An
assessment of the potential environmental impacts associated with the decommissioning/
demolition, construction and operation phases of the Project at the LPS has
been conducted in accordance with the requirements of the EIA Study Brief and EIAO-TM.
This Section summarises the
key environmental outcomes, potential environmental impacts and the recommended
mitigation measures (where necessary) associated with the Project.
The EIA
study predicted that the Project would be environmentally acceptable with the
implementation of the recommended mitigation measures. The key environmental outcomes, taking into
account the selection of environmentally friendly options on location, siting,
alternative method of electricity generation accrued from the environmental
considerations and analysis during the EIA study and the implementation of
environmental control measures of the Project, are summarised in the following
sections.
The
existing units (i.e. GT2, GT3, GT4, GT57 and GT6) within the GT Compound have
been in service since 1989 and are required to be retired as they approach the
end of the service life. The operation
of the aging units is increasingly less efficient and could potentially lead to
higher air emissions. New OCGTs are much
more efficient and capable of attaining a more stringent emission standards and
thus producing lower air emissions during operation, in particular NOx,
when generating the same amount of power as the existing OCGTs. Therefore, the Project is beneficial from an
environmental perspective and can be considered as part of the ongoing effort
of HK Electric to further reduce the overall air emissions from the operation
of LPS and contribute to the long-term air quality improvement in Hong Kong.
Different
alternative options have been explored to meet the requirement of providing the
necessary electricity demand during peak-lopping and emergency operations upon progressive
retirement and decommissioning of the existing units within the GT Compound,
having regard to various factors including project programme, technical
feasibility and environmental considerations.
The construction and operation of new OCGTs is considered the most
practicable, and the preferred option to pursue as this involves like-to-like
replacement, is fit for purpose, technically the most feasible, and can tie in
with the retirement schedule of the existing units.
Existing GT
Compound, L13 area and L3 Main Station Building within the LPS and LMX have
been identified as potential sites for accommodating the new OCGTs. The development of the new OCGTs would
require no foundation works and minimal civil works if the new units are to be
installed at the GT Compound, while the same would require extensive foundation
and civil works if they are installed at L13 area and/or L3 Main Station
Building. Waste generation and other
potential environmental impacts (e.g. air quality, noise) can be minimised with
the development of the new OCGTs at the GT Compound. From an environmental perspective, it is
therefore considered preferable to develop the new OCGTs at the GT Compound.
The
summaries of environmental impacts are structured as follows for each of the
technical assessment completed under this EIA study:
§ Sensitive
receivers/ assessment points;
§ Assessment
Methodology and Criteria;
§ Key
Construction Impacts;
§ Key
Operation Impacts;
§ Key
Mitigation Measures;
§ Residual
Impacts; and
§ Compliance
with the guidelines and criteria of the EIAO-TM.
Table 9.1
presents a summary of the key findings of the assessment of potential impacts
to air quality as a result of the decommissioning/ demolition, construction and
operation of the Project. Full details
of the assessment and mitigation measures are presented in Section 3 of this EIA
Report.
Table 9.1 Summary of Environmental Assessment and
Outcomes – Air Quality
|
Item |
Description |
|
Air Sensitive Receivers (ASRs) |
The
Assessment Area is defined as an area within 15km from the Project site
boundary as stated in Section 3.4.3.3 of the EIA Study Brief. The Assessment Area includes: § The Islands (Lamma Island, Cheung Chau, Peng Chau, Hei Ling Chau,
Northern and Eastern part of Lantau Island); § Southern District of Hong Kong Island; § Central and Western District of Hong Kong Island; § Eastern District of Hong Kong Island; § Kowloon; and § Tsing Yi. A total of 61 ASRs have been identified
in accordance with the criteria in EIAO-TM
Annex 12 and are illustrated in Figure
3.1. |
|
Assessment Methodology and Criteria |
§ The principal legislation for the management of air quality in Hong
Kong is the Air Pollution Control
Ordinance (APCO) (Cap 311). As the
new set of AQOs will be implemented on 1 January 2022, the new AQOs were used
as the assessment criteria for this assessment. § A maximum hourly TSP level of 500 mg
m-3 at ASRs is also stipulated in Annex 4 of the EIAO-TM to assess potential
construction dust impacts. The
measures stipulated in the Air
Pollution Control (Construction Dust) Regulation should also be followed
to ensure that any dust impacts are minimised. § Requirements stipulated in the Air
Pollution Control (Non-road Mobile Machinery) (Emission) Regulation and Air pollution Control (Fuel Restriction)
Regulation will be followed to control potential emissions from non-road
mobile machinery. § Requirements stipulated in the Air
Pollution Control (Marine Light Diesel) Regulation and Air Pollution Control (Fuel for Vessels)
Regulation will be followed to control potential marine vessel emissions. § As per Clause 3.4.3 of the EIA Study Brief, a comparative assessment
has been carried out to evaluate the potential air quality impacts arising
from the concerned units with and without the Project. The purpose of the comparative assessment
is to demonstrate that the potential air quality impacts from the operation
of new OCGTs (i.e. the proposed GT8, GT9, GT10 and GT11) are lower than those
