|
EIA Ref. |
EM&A Ref. |
Recommended Mitigation
Measures |
Who to implement the
measure? |
Location of the
measure |
When to implement the
measure? |
What requirements or
standards for the measure to achieve? |
Water Quality |
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|
3.8 |
2 |
Mitigation Measures for Dredging Although adverse water quality
impact is not predicted during the construction phase, implementation of the
following mitigation measures is recommended to minimise the potential SS
impact from dredging activities: · Dredging shall be carried out by closed grab dredger to minimize release of sediment and other contaminants during dredging; · The maximum production rate for dredging from the seabed for installation of the submarine gas pipelines shall not be more than 4,000m3 per day (and no more than 1 closed grab dredger); and · Deployment of frame type silt curtain to fully enclose the grab while dredging works are in progress. An illustration of a typical configuration of frame type silt curtain is shown in Figure 3.10. The frame type silt curtain shall
be designed to enclose local pollution caused by the grab dredger and
suspended by a steel frame mounted on the grab dredger and floating on water.
This frame type silt curtain shall be fabricated from permeable, durable,
abrasion resistant membrane like geotextiles and be mounted on a floating
boom structure. The frame type silt curtain shall also extend to the seabed
to cover the entire water column. Steel chain or ballast shall be attached to
the bottom of the silt curtain. Mid-ballast may be added as necessary. The
structure of the silt curtain shall be maintained by metal grids. The frame
type silt curtain shall be capable or reducing sediment loss to outside by a
factor of 4 (or about 75%). |
Construction
Contractor |
Construction
Work Sites (Along the alignment of dredging) |
During
Marine Dredging works |
WQO |
|
3.8 |
2 |
Other Good Site Practices for Dredging Other good site practices that shall
be undertaken during dredging includes: |
Construction
Contractor |
Construction
Work Sites (Along the alignment of dredging) |
During
Marine Dredging works |
WQO |
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· all vessels shall be sized so that
adequate clearance is maintained between vessels and the seabed in all tide
conditions, to ensure that undue turbidity is not generated by turbulence
from vessel movement or propeller wash; |
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· all barges / dredgers used shall be
fitted with tight fitting seals to their bottom openings to prevent leakage
of material; |
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· construction activities shall not
cause foam, oil, grease, scum, litter or other objectionable matter to be
present on the water within the site or dumping grounds; |
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· barges or hopper shall not be filled
to a level that will cause the overflow of materials or polluted water during
loading or transportation; and |
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· before commencement of dredging
works, the holder of the Environmental Permit shall submit detailed proposal
of the design and arrangement of the frame type silt curtain to EPD for
approval. |
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|
3.8 |
2 |
Effluent from Hydrostatic/ Commissioning Tests of the Gas Pipeline
System For hydrostatic testing of gas
pipelines, the gas pipelines would be filled with potable water (a nearly
incompressible liquid) and examined for leaks or permanent changes in shape
with a specified test pressure. The test would be carried out at room
temperature and dosing of chemicals into the water for testing is not
required. Water used for
testing shall be reused as far as possible (e.g. water spray for dust
suppression on site). To ensure compliance with the standards for effluent
discharged into the inshore waters or marine waters of Victoria Harbour WCZ
as shown in Tables 9a and 9b of the TM-DSS, sedimentation tanks with
sufficient capacity, constructed from pre-formed individual cells of
approximately 6 to 8 m3 capacities, are recommended as a general
mitigation measure which can be used for settling surface runoff prior to
disposal. The system capacity shall be
flexible and suited to applications where the influent is pumped. |
Construction
Contractor |
Construction
Work Sites (General) |
During
Hydrostatic Tests |
Practice
Note for Professional Persons with regard to site drainage (ProPECC PN 1/94)
and WQO |
|
3.8 |
2 |
Surface Runoff, Sewage and Wastewater from Construction Activities Appropriate measures shall be
implemented to control runoff and prevent high loads of SS from entering the
marine environment. Proper site
management is essential to minimise surface runoff and sewage effluents. · Construction site runoff shall be
prevented or minimised in accordance with the guidelines stipulated in the
EPD's Practice Note for Professional Persons, Construction Site Drainage
(ProPECC PN 1/94). All discharges from the construction site shall be
controlled to comply with the standards for effluents discharged into the
Victoria Harbour WCZ under the TM-DSS. Good housekeeping and stormwater best
management practices, as detailed below, shall be implemented to ensure all
construction runoff complies with WPCO standards and no unacceptable impact
on the WSRs as a result of construction of the proposed submarine gas
pipelines; |
Construction
Contractor |
Construction
Work Sites (General) |
Construction
period |
Practice
Note for Professional Persons with regard to site drainage (ProPECC PN 1/94)
and WQO |
|
|
|
· Sedimentation tanks with sufficient
capacity, constructed from pre-formed individual cells of approximately 6 to
8 m3 capacities, are recommended as a general mitigation measure
which can be used for settling surface runoff prior to disposal. The system capacity shall be flexible and
able to handle multiple inputs from a variety of sources and suited to
applications where the influent is pumped; |
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· Manholes (including newly
constructed ones) shall always be adequately covered and temporarily sealed
so as to prevent silt, construction materials or debris being washed into the
storm runoff being directed into foul sewers; |
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· All vehicles and plant shall be
cleaned before leaving a construction site to ensure no earth, mud, debris
and the like is deposited by them on roads.
