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Expansion of Hong Kong International Airport into a Three-Runway System |
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Figure 1.1 Land Contamination
Assessment Areas
Figure 3.1 Photographic Record
of Land Contamination Assessment Areas (Sheet 1 of 3)
Figure 3.2 Photographic Record
of Land Contamination Assessment Areas (Sheet 2 of 3)
Figure 3.3 Photographic Record
of Land Contamination Assessment Areas (Sheet 3 of 3)
Figure 4.1 Proposed Sampling
Locations for Fire Training Facility
1
Introduction
1.1
Background
The Environmental Impact Assessment (EIA)
Report (Register No.: AEIAR-185/2014) prepared for the “Expansion of Hong Kong
International Airport into a Three-Runway System” (the project) has been
approved by the Director of Environmental Protection, and an Environmental
Permit (EP) (Permit No.: EP-489/2014) has been issued for the project under the
Environmental Impact Assessment Ordinance.
As part of the EIA study, a Contamination
Assessment Plan (CAP) (hereafter referred to as the Approved CAP) was prepared
and presented as Appendix 11.1 of the approved EIA Report. In accordance to
Section 8.1.1.1 of the Updated Environmental Monitoring and Audit (EM&A)
Manual, which was submitted under Condition 3.1 of the EP, and Section
11.10.1.2 of the EIA Report, six areas (i.e. fuel tank room within Terminal 2
(T2) building, fuel tank room to the west of Civil Aviation Department (CAD)
antenna farm, seawater pump house, switching station, pumping station and fire
training facility), as presented in Figure 1.1,
were inaccessible for site reconnaissance at the time of preparing the EIA
Report.
According to Sections 11.5.4.14 and 11.5.4.37
of the EIA Report, it is anticipated that any potential land contamination
concern related to possible leakage/ spillage of fuel in the fuel tank room
within T2 building and fuel tank room to the west of CAD antenna farm will not
cause any insurmountable impact. Furthermore, as mentioned in Sections
11.5.4.38, 11.5.4.47 and 11.5.4.50 of the EIA Report, the seawater pump house,
switching station, pumping station and fire training facility are not
identified as potential contaminative land use types as given in Table 2.3 of
the Practice Guide for Investigation and Remediation of Contaminated Land,
hence no potential land contamination along these areas are anticipated.
As part of the ongoing detailed design of the
project, relocation of the switching station is no longer required for the
modification of existing North Runway. Hence site appraisal process for land
contamination potential at the switching station is considered not necessary.
Further site reconnaissance was conducted at the remaining five assessment
areas (i.e. the fuel tank room within T2 building, fuel tank room to the west
of CAD antenna farm, seawater pump house, pumping station and fire training facility)
in third quarter of 2016 and May 2017. Findings and consideration of the above
five assessment areas are summarized in this Supplementary CAP.
Through further review of the as-built drawings
when taking into account the latest design details of T2 Expansion project and
planned site investigation (SI), as well as follow-up site reconnaissance at T2
building undertaking in January 2018 and February 2018 (i.e. fuel tanks and
generators within the building), enhanced site investigation (SI) for T2
building are then proposed and included in this Supplementary CAP. Mott
MacDonald Hong Kong Limited (MMHK), as the project’s Environmental Team, was
appointed by Airport Authority Hong Kong (AAHK) to prepare the Supplementary
CAP to fulfil the EP Condition 2.20.
1.2
Objectives
This Supplementary CAP are to:
● Fulfil Environmental Permit (EP)
(Permit No.: EP-489/2014) Condition 2.20;
● Ascertain and review contamination
evaluation and SI proposed in EIA report in Year 2014 base on latest project
design and site condition;
● Present the findings of further
review of the as-built drawings;
● Present the findings of follow-up site reconnaissance in third quarter
of 2016, May 2017, as well as January and February 2018;
● Propose, where necessary, additional and enhancement on site
investigation (SI) with justification;
● Propose, where necessary, sampling and laboratory chemical analysis
required to confirm if any land contamination occurred, and
● Propose, where necessary, sampling and laboratory chemical analysis
required to determine the nature and extent of any potential land contamination
identified.
After the completion of SI works, if any, the
results will be reported in the Contamination Assessment Report (CAR).
Nevertheless, it is anticipated that any potential land contamination concern
related to possible leakage/ spillage of fuel is not anticipated to cause any
insurmountable impact.
1.3
Report Structure
Section
1 Introduction
Section
2 Assessment Criteria and
Methodology
Section
3 Appraisal of Land
Contamination Potential
Section
4 Proposed Site
Investigation Works
Section
5 Proposed Laboratory
Analysis
Section
6 Potential Remediation
Measures
Section
7 Conclusion
2
Assessment Criteria and Methodology
2.1
Relevant
Standards, Guidelines and Requirements
As described in Section 11.2 of the EIA Report,
EPD promulgated two guidelines for utilising the Risk-based Remediation Goals
(RBRGs) developed for Hong Kong, namely, “Guidance Note for Contaminated Land
Assessment and Remediation” (Guidance Note) in August 2007 and “Guidance Manual
for Use of Risk-based Remediation Goals for Contaminated Land Management”
(Guidance Manual) in December 2007. The land contamination assessment
should be carried out in accordance with the Guidance Manual and Guidance Note
as well as section 3 of Annex 19 of the Technical Memorandum on EIA Process
issued under the EIA Ordinance (EIAO-TM). In addition, reference would also be
made to the “Practice Guide for Investigation and Remediation of Contaminated
Land” (Practice Guide).
