3.1.
This EIA Study has identified and
quantified various potential environmental impacts associated with the
construction and operation of Project and has recommended effective mitigation
measures to ameliorate any potentially negative impacts on the environment.
3.2.
In accordance with the EIA Study
Brief, the following key areas were addressed in the EIA Study:
·
air quality impacts
·
noise impacts
·
water quality impacts
·
waste management implications
·
ecological impacts
·
fisheries impacts
·
visual and landscape impacts
3.3.
The findings of the assessments for
the above environmental issues are summarised in the following sections.
Construction Phase
3.5.
With the above mitigation measure, no
adverse cumulative construction dust impact is predicted.
3.6.
To further ensure compliance with the
guideline level and AQO limit at the ASRs at all times, the implementation of
the Air Pollution Control (Construction
Dust) Regulation and the inclusion of good site practice in the contract
clauses to minimize cumulative dust impact are also recommended. In addition, a comprehensive dust monitoring
and audit programme is recommended to ensure proper implementation of
mitigation measures. Details of the
monitoring and audit requirements are provided in a separate EM&A Manual.
Operation Phase
3.8.
The air quality inside the full
enclosures recommended for the proposed CPR was also calculated. The results indicate that no exceedance of
the Tunnel Air Quality Guideline is expected and therefore no mitigation measures
are required.
Construction Phase
3.9.
Unmitigated cumulative noise levels
arising from the construction activities of the Project at the representative
noise sensitive receivers (NSRs) have been predicted. The results indicate that without any mitigation, the cumulative
noise levels at most of the NSRs would exceed the EIAO-TM noise criteria.
3.10.
In order to alleviate the construction
noise impacts at the NSRs, noise mitigation measures are recommended including
adoption of good site practice, the use of quiet plant, movable noise barriers
and restriction on the usage of operating plant.
3.11.
With the adoption of the recommended
control measures, all the residential NSRs could be effectively protected
against the construction noise impact.
For the educational NSRs, the use of the recommended direct mitigation
measures would protect them from exceedance of the noise criterion for schools
during normal hours, but these measures would be insufficient to protect them
from exceedance of the noise criterion for school during examination period
(which is 5dB(A) lower). In order to
reduce the potential noise impacts on the schools, re-scheduling of
construction activities to avoid concurrent operations are required during the
examination period.
Operational Phase
3.12.
Potential road traffic noise impact
associated with the project has been assessed for the maximum traffic flows
expected to occur in 2022. About 170
residential dwellings and 25 classrooms are predicted to experience noise
levels, if unmitigated, exceeding the traffic noise criteria. Hence direct mitigation measures would be
required.
3.13.
With the implementation of the
recommended direct mitigation measures, the mitigated noise levels from new
roads at all the representative NSRs are predicted to be below 70dB(A) and the
contribution from new roads to the overall noise levels would be less than
1dB(A). It is estimated that about 30
residential dwellings would benefit by more than 1dB(A).
3.14.
The residual impacts have been
assessed against the noise insulation criteria. The results show that no residential dwellings, schools or
hospitals would meet the noise insulation criteria and therefore, indirect
technical remedies in the form of window insulation and air conditioning would
not be required.
Construction Phase
3.15.
The potential water quality impacts
associated with the dredging activities during the construction of the
reclamation and seawalls have been assessed by predicting the increases in
suspended sediment concentrations due to fine sediment lost to suspension.
3.16.
There are no sensitive receivers
identified within the Study Area. The
nearest receivers include Ma Wan Fish Cultural Zone (FCZ), fish nursery areas
in bays on north Lantau to the west of Kap Shui Mun Channel, Golden Beach and
Anglers’ Beach, which are all located outside the Study Area and are far away
from the works area of the Project. It
is anticipated that the unmitigated elevations in suspended sediment (SS) concentration
generated from the dredging activities of the project at these sensitive
receivers would not exceed the allowable elevations in SS concentrations. However, the cumulative elevated SS
concentrations from the proposed project and the identified concurrent projects
are predicted to exceed the allowable elevated SS concentration at the Ma Wan
FCZ. The use of closed grab dredgers
and silt curtains is therefore recommended to minimize the water quality impact
from the dredging works for the Project.
3.17.
With the use of closed grab dredgers
and silt curtains, the dredging works of the proposed project would not
contribute significantly to the total SS concentrations at the Ma Wan FCZ (less
than 3%). Further constraints on the
dredging activities of the proposed project could not further reduce the
predicted cumulative impact and therefore it would be the responsibility of the
concurrent projects to apply mitigation measures should unacceptable water
quality impacts be detected during construction.
3.18.
The potential impact arising from the
release of contaminants from sediment disturbed during the dredging works has
also been assessed. It was predicted
that because of the general absence of significant sediment contamination in
the dredging area, adverse water quality impacts arising from the release of
heavy metals, nutrients and organic compounds are not expected during the
dredging works.
3.19.
With the adoption of the recommended
mitigation measures, no unacceptable residual impacts on water quality impact
are expected.
Operation Phase
3.20.
The only source of potential impact on
water quality during the operation phase will be runoff from the road
surfaces. With the implementation of
the recommended mitigation measures for the surface water drainage system including
grit soil interceptors, it is anticipated that the water quality impacts
associated with the operation phase would be minimal and acceptable.
3.21.
A review of the sediment quality data
from the marine ground investigation works indicated that the majority of the marine
sediments in the proposed dredging area for the Tai Lam Kok reclamation and new
seawall from Tai Lam Kok to Ka Loon Tsuen are classified as category L. This dredged sediment will therefore be
suitable for open sea disposal. The
small volume of sediment classified as Category H at the Tai Lam Kok
reclamation will require confined marine disposal.