An adequately designed and located wheel washing bay shall be provided
at every site exit, and wash-water shall have sand and silt settled out and
removed at least on a weekly basis to ensure the continued efficiency of the
process. The section of access road
leading to, and exiting from, the wheel-wash bay to the public road shall be
paved with sufficient backfill toward the wheel-wash bay to prevent vehicle
tracking of soil and silty water to public roads and drains; |
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· Precautions shall be taken at any
time of year when rainstorms are likely. Actions shall be taken when a
rainstorm is imminent or forecast. Actions to be taken during or after
rainstorms are summarised in Appendix A2 of ProPECC PN 1/94. Particular attention shall be paid to the
control of silty surface runoff during storm events, particularly for areas
located near steep slopes; |
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· Fuel tanks and storage areas shall
be provided with locks and be located on sealed areas, within bunds of a
capacity equal to 110% of the storage capacity of the largest tank, to
prevent spilled fuel oils from reaching the coastal waters of the Victoria
Harbour and Western and Eastern Buffer WCZs; |
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· Portable chemical toilets shall be
used to handle construction workforce sewage prior to discharge to the
existing trunk sewer. Sufficient numbers of portable toilets shall be
provided by a licensed contractor to serve the construction workers. The Contractor should also be responsible
for waste disposal and maintenance practices. |
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Waste Management |
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|
4.6 |
3 |
Good Site Practices Adverse impacts related to waste
management are not expected to arise, provided that good site practices are
strictly followed. Recommendations for good site practices during the
construction activities include: |
Construction
Contractor |
Construction
Work Sites (General) |
Construction
period |
Waste
Disposal Ordinance (Cap.354); Waste Disposal (Chemical Wastes) (General)
Regulation |
|
|
|
· Nomination
of an approved person, such as a site manager, to be responsible for good
site practices, arrangements for collection and effective disposal to an
appropriate facility, of all wastes generated at the site |
|
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|
(Cap
354) and ETWBTC No. 15/2003, Waste Management
on Construction Site |
|
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·
Training of site personnel in proper waste
management and chemical handling procedures, separation of chemical wastes
with appropriate treatment which is mentioned in Section 4.6.5 |
|
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·
Provision of sufficient waste disposal points and
regular collection of waste |
|
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·
Barges filled with dredged sediment shall be towed
away immediately for disposal. In doing so, odour is not anticipated to be an
issue to distant sensitive receivers |
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·
Well planned delivery programme for offsite
disposal such that adverse impact from transporting sediment material is not
anticipated |
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·
Well maintained PME should be operated on site |
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·
Regular cleaning and maintenance of the drainage
systems for construction of the landing points |
|
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·
Appropriate measures to minimise windblown litter
and dust during transportation of waste by either covering trucks or by
transporting wastes in enclosed containers |
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4.6 |
3 |
Waste Reduction Measures Good management and control can
prevent the generation of a significant amount of waste. Waste reduction is best achieved at the
planning and design stage, as well as by ensuring the implementation of good
site practices. Recommendations to achieve waste reduction include: |
Construction
Contractor |
Construction
Work Sites (General) |
Construction
period |
|
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|
·
Sort C&D material from demolition and
decommissioning of the existing facilities to recover recyclable portions
such as metals; |
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·
Segregation and storage of different types of
waste in different containers, skips or stockpiles to enhance reuse or
recycling of materials and their proper disposal; |
|
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·
Encourage collection of aluminium cans by
providing separate labelled bins to enable this waste to be segregated from
