15 Conclusions. 15-1
15.1 Introduction.. 15-1
15.2 Air
Quality Impact. 15-1
15.3 Water
Quality Impact. 15-2
15.4 Ecological
Impact. 15-3
15.5 Fisheries
Impact. 15-4
15.6 Landscape
and Visual Impact. 15-4
15.7 Hazard
to Life Impact. 15-5
15.8 Landfill
Gas Hazard.. 15-5
15.9 Waste
Management Implications. 15-5
15.10 Land
Contamination.. 15-5
15.11 Noise
Impact. 15-6
List of
Appendices
Appendix 15.1 Key Assessment Assumptions and Limitations of Methodologies
Appendix 15.2 Summary of Environmental Impacts
15
Conclusions
15.1.1
This Environmental Impact Assessment (EIA)
Report presents an assessment of the potential environmental impacts associated
with the construction and operation of the Project.
15.1.2
The EIA has been conducted in accordance with
the requirements of the Technical Memorandum of EIA Process (EIAO-TM) and the
EIA Study Brief (No. ESB-321/2019) for the Project issued under the EIA
Ordinance (EIAO), covering the following environmental aspects:
n
Air Quality Impact
n
Water Quality Impact
n
Ecological Impact
n
Fisheries Impact
n
Landscape and Visual Impact
n
Hazard to Life Impact
n
Landfill Gas Hazard
n
Waste Management Implications
n
Land Contamination
n
Noise Impact
15.1.3
The key assessment assumptions and limitations
of methodologies of this EIA are presented in Appendix 15.1. A summary of environmental impacts
assessed under the EIA is given in Appendix 15.2. The EIA conclusions are presented in the
sections below.
Construction
Phase
15.2.1
The key air quality concern arising from the
construction phase of the Project would be the dust emissions from construction
activities, which have been quantitatively assessed in the EIA. With implementation
of mitigation measures recommended in the EIA, no unacceptable impact on Air
Sensitive Receivers (ASRs) during the construction phase is predicted.
Notwithstanding the above, dust monitoring and regular site inspections should
be carried out during the construction phase in order to
confirm that the recommended mitigation and control measures are properly
implemented and are working effectively.
Operational
Phase
15.2.2
Potential odour impacts from the operation of
the Project have been quantitatively assessed. With proper implementation of
the proposed plant design, provision of adequate ventilation and appropriate
deodorization systems, the predicted odour concentrations at all representative
ASRs would comply with the odour criterion stipulated in the EIAO-TM.
15.2.3
Potential air quality impacts due to gaseous
emissions from the combined heat and power generators in the Project site have
been quantitatively assessed. Based on the proposed plant design, full air
quality compliances are predicted at all representative ASRs.
15.2.4
No unacceptable air quality impact arising from
the operational phase of the Project is anticipated. Commissioning test is
recommended to be conducted prior to operation of the combined heat and power
generators and the deodorization systems of the Project to ascertain the air
quality impacts. Odour patrol is also proposed during the period of maintenance
of the deodorization system for the upgraded TPSTW.
15.3.1 Only land-based construction works will
be carried out under the Project. Water quality impacts may result from the
general construction activities, construction site run-off, sewage from
construction workforce, accidental chemical spillage, polluted runoff and
wastewater from contaminated materials and demolition works. The impacts could
be mitigated and controlled by implementing the recommended mitigation
measures. No unacceptable water quality impacts is
expected. Regular site inspections should be undertaken routinely to inspect
the construction activities and works area to ensure the recommended mitigation
measures are proper implemented.
Operational Phase
Project Effluent Discharge
15.3.2
Potential water quality impacts due to the
Project effluent discharge have been quantitatively assessed by mathematical
modelling.