from the operation of existing OCGTs/CCGT (i.e. GT2, GT3, GT4, GT57 and GT6)
at the identified representative ASRs within the Assessment Area. § If the result of the comparative assessment shows increased air
quality impacts at ASRs due to operation of the new OCGTs, cumulative assessment
would be carried out to evaluate the cumulative impacts at these ASRs against
the new AQOs. |
|
Key Decommissioning/ Demolition and Construction
Impacts |
Minor excavation works during
decommissioning/ demolition and construction phases of the Project are
identified to be the potential dust generating activities. Due to the small-scale demolition and
construction activities, and large separation distance between the worksite
and the nearest ASR, no adverse dust impact arising from the decommissioning/
demolition and construction activities of the Project is anticipated. |
|
Key Operation Impacts |
Stack emissions from the proposed new
OCGTs would be the major air emission source of operation phase air quality
impact. Results of the comparative
assessment show that contribution from the Project (i.e. NO2, SO2,
RSP and FSP) under all phases of “With Project” scenario is lower than that
under “Without Project” scenario at all relevant assessment heights for all
identified ASRs. No adverse air quality impact arising from
the operation of the Project is anticipated. |
|
Key Mitigation Measures |
Decommissioning/ Demolition and Construction
Phases: Dust control measures stipulated in the Air Pollution Control (Construction Dust)
Regulation will be implemented during the decommissioning/ demolition and
construction activities for the Project to reduce the potential fugitive dust
emissions. Requirements stipulated in
the Air Pollution Control (Non-road
Mobile Machinery) (Emission) Regulation and Air pollution Control (Fuel Restriction) Regulation will also be
followed to control emissions from construction plant. In addition, requirements stipulated in Air Pollution Control (Marine Light Diesel) Regulation and Air Pollution Control (Fuel for Vessels) Regulation will be
followed to control potential emissions from marine vessels. Operation Phase: With proper maintenance of the proposed
new OCGTs on a regular basis, no specific mitigation measures are required
during the operation phase. |
|
Residual Impacts |
Decommissioning/ Demolition and Construction
Phases: With the implementation of the
recommended dust control measures, no adverse residual impacts are
anticipated. Operation Phase: With proper maintenance of the proposed
new OCGTs on a regular basis, no adverse residual impacts are anticipated. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts
are acceptable and in compliance with the EIAO-TM
Annexes 4 and 12 and applicable
assessment standards/ criteria. |
Table 9.2
presents a summary of the key findings of the assessment of potential impacts
to ambient noise level as a result of the decommissioning/demolition,
construction and operation of this Project.
Full details of the assessment and mitigation measures are presented in Section
4 of this EIA Report.
Table 9.2 Summary of Environmental Assessment and
Outcomes – Noise
|
Item |
Description |
|
Noise Sensitive Receivers (NSRs) |
In
accordance with Section 3.4.4.2 of the EIA Study Brief, the Assessment Area
for the noise impact assessment covers a distance of 300 m from the boundary
of the Project site. No NSR
was found within the 300m Assessment Area.
Beyond the Assessment Area, two existing NSRs were identified at 810m
and 1,450m from the Project site boundary, and are illustrated in Figure 4.1. |
|
Assessment Methodology and Criteria |
The methodology for the
noise impact assessment is in accordance with the procedures outlined in the GW-TM, which is issued under the NCO and the EIAO-TM. |
|
Key Decommissioning/ Demolition and Construction
Impacts |
Potential
sources of noise impacts during the decommissioning/ demolition and construction
phases of the Project will mainly arise from powered mechanical equipment
(PME) operating at the construction work sites. No NSR was identified within the 300m Assessment
Area, and the nearest NSR is at least 810m from the Project site
boundary. Due to large separation
distance and screening by terrain and existing building structures, the
potential noise impacts arising from the demolition and construction works are
expected to be minimal. No
existing or planned NSR was identified within 300m distance from the Project
site boundary. All NSRs are located
far away from the LPS jetty (at least 1.6km) and further away from the marine
vessel route. With no more than 1 to 2
vessel trips within every 2 days, no adverse noise impact due to marine
traffic during decommissioning/ demolition, and construction phases are
anticipated. |
|
Key Operation Impacts |
Results of quantitative noise assessment
showed that the predicted noise levels at 1m from the façade of the
identified NSR (i.e. N2) comply with the respective noise criteria during
daytime and night-time periods. No adverse
noise impacts due to operation of the proposed new OCGTs are anticipated. |
|
Key Mitigation Measures |
In view of the insignificant noise
impact arising from the Project, no mitigation measures are therefore
required for both construction and operation phases. |
|
Residual Impacts |
In view of the insignificant noise
impact arising from the Project, no residual impacts are anticipated. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts
are in compliance with the EIAO-TM
Annexes 5 and 13 and applicable
assessment standards/ criteria. |
Table 9.3
presents a summary of the key findings of the assessment of potential impacts
to water quality as a result of the decommissioning/ demolition/ construction
and operation of this Project. Full
details of the assessment and mitigation measures are presented in Section
5 of this EIA Report.
