2.7
For
Alternative 3, if the proposed quarry exhibition cavern is situated at
platforms of level above +200mPD, there will be no direct connection, either
pedestrian or vehicular access, from the platform of the main ARQ Site
Development, which is at approximately +200mPD.
Additional vehicular access and pedestrian facilities, e.g. vertical
transfer system will be required for connection between the cavern and the ARQ
Site Development. This will not only
involve additional and substantial rock excavation and tree removal for the
formation of pedestrian and vehicular accesses to the cavern (substantial
construction waste and material generated as well as the associated
construction air quality and noise impacts), but it will also involve extra
energy consumption for the operation of the pedestrian connection (vertical
transfer system) and the vehicular access road (street lighting). Furthermore, the landscape and visual impacts
of Alternative 3 will be more significant and substantial comparing with the
recommended location, locations of Alternative 1 and Alternative 2 since it
will involve large scale site formation works for access roads and
facilities.
3.2.8
The
recommended location of the proposed cavern is within the boundary of and at
the same level as the future Quarry Park such that some common facilities, e.g.
visitor reception counter, loading and unloading facilities, car parking
spaces, etc. could be shared between the Quarry Park and the exhibition centre
cavern. This could reduce the amount of
land required and better utilization of facilities.
3.2.9
Moreover,
the proposed cavern for quarry exhibition centre will be situated adjacent to
the proposed public transport terminus.
This can encourage and facilitate the public visiting the exhibition
centre by means of public transport.
3.2.10
The
proposed location of the cavern is considered to be most suitable location
within the Quarry Park as the rock slope at this location will provide the
largest rock cover for the cavern, as the bedrock level will be dipping toward
the northern end of the rock slope. The
rock quality is better and the required temporary support for the cavern is
envisaged to be less substantial.
3.2.11
The
recommended location has the advantages of sharing the planned public transport
and access of the Quarry Park and only requiring an emergency vehicular access
for connection. Since no additional rock excavation and tree removal is
required for the formation of vehicular and pedestrian accesses to the proposed
quarry exhibition cavern under the recommended location, the adverse
environmental impacts including construction waste / material generation, noise
and air quality impacts and landscape and visual impacts of the recommended
location are comparatively less than the alternative locations. Summary of the
environmental benefits and dis-benefits of alternative options are shown below:
|
Environmental Consideration
|
Alternative 1
|
Alternative 2
|
Alternative 3
|
Recommended
|
|
Rock
Excavation Quantities
|
Extra
rock excavation required for formation of loading & unloading
facilities and assembly area
|
Extra
rock excavation required for formation of loading & unloading
facilities and assembly area
|
Substantial
rock excavation required for formation of loading & unloading facilities,
assembly area, vehicular access road and pedestrian connection facilities
|
No
extra rock excavation required as visitor facilities including assembly area,
loading and unloading facilities can be shared with the future Quarry Park.
|
|
Impacts
to Existing Trees
|
Removal
of additional trees on rock slopes required due to the site formation works
of loading & unloading and assembly area facilities
|
Removal
of additional trees on rock slopes required due to the site formation works
of loading & unloading and assembly area facilities
|
Removal
of additional trees on rock slopes required due to the site formation works
of loading & unloading, assembly area facilities, vehicular access road
and pedestrian connection facilities
|
No
additional tree removal is required.
|
|
Nuisance
of Operation to Nearby Development Sites
|
Close
to the residential area and level of nuisance is slightly to moderate
|
No
direct vehicular & pedestrian access from public road to quarry
exhibition cavern. Access will be in close proximity to development
sites. Nuisance to nearby development
sites is substantial.
|
Quarry
exhibition cavern will be at higher level platform of existing rock slopes
and will be away from development site. Nuisance is minor comparatively.
|
Quarry
exhibition cavern will be within future Quarry Park and away from the
development sites. Nuisance is
minimal.
|
|
Construction
Noise & Air Quality Impacts
|
Larger
extent of rock excavation due to site formation works for loading & unloading
area for quarry exhibition cavern comparing with the recommended location.
