This Section identifies and assesses the
potential land contamination impacts due to historical and current land uses
within the Project site. The assessment
was undertaken in accordance with the criteria set out in Annex 19 of the EIAO-TM.
As part of
the land contamination assessment, a Contamination Assessment Plan (CAP) has
been prepared to identify the presence of potential land contamination areas and
investigate the associated land contamination impacts within the Project site due
to past and present operations, and subsequently devise a sampling and testing
plan. The CAP was endorsed by EPD on 13
July 2021 and is provided in Appendix
7A.
The following EPD’s guiding documents are
referenced for this land contamination assessment:
§ Annex 19 of the Technical
Memorandum on Environmental Impact Assessment Process
(Annex 19 of EIAO-TM);
§ Guidance Note for Contaminated Land
Assessment and Remediation (the RBRGs Guidance Note);
§ Guidance Manual for Use of
Risk-based Remediation Goals for Contaminated Land Management (the
RBRGs Guidance Manual); and
§ Practice Guide for Investigation
and Remediation of Contaminated Land (the
Practice Guide).
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 this Project:
§ Dangerous Goods Ordinance
(Cap 295);
§ 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.
The
existing GT2, GT3, GT4, GT57 and GT6 and its auxiliaries, including the transformers,
generator coolers and aboveground lube oil tanks, will be demolished for the installation
of new GT8, GT9, GT10 and GT11. The existing foundation piles and concrete
structure will be reused to support the new units, therefore no corresponding
excavation works will be required for the installation of new units. As part of the Project, the lube oil tank
adjacent to GT5, the existing BSGT at the northwest corner of the GT Compound
and the miscellaneous storage shed immediate south of the BSGT will be
demolished. A new BSGT will be installed
at the same location as the existing BSGT.
Upon
retirement of GT57, the existing GTAB will be converted to a new 132kV Switching
Station. Existing equipment inside the
GTAB (i.e. the main oil tank, chemical dosing pit, miscellaneous gas tanks,
cooling water pumps, generator, generator coolers and lube oil coolers, etc)
will be removed. As part of the
conversion to a new 132kV Switching Station, the existing Turbo Block structure
inside the GTAB will be demolished for reconstruction works which will involve
minor excavation down to 2.6m below ground level (bgl). The construction of new 132kV cable trenches
for the new units will also require minor excavation down to 1.8m bgl. In addition, a New Staircase and Lift will be
constructed at the immediate east of existing GTAB which is currently a
Circulating Water Pipe Room to be demolished under the Project. The construction of the New Staircase and Lift
will require excavation down to 5m bgl and new piles will be installed to
support the said New Staircase and Lift. The existing stacks (80 m tall) serving the
existing OCGTs and CCGT will be retained for the new units. Other existing building structures and
equipment, including the Gas Turbine 132kV Switching Station and Gas Turbine
Equipment Building, will be retained.
In general,
the demolition of abovementioned structures and installation of new OCGTs and
BSGT will not involve earthworks, except minor excavation (down to about 1.8m
bgl) required for the new cable trenches for the new units. The work areas requiring structure removal/demolition
and minor excavation are highlighted in Figure
7.1.
The assessment of potential land contamination impact
within the Project site was conducted by undertaking:
§
A
desktop study to review the hydrogeology of the Site from previous SI conducted
within/ at vicinity of the Project site;
§
A
desktop study to review the current and historical land use information from
Lands Department (LandsD) and publicly available information;
§
A site
walkover to identify the current land uses;
§
A
proposed SI programme, including soil and groundwater sampling and testing at
proposed sampling locations; and
§
Review
of potential contamination sources and possible remediation methods.
A review of
past land uses of the Concerned Areas were conducted by reviewing the aerial
photographs in the years of 1978, 1985, 1991, 1995, 1999, 2002 and 2019. The aerial photographs were obtained from the
Surveys and Mapping Office of the Lands Department. The historical land uses of the Project Site
are presented in Table 7.1.
Table 7.1 Summary of Historical Land Uses of Project
Site
|
Date Began/ Period |
Description
of Site History |
|
1970s
to 1980s |
The
land where the Project site is situated was previously the coastline of Lamma
Island. |
|
1985 |
Reclamation
for LPS was completed between late 1970s and early 1980s.