2.2
Assessment
Methodology
Site reconnaissance was undertaken to identify
the presence of any potentially contaminative land within the assessment areas.
Relevant information was gathered with collection of latest records from the
relevant Government departments and reviewed in preparing the Supplementary
CAP, including:
● The Approved CAP;
● Records of active (current) and inactive (past) registered chemical
waste producers at the assessment areas from the EPD;
● Records of current and past dangerous goods (DG) licences at the
assessment areas from the Fire Services Department (FSD);
● Records of accidents that involved spillage/ leakage of chemical waste
or DG from EPD and FSD; and
● Relevant as-built drawings.
Follow-up site reconnaissance was then
conducted accordingly to countercheck with the consolidated information.
3
Appraisal of Land
Contamination Potential
3.1
Review
of Relevant Information from Government Departments
Information from the EPD and FSD have been
collected and reviewed during the EIA stage. The EPD and FSD have been
re-contacted to collect the latest information of the assessment areas to
confirm the findings in the EIA Report. Latest information collected are listed
below:
● Records of active (current) and inactive (past) registered chemical
waste producer(s) and any reported accidents of chemical spillage/leakage at
the assessment areas; and
● Records of any licensed DG store(s) and any reported accidents of
spillage/ leakage of DG at the assessment areas.
Relevant documentation from EPD and FSD is
provided in Appendix A and the information
provided is summarised below.
3.1.1
Environmental
Protection Department
A review of the chemical waste producer (CWP)
records was conducted at the EPD’s Territory Control Office. No registered CWP
was identified at the assessment areas.
Based on the information given by EPD, there is
no record of chemical spillage/ leakage within the assessment areas as shown in
Appendix A.
The above-mentioned findings are consistent
with the information presented in Section 11.5.1.3 of the EIA Report.
3.1.2
Fire
Services Department
According to the reply from FSD, there are
three DG records at the assessment areas including a 900 L diesel tank at the
fuel tank room to the west of CAD antenna farm, a 3,000 L above-ground diesel
tank at the fuel tank room within T2 building and a 10,000 L above-ground
kerosene tank at the fire training facility. The DG records are considered
valid based on the findings of the site reconnaissance survey as presented in Section
3.2.
FSD reported that no incident of
spillage/ leakage of DG was found within the assessment areas. The response
from FSD is shown in Appendix A.
3.2
Site Reconnaissance Survey
As mentioned in Sections 11.5.4.14 and
11.5.4.37 of the EIA Report, the fuel tank room to the west of CAD antenna farm
and fuel tank room within T2 building were inaccessible due to safety and
operational issues. SI has been proposed at these areas based on relevant
drawings during EIA stage. As mentioned in Sections 11.5.4.38, 11.5.4.47 and
11.5.4.50 of the EIA Report, seawater pump house, pumping station and fire
training facility were inaccessible. Relevant site reconnaissance surveys of
these areas have been conducted in 2016 and 2017. A site walkover checklist has
been filled in upon completion of site reconnaissance at each assessment area.
Follow-up site reconnaissance survey of
concerned fuel tanks and generators within T2 building was conducted in January
and February 2018, so as to countercheck the site condition with consolidated
information and as-built drawings, with details elaborated in Section 3.2.5
of this Supplementary CAP.
3.2.1
Fuel Tank Room to the West of CAD Antenna Farm
Access to the fuel tank room to the west of CAD
antenna farm was granted by CAD operator and site reconnaissance survey was
carried out on 18 May 2017. During the survey, a 900 L above-ground tank
containing diesel fuel was found. The diesel fuel is used for the emergency
power supply system. The tank is located on a concrete-paved ground and
equipped with drip tray. Bund wall is also provided in the access of the fuel
tank room. No oil stain or crack was found on the ground. SI has been proposed
in Section 11.6.2.4 of the EIA Report for the above-ground fuel tank to
ascertain any potential contamination issues before commencement of any
construction works at this area. The proposed SI locations in the EIA Report
(i.e. BH16 and BH17) are still considered valid. The drawing
MCL/P132/EIA/11-015 documented in the EIA Report is presented in Appendix C.1 for reference.
The completed site walkover checklist and the
photographic records of the fuel tank room to the west of CAD antenna farm are
provided in Appendix B.1 and Figure 3.1 respectively.
3.2.2
Seawater
Pump House
As described in Section 11.5.4.38 of the EIA
Report, the seawater pump house is used for delivering cooling water to
different facilities for the operation of airport. A site reconnaissance survey
was carried out at the seawater pump house on 22 September 2016. During
the survey, it was observed that only seawater pumps and control panels are
located in the seawater pump house. The ground surfaces of seawater pump house
are fully paved with intact concrete and no apparent stains were observed. Therefore,
no signs of land contamination were observed at the seawater pump house during
the survey.
