10.1 This EIA study has provided an assessment of the potential environmental impacts associated with the construction and operation phases of the proposed TM54SPS. The environmental issues below have been assessed in the EIA Study, in accordance with the EIA Study Brief (No. ESB-157/2006) registered under the EIAO for the Project:
•
Air Quality Impact
•
Noise Impact
•
Water Quality Impact
•
Waste Management Implications
•
Landscape and Visual Impact
•
Cultural Heritage Impact
10.2
Specific
mitigation measures necessary for avoiding or reducing impacts from the Project
to acceptable levels, as well as environmental monitoring and auditing
procedures to ensure full implementation of all mitigation measures and
compliance with relevant standards and guidelines, have been developed during
the detailed assessments. The
Implementation Schedules listing the recommended mitigation measures are
presented in Section 11. The environmental
outcomes and principal findings of this EIA Report are summarized below.
10.3
The
major sensitive areas within the study area include residential buildings and
educational institutions. With the
implementation of the proposed mitigation measures, no adverse environmental impacts
would be expected at the air, noise and water quality sensitive receivers
within the study area during both construction and operational phases. A summary of the key environmental
outcomes arising from the EIA study and benefits of the environmental
protection measures recommended are presented in Table 10.1 below.
Table 10.1 Summary of Key Environmental Outcomes/Benefits
|
Issue |
Environmental
Outcomes/Benefits |
|
The
Project |
Requirements: ·
Construction of a new sewage pumping station at Site Benefits: ·
TM54SPS is to convey sewage from the proposed development
in Area 54, the four recognized villages within Area 54 namely Tsz Tin Tsuen,
Po Tong Ha, Kei Lun Wai and Siu Hang Tsuen and the proposed Tuen Mun North
Sewage Pumping Station in Area 52 to the existing trunk sewer at |
|
Alternatives
|
The sewage pumping station was moved to Site 4A which
was a relatively low point within the sewerage basin area. This enables the connection of gravity
feed sewers from the proposed development in Tuen Mun Area 54 and the
existing villages. During the
public consultation, three alternative locations are aligned adjacent to the
future Road L54B. All the 3
locations are feasible and acceptable for accommodating the TM54SPS in view
of engineering aspects. However,
the preferred location is more favorable when summing up the grave public
concern. In view of environmental aspects, all 3 locations are considered to be
similar in environmental impacts associated with the construction and
operation of the TM54SPS. |
|
Construction
Air Quality Impact |
Impact/Problem ·
Potential
air quality impacts are dust nuisance. Environmental benefits of environmental protection
measures recommended & Environmentally sensitive areas protected
: ·
Mitigation
measures: implement the Air Pollution Control (Construction Dust) Regulation and good site
practices. ·
No
adverse air quality impacts are anticipated at nearby existing ASRs at |
|
Operational
Air Quality Impact |
Impact/Problem ·
Potential odour impacts from wet wells and screen chambers
of TM54SPS are anticipated at the existing and future ASRs. Environmental benefits of environmental protection
measures recommended & Environmentally sensitive areas protected
: ·
Mitigation measures: installation
of a deodourization
unit with 90% odour removal efficiency.