The Project site was vacant. |
|
1991 |
Construction
of six (6) OCGTs, i.e. GT2 to GT7, was completed and its operation
commissioned in 1989. |
|
2002
- present |
Two
(2) of the OCGTs, i.e. GT5 and GT7, were later converted into a CCGT, i.e.
GT57, in 2002. Reportedly, no
historical spillage and leakage incidents occurred during the conversion
works in 2002. GTAB was constructed at the eastern boundary of
the Project site in early 2000s with the purpose of housing
the steam turbine and the auxiliaries.
The operation of GT compound remained unchanged since 2002 until present. |
Site walkover and site management interview were conducted on 5 January
2021 to observe the Project site conditions and identify signs of potential
contamination. Site observations and
findings were summarised in Table 7.2.
Table
7.2 Summary of Current Land Uses of Project Site
|
Site |
Description of Site Walkovers and Interviews Findings |
|
|
GT Compound |
General |
The outdoor portions of whole Project
site, including vehicle access roads and outdoor area, were concrete paved
and in good condition. No signs of oil
stains or chemical stains were noted along the access roads as well as the
proposed new cable trenches during the site walkover. |
|
|
Six (6) GTs and its auxiliaries |
Each GT was mounted on
foundation pile and concrete structure with support from external steel
reinforcement. Each GT contained one
(1) lube oil tank installed at about 3m aboveground. No underground storage tank (UST) was
installed. Each GT’s auxiliaries, including
transformer and generator cooler, were installed side by side to the GT. Each transformer was constructed within a
concrete containment bund filled with pebbles inside an isolated area. No signs of oil stains were observed. Reportedly, no historical leakage or
spillage incidents were recorded. Each
generator cooler was supported by metal structure and mounted on concrete
footings. The operation of generator
coolers did not require use of fuel and chemicals. During the site walkover, no
significant signs of oil stain and leakage or spillage marks were observed on
the floor of each GT and its auxiliaries. No signs of cracks were noted on the floor. Lube oil pipes and fuel pipes connected to
the GTs were observed in good conditions with no signs of seepage or
corrosion. Six GT transformers were
observed to be well maintained. No
significant signs of stains or odour were noted during the site walkover.
Reportedly by the site management, the composition of transformer oil used
was free of PCBs. Reportedly by site management,
no historical fuel/ chemical spillage or leakage were occurred at the six (6)
GTs and its auxiliaries. |
|
Lube Oil Tank area |
A lube oil tank of about 30,000L
capacity adjacent to GT5 was installed above two (2) concrete footings and
placed within a concrete bund. During
the site walkover, minor black colour deposits (1m2) were noted at
the bottom of the lube oil tank footings and under several pipe joints. The
black deposits were in powder / granular form with no signs petroleum odour
or colour. Reportedly by the site
management, no lube oil leakage incident was recorded in its operation
history. As a result, the black deposits
were likely caused by the erosion of screws / steel bars in the concrete
footings of the lube oil tank. |
|
|
BSGT |
The BSGT comprised one (1) diesel
generator and three (3) air compressor units. No onsite diesel tank was equipped with the BSGT.
Reportedly, diesel was supplied from
an offsite source located 300m north of the Project site to the BSGT. Minor fuel seepage from the
diesel supply pipes was observed to be absorbed by pipe wrapping materials.
No signs of oil leaks on ground were noted during the site walkover. In addition, minor oil stain was observed
in one of the air compressor units. The concrete slabs supporting the BSGT
and air compressor units were intact. |
|
|
GTAB |
One (1) Main Oil Tank of about
30,000L was installed on the ground floor of this building in 2001 and was put into operation in 2003. The Main Oil Tank was constructed within a
concrete bund. No signs of oil leakage
or spillage stains were observed within the bunded area. Oil pipes were also observed in good condition
without signs of seepage or corrosion. The main oil tank and its oil pipes have
been maintained in good condition as they are located in an indoor
environment and protected from extreme weather. No signs of corrosion or cracks were noted
during the site walkover. Reportedly
by site management, no historical fuel/ chemical spillage or leakage
incidents were occurred at the Main Oil Tank. One (1) Chemical Dosing Pit (Hydrazine
Hydrate Tank), which is also a licensed Cat.4 DG storage, was also installed
on the ground floor of this building and it is equipped with mechanical pump
for dosing operation. No signs of
chemical leakage or spillage were observed during the site walkover.
