8.1.1
This section further elaborates the
requirements of environmental monitoring and audit (EM&A) for the
construction and operation phases of the Project, based on the assessment
results of the various environmental issues.
The objectives of carrying out EM&A for the Project include the
following:
·
to provide a database against which any short or long
term environmental impacts of the Project can be determined;
·
to provide an early indication should any of the
environmental control measures or practices fail to achieve the acceptable
standards;
·
to monitor the performance of the Project and the
effectiveness of mitigation measures;
·
to verify the environmental impacts predicted in the
EIA Study;
·
to determine project compliance with regulatory
requirements, standards and government policies;
·
to provide a plan for
remedial action if unexpected problems or unacceptable impacts arise;
and
·
to provide data to enable an environmental audit.
8.1.2
The following sections summarise the
recommended EM&A requirements for the various environmental impacts of this
Project. Details of the specific
requirements are provided in a stand-alone EM&A Manual prepared according
to the findings and recommendations of this EIA Study.
8.2.1
Potential dust impacts would be
generated from site clearance, excavation, materials handling, and wind
erosion. The construction works are
controlled by the Air Pollution Control
(Construction Dust) Regulation, and mitigation measures such as watering
are required under the regulation to limit its dust emission. Dust monitoring requirements have been
recommended in the EM&A Manual to ensure that the mitigation measures are
properly implemented and are effective.
8.2.2
The predicted air quality during the
TPSTW operation at the ASRs complies with the criteria. It is recommended that H2S
monitoring should be carried out during the operation phase to ensure that the
odour criteria are satisfied at the ASRs.
Details of the monitoring programme are presented in the EM&A
Manual.
8.3.1
The model
predicted that the Project would not have adverse impact on Victoria
Harbour. With upgrading of the Tai Po
and Sha Tin effluent pumping stations and associated facilities, the Project
would not cause any adverse impact on the water quality of Tolo Harbour during
normal operation. The need for a
comprehensive post project monitoring programme in Victoria Harbour would
depend on the prevailing environmental conditions at the time near commissioning of the Project. Details of the programme will be subject to EPD’s endorsement.
8.3.2
With upgrading of the Tai Po and Sha
Tin effluent pumping stations and associated facilities, the Project would not
cause any adverse impact on the water quality of Tolo Harbour under normal
operation. Nevertheless, a 3-month
water quality monitoring will be carried out after full commissioning of the
Project to collect water quality information at the WSD seawater intakes at Tai
Po and Shatin during normal operation.
8.3.3
Marine water
quality monitoring is also recommended in Tolo Harbour for emergency discharge
due to plant failure and THEES maintenance periods during the construction
phase and a 3 years post commissioning period.
Marine water quality parameters such as SS, BOD5, E.coli,
chlorophyll-a, TIN and NH3-N should be monitored at six selected
monitoring stations, including the WSD seawater intakes at Tai Po and Shatin. A six-month baseline monitoring programme
covering both dry and wet seasons is proposed at a frequency of once per month
to establish the baseline water quality conditions at these monitoring
points. In case of emergency discharge,
daily marine water monitoring should be conducted throughout the whole discharge
period until the normal water quality resumes or at least 1 week after the
normal plant operation is restored. For
THEES maintenance, marine water quality data should be collected throughout the
whole discharge period at a frequency of 3 times per week until the baseline
water quality is restored or at least 4 weeks after the end of maintenance
period.
8.3.4
Monitoring of effluent qualityis
also recommended. Parameters to be monitored include pH, BOD5, SS, TIN, NH3-N and E.coli.
8.3.5
Details of the water quality
monitoring requirements are presented in the EM&A Manual.
8.4.1
During construction stage, waste
management will be the contractor’s responsibility. The Contractor must ensure that all wastes produced during the
construction of the Project are handled, stored and disposed of in accordance
with the recommended good waste management practices and EPD’s regulations and
requirements. The mitigation measures
recommended in Section 5 should form the basis of a Waste Management Plan to be
developed by the Contractor at the construction stage.
8.4.2
It is recommended that the waste
arisings generated during the construction activities should be checked against
the Waste Management Plan. In addition,
the routine site inspections should check the implementation of the recommended
good site practices and other waste management mitigation measures.
8.5.1
A landfill restoration monitoring
programme, conducted on a monthly basis, is part of the Restoration Contract
for Shuen Wan Landfill. However, monitoring for landfill gas within the
proposed project site boundary is still considered necessary during the
construction and operational phase of the TPSTW in order to identify any
migration between the landfill and the site and to ensure the safety of the
Contractor’s personnel.
8.5.2
During the construction phase,
portable gas detectors shall be used regularly to check the levels of methane,
carbon dioxide and oxygen in depressions, trenches, and excavations. The
regular monitoring shall be undertaken at least for the beginning of each half
working day (i.e. morning and afternoon) for the entire period the excavation
remains open.
8.5.3
During the operational phase,
atmosphere within utility manholes and chambers shall be checked for methane,
carbon dioxide and oxygen prior to entry. The Code of Practice on Safety and
Health at Work in Confined Space should be followed before entering into the
utility manholes and chambers.
8.6.1
Construction activities would, if
unmitigated, generate high noise levels exceeding 75 dB(A) Leq(30-min) at the
NSR identified in close proximity
to the Tai Po Sewage Treatment Plant. By adopting
silenced equipment and good site practices, the mitigated noise levels at the
NSR due to this Project would comply with the daytime construction noise
standard as set out in the EIAO-TM.
8.6.2
Noise monitoring during construction
phase would have to be carried out to ensure that such mitigation measures
would be implemented properly. Detailed monitoring requirements are addressed
in the stand-alone EM&A Manual.