·
No adverse odour impacts are anticipated at the nearby
existing ASRs ( |
|
Construction
Noise Impact |
Impact/Problem · Unmitigated
construction noise levels due to the Project: 63 dB(A) to 80 dB(A). · Mitigated construction noise
levels due to the Project: 56 dB(A) to 69 dB(A). · Taking into account of
concurrent project, cumulative construction noise levels would be 67 dB(A) to
70 dB(A). Environmental benefits of environmental protection
measures recommended & Environmentally sensitive areas protected
: · Recommended mitigation
measures: adopting quiet construction plant and implementing good site
practices for the Project. ·
With the implementation of mitigation measures for the Project,
the nearest existing NSRs at Unicorn Garden, Kei Lun Wai and Siu Hang Tsuen
would be protected to comply with the daytime construction noise standard as
set out in the EIAO-TM. |
|
Operational
Noise Impact |
Impact/Problem/Environmental benefit of proper
design ·
No adverse operational noise impacts are expected at the
existing and future NSRs with the installation of
acoustic silencers at the exhaust fan of deodorizing unit and louvers of the
pump house, enclosed reinforced concrete structure design for transformer,
pump sets and mechanically raked screens. The estimated population of existing
residents within |
|
Construction
Water Quality Impact |
Impact/Problem · General construction
activities associated with the construction of the Project could lead to site
runoff. Environmental benefits of environmental protection
measures recommended: · All of the recommended
mitigation measures are implemented and all construction site / work area
discharges comply with the TM-DSS standards. ·
No unacceptable residual water quality impacts are
expected during the construction of TM54SPS. |
|
Operational
Water Quality Impact |
Impact/Problem · Emergency sewage
overflow due to the events of pump failure and power supply failure. Environmental benefits of environmental protection
measures recommended: · Mitigation measures:
regular check and maintain plant equipment, provision of a stand-by pump and
backup power supply. · With the incorporation
of various precautionary measures, minimal residual operational water quality
impact would be expected. |
|
Waste
Management Implications |
Impact/Problem ·
Wastes generated by construction activities: general refuse
from the workforce, chemical waste from plant and equipment maintenance,
C&D material from excavation works, and screenings Environmental benefits of
environmental protection measures recommended: · Surplus material would
require disposal to a public fill reception facility for other beneficial
uses. ·
C&D material with suitable characteristics should be
reused on-site as far as practicable. ·
With the implementation of the recommended mitigation
measures and practices for the handling, transportation and disposal of the
identified waste arisings, no adverse environmental impacts are expected. |
|
Landscape
and Visual Impact |
Impact/Problem &
Environmentally friendly designs
recommended · After the implementation
of mitigation measure both LR1 and LCA1 Landscape Impact will be lessen as
sight as additional tree will be planted along the boundary of TM54SPS for
screening and possible loss of greenery. · All residual adverse
landscape impacts in the operational phase of Day 1 will be of insubstantial
significance. After all landscape mitigation measures are implemented and
have matured over 10 years, there would be no residual adverse landscape
impacts of any significance in Year 10. · Residual impact on residents
in existing villages of Union Garden and Kei Lun Wai (V1) will be still
moderate after mitigation measure as the proposed buffer planting is still
under constructional stage will be achieve potential screening effect. · Residents in existing
high rise residential development of Siu Hong Court (R4) and Users in planned
institutional development (3 nos. primary schools and 3 nos. Secondary
schools) at Site 4A (GIC1) will have intermittent and distant views to the
proposed SPS both residual impact is slight. · After the proposed
mitigation measures have been implemented, the proposed tree planting would
carry out ultimate screening, all residual adverse visual impacts in the
operational phase will be of insubstantial significance. |
|
Cultural
Heritage Impact |
Impact/Problem · Since the site of the
proposed TM54SPS falls within Kei Lun Wai archaeological sites, construction
of the proposed TM54SPS would likely have direct impacts on the
archaeological resources within the archaeological site. It is recommended
that Site 4A of Tuen Mun Area 54 be added to the programme of archaeological
survey and rescue excavation to be undertaken by the Antiquities and
Monuments Office (AMO) of LCSD for the proposed development at Tuen Mun Area
54 prior to the commencement of construction works. As the archaeological survey cannot be
conducted in this EIA stage due to land access constraint, the proposed works
area for the TM54SPS which is located within Site 4A would be assessed in the
future archaeological survey and rescue excavation. · Since there are no
built heritage resources within the study area, impact on built heritage
resources is not expected. |
10.4
With
the implementation of mitigation measures specified in the Air Pollution
Control (Construction Dust) Regulation, dust nuisance at ASRs would not be
expected. An EM&A programme is recommended for the construction phase to
ensure that the dust criteria would be satisfied at the ASRs.
10.5
No
potential odour impact would be expected at nearby ASRs during operation of
TM54SPS with the installation of a deodourization unit. Odour monitoring is proposed during the
operational phase to ensure the compliance of odour criteria at the ASRs.
10.6
The
potential noise impact arising from construction of TM54SPS on the nearest
representative NSRs was assessed. Results indicated that noise exceedance was
predicted at the NSRs N1 and N2 during some construction activities. With the adoption of quiet PME during
these construction activities, the predicted construction noise levels at NSRs
N1 and N2 would all comply with the relevant noise criteria. Good site practices were also proposed
to further abate the impacts on the NSRs.