Reportedly by site management, no historical chemical spillage or leakage
incidents were occurred. However, the
potential of mechanical pump oil leakage from the mechanical pump could not
be ruled out. Immediate east to the GTAB is
the Circulating Water Pipe Room. The
emerging sections of two (2) circulating water pipes connected to the
Condenser inside the GTAB were enclosed in this room. No signs of ground contamination was
observed. No current and historical
land contamination activities were noted.
The rest of the ground floor was
occupied by cooling water pumps and miscellaneous gas tanks. No chemical storage or signs of
contaminations were observed during the site walkover. The generator, generator
coolers, lube oil coolers were installed on 1/F and above floors. No potential land contamination impacts
were observed. |
|
|
Miscellaneous
Storage Shed |
Approximately 20 empty chemical
containers without secondary containers were placed in the vicinity of the
Miscellaneous Storage Shed. Several
black stains of about 1m2 were observed on the ground of the
shed’s entrance. |
|
The Project
site are divided into different areas based on their types of structures and
equipment installed to evaluate the likelihood and presence of potential land
contamination hotspots, and the need of SI to assess potential land
contamination impacts.
§
General
§
Six (6)
GTs and its auxiliaries
§
Lube
Oil Tank area
§
BSGT
§
Main
Oil Tank area in GTAB
§
Chemical
Dosing Pit (Hydrazine Hydrate Tank) in GTAB
§
Circulating
Water Pipe Room
§
Miscellaneous
Storage Shed
The
demolition of abovementioned structures and installation of new OCGTs will not
involve any forms of earthworks, such as ground breaking, trenching and
excavation, except minor excavation required for associated new cable trenches
for the new OCGTs (down to about 1.8m bgl).
Minor excavation will also be required for the construction of the New
Staircase and Lift (down to about 5m bgl) and the reconstruction works within
GTAB (down to about 2.6m bgl).
Based on
the site walkover observation, the outdoor portions of whole Project site,
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.
Although
minor excavation works will be required for the construction of new 132kV cable
trenches, the concrete paved surface of Project site was observed to be in good
condition. No historical land
contaminations were identified. Therefore,
the land contamination potential of the outdoor portions of Project Site is
unlikely in general and no sampling locations are required.
No obvious
signs of potential land contamination were noted at the six (6) GTs and its
auxiliaries during the site walkover and review of its operation history.
Each GT was
mounted on a concrete made foundation pile which provided a barrier to prevent
any potential fuel leakage from entering the soil. Each transformer was constructed within a
concrete containment bund filled with pebbles inside an isolated area, which
prevents contamination from entering the ground beneath of the
transformer. No signs of oil stains were
observed. The composition of transformer
oil used was reportedly free of PCBs.
The generator coolers for GT did not require use of fuel and
chemicals. Based on the site walkover
and interview with site management, no historical fuel / or chemical spillage
or leakage were occurred at the six (6) GTs and its auxiliaries.
Review of
historical information indicated the operation in this area remained unchanged
since its operation started in 1989, except the conversion works for OCGT (GT5
and GT7) to CCGT (GT57) in 2002. Reportedly, no historical spillage and leakage
incidents occurred during the conversion works in 2002.
In
addition, no excavation works will be required during demolition of GT structures
and installation of new OCGTs. Therefore,
the overall land contamination potential at the six (6) GTs and its auxiliaries
is considered unlikely. No sampling
locations are required at the six (6) GTs and its auxiliaries.
Based on
the site observation and operation history of the lube oil tank, the black
deposits were likely caused by erosion of screws / steel bars in the concrete
footings of the lube oil tank and at the several pipe joints. The
lube oil tank structure and its piping are also exposed to ambient environment,
thus it could be damaged under extreme weather conditions over the years. Although no significant
signs of potential land contamination were noted in the lube oil tank area, the
potential land contamination risks as a result of long term usage and extreme
weather impacts could not be ruled out.
Considering the lube oil tank was installed within a concrete bund to
contain any potential oil leakage or spillage, the extent of potential
contamination is likely localised.
Therefore,
one (1) sampling location is proposed at the centre of Lube Oil Tank area based
on hotspot sampling approach to represent the overall land condition.
Minor fuel seepage was noted from the diesel supply pipes. Minor oil stains was also observed in one of
the air compressor units. The diesel
supply pipes are also exposed to ambient environment, thus it could be damaged
under extreme weather conditions over the years. Due to its long operation history and its
direct exposure without physical protection, potential land contamination
caused by the fuel leakage could not be ruled out. Since no significant oil stains were noted on
the ground of the BSGT, the extent of potential
contamination is likely localised.