Hence, the construction noise and air quality impacts are higher as well.
|
Larger
extent of rock excavation due to site formation works for loading &
unloading area for quarry exhibition cavern comparing with the recommended
location. Hence, the construction noise and air quality impacts are higher as
well.
|
Extent
of site formation works and rock excavation works will be the greatest
amongst all 4 location options due to the provision of vehicular and
pedestrian accesses. Hence, the
construction noise and air quality impacts are the most significant.
|
No
additional rock excavation will be required for the provision of access road
and loading & unloading facilities of the quarry exhibition cavern as
they are all within the future Quarry Park area. Hence, the construction noise & air
quality impacts are the least amongst the 4 options.
|
|
Visual
Impacts
|
Insignificant
|
Insignificant
|
Critical
as the provision of vehicular access road and pedestrian connection
facilities will involve substantial rock excavation and tree removal at
existing rock slopes
|
Insignificant
|
Alternative use of cavern apart from
exhibition centre
3.2.12
Apart
from the use of quarry exhibition centre, the proposed cavern has been
considered for other alternative functional or operational uses, e.g. public
utilities facilities like the proposed fresh and salt water pumping stations of
the ARQ Development.
3.2.13
Placing
public utilities facilities like the proposed fresh and salt water pumping
stations into the proposed cavern is technically feasible in general. However, the proposed fresh and salt water
pumping station of the ARQ Site Development will be fed from the existing
Anderson Road No. 3 Freshwater Service Reservoir (AR3-FWSR) and Anderson Road
Saltwater Service Reservoir (ARSWSR) respectively. These two service reservoirs
are currently situated level of +190mPD to +200mPD approximately which is the
slightly below the level of the proposed cavern for the quarry exhibition
centre. In case the proposed cavern is
changed for pumping station use, the pressure head difference between the
service reservoirs and the pumping stations is inadequate to drive the water
pumps and hence the cavern for accommodating the pumping stations should be
excavated deeper in order to achieve the functional requirement of pumping
stations and hence increasing the construction difficulties and volume of rock
excavation for cavern (i.e. the environmental dis-benefit would be increasing
the quantity of construction and demolition materials/waste in construction
stage) and associated pipe works.
3.2.14
Furthermore,
the vehicular maintenance access for the pumping stations would pass through
the future Quarry Park and impose significant disturbance and constraints to
the operation and design of the Quarry Park.
In view of the above concerns, the proposed cavern is not recommended to
be used for other public facilities.
3.2.15
In
consideration of the regional significance of the future Quarry Park, a cavern
for museum or exhibition centre is important and appropriate use for showcasing
the quarrying history of the ARQ over other possible uses of the cavern.
3.3.1
There
are a number of rock excavation methods to be used such as mechanical means by
drill and split (or drill and break), use of chemical expansion agent, Cardox
method and drill-and-blast technique.
Mechanical excavation method
3.3.2
The
excavation method is by means of hydraulic excavator, hammer and hydraulic
splitter. The hydraulic splitter acts by increasing the tensile strength beyond
that of the material and a split will occur. This method is suitable for small
portion excavation, and an excavation conducts very close to sensitive receiver
from vibration, i.e. gas & water mains, railway track, information
transmission system / communication cables, etc. Disadvantage Slow production
rate for high strength rock mass (less than 40 m³ per 8-hrs per one-work-site,
including rock removal). For worst scenario of MTR West Kowloon Terminal
experience, only 30m3 per day, with 4 drill rigs and 3
breakers.
Use of chemical expansion agent
3.3.3
This
method makes use of the expansion force of the injected very high expansive capability
chemical slurry. After self-expansive chemical slurry is poured into holes
drilled in rocks, the expansive stress gradually increases with time, and
generates the expansive stress. The material will then be cracked down.
Therefore, this fracture mechanism is distinguished from a breakage by
blasting. This method is suitable for small portion excavation, and an
excavation conducts very close to sensitive receiver from vibration, i.e. gas
& water mains, railway track, information transmission system/communication,
etc. Disadvantage of this method is slow production rate (< 40 m³ per 8-hr
shift), long standing time (up to 24 hours), and not suitable for fractured
& weak rock mass.