15.3.3 Following
the existing practice, the treated effluent from the Project will be discharged
to the Victoria Harbour through the Tolo Harbour Effluent Export Scheme (THEES)
under normal operation. The treated effluent would be discharged into the Kai
Tak Approach Channel and Kwun Tong Typhoon Shelter and eventually into the open
channel of Victoria Harbour. The model results showed that there would be no
unacceptable water quality impacts arising from the Project at all
representative Water Sensitive Receivers (WSRs) identified in the assessment
area. No adverse water quality impact
upon Victoria Harbour would
arise from this Project.
15.3.4
Maintenance of the THEES is required to ensure
proper functioning and integrity of the system. During the inspection or
maintenance of the THEES tunnel, temporary suspension of the normal THEES
operation with effluent bypass into the Tolo Harbour is unavoidable to provide
a safe and dry zone within the tunnel. The model results indicated that the
pollution level in certain WSRs in Tolo Harbour would be temporarily increased
during the THEES maintenance period, but the pollution elevation associated with
the maintenance discharge would be reversible. The THEES maintenance discharge
would be scheduled outside the algae blooming season (December to April/May) to
minimize the risk of red tide occurrence. The scheduling of the maintenance
discharge would also take into account any ongoing
blooming event in the area, which may occur outside the blooming season. An
event and action plan and a marine water quality monitoring programme (as
presented in the standalone EM&A Manual) are also proposed for the THEES maintenance
event to minimize the water quality impact.
15.3.5
Emergency discharge from the Project would be
the consequence of pump failure, interruption of the electrical power supply or
failure of treatment units. Mitigation measures, including dual power supply or
ring main supply from CLP, standby pumps, treatment units and equipment, would
be provided to avoid the occurrence of any emergency discharge. In case of emergency situation, the procedures and follow up actions
stipulated in the existing contingency plan formulated by DSD shall be
implemented to minimize the impact of emergency discharge and facilitate
subsequent management of the emergency situation. An event and action plan and a marine
water quality monitoring programme (as presented in the standalone EM&A
Manual) are also proposed for the emergency discharge event to minimize the
water quality impacts.
Others
15.3.6
Potential water quality impacts may also arise
from the handling and transportation of pre-treated food waste, wastewater
generated from the sludge / pre-treated food waste related processes, non-point
source surface runoff from paved areas and accidental chemical spillage during
the operational phase. The potential water quality impacts can be prevented by
implementation of the recommended mitigation measures. No unacceptable water quality impacts is expected.
Terrestrial Ecology
15.4.1
Literature review and ecological surveys
covering August 2020 to January 2021 have been conducted. A total of six
habitat types, including developed area, plantation, grassland, sea, artificial
seawall and semi-natural watercourse, were recorded in
the 500m assessment area, with developed area being the only habitat recorded
within the Project site. The ecological value of developed area within the
Project site is Low to Moderate, with 12 bird species of conservation
importance recorded. Within the 500m assessment area, the ecological values of
the plantation and grassland within the Shuen Wan Restored Landfill (SWRL) are
evaluated as Moderate whereas the ecological value of the artificial seawall is
evaluated as Low to Moderate. The other plantations and the semi-natural
watercourse are considered of Low ecological value. Developed area outside the
Project site, including the Tai Po Industrial Estate (TPIE), is evaluated as
having Very Low ecological value.
15.4.2
The Project site and the SWRL supported a
significant number of Collared Crows in Hong Kong. Pre-roosting and roosting
sites were identified within the SWRL but the
locations are likely to change irregularly as observed across the survey
period. No direct impact to roosting/pre-roosting sites of Collared Crows is
expected. The Project works will cause a temporary loss of foraging habitat. It
is expected that birds foraging in the TPSTW will become quickly habituated to
the upgraded facilities of the Project. For the duration of
demolition/construction, the eastern portion of the TPSTW and other surrounding
areas will be available as foraging/loafing habitats to all bird species
currently utilizing this highly disturbed habitat. The ecological impact of
this temporary habitat loss (developed area) is anticipated to be Minor.
15.4.3
No potential direct impact on natural habitats
within the assessment area is identified as the assessment area consists
largely of man-made habitats.