Therefore, two (2) sampling locations are proposed at BSGT, i.e. the
bottom of diesel generator and the bottom of an air compressor unit, based on
the hotspot sampling approach to investigate the potential contamination.
No signs of potential land contamination, including oil stain or colour stain,
were observed at the main oil tank area during the site walkover. According to
the information provided by HK Electric, the Main Oil Tank was fabricated in
2001 and put into operation in 2003. The
Main Oil Tank and its oil pipes have been maintained in good condition as they are
located in an indoor environment. In
addition, the concrete bund that contains the Main Oil Tank and its oil pipes
prevents contamination from entering the ground beneath. No signs of corrosion or damages were noted
at the tank structure and its oil pipes during the site walkover.
Therefore, the good condition of tank structure and oil pipes and the
concrete bund indicated that there’s a remote chance of historical oil leakage
or spillage at the Main Oil Tank area.
In addition, no excavation works will be required during demolition
of main oil tank.
Hence, the land contamination potential is considered
unlikely. No sampling locations are
required at the Main Oil Tank Area.
Minor excavation down to 1.8m bgl
will be required for the construction of new cable trenches for the new OCGTs
under the existing chemical dosing pit (hydrazine hydrate tank) at GTAB after
demolition.
Based on site walkover observation
and interview with site management, the Chemical Dosing Pit (Hydrazine Hydrate
Tank) appeared to be well maintained. No signs of chemical leakage or spillage
were observed. Moreover, the concrete
containment bund surrounding the Chemical Dosing Pit (Hydrazine Hydrate Tank)
prevents contamination from entering the ground beneath. Reportedly by site management, no historical
chemical spillage or leakage incidents were occurred. The risk of hydrazine hydrate being released
into the soil is very low. However,
potential mechanical pump oil leakage as a result of long term usage of the
mechanical pump of the dosing pit could not be ruled out. Due to the small footprint of mechanical
pump, the extent of potential contamination is likely localised.
Therefore, one (1) sampling
location is proposed at the bottom of the mechanical pump of Chemical Dosing
Pit (Hydrazine Hydrate Tank) based on hotspot sampling approach to investigate
the potential land contamination. Due to
shallow excavation depth required for the new cable trenches, trial pit is
recommended as site investigation (SI) method.
No signs of
potential land contamination, including oil stain or colour stain, and no
chemical storage were observed at the Turbo Block structure, miscellaneous gas
tanks and cooling water pumps on G/F during the site walkover. No potential land contamination impacts were
observed at the generator, generator coolers and lube oil coolers that were
installed on 1/F and above floors.
Although
minor excavation works down to 2.6m bgl will be undertaken for the demolition
and reconstruction works at the Turbo Block structure, the chances of
encountering contaminated materials under the Turbo Block structure is very
low. Hence, no sampling location is required
at the other facilities in GTAB.
The
Circulating Water Pipe Room only served to enclose the emerging section of two
(2) circulating water pipes connected to the Condenser inside the GTAB. No current and historical land contamination
activities were noted. Although deep excavation works down
to 5m bgl will be undertaken for the construction of New Staircase and Lift,
the chances of encountering contaminated materials under the Circulating Water
Pipe Room during the construction phase is very low. Therefore, no sampling location is proposed at the Circulating Water Pipe
Room.
Based on
the observation during the site walkover, approximately 20 empty chemical
containers without secondary containers were placed in the vicinity of the
Miscellaneous Storage Shed. The area of
Miscellaneous Storage Shed is about 40 m2. In addition, two black stains of about 1m2
in total were observed on the ground of the shed’s entrance. The potential land contamination from fuel or
chemical leakage is likely. Considering the small footprint of black stains
observed onsite, the extent of potential contamination is likely localised.
Therefore, one (1) sampling location is proposed at the shed entrance based
on hotspot sampling approach to
investigate the potential contamination at the black stains.
A SI plan
was proposed in the CAP provided in Appendix
7A to assess the potential contamination in the hotspots locations
of Project site.