Cardox method
3.3.4
The
Cardox system is based on liquid carbon dioxide being converted to high
pressure carbon dioxide gas with ignition. Tubes are filled with liquid carbon
dioxide. When energized by the application of a small electrical charge, the
chemical heater instantly converts the liquid carbon dioxide to a gas. This conversion
expands the CO2 volume and builds up pressure inside the tube. This
instantaneous build-up in pressure reaches the yielding pressure of the rupture
(shear) disc which bursts releasing a heaving mass of carbon dioxide which
breaks the surrounding material. The advantages are low vibration effects to
surroundings, environmental friendly, highly safe of rock breaking method and
have similar production to drill-and-split. However, the disadvantages of the
Cardox method are relative high operation cost and not suitable for very high
strength rock such as Tuff and Granite.
Conventional drill and blast method
3.3.5
This
method is suitable for bulk excavation in non-sensitive area (i.e. remote
area). Approx. production rate: > 100 m³ per 8-hrs per one-work-face.
Disadvantage explosive handling including supply, transportation and storage
is an issue on hazards for this project. It also requires longer process time
(normally longer than 9 months) applying blast permit. Geotechnical features
surrounded the caverns will be key sensitive receivers to control the blasting
works. Hence, 2m round per blast for excavation and 2 days per blast (which
considers drill, blast, muck out and installation of temporary support) may be
expected.
3.3.6
Having
reviewed the general layout of the museum cavern, the anticipated excavation
sequence of the entrance and exit adits of the cavern, where the section
locates below the berm +210 mPD, cut-and-cover method will be adopted due to
the rock cover is very shallow of 2 m. The remaining section of adits will be
full face excavation. The main cavern will be excavated by using top head and
bench method.
Environmental benefits and dis-benefits for construction methods
3.3.7
Common
to the mechanical excavation method, use of chemical expansion agent and Cardox
method, they are purposed to control the rock breaking process and the
environmental impacts particularly noise and dust are minimized. As the works will be carried out inside the caverns,
the environmental impacts to the surroundings are controlled and
minimized. The dis-benefits would be the
long construction time. For the drill
and blast method, the environmental benefit is the faster construction time,
while the environmental dis-benefit is the hazards to the surroundings arising
from the handling, transportation and storage of explosive. Balancing the benefits and disbenefits, use
of chemical expansion agent and Cardox is not suitable for hard rock found in
the site and the production rate would be low with long construction period
(which means longer duration of environmental impacts e.g. noise and dust
emission). Therefore, the method is
considered not suitable for meeting the programme of this Project.
3.4.1
Based on the general
layout of the quarry museum cavern, the calculated total excavation volume is
about 14,820 m³.
3.4.2 The most likely excavation method would
be mechanical or drill-and-blast methods. Further comparison with mechanical
and drill-and-blast methods (only for museum cavern excavation) is summarized
in the table below:
|
|
Mechanical
|
Drill-and-Blast
|
|
Production rate (per 8hr shift)
|
30 m³ (nominal) per 1-work site-machine
[60 m³ (nominal) per 2-work site-machines, and so on]
|
> 100 m³
|
|
Environmental Benefits
|
Controllable production rate and minimize the adverse impact
Impacts controlled inside the caverns
|
Shorter construction time
|
|
Environmental Disbenefits
|
Slower production and longer construction time
|
Handling, transportation and storage of explosives having hazards to
surroundings
Additional control/restrictions during blasting
|
|
Permit application duration
|
Not applicable
|
At least 9 months
|
|
Excavation duration
|
If 2-work site-machines
deployed:
14,820 /
60 = 247 days
|
14,820 / 100 = 149 days
|
|
Total duration
|
247 days
|
9 months + 149 days = 419 days
|
3.4.3
The
above calculation shows that mechanical excavation method (i.e. by means of
drill-and-split) will be the most preferable excavation method from a
construction progress view point. The
method has less environmental impacts in terms of construction noise and dust
emission, as the excavation works for the cavern space will be conducted within
the cavern space. It does not involve
delivery storage and handling of explosive and hence minimises the hazard to
the public.
4.1
Air
Quality
Construction Phase
4.1.1
Fugitive
dust impact assessment taking into cumulative impact from concurrent projects
within the study area has been conducted. With the provision of suitable dust
mitigation measures, results indicate that all air sensitive receivers (ASRs)
would comply with the 1-hour TSP EIAO-TM, 24-hour average Respirable Suspended
Particles (RSP) / Fine Suspended Particles (FSP) and annual average RSP/FSP
criteria under AQOs.