As mentioned in Section 11.5.4.38 of the EIA
Report, seawater pump house is not identified as one of the potential
contaminative land use types in accordance with Table 2.3 of the Practice
Guide. Therefore, taking into account the latest available information and the
findings of site reconnaissance survey, no potential land contamination is
anticipated at the seawater pump house and thus SI has not been recommended.
The completed site walkover checklist and the
photographic records of the seawater pump house are provided in Appendix B.2 and Figure
3.1 respectively.
3.2.3
Pumping
Station
As mentioned in Section 11.5.4.47 of the EIA
Report, the pumping station is used to convey sewage from T2 building. A site
reconnaissance survey was carried out at the pumping station on 8 December
2016. During the survey, it was observed that control panels are located on the
concrete-paved ground. Two sewage pumps are located underground to convey
sewage from T2 building. No apparent stains were observed at the ground
surface. As mentioned in Section 11.5.4.47 of the EIA Report, pumping station
is not identified as one of the potential contaminative land use types in
accordance with Table 2.3 of the Practice Guide. Therefore, taking into account
the latest available information and the findings of site reconnaissance
survey, no potential land contamination is anticipated at the pumping station
and thus SI has not been recommended.
The completed site walkover checklist and the
photographic records of the pumping station are provided in Appendix B.3 and Figure
3.2 respectively.
3.2.4
Fire
Training Facility
As mentioned in Section 11.5.4.50 of the EIA
Report, the fire training facility is used for fire training exercises. Access
was granted by FSD operator and a site reconnaissance survey was carried out at
the fire training facility in May 2017. A simulator is located at the centre of
facility for fire training exercise. The whole training area is concrete paved.
No oil stain or crack was found on the ground. An effluent pit is located under
the simulator for collection of stormwater and water generated from fire
training exercise. The collected stormwater will be stored in the three
underground storage tanks and convey to the wastewater treatment plant for
treatment.
As mentioned in Section 11.5.4.50 of the EIA
Report, fire training facility is not identified as one of the potential
contaminative land use types as given in Table 2.3 of the Practice Guide.
During the survey, a 10,000 L above-ground tank containing kerosene was found.
The tank is located on a concrete-paved ground and is surrounded by concrete
bund wall on all four sides. No oil stain or crack was found on the ground.
According to the latest information from detailed design consultant, a new fire
training facility is planned to be constructed in the western support area to
replace the existing training facility; however, demolition of the existing
above-ground kerosene tank is yet to be confirmed and still subject to detailed design. SI is
proposed for the kerosene tank to ascertain any potential contamination issues
before commencement of any construction works at this area, and details will be
discussed in Section 4. Nevertheless, it is anticipated that any
potential land contamination concern related to possible leakage/spillage of
fuel will not cause any insurmountable impact.
The completed site walkover checklist and the
photographic records of the fire training facility are provided in Appendix B.4 and Figure
3.3 respectively.
3.2.5
T2 Building
T2 building comprises northern and southern
sections, where each section consists of number of Emergency Generator Rooms
and Fuel Tank Rooms. A site reconnaissance survey was carried out at one of the
Fuel Tank Room within T2 building in May 2017, focusing on the 3,000 L
above-ground fuel tank (i.e. BH9). Relevant site walkover checklist and
photographic records are presented in Appendix B.5
and Figure 3.2 respectively.
Follow-up site reconnaissance survey conducted
in early 2018 has covered Fuel Tank Rooms and Emergency Generator Rooms in T2
building, including location BH1 – BH10 proposed in the EIA Report, as well as
several concerned facilities identified in the as-built drawings. Those
identified as potential land contamination sources are provided in Table 3.1. Newly identified potential sources
thereafter annotated as HS. Locations please refer to the drawing for T2
building MCL/P132/EIA/11-014 with mark-up and associated zoom-in view in Appendix C.2.
Table 3.1: Potential Land Contamination Sources in T2 building
Northern Section of T2 Building
Emergency Power Supply System No.1 (BH1, BH2,
BH3 and BH4)
This set of emergency power supply system
comprises underground and above-ground section.
Underground section refers to the 2,500 L
underground fuel tank containing diesel fuel (i.e. BH1) and its associated
underground fuel pipelines 53 m in length (i.e. BH2). The 2,500 L underground
fuel tank is fully encased in a 300 mm thick concrete chamber with manhole
chamber at floor level for inspection purpose, while space between the tank and
the concrete chamber is filled with sand. The quantity of fuel inside the tank is automatically monitored by level sensor.
According to available maintenance record, the sensor has been malfunction
since August 2016. Instead, manual monthly fuel level measurement and
monitoring have been conducted by using dipstick since then. As no abnormality
on fuel re-filling record have been observed, it is considered that there have
been no loss of fuel as reported by the maintenance staff. The 53
meter-in-length underground pipeline is laid inside 100mm thick concrete trench
backfilled with sand, located approximately 1.5 m below ground level.