Details of
the proposed SI plan are summarised in Table 7.3. The proposed sampling locations are presented
in Figure 7.2. Since the Project site area is still in use
at the time of preparing this EIA, the proposed sampling locations are not
accessible at the moment. SI and
sampling shall be carried out when the proposed sampling locations are
available after the demolition stage.
During the
demolition stage, a Land Contamination Specialist shall oversee the removal /
demolition process and record any new visual signs of potential contamination
such as oil leakage or oil stains. The Land Contamination Specialist shall also
review the need of additional sampling to capture potential contamination
observed during the demolition stage.
Table 7.3 Summary of
SI Plan
|
Potentially Contaminated Area |
Sampling Location ID |
Proposed Coordinates (a) |
RBRGs Land Use Scenario |
Proposed Testing Parameters |
Soil Sampling |
Groundwater |
|
Depths (m bgl) |
Sampling Depths (m bgl) |
|||||
|
Lube Oil Tank area |
BH1 |
E: 828818.021 N: 808678.132 |
Industrial |
Metals (b), PCRs (c), VOCs (d), SVOCs (e) |
Manual excavation of Inspection Pit (0-1.5m bgl): n To
collect disturbed sample at 0.5m bgl Rotary Drilling of boreholes (1.5-7.0m bgl): n Continuous
drilling and retrieving of soil materials for visual inspection at every 1m
from the bottom of inspection pit to a maximum depth of 7 m bgl or 2m below
static groundwater level, whichever shallower. To collect undisturbed soil samples at 3.0 m and 6.0 m bgl |
Collect one (1) groundwater sample at static groundwater
level, if groundwater is encountered before end of borehole. |
|
BSGT |
BH2 |
E:828699.830 N:808748.382 |
Industrial |
Metals (b)
PCRs (c), VOCs (d) , SVOCs (e) |
||
|
BH3 |
E:828702.277 N:808740.643 |
Industrial |
Metals (b)
PCRs (c), VOCs (d) , SVOCs (e) |
|||
|
Miscellaneous Storage Shed Entrance |
BH4 |
E:828699.301 N:808729.200 |
Industrial |
Metals (b)
PCRs (c), VOCs (d), SVOCs (e) |
||
|
Mechanical Pump of Chemical Dosing Pit
(Hydrazine Hydrate Tank) |
TP1 |
E: 828922.015 N: 808675.576 |
Industrial |
Metals (b)
PCRs (c), VOCs (d), SVOCs (e) |
Manual excavation of trial pit (0-2.0m bgl): n To
collect disturbed sample at 0.5m, 1.0m and 2.0m bgl |
No groundwater sampling is required as the excavation
depth of trial pit is shallower than the anticipated groundwater table at
3.85m bgl. |
|
Notes: m bgl = meter below ground level. (a) By
experience, the exact sampling locations will be determined by on-site Land
Contamination Specialist and subject to adjustment due to site-specific
conditions/ constraints (e.g. presence of underground utilities,
foundations, insufficient headroom, spaces occupied by vehicles, etc) during
the actual SI. (b) Metals:
For soil: Antimony, Arsenic, Barium, Cadmium, Cobalt, Copper, Lead, Manganese, Molybdenum, Nickel,
Tin, Zinc, Mercury, Chromium (III) and Chromium (VI); For groundwater: Mercury (c) PCRs:
C6 – C8, C9 – C16 and C17 – C35 (d) VOCs:
For soil and groundwater: Acetone, Benzene, Bromodichloromethane,
2-Butanone, Chloroform, Ethylbenzene, Methyl tert-Butyl Ether, Methylene
Chloride, Styrene, Tetrachloroethene, Toluene, Trichloroethene and Xylenes
(Total) (e) SVOCs:
For soil: Acenaphthylene, Acenaphthene, Anthracene, Benzo(a)anthracene,
Benzo(a)pyrene, Benzo(b)fluoranthene, Benzo(k)fluoranthene,
Benzo(g,h,i)perylene, Bis-(2- ethylhexyl)phthalate, Chrysene,
Dibenz(a,h)anthracene, Fluoranthene, Fluorene, Hexachlorobenzene,
Indeno(1,2,3cd)pyrene, Naphthalene, Phenanthrene, Phenol and Pyrene. |
||||||
Based on
the site appraisal findings, only four (4) areas, i.e. Lube Oil Tank area, BSGT,
Miscellaneous Storage Shed Entrance, and Mechanical Pump of Chemical Dosing Pit
(Hydrazine Hydrate Tank) were identified as potential land contamination
hotspots. The land contamination issues
are considered surmountable due to the following reasons as discussed below.