Operational Phase
4.1.2
Based
on the preliminary traffic forecast, the induced daily traffic (2-way) would be
in the order of 50 vehicles/day induced on the local distributor road and the
traffic is mainly attributed to the maintenance activities (wastes collection
and daily necessities delivery) and work-related transport (e.g. exhibition
materials transport). Comparing to the traffic flows of nearby local
distributors (i.e. Road L1 & L2) which have around 4000 vehicles /day, the induced traffic volume is
small and hence it would not cause adverse air quality to the surroundings.
4.1.3
Reference
has been made to the approved Schedule 3 EIA Report for Anderson Road Quarry
Development (Register No.: AEIAR-183/2014) for the predicted air quality
condition in the vicinity of the cavern development during the operational
phase of ARQ Site. The predicted representative air pollutants concentration
including NO2, RSP and FSP at the worst-case year (i.e. Year 2026)
on areas nearby the cavern development are well complied to the AQOs with taken
the nearby emission sources into account. Provided that the location of fresh
air intake for the cavern will be properly located with sufficient buffer
distance to emission sources, adverse air quality impact is not anticipated to
the proposed exhibition area/resource centre in cavern.
Construction Phase
4.2.1
Noise
impacts arising from the construction activities of the project are assessed
for noise sensitive receivers (NSRs) located in proximity of the works areas.
Cumulative unmitigated construction noise levels at the representative NSRs are
predicted to be in the range of 61 to 72 dB(A), complying with the construction
noise criterion of 75 dB(A). No adverse construction noise impact is therefore
anticipated.
4.2.2
With
respect to the Projects contribution alone, it is recommended that the future
contractors should follow the requirements set out in the Recommended Environmental
Pollution Control Clauses published by EPD and adopt good site practice to
minimise construction noise impacts on the surrounding environment.
Operational Phase
4.2.3
The
maximum permissible sound power levels at daytime/evening time and night-time of
the ventilation shaft of the cavern are determined. With the proper selection
of plant and adoption of acoustic treatment, the NSRs would not be adversely
affected.
Construction Phase
4.3.1
Water
Sensitive Receivers (WSRs)
were identified for the water quality impact assessment. The
key issue from the land-based construction activities would be the potential
release of wastewater from surface works areas, open cut excavation and groundwater
infiltration during the formation of rock cavern. Minimization of water quality
deterioration could be achieved through implementing adequate mitigation
measures, such as control of construction site run-off and effluent. A water
quality monitoring and audit programme will be implemented to ensure the
effectiveness of the proposed water quality mitigation measures.
Operational Phase
4.3.2
The
key source of potential impact on water quality during the operational phase
would be the sewage and wastewater generated from the rock cavern development.
However, no adverse water quality impact associated with the operational phase
would be anticipated, provided that adequate sewerage and sewage treatment
facilities are properly implemented to accommodate all the sewage effluents.
4.4.1
The
proposed sewer network in the ARQ development will be designed to cater for
future residential development, commercial activities and sewage flow arising
from the cavern development.
4.4.2
The
sewage flow from the cavern development is estimated to be about 8.4m3/day,
which is around 0.1% of the total sewage flow of ARQ (i.e. 8,863m3/day),
and has been taken in account in the design of ARQ sewerage system. Therefore,
sewerage and sewage implications arising from cavern development are not
anticipated.
Construction Phase
4.5.1
Construction
and demolition (C&D) materials would be generated from excavation works for
museum cavern which include: Main Museum, Entrance/Exit Adits and M&E
Niches. The C&D materials would comprise both inert and non-inert
components, such as soil, artificial hard materials (AHM) (i.e. broken
concrete, etc.), rocks, wood and metals. The Engineer has estimated the volume
of surplus C&D materials to be approximately 18,175m3 of inert
materials and approximately 310m3 of non-inert materials. There is
no sediment present requiring marine disposal.
4.5.2
The
C&D materials would be sorted on-site and the inert portion would be stored
in different containers, skips or stockpiles to re-use on-site as far as
possible to minimise the net amount of C&D materials generated from this
Project. Surplus excavated materials, mainly the excavated rock material of size
over 200mm, would be recycled and crushed into aggregates for reuse either at
the main site of the ARQ project or other construction projects. The
potential environmental impacts arising from the handling and disposal of the
inert C&D materials, such as air and odour emissions, noise and potential
hazard, would be negligible. Appropriate measures should be taken to minimise
potential adverse impacts from dust during the transportation of C&D
materials. Non-inert C&D materials generated would be reused and recycled
as much as possible before disposing to landfills.