Above-ground section refers to the
450 L above-ground fuel tank containing diesel fuel equipped with drip tray
(i.e. BH 3) and the emergency generator (i.e. BH 4) both located at an
Emergency Generator Room. Both fuel tank and generator are mounted on intact
concrete floor with no oil stain. The above-ground fuel tank was surrounded by
concrete curb. The fuel pipelines running through BH3 and BH4 are buried by
sand inside a concrete and brick trench at floor level. Physical check of
pipelines is possible by removing the chequer plate cover. System details are
shown in drawings in Appendix E.1.
With regard to operation, this set of emergency
power supply system (i.e. BH1 – BH4) has operated only for monthly test run
(30-60 minutes for each run) since installation. The manhole chamber of
underground fuel tank is checked monthly, while the underground fuel tank is
re-filled approximately every 6 months.
For above-ground section (i.e. BH3 and BH4),
taking into account of the facilities setup and operational schedule, with no
record of fuel leakage, the potential of
contamination is considered to be very unlikely; therefore, SI is considered
not required for the 450 L above-ground fuel tank and the emergency generator.
On the contrary, final inspection and record checking should be conducted right
before decommissioning/ demolition of these facilities to ensure no
contaminative activities during the period from now on till the decommissioning.
For underground section (i.e. BH1 and BH2),
even the facilities are installed underground making physical inspection not
possible, the high-standard engineering design (i.e. 300 mm thick concrete
chamber of the fuel tank and 100 mm thick concrete trench of fuel pipelines),
plus no record implying fuel leakage, the potential of contamination is
anticipated to be unlikely. To confirm no potential land contamination taken
place, an
enhanced SI programme is designed for the concerned underground facilities. Therefore,
the proposed SI locations in the EIA Report (i.e. BH1 and BH2) are still
considered valid in this Supplementary CAP.
Emergency Power Supply System No.2 (BH9 and
HS1)
The 3,000 L above-ground fuel tank with drip
tray (i.e. BH9) at Fuel Tank Room containing diesel fuel, as recorded in the
site reconnaissance survey in May 2017, is connected to two emergency
generators located at the adjacent Emergency Generator Room (i.e. HS 1) which
was newly identified in January 2018. Fuel pipelines running through the two
facilities are either wall penetrating, or through concrete and brick trench
filled with sand at floor level. Physical check of pipelines is possible by
removing the chequer plate cover. Both of the concerned facilities (i.e. BH9
and HS1) being mounted on intact concrete floor with no oil stain. Bund wall is
provided in the access of the fuel tank room. Reference to be made to drawings
in Appendix E.2.
In terms of operation, this set of emergency
power supply system has operated only for monthly test run (30-60 minutes for
each run) since installation. The fuel tank is checked monthly and re-filled
approximately every 6 months. The quantity of fuel inside the tank is monitored
by level sensor while no sign of leakage being detected.
In view of facilities setup and operational
schedule, with no record of fuel leakage, the potential of contamination is
considered to be very unlikely; therefore, SI is considered not required for
the above-ground fuel tank (i.e. BH9). For HS1, even though lubricating oil
seepage during machine operation (i.e. Solely monthly test run) from engine
flywheel/ engine body of one of the generators was recorded from June 2016 to
March 2018 as shown in the available maintenance record, maintenance staff
ensured that immediate clean-up of seepage was undertaken after every
operation.
No cracks or oil stain on the intact concrete
plinth underneath HS1 was observed according to site reconnaissance survey in
January 2018. Based on the facility setup and site survey findings, it is
considered that the contamination potential of
seepage lubricating oil is very unlikely. (Refer to photo records in Appendix E.2). Hence, HS1 shared the same
strategy with BH9 where SI works is considered not required. Instead, final
inspection and record checking should be conducted right before
decommissioning/ demolition of these facilities to ensure no contaminative
activities during the period from now on till the decommissioning.
Southern Section of T2 Building
Emergency Power Supply System No.3 (BH5, BH6,
BH7 and BH8)
This set of emergency power supply system
comprises underground and above-ground section, shared similar component design
to the Emergency Power Supply System No.1 (i.e. BH1 – BH4) at northern section.
Underground section refers to the 3,000 L
underground fuel tank containing diesel fuel and its associated underground
fuel pipelines 26 m in length, known as sampling locations BH5 and BH6
respectively. The 3,000 L underground fuel tank is fully encased in a 300 mm
thick concrete chamber with a manhole chamber at floor level for inspection
purpose, while space between the tank and the concrete chamber is filled with
sand. The quantity of fuel inside the tank is automatically monitored by level
sensor while no sign of leakage has been detected. The 26 meter-in-length
underground pipeline is laid in 100mm thick concrete trench backfilled with
sand.
Above-ground section refers to the 450 L
above-ground fuel tank containing diesel fuel equipped with drip tray (i.e.
BH7) and the emergency generator (i.e. BH8) both located at an Emergency
Generator Room. Both fuel tank and generator are mounted on intact concrete
floor with no oil stain.
The above-ground fuel tank was surrounded by
concrete curb. The fuel pipelines running through BH7 and BH8 are laid inside
sand filled concrete and brick trench at floor level. Physical check of
pipelines is possible by removing the chequer plate cover. System details are
shown in drawings in Appendix E.3.