15.4.4
An occasional ardeid night roost was identified
within the TPSTW. During the survey period, ardeids were only recorded three
times roosting at the southwestern tree group to the immediately north of the
proposed expansion site. The tree group will be compensated by transplanting or
replanting of suitable trees, to provide a potential roosting habitat within
the upgraded TPSTW in long term. Felling/removal/transplantation of the
concerned tree group as well as noisy construction works within 100m from the
existing / transplanted / compensated tree group shall be ceased at least 1
hour before the sunset to avoid disturbance to the night roosting activities.
No residual impact is expected in term of loss of ardeid roosting habitat.
15.4.5
With implementation of recommended mitigation
measures (e.g. use of quieter piling method, adoption
of good site practices, deployment of temporary noise barriers, careful phasing
of construction activities, use of quality powered mechanical equipment and
clear delineation of construction works boundary, etc.), no unacceptable
disturbance impacts would be expected.
15.4.6
Ecological monitoring should be conducted during
construction phase to monitor the effectiveness of proposed mitigation measures
and detect any unpredicted indirect ecological impacts arising from the
proposed Project. Regular site inspections should be undertaken routinely to
inspect the construction activities and works area to ensure the recommended
mitigation measures are proper implemented. Ecological monitoring should also
be conducted during operational phase to monitor any changes in foraging
habitats caused by the proposed Project.
Marine Ecology
15.4.7
There
would be no direct disturbance to seabed or riverbed sediments under the
Project. No loss of marine habitat will be resulted from this Project. Indirect marine ecological impact may
arise from water quality changes under the THEES maintenance event and emergency situation
(see Section 15.3).
The water quality changes are however predicted to be short-term and
reversible. The frequency of such occurrence would be remote. Mitigation
measures and monitoring programme recommended under the water quality impact
assessment would also serve to protect the marine ecology. No unacceptable
marine ecological impacts are predicted for the Project.
15.5.1
A study on
commercial fisheries resources and fishing operations within
the waters of the assessment areas of the Project. Sites of fisheries
importance have been identified.
15.5.2
The
Project will only involve land-based construction works in TPIE. There will be
no disturbance to marine
bed or riverbed sediments. No loss
of fishing ground would arise.
15.5.3
Indirect
fisheries impacts due to water quality changes under
the THEES maintenance event and emergency situation (see Section 15.3) are
predicted to be short term and reversible. The frequency of such occurrence
would be remote. Mitigation measures and monitoring programme recommended under
water quality impact assessment would also serve to protect the fisheries. In
particular, the THEES maintenance discharge would be scheduled outside the
algae blooming season (December to April/May) to minimize the risk of red tide
occurrence. The scheduling of the maintenance discharge would also take into account any ongoing blooming event in the area,
which may occur outside the blooming season. No unacceptable fisheries impacts
are predicted for the Project.
15.6.1
During construction phase, potential landscape
impacts would arise from removal of existing trees and construction activities
including demolition of existing structures, excavation works, construction of
new buildings/facilities. With the implementation of mitigation measures
including preservation of existing trees, transplanting of affected trees,
compensatory tree planting, erection of decorative screen hoarding and good
construction site management and practices, no unacceptable landscape
and visual impacts from construction of the Project would be anticipated.
15.6.2
During operational phase, responsive building
design will be taken into account in the design of the Project, such as
aesthetically pleasing design for the new buildings / structures so as to blend
in the buildings and structures to the adjacent landscape and visual context.
Landscaping works, including tree planting along the site boundary, infill
planting of trees, vertical greening and green roof would be undertaken to
enhance the general outlook of the proposed Project. No unacceptable landscape
and visual impact would be anticipated with mitigation.
15.7.1
Quantitative
Risk Assessment (QRA) has carried out to assess the potential hazard to life
impact due to the implementation of biogas related facilities within the
Project site and due to neighbouring hazardous facilities including the Tai Po
Gas Production Plant, the liquified petroleum gas storage facility at Apex
Print Limited and Zama Industries Limited, and the dangerous goods storage at Linde HKO Limited.