Operational Phase
4.5.4
It
is expected that general refuse will be generated during the operational phase
of the Project. As advised by Leisure and Cultural Services Department,
the area of the quarry exhibition and supporting facilities will be 1,000m2
and 800m2 respectively. It is assumed that (1) each customer occupy
2.6 m2, (2) 1 retail staff serves 13 visitors, (3) waste generation
rate = 2.69 kg/person/day. By using the above assumptions, it is expected
during the operation of the Project there will be 385 customers and 30 retail
staff per day. As such, the general refuse generated will be about 1,116
kg/day.
4.5.5
Sufficient recycling containers are recommended to be provided at
suitable locations to encourage recycling of such waste as aluminium cans,
plastics and waste paper. The refuse must be
disposed at approved waste transfer or disposal facilities by refuse collection
vehicle. As such it is considered to have no adverse or minimal environmental
impacts.
4.6.1
The
scale of the Rock Cavern Development (RCD) is small and is located in the rock
slope adjacent to the proposed Open Space, which is currently semi-barren with
some vegetation on slope platforms. Landscape impact is, therefore, minimal and
is limited only to the works area, whilst visual impact is slight to
Insubstantial due to its small scale and great distance from potential visually
sensitive receivers. Landscape and visual impacts are minimized through
revegetation proposals and proposed hardscape/façade treatment to the future
Quarry Museum of the RCD. It is considered that the RCD scheme will complement
the proposed Open Space stipulated in Kwun Tong (North) Outline Zoning Plan
(OZP) No. S/K14N/14 gazetted on 26 June 2015 and will have enhancement to both
landscape and visual perspective.
4.6.2
Based
on the tree survey, 30 existing trees which located in front of and above the
proposed RCD would be impacted by the RCD. These trees are common species
including Acacia confusa and Casuarina equisetifolia. Most trees are generally
in poor form, poor structural condition and fair health condition. Aesthetic value is moderate. All of the 30
existing trees are in conflict with the development works area and are proposed
to be felled. 30 compensatory trees are
proposed near the entrance to cavern and on the platform to maximize greening
opportunity and minimize visual impacts.
4.6.3
Only
quarry site and trees in front of and above the proposed RCD are impacted by
the proposed RCD due to site formation works, stockpiling of construction and
demolition materials and construction of Portal within the works area.
Sensitivity of change of trees in front of and above the proposed RCD is
medium. Magnitude of Change to those trees is expected to be large. Impact
Significance Threshold of trees in front of and above the proposed RCD is
substantial before mitigation but is reduced to moderate after mitigation.
Impact Significance Threshold of quarry site
is slight before mitigation and is reduced to insubstantial after mitigation.
Landscape treatment to slope, compensatory tree planting and shrub planting are
proposed as mitigation measures to landscape impact to trees in front of and
above the proposed RCD.
4.6.4
The
scale and the extent of RCD are small. The proposed RCD is visible mainly at
the quarry within the proposed Open Space and the residential areas immediately
adjacent to the Open Space. Since the RCD is located at 200mPD and other
existing residential areas to the west to the development are located around
50mPD 100mPD, the RCD is non-visual from these areas due to the topography of
the site. Impacts to visually sensitivity receivers from within the site and
from the planned Development at Anderson Road (DAR) have been assessed. Impact
Significance Threshold for all visually sensitivity receivers is slight before
mitigation and is further reduced to insubstantial after mitigation. Decorative
screen hoarding, sensitive and aesthetically pleasing cavern portal design,
landscape treatment to slope, and compensatory tree planting and shrub planting
are proposed as mitigation measures to visual impacts to visually sensitivity
receivers.
4.6.5
The
project will help enhance the landscape and visual quality of the existing
barren rocky slope. While the overall planning of the ARQ development will
provide large area of greening, mitigation measures for RCD will be applied to
improve landscape area adjacent to the Rock Cavern and will benefit the whole
development in the long term.
4.6.6
Overall,
the landscape and visual impacts due to the RCD are considered to be
acceptable. With the implementation of the appropriate mitigation measures,
both landscape and visual impacts will be insubstantial.
