12.1.1 Section 2 outlines the details and benefit of the Project together with the consideration of alternatives during the preliminary design stage, which has taken into account the findings of various engineering and environmental review. The technical assessments in Sections 3 to 10 have demonstrated that all the statutory requirements in EIA Study Brief (ESB-356/2022) and EIAO-TM have been compiled with.
12.1.2 This section summarizes the key environmental outcomes arising from this EIA study, the approaches that have been adopted to either avoid or minimize various environmental impacts throughout the design process, and the associated environmental enhancements and mitigation measures.
12.2.1 With the Project in place, the traffic loading and congestion level on YLH is expected to be relived. It is an opportunity to alleviate the associated air and noise pollution within the area by means of improving traffic performance and establishing noise mitigation measures, which in turns reducing the vehicular emission and road traffic noise.
12.3.1 Avoidance of environmental impacts is one of the main considerations throughout elevation and development of alignment options. In case due to limitation of actual site situation that environmental impacts could not be completely avoided, environmentally friendly alternatives or designs were taken as much as practicable for compliance with relevant EIA requirements. The following approaches to avoid environmental impacts have been suitably incorporated into the layout of the preferred alignment option, as discussed below.
Avoiding
construction works at both sides to YLH
12.3.2 The recommended scheme of widening of YLH has been taken into account the site constraints and anticipated environmental impact due to the construction. The widening works would avoid the need of extensive slope works and minimized utility diversion, which would greatly affect the environment. Construction period has also been optimised, which environmental impact during construction would be much avoided.
12.4.1 Other than initiatives to avoid environmental impacts as summarized in Section 12.3, further efforts have been exercised to minimize impacts. The need for any environmental designs required to mitigate the associated impacts have also been identified and will be implemented, as appropriate. A summary of these approaches is given below:
· Adoption of environmentally friendly construction method;
· Implementation of trip-ticket system; and
· Implementation of environmental monitoring and auditing system.
Adoption
of environmentally friendly construction method
12.4.2 Precast construction method will be adopted as far as possible, with bridge deck formed from precast concrete sections which will be manufactured off site and joined together on site, which minimize the extent and duration of construction activities required on site and hence the potential environmental impacts in the vicinity during construction. Other construction methods will be considered only when precast construction method is not feasible.
Implementation of Trip-Ticket System
12.4.3 In order to monitor, document and verify the disposal of C&D materials at landfills and public fill reception facilities, as appropriate, and to control fly tipping, a trip-ticket system for disposal of construction and demolition materials would be implemented.
Implementation of Environmental Monitoring and Auditing System
12.4.4 In addition to the mitigation measures as described above, a comprehensive environmental monitoring and auditing programme would be implemented to cover various aspects of concern. An independent environmental checker would also be employed to ensure that all the necessary mitigation measures are implemented in a timely and orderly manner.
12.5.1 Sections 12.3 and 12.4 have summarized the key approaches adopted in the current proposal to avoid, minimize and mitigate environmental impacts. Some of these approaches have contributed to avoid a number of environmental problems and to protect a number of environmentally sensitive areas. Table 12.1 presents the key environmental problems that have been avoided and any sensitive areas protected by these approaches.
Table 12.1 Key Recommended Mitigation Measures
|
Design Approach |
Environmental Problems
Avoided and Sensitive Areas Protected |
|
Adoption of
environmentally friendly construction method (Section 2) |
·
Adoption of quiet piling method to minimize the
construction noise impact to nearby sensitive receivers. ·
Works are carried out in phases to minimize the
construction dust impact to nearby sensitive receivers. |
|
Avoidance of illegal
dumping (Section 6) |
The recommended
preventive measures would avoid/minimize the chance of illegal dumping |
|
Bird friendly design for
noise barriers (Section 8) |
Minimize potential bird
collision |
|
Implementation of
Environmental Monitoring and Auditing System (Section 11) |
Ensure all the
recommended measures are properly in place and their effectiveness |
12.6.1 Summary of assessment methodology, key assessment assumptions adopted in the study, limitations of assessment methodologies / assumptions & Prior Agreements with the Director or other Authorities are summarized in Appendix 12.1.
12.7.1 Mitigation measures have been recommended to further reduce the environmental impacts during construction and operation phases of the Project. Key recommended mitigation measures and any associated benefits are summarized in Table 12.2 below.