In operational means, this set of emergency
power supply system (i.e. BH5 – BH8) has operated only for monthly test run
(30-60 minutes for each run) since installation. The manhole chamber of
underground fuel tank is checked monthly, while the underground fuel tank is
re-filled approximately every 6 months. Even seepage of lubricating oil from
side cover of the emergency generator (i.e. BH8) had been recorded from Jun
2016 to Feb 2017 as shown in the available maintenance record, maintenance
staff ensured that immediate clean-up of seepage was undertaken after every
operation. The lubricating oil seepage problem was then solved in a
comprehensive repair conducted in Feb 2017. Neither cracks nor oil stain was
observed on the intact concrete plinth underneath BH8 in site reconnaissance
survey in January 2018. Taking into account of facility setup and site survey
observation, it is considered that the contamination potential of seepage
lubricating oil is very unlikely. (Refer to photo record in Appendix E.3)
For above-ground section (i.e. BH7 and BH8), in
view of the facilities setup and operational schedule, with no record of fuel
leakage, the potential of contamination is considered to be very unlikely;
therefore, SI is considered not required for the 450 L above-ground fuel tank
and the emergency generator. On the contrary, final
inspection and record checking should be conducted right before
decommissioning/ demolition of these underground facilities to ensure no
contaminative activities during the period from now on till the
decommissioning.
For underground section (i.e. BH5 and BH6),
even the facilities are installed underground making physical inspection not
possible, the high-standard engineering design (i.e. 300 mm thick concrete
chamber of the fuel tank and 100 mm thick concrete trench of fuel pipelines),
plus no record implying fuel leakage, the potential of contamination is
anticipated to be unlikely. To confirm no potential contamination taken place,
an enhanced SI programme is designed for the concerned underground facilities.
Therefore, the proposed SI locations in the EIA Report (i.e. BH5 and BH6)
are still considered valid in this Supplementary CAP.
Emergency Power Supply System No. 4 (BH10, HS2
and HS3)
The system comprises the 1,500 L above-ground
fuel tank containing diesel fuel at Fuel Tank Room equipped with drip tray
(i.e. BH10) and a newly identified emergency generator at Emergency Generator
Room (i.e. HS2) and the 44 m-in-length underground fuel pipelines running
through the two facilities (i.e. HS3).
High-standard engineering design was found in
facilities setup. Both above-ground facilities (i.e. BH10 and HS2) are mounted
on intact concrete floor with no oil stain. Curb by builder is also provided in
the Fuel Tank Room. The underground pipeline (i.e. HS3) is laid in concrete
trench 1 m below ground level backfilled with mass/sand. System details are
shown in drawings in Appendix E.4.
In terms of operational schedule, this set of
emergency power supply system (i.e. BH10, HS2 and HS3) has operated only for
monthly test run (30-60 minutes for each run) since installation. The fuel tank
is checked monthly and re-filled approximately every 6 months. Level sensor is
incorporated in the above-ground fuel tank to monitor the quantity of fuel
while no sign of leakage being detected as illustrated in the available
maintenance record.
Through taking into account the facilities
setup and operational means, the potential of contamination from BH10 and HS2
are therefore considered to be very unlikely. SI is considered not required for
the 1,500 L above-ground fuel tank (i.e. BH10) and the emergency generator
(i.e. HS2). For the underground fuel pipelines (i.e. HS3), even physical
inspection is not possible, the high-standard engineering design (i.e. concrete
trench filled with mass/sand), plus no record implying leakage, supported that the
potential of contamination is therefore considered to be unlikely. To confirm
no potential contamination taken place, an enhanced SI programme is designed
for the concerned underground facilities.
Emergency Power Supply System No. 5 (HS4 and
HS5)
This set of emergency power supply system are
newly identified in further as-built drawings review. The system comprises the
1,500 L above-ground fuel tank containing diesel fuel with drip tray at Fuel
Tank Room (i.e. HS4) and the emergency generator at Emergency Generator Room
(i.e. HS5). The fuel pipelines running through the two facilities are either
wall penetrating or laid in a concrete and brick trench filled with sand at
floor level. Physical check of pipelines is possible by removing the chequer
plate cover. Both concerned facilities (i.e. HS4 and HS5) are mounted on intact
concrete floor with no oil stain. Curb wall is also provided in the access of
the fuel tank room. System details are shown in drawings in Appendix E.5.
In terms of operation, this set of emergency
power supply system has operated only for monthly test run (30-60 minutes for
each run) since installation. The fuel tank is checked monthly and re-filled
approximately every 6 months. The quantity of fuel inside the tank is monitored
by level sensor while no sign of leakage being detected. Based on the facility
setup and site survey observation, it is considered that the contamination
potential is very unlikely. (Refer to photo record in Appendix E.5)
Even though lubricating oil seepage from engine
body and engine flywheel of the emergency generator (i.e. HS5) was recorded
from January 2017 to March 2018 in reviewed maintenance record, maintenance
staff ensured that immediate clean-up of seepage was undertaken after every
operation. Neither cracks nor oil stain was observed on the intact concrete
plinth underneath HS5 in site reconnaissance survey in February 2018. Taking
into account of facility setup and site survey observation, it is considered that
the contamination potential is very unlikely. (Refer to photo record in Appendix E.5)
In view of facilities setup and operational
schedule, with no record of fuel leakage, the
potential of contamination is considered to be very unlikely. Therefore, SI is
considered not required for the 1,500 L above-ground fuel tank and the
emergency generator. Instead, final inspection and record checking should be
conducted right before decommissioning/ demolition of these facilities
to ensure no contaminative activities during the period from now on till the
decommissioning.