4.7.1
The
EIA report has provided information on the nature and extent of environmental
impacts arising from the construction and operation of the Project, and the
nearby project operating concurrently which they are summarized in Appendix
A.
5.1.1
An environmental monitoring and audit
(EM&A) programme was recommended for air quality, noise, water quality,
waste management, and landscape and visual during construction phase. Site
inspection/audit was also recommended to check the implementation of the air
quality, noise, water quality, waste management, and landscape and visual
mitigation measures during the construction phase. A summary of the EM&A requirements by
each of the environmental parameters is presented in Table 5.1 below.
Table 5.1 Summary of EM&A Requirements
|
|
Prior to Construction
|
Construction Phase
|
Operational Phase
|
|
Air
Quality
|
O
|
ü
|
O
|
|
Noise
|
O
|
ü
|
O
|
|
Water
Quality
|
ü
|
ü
|
O
|
|
Sewerage
and Sewage Treatment
|
O
|
O
|
O
|
|
Waste
Management
|
O
|
ü
|
O
|
|
Landscape
and Visual
|
ü
|
ü
|
ü
|
Air Quality
5.1.2 Given the mitigated Total Suspended
Particles, RSP and FSP levels (with implementation of recommended mitigation
measures) would comply with the relevant air quality criteria/AQOs and minimal
dust impact will be anticipated from the Project works itself, environmental
monitoring for the Project is considered unnecessary. Nevertheless, regular
audit during construction phase is recommended to ensure the effectiveness of implementation of recommended mitigation measures.
5.1.3 No adverse impact would be generated
during the operational phase of this Project. Therefore, the EM&A works
related to air quality for the operational phase is considered unnecessary.
Noise
5.1.4
No
adverse construction noise impacts were predicted and construction phase noise
monitoring is not necessary under the EM&A programme. Nevertheless, regular
audit during construction phase is recommended to ensure the effectiveness of implementation of recommended mitigation measures.
Water Quality
5.1.6
Water
quality monitoring is recommended to be carried out at the Tseng Lan Shue
Stream before the construction commences as well as during the site clearance
and slope excavation works.
5.1.7
It
is recommended that regular site inspections during the construction phase
should be undertaken to inspect the construction activities and works areas in
order to ensure the recommended mitigation measures are properly implemented.
Sewerage and Sewage Treatment
5.1.8 Since the sewage flow from the cavern
has been taken in account in the design of ARQ sewerage system, sewerage and
sewage implications arising from cavern development are not anticipated. Thus,
EM&A works is considered unnecessary.
Waste Management
5.1.9 It will be the contractors responsibility
to ensure that any wastes produced during the construction of the Project are
handled, stored and disposed of in accordance with good waste management
practices and relevant regulations and other legislative requirements. Regular audit during construction phase
is recommended to ensure the effectiveness of implementation
of recommended mitigation measures.
Landscape and Visual
5.1.10 Landscape and visual mitigation measures is
recommended at construction and operational phase to ensure the landscape
resources or character can be reinstated or enhanced to compatible with
surrounding context in accordance with relevant regulations. The construction
phase mitigation measures should be adopted from the commencement of
construction and should be in place throughout the entire construction period.
The operational phase mitigation measures should be adopted during the detailed
design, and be built as part of the construction works so that they are in
place at the date of commissioning of the Project.
5.1.11
Regular
audit during construction phase and operational phase are recommended to ensure
the effectiveness of implementation of recommended
mitigation measures in order to reduce the visual impact during
construction and operation. Also, mitigation measures to reinstate or enhance
the landscape by proper landscape treatment at operational phase are applied.
EM&A works is considered necessary.
6.1.1 The findings of the EIA provided information
on the nature and extent of the environmental impacts likely arise from the
construction and operation of the Rock Cavern Development. The EIA has, where
appropriate, identified mitigation measures to ensure compliance with
environmental legislation and standards.
6.1.2 Overall, the EIA concluded that the Rock
Cavern Development would comply with the requirements of the EIA Study Brief
(ESB-269/2014) and EIAO-TM with the implementation of the recommended
mitigation measures during the construction and operational phases. The
schedule of implementation of the recommended mitigation measures has been
provided in the EIA report. An EM&A programme has also been recommended to
check the effectiveness of the proposed mitigation measures.