Table 9.3 Summary of Environmental Assessment and
Outcomes – Water Quality
|
Item |
Description |
|
Water
Sensitive Receivers (WSRs) |
In accordance with Section 3.4.5.2 of the EIA Study Brief, the
Assessment Area for the water quality impact assessment includes areas within
500m from the boundary of the Project site and covers the Southern WCZ under
the WPCO. A total of five existing WSRs were
identified and illustrated in Figure
5.1. |
|
Assessment
Methodology and Criteria |
The
potential impacts due to the decommissioning/ demolition, and construction of
the Project were assessed following the EIAO-TM
Annex 6 guidelines and the impacts evaluated based on the criteria in EIAO-TM Annex 14. Potential water quality impacts on WSRs
were evaluated according to the corresponding WQO criteria or other proposed
assessment criteria. |
|
Key
Decommissioning/ Demolition and Construction Impacts |
Wastewater, chemical waste or effluent may be generated from the
cleaning process during the decommissioning of the existing units. Sewage effluent from construction workforce
and runoff from work sites may also be generated during the decommissioning/ demolition,
and construction phases. With the
implementation of the recommended management and mitigation measures, no unacceptable
water quality impact is expected from the decommissioning process,
demolition/ construction activities, or sewage effluent from construction
workforce. |
|
Key Operation Impacts |
There will be no cooling water discharge
associated with the operation of the Project and thus water quality impacts
during operation phase are not expected. |
|
Key Mitigation Measures |
Decommissioning Phase: Wastewater, chemical waste and effluent
from cleaning of the existing OCGTs would be collected, stored for proper
disposal by licensed contractor.
Dismantled parts of the existing OCGTs would be removed from the site
as soon as practicable. Before their
removal, these parts would be placed at impervious surface and be protected
from rain. Demolition and Construction Phases: Standard site practices outlined in ProPECC PN 1/94 “Construction Site
Drainage” will be followed as far as practicable in order to reduce
surface runoff, and also to retain and reduce any SS prior to discharge. |
|
Residual Impacts |
With the implementation of the
recommended mitigation measures, no residual impacts are anticipated during
decommissioning/demolition, and construction phases. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts
are in compliance with the EIAO-TM
Annexes 6 and 14 and applicable
assessment standards/ criteria. |
Table 9.4
presents a summary of the key findings of the assessment of the waste
management implications associated with the decommissioning/demolition, construction
and operation of this Project. Full
details of the assessment and mitigation measures are presented in Section
6 of this EIA Report.
Table 9.4 Summary of Environmental Assessment and
Outcomes – Waste
|
Item |
Description |
|
Assessment
Methodology and Criteria |
The potential environmental
impacts associated with the handling and disposal of waste arising from the decommissioning/
demolition, construction and operation of this Project have been assessed in
accordance with the criteria presented in Annexes
7 and 15 of the EIAO-TM: § Estimation of the types and
quantities of the wastes to be generated; and § Assessment of the secondary
environmental impacts due to the management of waste with respect to
potential hazards, air and odour emissions, noise, wastewater discharges and
traffic. The Project would
only generate limited quantity of waste and is not expected to cause any
impacts on the capacity of waste facilities.
The potential impacts on the capacity of waste collection, transfer
and disposal facilities is thus not assessed. |
|
Key
Decommissioning/ Demolition and Construction Impacts |
The key potential impacts during the decommissioning/ demolition, and construction
phases are related to wastes generated from (1) demolition and removal of
existing units and associated equipment, (2) excavation for the construction
of new cable trenches, new staircase and lift, and reconstruction works at
GTAB, (3) Minor civil works for the construction of the new staircase and
lift, (4) chemical waste from decommissioning of existing units, maintenance
of construction plant and equipment, and commissioning of new units, and (5)
general refuse from construction workforce.