(1) Localised
contamination in the identified hotspots:
Based on
the site appraisal, these potential contamination hotspots have small footprint
in general. These areas are typically affected by potential contaminating
activities such as small scale of fuel or chemical storage. Therefore, it is anticipated that the extent
of land contamination, if any, would be localised.
(2) Chemical
of Concerns (COCs) identified are treatable with existing remediation
techniques:
Based on
the site appraisal, the identified COCs include metals, VOCs, SVOCs and PCRs. Remediation methods that have demonstrated to
effectively treat the aforementioned soil and groundwater contaminants include
biological treatment and physical / chemical treatment.
In addition, the soil contaminated with the abovementioned COCs had
successfully been remediated in Hong Kong using proven remediation techniques. Notable local remediation projects include the
following:
§
Decommissioning
of Kai Tak Airport North Apron;
§
Decontamination
works at the Cheoy Lee Shipyard;
§
Reclamation
works at North Tsing Yi Shipyard site;
§
Decommissioning
of Kwai Chung Incinerator; and
§
Isolated
sites in the Deep Bay Link project.
Provided
that the soil and groundwater contamination identified during the SI, if any,
are properly treated using the appropriate remediation techniques in accordance
with the approved Remediation Action Plan (RAP), adverse land contamination
impacts associated with the Project is not expected.
As adverse
land contamination impacts associated with the Project is not expected, no
mitigation measures specific to the Project are recommended.
However, a
number of recommendations as discussed in the following sub-sections should be
followed during the demolition and construction phases of the Project in order
to minimise the risk of land contamination.
Prior to
commencement of demolition works in the Project site, the leftover diesel or
other petroleum products in the equipment to be demolished shall be removed as
much as possible. The removed diesel and other petroleum products are
considered as chemical waste and are controlled under the Waste Disposal (Chemical Waste)(General) Regulation. The demolition contractor who will generate the
chemical waste or cause it to be produced should register with the EPD as a
chemical waste producer. Removed diesel
and petroleum products shall be labelled and stored in accordance with the
requirement stipulated in the Code of
Practice on the Packaging, Labelling and Storage of Chemical Wastes issued
by EPD. The removed petrol and petroleum
products are required to be collected by licensed chemical waste collector for
disposal. Trip tickets system shall be
implemented during the collection and disposal of removed petrol and diesel.
During
demolition and construction phases, the following good housekeeping practices
shall be implemented to ensure that risk of ground contamination as a result of
oil spills or leaks is kept to a practical minimum:
§
Regular
visual inspections to detect any early signs of fuel leakage prior to
demolition;
§
Provision
of impermeable lining or absorbent materials to contain leaks;
§
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;
§
Provision
of secondary containment for the temporary storage of removed diesel or
petroleum products, demolished structures and pipes;
§
Provision
of spill control materials and equipment;
§
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.
To ensure the recommendations discussed in Section
7.9 are properly implemented, regular site inspections should be
carried out during the demolition and construction phases of the Project.
Based on the site appraisal findings, Lube Oil Tank area, BSGT, Chemical
Dosing Pit (Hydrazine Hydrate Tank) and Miscellaneous Storage Shed are considered
as the potential land contamination hotspots within the Project site. Five (5) sampling locations (BH 1 to BH4 and
TP1) are proposed for SI to collect soil and groundwater samples for laboratory
testing.
Since the
Project site is still under active operation at the time of preparing this EIA,
the proposed sampling locations are not accessible at the moment. SI and sampling shall be carried out when the
proposed sampling locations are available after the demolition stage.
During the
demolition stage, a Land Contamination Specialist shall oversee the removal /
demolition process and record any new visual signs of potential contamination
such as oil leakage or oil stains. The Land Contamination Specialist shall also
review the need of additional sampling to capture potential contamination
observed during the demolition stage.
Provided that the soil and groundwater
contamination identified during the SI, if any, are properly treated using the
appropriate remediation techniques in accordance with the approved Remediation
Action Plan (RAP), adverse land contamination impacts associated with the
Project is not expected.
Upon
completion of the remediation works (if necessary), a Remediation Report (RR)
will be prepared and submitted to EPD for approval. No
construction works within the contaminated area should be carried out prior to
the approval of the RR by EPD.