Two other projects (Site formation and infrastructural works for Site 2
under the project “Formation, Roads and Drains in Tuen Mun Area 54 – Phase 1
and 2, Private and Public Rental Housing Development in Tuen Mun Area
10.7
The
noise impacts associated with the operation of the Project were also assessed.
As the pump sets, mechanically raked screens and transformer would be housed in
reinforced concrete structures with soundproof doors, and silencer would be
provided for louvers of the pump house and exhaust fan of the deodorization unit,
the operation noise levels at representative NSRs would comply with the
daytime, evening time and night time noise criteria. No mitigation measures were
proposed.
10.8
The
key issue in terms of water quality during the construction phase of the
Project would be the potential for release of sediment-laden run-off from the
works areas. Minimisation of water
quality deterioration could be achieved through implementing adequate
mitigation measures such as control measures on site run-off and drainage from
the works areas to minimise construction site run-off. Proper site management and good
housekeeping practices would also be required to ensure that construction
wastes and other construction-related materials would not enter the Tsing Lun
Nullah. Sewage effluent arising
from the construction workforce would also be handled through provision of
portable toilets. With the
implementation of these recommended mitigation measures, the construction works
for the Project would not be expected to result in unacceptable impacts on
water quality. Site inspections
should be undertaken routinely to inspect the works areas in order to ensure
the recommended mitigation measures are properly implemented.
10.9
In
view of the potential adverse effect of emergency sewage bypass on the quality
of the receiving waters, various precautionary measures are proposed to be
incorporated in the design of TM54SPS to avoid emergency bypass of sewage to
the maximum practicable extent. With the incorporation of these precautionary
measures, the possibility of emergency sewage bypass would be extremely
remote.
10.10
Waste
types generated by the construction activities are likely to include C&D
material from excavation works, general refuse from the workforce, and chemical
waste from the maintenance of construction plant and equipment. Provided that these wastes are handled,
transported and disposed of using approved methods and that the recommended
good site practices are strictly followed, adverse environmental impacts are
not expected during the construction phase.
10.11
The
only waste generated during operation of TM54SPS would be screenings removed
from the mechanical screens in the inlet chamber. The small quantity of screenings will
require disposal to the designated landfill site.
10.12
There
are no tree would be affected within the site boundary.
10.13
The
landscape resources of LR1 and landscape character area of LCA2 will be
moderate impact by the construction of an incongruous building mass, temporary
works areas, additional construction traffic, storage of construction material
and general loss of farmland plantation. After the implementation of mitigation
measure both LR1 and LCA2 landscape Impact will be lessen as sight as
additional tree will be planted along the boundary of the proposed pumping
station for screening and possible loss of greenery.
10.14
Residents
in existing villages of
10.15
After
the proposed mitigation measures have been implemented, the proposed heavy
standard sized tree planting will carry out ultimate screening, all residual
adverse landscape and visual impacts in operational phase will be of
insubstantial significance. Except on VSRs V1, GIC1 and O1 will have slight
adverse visual impact which will be lessen as insubstantial after 10 years of
implementation of mitigation measures.
10.16
As
the site of the proposed TM54SPS falls within the boundary of the Kei Lun Wai
Archaeological Site, construction of the proposed TM54SPS would likely have direct
impact on the archaeological resources within the archaeological site. It is recommended that Site
10.17
Since
there are no built heritage resources within the study area, impact on built
heritage resources is not expected.
10.18
The
findings of this EIA Study have determined the likely nature and extent of
environmental impacts predicted to arise from the construction and operation
phases of the Project. The EIA has,
where appropriate, identified mitigation measures to ensure compliance with
environmental legislation and standards.
10.19
Overall,
the EIA Study for TM54SPS has predicted that the Project, with the
implementation of the proposed mitigation measures for construction and operation
phases, would comply with all applicable environmental standards and
legislation. This EIA has also
demonstrated the acceptability of the residual impacts from the Project and the
protection of the population and environmentally sensitive resources. Environmental monitoring and audit
mechanisms have been recommended, where necessary, to verify the accuracy of
the EIA predictions and the effectiveness of recommended mitigation measures.