All the wastes produced during the decommissioning/ demolition, and construction
phases are of small quantity and will be disposed of accordingly to their
nature and relevant regulations, avoiding any potential adverse impact. |
|
Key Operation Impacts |
General refuse and chemical waste will
be produced during the operation phase. The potential environmental impacts
associated with waste storage, handling, collection, transport and disposal
will meet the criteria specified in the EIAO-TM,
thus no unacceptable operational waste management impact is anticipated. |
|
Key Mitigation Measures |
Decommissioning/ Demolition, and
Construction Phases: A Waste Management Plan (WMP) will be
devised which incorporates recommended mitigation measures that have been
proposed to avoid or reduce potential adverse environmental impacts
associated with handling, collection, transport and disposal of waste arising
from the decommissioning/ demolition and construction of this Project. Operation Phase: General refuse will be collected,
handled, transported and disposed of by existing waste management contractor
at LPS following the existing waste management practices at LPS. Chemical waste will be collected by licenced
chemical waste collectors and delivered to the CWTC for disposal. |
|
Residual Impacts |
With the implementation of the
recommended mitigation measures, in particular the establishment and
implementation of the WMP, no adverse residual impacts are anticipated from
the decommissioning/demolition, construction and operation of this Project. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts
are in compliance with the EIAO-TM
Annexes 7 and 15 and applicable
assessment standards/ criteria. |
Table 9.5
presents a summary of the key findings of the assessment of the potential land
contamination impacts to future land users within the Project site. Full details of the assessment and mitigation
measures are presented in Section 7 of this EIA Report.
Table 9.5 Summary of Environmental Assessment and
Outcomes – Land Contamination
|
Item |
Description |
|
Assessment Methodology and Criteria |
The following legislation and
guiding documents have been considered in the land contamination assessment. § Annex 19 of EIAO-TM; § Guidance Manual for Use of Risk-based Remediation Goals for
Contaminated Land Management (The RBRGs Guidance
Manual); § Guidance Note for Contaminated Land Assessment and Remediation (The Guidance Note); and § The Practice Guide for Investigation and Remediation of
Contaminated Land (The Practice Guide). Apart from the abovementioned,
the following legislation, documents and guidelines may cover or have some
bearing upon the assessment of contamination and the handling, treatment and
disposal of contaminated materials for the Project: § Water Pollution Control Ordinance (WPCO) (Cap 358); § Waste Disposal Ordinance (WDO) (Cap 354); § Waste Disposal (Chemical Waste) (General) Regulation (Cap 354C); and § Code of Practice on the Packaging, Labelling and Storage of
Chemical Wastes. |
|
Key Decommissioning/ Demolition and
Construction Impacts |
The
reclamation for LPS was completed between late 1970s and early 1980s during
which the Project site was vacant. The
existing GT2, GT3, GT4, GT5, GT6 and GT7 were constructed within the Project
site and put into operation in 1989.
GT5 and GT7 were later converted into a CCGT (i.e. GT57) in 2002. The operation of GT compound remained
unchanged since 2002 until present with no historical spillage or leakage
incidents reported. Based on
observations from site walkover conducted in January 2021, the outdoor
portions of whole Project area, including vehicle access roads and outdoor
area, was concrete paved and in good condition. No signs of oil stains or chemical stains
were noted along the access roads as well as the alignment of proposed new
cable trenches during the site walkover. Based on
the site appraisal findings and review of land contamination potentials in
the Project area, SI is recommended at five hotspot locations (i.e. 4
boreholes and 1 trial pit) to assess the potential land contamination impacts
within the Project site. SI and
sampling will be undertaken when the proposed sampling locations are made
available after the demolition of the existing units and structures. |
|
Key Operation Impacts |
Land contamination impacts during the
operation phase are not anticipated. |
|
Key Mitigation Measures |
No mitigation measures are
required. During decommissioning/ demolition,
and construction phases, good house-keeping practices shall be maintained by
the contractor(s) to minimise the risk of land contamination due to
decommissioning/ demolition, and construction activities, including but not
limited to the following: § Minimise the chemical stock
within the Project site, only store the amount of chemicals needed; § Designated chemical/ chemical
waste storage shall be established on concrete paved ground, as far as
practicable. Secondary containments
shall be provided for storage of chemicals/ chemical wastes; § Conduct regular maintenance and
inspection on plants and equipment, particularly those involve the use of
fuel, hydraulic oil or any sort of chemicals; and § Divert rainfall and surface
run-off around construction areas. |
|
Residual Impacts |
No residual impact in respect of land
contamination within the Project site is expected. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts
are in compliance with the EIAO-TM
Annex 19 and applicable assessment standards/ criteria. |
The assessment
of the potential environmental impacts associated with the decommissioning/
demolition, construction and operation phases of the Project at the LPS demonstrated
that the implementation of the Project will not cause adverse or unacceptable
environmental impacts in accordance with the requirements of the EIA Study
Brief and criteria stipulated in the EIAO-TM.
An
environmental audit programme will be implemented to audit the environmental
performance of the Contractor(s) during the implementation of the
decommissioning/ demolition and construction activities and verify the findings
of the EIA study.