other general refuse generated by the work force; |
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·
Proper storage and site practices to minimise the
potential for damage or contamination of construction materials; and |
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·
Plan and stock construction materials carefully to
minimise amount of waste generated and avoid unnecessary generation of waste. |
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4.6 |
3 |
C&D Material In order
to minimise impacts resulting from collection and transportation of C&D
material for off-site disposal, the excavated materials shall be reused
on-site as backfilling material and for landscaping works as far as
practicable. Surplus C&D material
generated from excavation works shall be disposed of at public fill reception
facilities for other beneficial uses. Other mitigation requirements are
listed below: |
Construction
Contractor |
Construction
Work Sites (General) |
Construction
period |
ETWB
TCW No. 31/2004 |
|
|
|
·
A Waste Management Plan shall be prepared; |
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·
A recording system for the amount of wastes
generated, recycled and disposed (including the disposal sites) shall be
proposed; and |
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·
In order to monitor the disposal of C&D
material and solid wastes at public filling facilities and landfills, and to
control fly-tipping, a trip-ticket system (e.g. ETWB TCW No. 31/2004) shall
be included. |
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|
4.6 |
3 |
General
Refuse General
refuse shall be stored in enclosed bins or compaction units separate from
C&D material. A reputable waste
collector shall be employed by the contractor to remove general refuse from
the site, separately from C&D material.
Preferably an enclosed and covered area shall be provided to reduce
the occurrence of 'wind blown' light material. |
Construction
Contractor |
Construction
Work Sites (General) |
Construction
period |
|
|
4.6 |
3 |
Chemical Waste Good
quality containers compatible with the chemical wastes shall be used, and
incompatible chemicals shall be stored separately. Appropriate labels shall be securely
attached on each chemical waste container indicating the corresponding
chemical characteristics of the chemical waste, such as explosive, flammable,
oxidizing, irritant, toxic, harmful, corrosive, etc. The Contractor shall use a licensed
collector to transport and dispose of the chemical wastes, to either the
approved Chemical Waste Treatment Centre, or another licensed facility. |
Construction
Contractor |
Construction
Work Sites (General) |
Construction
period |
Code
of Practice on the Packaging, Labelling and Storage of Chemical Wastes, Waste
Disposal (Chemical Waste) (General) Regulation |
|
4.6 |
3 |
Marine Dredged Sediment During
transportation and disposal of the dredged marine sediments, the following
measures shall be taken to minimise potential impacts on water quality: |
Construction
Contractor |
Construction
Work Sites (Along the alignment of dredging) |
During
Marine Dredging works |
ETWB
TCW No. 34/2002 |
|
|
|
·
Bottom opening of barges shall be fitted with
tight fitting seals to prevent leakage of material. Excess material shall be
cleaned from the decks and exposed fittings of barges and dredgers before the
vessel is moved; |
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·
Monitoring of the barge loading shall be conducted
to ensure that loss of material does not take place during
transportation. Transport barges or
vessels shall be equipped with automatic self-monitoring devices as specified
by the EPD; and |
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·
Barges or hopper barges shall not be filled to a
level that would cause the overflow of materials or sediment laden water
during loading or transportation. |
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·
The use of 300m3 geosynthetic
container, with outer woven fabric tensile strength of 200 kN/m and seam
strength of 140 kN/m for effective
method for contained disposal which meets ETWB TCW No. 34/2002 requirements
for assuring negligible loss of contaminants to marine environment during
disposal. |
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·
Allocation of marine disposal sites and all
necessary permits shall be applied from relevant authorities for disposal of
dredged sediment. Project Proponent will obtain confirmation from CEDD/Marine
Fill Committee (MFC) on the disposal options before commencement of the
Project. |
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Marine Ecology |
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|
5.7 |
4 |
Placement of a second silt curtain between
the dredger and the To Kwa Wan breakwater. The silt curtain shall be 75m long.
This curtain shall be moved along with the dredger as the work progresses.