The completed site walkover checklist and the
photographic records of concerned T2 building facilities are provided in Appendix B.6 and Appendix
E respectively.
3.3
Identification of Land Contamination Potential
Through consolidation of the findings from
further as-built drawing review and the follow-up site reconnaissance survey,
sampling location BH1, BH2, BH5, BH6 is still considered to be valid and to be
included in the enhanced SI programme. The newly identified underground
pipelines (i.e. HS3) of Emergency Power Supply System No. 4 at southern T2
building has also been included as enhancement of SI recommendation. Enhanced
SI programme details will be presented in Section 4.3.
As described in Section 3.2.1,
the proposed SI locations at the fuel tank room to the west of CAD antenna farm
presented in the EIA Report (i.e. MCL/P132/EIA/11-015 in Appendix C.1) is still considered valid.
As presented in the EIA Report Table 3.3 and
Section 4.2.2, petrol filling station covered by modification of existing North
Runway was considered to have potential leakage/spillage of fuel which may
cause land contamination concern. Therefore, site investigation was proposed
for the location in sampling location BH11 to BH15. As for the latest programme
in July 2018, the detailed design of the present North Runway modification is
under review. The petrol filling station remains operating unless the final design
being settled and thus confirm the necessity of filling station decommission.
The sampling locations (i.e. BH11 – BH15) are still considered to be valid in
this supplementary CAP. Subject to the result of detailed design review, site
re-appraisal shall be conducted upon affirmation of the need for decommission
of the petrol filling station. The proposed SI programme details will be
presented in Section 4.1.3.
A summary of further site investigation
recommended with reference to the observations of site reconnaissance survey
conducted in third quarter of 2016 and May 2017 is presented in Table 3.2. Enhanced SI recommended for T2
building with reference to the observations of site reconnaissance survey
conducted in early 2018 is presented in Table 3.3.
All SI proposed to the latest available information at different stages are
summarized in Table 3.4.
Table 3.2: Summary of Further Site
Investigation Recommended
|
Potential Land Contamination Impact |
Need for Further Site Investigation |
Figure No. |
|
|
Fuel Tank Room to the West of CAD Antenna Farm |
A 900 L above-ground tank containing diesel fuel was found during the site reconnaissance survey. Potential leakage or spillage of fuel may cause land contamination concern. |
SI locations have been proposed during EIA stage and are still considered valid. SI will be conducted prior to the commencement of construction works at site. * |
Figure 3.1 and EIA drawing MCL/P132/EIA/11-015 as presented in Appendix C.1 |
|
Fuel Tank Room within T2 Building |
After consolidating latest information, the approach towards this facility is updated. Please refer to Potential Contamination Source Reference ID BH9 in Table 3.3.
|
||
|
Seawater Pump House |
No contaminative land use types were identified. |
No |
|
|
Switching Station |
During detailed design of the project, relocation of the switching station is no longer required. Therefore, site appraisal process for land contamination potential is considered not necessary. |
||
|
Pumping Station |
No contaminative land use types were identified. |
No |
|
|
Fire Training Facility |
A 10,000 L above-ground tank containing kerosene was found during the site reconnaissance survey. Potential leakage or spillage of fuel may cause land contamination concern. |
Yes, SI will be conducted prior to the commencement of construction works at site. * |
|
* The necessity of recommended
Site Investigation (SI) is subject to review after the site re-appraisal to be
conducted prior to commencement of SI works. Details is
provided in Section 4.1.1 and Section 4.2.1 respectively.
Table 3.3: Summary of Enhanced Site
Investigation Recommended for T2 building
|
Potential Land Contamination Impact |
Need for Enhanced Site Investigation |
Figure No. |
|
|
Northern Section |
|||
|
BH1
|
The 2,500 L underground fuel tank containing diesel fuel was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be unlikely.
|
SI locations have been proposed during EIA stage and are still considered valid. Enhanced SI will be conducted in decommissioning stage.
|
System details in Appendix E.1 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
BH2 |
The 53 m-in-length underground fuel pipelines connecting the underground fuel tank (i.e. BH1) and the above-ground fuel tank (i.e. BH3) was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be unlikely.
|
SI location has been proposed during EIA stage and are still considered valid. Enhanced SI will be conducted in decommissioning stage. |
System details in Appendix E.1 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
BH3* |
The 450 L above-ground fuel tank containing diesel fuel was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be very unlikely. |
No |
System details in Appendix E.1 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
BH4* |
The emergency generator site was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be very unlikely. |
No |
System details in Appendix E.1 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
BH9* |
The 3,000 L above-ground fuel tank containing diesel fuel was further reviewed through site reconnaissance survey and as-built drawings. The previously concerned potential land contamination caused by leakage or spillage of fuel was considered to be very unlikely. |
No |
System details in Appendix E.2 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
HS1* |
The two emergency generators were identified in site reconnaissance survey. Potential land contamination caused by leakage or spillage of fuel was reviewed and considered to be very unlikely.