Table 12.2 Key Recommended Mitigation Measures
|
Mitigation Measure and any Associated
Benefit |
||
|
Air Quality Impact |
Construction Phase: ·
Use of regular watering to reduce dust emissions from exposed site
surfaces and unpaved roads, particularly during dry weather. ·
Use of frequent watering for particularly dusty construction areas and
areas close to ASRs. ·
Side enclosure and covering of any aggregate or dusty material storage
piles to reduce emissions. Where this
is not practicable owing to frequent usage, watering shall be applied to
aggregate fines. ·
Open stockpiles shall be avoided or covered. Where possible, prevent placing dusty
material storage piles near ASRs. ·
Tarpaulin covering of all dusty vehicle loads transported to, from and
between site locations. ·
Establishment and use of vehicle wheel and body washing facilities at
the exit points of the site. ·
Provision of wind shield and dust extraction units or similar dust
mitigation measures at the loading area and use of water sprinklers at the
loading area where dust generation is likely during the loading process of
loose material, particularly in dry seasons/ periods. ·
Provision of not less than 2.4m high hoarding from ground level along
site boundary where adjoins a road, streets or other accessible to the public
except for a site entrance or exit. ·
Imposition of speed controls for vehicles on site haul roads. ·
Where possible, routing of vehicles and positioning of construction
plant should be at the maximum possible distance from ASRs. ·
Instigation of an environmental monitoring and auditing program to
monitor the construction process in order to enforce
controls and modify method of work if dusty conditions arise. ·
Temporarily stockpile odorous material as far away from ASRs as
possible. |
|
|
Environmental Aspect |
Mitigation Measure and any Associated
Benefit |
|
|
Air Quality Impact (Cont’d) |
·
Temporary stockpiles of odorous material will be properly covered with
tarpaulin to avoid any odour nuisance arising. ·
Connecting construction plant and equipment to mains electricity
supply and avoid use of diesel generators and diesel-powered equipment; ·
Exempted NRMMs are not allowed; and Provision of site hoarding
(>4m) for ASRs located in close proximity to
works areas (e.g., A5, A12, and A30) Operation Phase: ·
No mitigation measures would be required. |
|
|
Noise Impact |
Construction Phase: ·
NSRs are protected with implementation of good site practices, use of
quieter type blade saw, adopting quieter construction method and PME (refer Appendix 4.5), erection of movable
noise barriers and temporary noise barriers (refer Appendix 4.6) and full enclosure during construction phase of the Project. The
predicted mitigated noise levels arising from the Project at all NSRs
selected for the construction noise impact assessment would comply with the
EIAO-TM construction noise criteria during non-restricted hours and
restricted hours. Operation Phase: ·
Installation of acoustic windows at planned residential developments. ·
Low Noise Road Surfacing (LNRS) on some Project Road sections (refer Figure
4.8a); and ·
Vertical noise barriers and cantilevered noise barriers (refer Figure
4.8b, Figure 4.9 and Figure 4.10) |
|
|
Water Quality Impact |
Construction Phase: ·
ProPECC PN 1/94 "Construction Site Drainage" should be
followed to minimize construction runoff. ·
ETWB TC (Works) No. 5/2005 Protection of natural streams / rivers
from adverse impacts arising from construction works should be adopted
where applicable to minimise the water quality
impacts on any natural streams or surface water systems. Operation Phase: ·
The design of site drainage should follow the relevant guidelines and
practices in accordance with the ProPECC PN 5/93. ·
Implementation of Best Management Practices (BMPs) for storm water discharge
are recommended to reduce the stormwater pollution arising from the Project. |
|
|
Waste Management Implications |
Construction Phase: ·
Implementation of good site practices and waste reduction measures (e.g. reuse of construction and demolition (C&D) materials
before off-site disposal or develop a materials recovery and recycling programme during construction and operation) |
|
|
Environmental Aspect |
Mitigation Measure and any Associated
Benefit |
|
|
Waste Management Implications (Cont’d) |
·
Preparation of a Waste Management Plan (WMP), which becomes part of
the EMP in accordance with ETWB TCW No. 19/2005 ·
Good Management for storage, collection and
transportation of waste ·
Implement a trip-ticket system in accordance with DEVB TCW No.