15.7.2
Overall, the
QRA has confirmed that the construction and operation of the proposed Project
would not cause any significant increase to the existing risk levels of TPSTW
and neighbouring hazardous facilities. Risk mitigation measures have been
recommended to further reduce the risk.
15.8.1
Qualitative risk assessment has been conducted
for the Project to evaluate the landfill gas hazard posed by the Shuen Wan
Restored Landfill. Based on the assessment results, the overall landfill gas
hazard of the proposed Project would be Low to Medium for both construction and
operational phase. Safety measures and landfill gas monitoring are recommended
during the construction phase. Building protection design and safety measures
for entry to confined spaces are recommended for the Project operation. With proper
implementation of the recommended precautionary and protection measures, the
safety of all personnel presence at the Project site would be safeguarded
during the construction and operational phases. Thus, there would be no unacceptable
landfill gas hazard arising from the Project.
15.9.1 Wastes generated by the Project
construction activities would include Construction and Demolition (C&D) materials, excavated
sediments, general refuse and chemical waste. Inert C&D materials generated from
the Project would be reused on-site as far as possible and the surplus inert
C&D materials would be disposed of at designated public fill
reception facility. Non-inert C&D materials would
be recycled as far as possible and the surplus
non-inert C&D materials would be disposed of at designated landfill. Excavated
sediments generated during construction phase would be managed
and disposed of in accordance with the requirements of ETWB TC(W) No. 34/2002
Ą§Management of Dredged / Excavated SedimentĄ¨. Chemical waste would be collected by
licensed chemical waste collector for disposal at licensed treatment
facilities. General refuse would be collected by waste collector for disposal
of at waste transfer/disposal facilities and then to landfill.
15.9.2 During operational phase, screenings
and grits would be generated at the inlet works while dewatered sludge would be generated from
sewage treatment and co-digestion. The collected screenings and grits would be
disposed of at landfill by waste collector while the dewatered sludge/digestate
would be disposed of at TĄP Park in Tuen Mun.
15.9.3
With
the implementation of the recommended waste management measures and good site
practices, no unacceptable waste management implications are anticipated.
Regular site inspections are recommended during construction phase to ensure
the measures are implemented properly.
15.10.1 Site
appraisal including site walkovers was carried out under this EIA. Based on the
site appraisal results, there are areas within the proposed construction site
with potential contamination concerns as documented in the Contamination
Assessment Plan (CAP) prepared under this EIA. The potential contaminative
areas identified in the CAP were in operation at the time of conducting this
EIA. Site Investigation (SI) at these areas was not possible at the EIA stage.
After decommissioning of the relevant existing facilities and before the
commencement of the construction work at these areas, site re-appraisal and
preparation of a supplementary CAP covering the whole construction works area
of the Project should be undertaken for EPD endorsement. Land contamination SI
should be conducted in accordance with the endorsed supplementary CAP. A
Contamination Assessment Report (CAR) shall be prepared to summarize the
results of the SI and confirm the extent of land contamination. If land
contamination is identified, Remediation Action Plan(s) (RAP(s)) shall be
prepared to provide details of the proposed remediation methods. Remediation
action, if necessary, should be carried out according to EPD endorsed RAP(s)
and Remediation Report(s) (RR(s)) should be submitted after completion of the
remediation action. The RR(s) should be endorsed by EPD prior to the
commencement of construction works at the respective identified contaminated
areas (if any).
15.10.2 With
the implementation of the recommended further works for the Project, any soil/groundwater
contamination would be identified and properly treated prior to the
construction works. No
insurmountable land contamination impacts to the Project are therefore
anticipated.
15.11.1 No
existing, committed or planned noise sensitive receiver
is identified within the noise impact assessment area of this Project. Good
site practices have been recommended in this EIA to minimize the construction
noise impact to the surroundings. During operational phase, the noise emitting
plants (pumps, air blowers, etc.) would be enclosed within building structures.
No unacceptable noise impact would be generated from the construction and
operation of the Project.