The curtain shall be arranged so that at least 15m of the curtain shall
extend past the dredger in each direction. This curtain shall remain in a
suitable position between the dredger and the corals until the dredger is
250m from the corals. |
Construction
Contractor |
Proposed dredging near To Kwa Wan breakwaters |
Construction
period |
EIAO-TM |
|
Hazard to Life |
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|
7.6.3.1 |
6 |
·
Proper general traffic
management measures. ·
Minimisation of works
activity footprint – dredging and backfilling. ·
Safety provision during
dredging and backfilling. ·
Liaison with relevant
Government Departments before and during construction stage. ·
Requirements during the
submarine pipe pulling. |
Construction
Contractor |
Construction
Work Sites |
Construction
period |
|
|
7.6.3.2 |
6 |
Risk mitigation measures to prevent the
damage of submarine pipeline during operation will be adopted. They are
listed as follows: 1. The submarine gas pipeline will be
covered by armour rock, damage from anchor drop could be prevented. |
Construction
Contractor |
Construction Work Sites |
Construction
period |
|
|
Landscape |
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|
Table 8.2 |
7 |
Screening of construction works by hoardings/noise
barriers around Works area in visually unobtrusive colours, to screen Works. |
Construction
Contractor |
Construction
Work Sites |
Construction
period |
EIAO-TM |
|
Table 8.2 |
7 |
Hydroseeding or sheeting of soil stockpiles with visually
unobtrusive material (in earth tone). |
Construction
Contractor |
Construction
Work Sites |
Construction
period |
EIAO-TM |
|
Table 8.2 |
7 |
Ensure no run-off into the harbour adjacent to the site. |
Construction
Contractor |
Construction
Work Sites |
Construction
period |
EIAO-TM |
|
Table 8.3 |
7 |
The design and finish of the gas pigging station will be
aesthetically compatible with the surroundings. |
Construction
Contractor |
Proposed
pigging stations |
Operation
period |
Approved
planning permission applications No.A/K9/240 and A/H8/403 under S16 of the
TPO |
|
Table 8.3 |
7 |
Trellises will be constructed to screen the exposed pipes
inside the proposed pigging stations. |
Construction
Contractor |
Proposed
pigging stations |
Operation
period |
Approved
planning permission applications No.A/K9/240 and A/H8/403 under S16 of the
TPO |
|
Table 8.3 |
7 |
A planting strip of 1.5m width will be reserved in front
of the boundary wall of the proposed To Kwa Wan pigging station. |
Construction
Contractor* |
Proposed To Kwa Wan pigging station |
Operation
period |
Approved
planning permission application No.A/K9/240 under S16 of the TPO |
|
Table 8.3 |
7 |
A 300mm wide planting strip will be provided at the
seafront side along the boundary fence within the proposed North Point pigging
station. |
Construction
Contractor |
Proposed North Point pigging station |
Operation
period |
Approved
planning permission application No.A/H8/403 under S16 of the TPO |
|
Table 8.3 |
7 |
A 300mm wide planting strip together with a 2m high visual
barrier inside the existing fence will be provided on the east boundary along
|
Construction
Contractor |
Proposed North Point pigging station |
Operation
period |
Approved
planning permission application No.A/H8/403 under S16 of the TPO |
|
Cultural
Heritage |
||||||
|
9.8 |
8 |
A Monitoring Brief shall be conducted as set out in Appendix H2 of the EIA. This can be done in parallel with the monitoring of barge
loading as set out in section 4.6. |
Construction Contractor |
Construction Work Sites |
Construction period |
EIA
Report |
|
Noise |
||||||
|
10.6 |
9 |
Construction Noise Impact from Test before Backfilling and
Hydrostatic/ Commissioning Test The total maximum allowable SWL of
the test before backfilling and hydrostatic/ commissioning test is ranged
from 112-126 dB(A) at different location and period, the Contractor shall
strictly follow the specification listed above to meet the noise criteria and
closely liaise with the schools nearby before carrying out the
activities. Noise mitigation measures
including the use of movable noise barriers and/ or noise enclosure to block
the direct line of sight to the receivers, installation of mufflers and/ or
silencers on the machine(s) should be implemented if necessary. |
Construction
Contractor |
Construction
Work Sites (Landmain work) |
Construction
period |
PN
2/93 Noise from Construction Activities & EIAO |
|
10.7 |
9 |
Using Quiet PME The use of quiet PME recognized by
the Noise Control Authority for the purpose of CNP application can
effectively reduce the noise generated from the construction plants. Quiet PME are construction plants and
equipments that are notably quieter, more environmental friendly and
efficiently. The noise level reduction ranges from 5 – 10 dB(A) depending on
the type of equipment used. The Contractor should note the required
procedures involved in application of the QPME. A list of QPME recommended is list in Table 10.11 of the EIA report. |
Construction
Contractor |
Construction
Work Sites (Along the alignment of dredging and landmain works) |
Construction
period |
PN
2/93 Noise from Construction Activities & EIAO |