|
No |
System details in Appendix E.2 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
Southern Section |
|||
|
BH5 |
The 3,000 L underground fuel tank containing diesel fuel was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be unlikely. |
SI location has been proposed during EIA stage and are
still considered valid. Enhanced SI will be conducted in decommissioning stage. |
System details in Appendix E.3 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
BH6 |
The 26 m-in-length underground fuel pipelines connecting the underground fuel tank (i.e. BH5) and the above-ground fuel tank (i.e. BH7) was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be unlikely. |
SI location has been proposed during EIA stage and are still considered valid. Enhanced SI will be conducted in decommissioning stage. |
System details in Appendix E.3 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
BH7* |
The 450 L above-ground fuel tank containing diesel fuel was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be very unlikely. |
No |
System details in Appendix E.3 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
BH8* |
The emergency generator was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be very unlikely. |
No |
System details in Appendix E.3 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
BH10* |
The 1,500 L above-ground fuel tank containing diesel fuel was reviewed through site reconnaissance survey and as-built drawings. Potential land contamination caused by leakage or spillage of fuel was considered to be very unlikely. |
No |
System details in Appendix E.4 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
HS2* |
The emergency generator was identified in site reconnaissance survey. Potential land contamination caused by leakage or spillage of fuel was reviewed and considered to be very unlikely. |
No |
System details in Appendix E.4 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
HS3 |
The 44 m-in-length underground fuel pipelines connecting the above-ground fuel tank (i.e. HS4) and the emergency generator (i.e. HS5) were identified in site reconnaissance survey. Potential land contamination caused by leakage or spillage of fuel was reviewed and considered to be unlikely. |
Yes, Enhanced SI in decommissioning stage. |
System details in Appendix E.4 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
HS4* |
The 1,500 L above-ground fuel tank containing diesel fuel was identified in site reconnaissance survey. Potential land contamination caused by leakage or spillage of fuel was reviewed and considered to be very unlikely. |
No |
System details in Appendix E.5 and EIA drawing MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2
|
|
HS5* |
The emergency generator was identified in site reconnaissance survey. Potential land contamination caused by leakage or spillage of fuel was reviewed and considered to be very unlikely. |
No |
System details in Appendix E.5 and EIA drawing
MCL/P132/EIA/11-014 with mark-up as presented in Appendix C.2 |
* Subject to final inspection
and record checking conducted right before decommissioning/ demolition of the
facility to ensure no contaminative activities during the period from now on
till the decommissioning.
Table 3.4: Summary of All Site Investigation
|
Potential Land Contamination Source Reference ID |
Location |
Source Description |
Site Investigation strategy |
|
BH11, BH12, BH13, BH14, BH15 |
Airside Petrol Filling Station |
The underground fuel storage tanks and the petrol dispensers |
As in EIA stage * |
|
BH16, BH17 |
Fuel Tank Room to the West of CAD Antenna Farm |
The 900 L above-ground tank containing diesel fuel |
As in EIA stage** |
|
BH18 |
Fire Training Facility |
The 10,000 L above-ground tank containing kerosene |
As additional site investigation** |
|
BH1 |
Northern Section of T2 |
The 2,500 L underground fuel tank containing diesel fuel |
As enhanced site investigation |
|
BH2 |
Northern Section of T2 |
The 53 m-in-length underground fuel pipelines connecting the underground fuel tank (i.e. BH1) and the above-ground fuel tank (i.e. BH3) |
As enhanced site investigation |
|
BH5 |
Southern Section of T2 |
The 3,000 L underground fuel tank containing diesel fuel |
As enhanced site investigation |
|
BH6 |
Southern Section of T2 |
The 26 m-in-length underground fuel pipelines connecting the underground fuel tank (i.e. BH5) and the above-ground fuel tank (i.e. BH7) |
As enhanced site investigation |
|
HS3 |
Southern Section of T2 |
The 44 m-in-length underground fuel pipelines connecting the above-ground fuel tank (i.e. HS4) and the emergency generator (i.e. HS5) |
As enhanced site investigation |
* The
necessity of recommended Site Investigation (SI) shall be subject to the result
of detailed design review. Details are provided in Section 4.1.3.
**The
necessity of recommended Site Investigation (SI) shall be subject to review
after the site re-appraisal prior to commencement of SI works. Details are provided in Section 4.1.1 and Section
4.2.1 respectively.
4
Proposed Site Investigation Works
4.1
Site
Investigation Works Proposed in EIA Stage
4.1.1
Fuel
Tank Room to the West of CAD Antenna Farm
As mentioned in Section 3.2.1, a 900 L
above-ground tank containing diesel fuel was found during the site
reconnaissance survey. A total of two boreholes (i.e. BH16 and BH17) were
proposed in the EIA drawing MCL/P132/EIA/11-015 as presented in Appendix C.1 for the above-ground fuel tank. The
proposed SI locations were still considered valid in this Supplementary CAP.