3.22.
An assessment of the potential
environmental impacts of waste arising from the construction of the Project has
been conducted. Wastes generated by the
construction activities are likely to include construction and demolition
(C&D) materials, general refuse and chemical waste. Provided that these identified wastes are
handled, transported and disposed of using approved methods and that the
recommended good site practice is adhered to, adverse environmental impacts are
not expected.
Terrestrial Ecology
3.23.
The ecological resources within the
study area comprise a variety of habitat types including woodland, tall shrubland,
grassland/shrubland mosaic, backshore vegetation, mudflat, village/orchard,
developed area, active/abandoned farmland, wasteland, plantation, fishpond and
Tai Lam Chung River.
Grassland/shrubland mosaic was found to support three rare/protected
plant species: Alloteropsis semialatus,
Platycodon grandiflorus and Thysanotus
chinensis. All these rare/protected plant species are located outside the
construction boundary. No direct impact
to the rare/protected plant species due to construction is anticipated.
3.24.
The road improvement works will result
in the permanent loss of approximately 2 ha of backshore vegetation, 0.2 ha of
wasteland, 0.4 ha of plantation and 0.1 ha of tall shrubland. All these habitats are of low ecological
value and therefore adverse impact to the terrestrial ecology is not
anticipated. With the implementation of
the recommended mitigation measures, no adverse residual impact is expected.
Marine Ecology
3.25.
Literature reviews of existing
information supplemented with the results of recently undertaken field surveys
on marine ecological resources indicate that the intertidal habitats and soft
benthic habitats within the study area are of low ecological value.
3.26.
The dredging / reclamation and the
road improvement works will result in the permanent loss of approximately
14,348 m2 of soft bottom benthic habitat and approximately 1.1 km of
artificial intertidal habitat. Since
the benthic community and intertidal community in the study area are of low
ecological value and rubble-mound seawall will replace much of the lost
intertidal habitat, no adverse impact is anticipated.
3.27.
Fisheries resources sensitive to the
project have been identified. In terms
of fish production, the fishing areas concerned contribute a small proportion
to the territory’s total thus the overall fisheries impacts are predicted to be
minimal. No specific mitigation measure is necessary as no adverse impact is
identified.
3.28. The main landscape and visual impacts of the proposed alignment are
summarized as follows:
Landscape Impacts:
·
Significant
Adverse landscape impact from loss of natural shoreline, tidal reach and
backshore vegetation at Tai Lam Kok and Ma Wan coastal areas (LCA1)
·
Moderate Adverse
landscape impact from loss of amenity planting at Siu lam Interchange and from
loss of pocket tree planting along Castle Peak Road (LCA2)
Visual
Impacts:
·
Moderate Adverse visual impact to local commuters,
shipping, fishing boats and tourist vessels at Ma Wan Coast (SVR1)
·
Moderate / Significant Adverse visual impact to users
of Tuen Mun Road and existing transport corridor (SVR2)
·
Moderate Adverse visual impact to residents and staff
at Sui Lam Hospital (SVR3) and Siu Lam Psychiatric Centre (SVR4)
·
Significant Adverse visual impact to residents of Siu
Lam Police Quarters (SVR5)
·
Moderate Adverse visual impact to upper level residents
at Poseidon Coast Housing Development (SVR6)
·
Moderate / Significant Adverse visual impact to staff
and residents at Seaman’s Training Centre (SVR7)
·
Moderate Adverse visual impact to future residents at
Tai Lam Chung CDA (SVR8)
·
Slight / Moderate Adverse visual impact to hikers on
Tai Lam Ridge footpaths (SVR9)
3.29 The recommended Landscape Mitigation Measures
(LMMs) are summarised as follows:
·
LMM-1: Construction programming and management- the
construction programme should be reduced to the shortest possible period,
particularly in those locations where server of high landscape or visual
impacts are expected. Keeping the periphery of the work area at street level
clean, tidy and attractive and convenient for pedestrians. Use of colourful
hoarding with interesting motifs.
·
LMM-2: Advanced planting and erosion works- advance planting
of trees and landscape areas.
·
LMM-3: maximisation of amenity planting in road
corridor- opportunities to incorporate amenity areas along the alignment should
be maximised to provide visual relief in this otherwise congested traffic
environment including removal of the footpath from the immediate road edge.
·
LMM-4: Design, materials and finishes of engineering
structures- consideration for modern and attractive structures.
·
LMM-5: Maximisation of woodland planting on disturbed
land-compensatory planting.
·
LMM-6: Urban area under-viaduct hard and soft landscape
works- restoring and enhancing sterilised viaduct spaces.
3.30 The main landscape and visual implications of the proposed
alignment are summarized as follows:
·
The proposal is considered to be compatible with the
Government’s statutory planning framework.
·
Visual impacts are of a limited scale to the majority
of highly sensitive receivers. Significant impacts where they occur are
restricted to receivers of lower sensitivity.
·
The baseline landscape condition is not highly
sensitive nor of rare or unusual value. However without care the road proposal
could create an environment of extremely low visual landscape and amenity value
in its place. The incorporation of landscape and visual mitigation measures
into the Project will reduce some of the more severe landscape and visual
impacts.
·
The significance of the proposals in visual terms is
changed considerably with the construction of the Route 10 – NLYLH’s Siu Lam
Link Roads should they proceed. The baseline condition will be changed to a
point where the visual implications become far less noticeable with regard to
the construction of the high level viaduct.