6/2010 to ensure that the disposal of C&D materials are properly documented and verified. ·
Adaptation of global positioning system (GPS) equivalent system at
C&D waste collection vehicles ·
Handling of chemical waste in accordance with the Code of
Practice on the Packaging, Labelling and Storage of Chemical Wastes, and
disposal of chemical waste at licensed chemical waste recycling / treatment
facilities. ·
General refuse should be stored in enclosed bins or compaction units
separately from chemical and C&D materials. ·
The recyclable component of general refuse, such as aluminium cans, paper and cleansed plastic containers
shall be separated from other wastes. ·
A reputable licensed waste collector should be employed to remove
general refuse on a daily basis to minimize odour, pest and litter impacts. Operation Phase: ·
The operators of various industrial uses should register with EPD as
chemical waste producers. Chemical wastes should be stored in appropriate
containers and collected by a licensed chemical waste contractor. Chemical
wastes should be recycled at an appropriate facility as far as possible,
while the chemical waste that cannot be recycled should be disposed of at
either the CWTC, or another licensed facility, in accordance with the Waste
Disposal (Chemical Waste) (General) Regulation. ·
Adequate number of rubbish bins should be provided to collect the
roadside littering and frequent clearing of bins should be arranged by FEHD.
Scrap metal from maintenance of the project will be collected and recycled at
licensed metal recycling collectors. |
|
|
Ecology |
·
Proper phasing and sectional completion of works ·
Use of screening during construction ·
Establishing of site hoarding before the commencement of work ·
Brief regarding the sensitivity of the areas before the commencement
of the works and requested not to disturb any areas nearby for construction
workers. ·
The site boundary will be clearly defined (i.e., fenced with the
screening materials mentioned). ·
Any works beyond the boundary strictly prohibited. ·
Use of quieter Quality Powered Mechanical Equipment (QPME) ·
Use of movable noise barriers or noise shield for mechanical
equipment. |
|
Environmental Aspect |
Mitigation Measure and any Associated
Benefit |
|
|
Ecology (Cont’d) |
·
Provision of higher density fixed opaque and non-reflective temporary
noise barrier (3m tall) with color scheme blended with the environment will
also be implemented to reduce construction noise and disturbances with better
noise insulation. ·
Bird friendly design should be adopted for the noise barriers, such as
using falcon sticker and tinted materials. The use of transparent/reflective
materials should be avoided or minimized. Guidelines on Design of Noise
Barriers (EPD & HyD, 2003) and Practice Notes No. BSTR/PN/003 (Revision
E) Noise Barriers with Transparent Panels (HyD, 2020) could be referred for
the design of the noise barrier/enclosure to avoid and minimize bird
mortality from collisions. ·
Any potential bat roosts in the close vicinity of the works area (i.e. 50m) should be inspected by a suitably qualified
ecologist, prior to the commencement of works. ·
Suitable screening should be applied to separate disturbance due to
workers and/or noise from the potential bat roosts. ·
Sites should be checked for the presence of bat roosts by a suitably qualified
ecologist prior to the felling and/or transplanting of trees. If roosts are
found, any tree removal work should be postponed until the roost is vacated. |
|
|
Landscape and Visual |
Construction Phase: ·
Careful Site Planning and Management ·
Tree Preservation and Inspection of Tree Works ·
Transplantation of Affected Trees ·
Provision of Decorative Site Hoarding ·
Minimisation of Light Impact ·
Reinstatement of Temporarily Disturbed Areas Operation Phase: ·
Landscape and Compensatory Planting ·
Slope Greening ·
Provision of Aesthetically Pleasing Design of Noise Barrier ·
Provision of Sensitively Designed Highway Structures |
|
|
Land Contamination |
No land contamination
impact arising from the Project is anticipated and no mitigation measure is
considered necessary. |
|
|
Cultural Heritage Impact |
No impact to cultural
heritage would be anticipated from the construction and operation of the
Project. Hence, no mitigation measure
would be required. |
|
12.8.1 Population and environmental sensitive areas in the vicinity of the Project site have been protected through the avoidance and/or minimisation of environmental impacts from the construction and operation of the Project. Population protected from air quality impacts include air sensitive receivers within 500m from the Project Boundary including residential buildings, commercial buildings, industrial buildings, cultural uses, educational uses, recreational uses, places of public worship, and government/institutional or community uses. Population protected from noise impacts include noise sensitive receivers within 300m from the Project Boundary including residential buildings. Population protected from water quality impacts include water sensitive receivers within 500m from the Project Boundary.