|
10.7 |
9 |
Using Movable Noise Barriers Movable noise barriers to be erected
near to the construction plants would reduce the noise levels for commonly 5
– 10 dB(A) depending on the types of items of PME and materials of the
barriers. It is recommended that the Contractor should screen noisy works and
noise from stationary items of PME whenever practicable. |
Construction
Contractor |
Construction
Work Sites (Landmain work) |
Construction
period |
PN
2/93 Noise from Construction Activities & EIAO |
|
10.7 |
9 |
Good Site Practices Good site practice and noise
management can significantly reduce the impact of construction site
activities on nearby NSRs. The
following package of measures shall be followed during construction: |
Construction
Contractor |
Construction
Work Sites (Along the alignment of dredging and landmain works) |
Construction
period |
PN
2/93 Noise from Construction Activities & EIAO |
|
|
|
· The Contractor shall adopt the Code
of Practice on Good Management Practice to Prevent Violation of the Noise
Control Ordinance (Chapter 400) (for Construction Industry) published by EPD; |
|
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|
· The Contractor shall observe and
comply with the statutory and non-statutory requirements and guidelines; |
|
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|
· Before commencing any work, the
Contractor shall submit to the Engineer Representative for approval the
method of working, equipment and noise mitigation measures intended to be
used at the site; |
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|
|
· The Contractor shall devise and
execute working methods to minimise the noise impact on the surrounding
sensitive uses, and provide experienced personnel with suitable training to
ensure that those methods are implemented; |
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|
|
· Unused equipment shall be turned
off. Number of operating PME shall be
kept to a minimum and the parallel use of noisy equipment / machinery shall
be avoided; |
|
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|
|
· Regular maintenance of all plant
and equipment; and |
|
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|
|
· Material stockpiles and other
structures shall be effectively utilised as noise barriers, where
practicable. |
|
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|
|
Construction Dust |
||||||
|
11.5 |
10 |
Mitigation Measures for Fugitive Dust To mitigate fugitive dust impact,
all dust control measures recommended in the Air Pollution Control
(Construction Dust) Regulation, where applicable, shall be implemented. Relevant dust
control measures include: |
Construction
Contractor |
Construction
Work Sites (General |
Construction
period |
EIAO-TM
and Air Pollution Control (Construction Dust) Regulation |
|
|
|
· The works area for site clearance shall
be sprayed with water before, during and after the operation so as to
maintain the entire surface wet; |
|
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|
|
· Restricting heights from which
materials are to be dropped, as far as practicable to minimise the fugitive
dust arising from unloading/ loading; |
|
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|
|
· Immediately before leaving a
construction site, all vehicles shall be washed to remove any dusty materials
from the bodies and wheels. However,
all spraying of materials and surfaces should avoid excessive water usage; |
|
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|
|
· Where a vehicle leaving a
construction site is carrying a load of dusty materials, the load shall be
covered entirely by clean impervious sheeting to ensure that the dusty
materials will not leak from the vehicle; |
|
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|
|
· Any stockpile of dusty materials shall
be covered entirely by impervious sheeting; and/or placed in an area
sheltered on the top and 4 sides; and |
|
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|
· All dusty materials shall be
sprayed with water immediately prior to any loading, unloading or transfer
operation so as to maintain the dusty materials wet. |
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|
* According
to the approved planning permission application for the To Kwa Wan gas pigging
station under Section 16 of the Town Planning Ordinance, a planting strip of
1.5m width will be reserved in front of the boundary wall to further soften the
physical appearance of the To Kwa Wan gas pigging station. As the gas
pigging station will be located within the future Hoi Sham Park Extension,
plant species shall be selected to match the surrounding planting theme.
The details of the planting strips and its construction and maintenance
arrangement will be liaised and agreed between the Project Proponent and
relevant government departments. Parties of the OM3 shall be subject to the conditions
under the land grant for the pigging station.
The Project Proponent will implement and maintain the approved
landscaping and plantations works of the strip until the handover of the works
to the management and maintenance authority of the future waterfront promenade.