It should be noted that site re-appraisal will
be conducted prior to commencement of SI works to ascertain initial
contamination evaluation of the area and review the necessity of site
investigation works proposed in the aforementioned submission. The findings of
the re-appraisal will be documented appropriately and seek EPD agreement prior
to the commencement of site investigation works, if require. Subsequent
sampling and testing works will be conducted prior to commencement of any
construction works at this area.
4.1.2
T2
Building
Further to the elaboration in Section 3.2.5,
SI locations proposed in EIA stage are reviewed after consolidating site
reconnaissance survey findings, as-built drawings and on-site personnel
interview. SI approach of T2 Building facilities are proposed and presented in Table 3.3. Associated enhanced SI programme are
elaborated in Section 4.3.
4.1.3
Airside
Petrol Filling Station
Further to Section 3.3, a total of five
boreholes (i.e. BH11 to BH15) were proposed for the airside petrol filling
station and the tentative sampling locations are shown in the EIA drawing
MCL/P132/EIA/11-015 as presented in Appendix C.1.
Since there is no change in land use, the proposed SI locations were still
considered valid in this Supplementary CAP.
Subject to the result of detailed design review
(as in July 2018), site re-appraisal shall be conducted upon affirmation of the
need for decommission of the petrol filling station. The findings of the
re-appraisal (if any) will be documented appropriately and seek EPD agreement
prior to the commencement of site investigation works.
4.2
Additional Site Investigation Works
4.2.1
Fire
Training Facility
As mentioned in Section 3.2.4, the fire
training facility is not identified as one of the potential contaminative land
use types as given in Table 2.3 of the Practice Guide. A 10,000 L above-ground
tank containing kerosene fuel was found during the site reconnaissance survey,
hence SI is proposed for this above-ground kerosene tank.
One new borehole (BH18) is proposed at the
10,000 L above-ground fuel tank inside the fire training facility. The
tentative sampling location is shown in Figure 4.1.
To ascertain contamination evaluation of this
facility and review the necessity of additional site investigation works
proposed, site re-appraisal will be conducted prior to commencement of SI
works. The findings of the re-appraisal will
be documented appropriately and seek EPD agreement prior to the commencement of
site investigation works, if require. Subsequent sampling and testing works
will be conducted prior to commencement of any construction works at this area.
4.3
Enhanced Site Investigation Works for T2 Building
As mentioned in Section 3.2.5, enhanced
SI is recommended for the underground facilities in T2 building. Sampling
locations included in enhanced SI are provided in Table
3.4.
Four sampling locations, BH1, BH2, BH5 and BH6
proposed in the EIA drawing MCL/P132/EIA/11-014 are still considered valid,
while sampling location HS3 for the 44 m-in-length underground fuel pipelines
at southern section is newly proposed as shown in marked-up EIA drawing
MCL/P132/EIA/11-014 in Appendix C.2.
Sampling and testing works of the enhanced SI will be conducted along with
decommissioning/demolition of concerned facilities.
4.4
Sampling
Details
4.4.1
Sampling
and Testing Plan
The sampling and testing plan for the airside
petrol filling station, the fuel tank room to the West of CAD Antenna Farm and
Fire Service Facility, including sampling locations and depths, is recommended
in accordance with the EPD’s Practice Guide for Investigation and Remediation
of Contaminated Land as shown in Table 4.2.
Enhanced sampling and testing plan for
concerned underground facilities of T2 Building, including sampling location
and depths, are presented in Table 4.3. The
exact locations and depths for sand and soil sampling shall be determined by
on-site land contamination specialist to suit the actual site condition during
site investigation.
4.4.2
Sampling
Method and Depth of Sampling
All soil boring/ excavation and sampling should
be supervised by a land contamination specialist.
At each sampling location/depth, sufficient
quantity of soil/sand sample (as specified by the laboratory) should be taken.
All soil/sand samples should be uniquely labelled. Backup samples should
be retained and stored at 0-4 ºC in laboratory.
Borehole and Trial Pit Sampling for Airside
Petrol Filling Station, West of CAD Antenna Farm and Fire Service Facility
Borehole sampling is designated to sampling
plan for the airside petrol filling station, fuel tank room to the West of CAD
Antenna Farm and Fire Service Facility.
Borehole should be undertaken by means of dry
rotary drilling method, i.e. without the use of flushing medium, to prevent
cross-contamination during sampling. For safety reasons, an inspection
pit should be excavated down to 1.5 m below ground surface (bgs) to inspect for
underground utilities at the proposed borehole location. Disturbed soil samples
should be collected at depth of 0.5 m bgs. Soil boring using drill rigs
should then be performed from depth of 1.5 m bgs to the maximum boring depth.
Undisturbed U100/U76 soil samples should be collected at 1.5 m and 3.0 m bgs as
well as above groundwater level. Groundwater samples should be collected at the
level of groundwater (if encountered).
Where borehole drilling is not possible due to
site constraints (e.g. insufficient head room or accessibility of drilling
rigs), sampling using trial pit methods will be adopted. For trial pit methods,
disturbed soil samples, using stainless steel hand tools, will be taken at 0.5
m, 1.5 m and 3.0 m bgs in order to delineate the vertical profile of
contamination.
Appropriate safety precautionary measures such
as shoring support, stepping/sloping of sides will be implemented for the
excavation of trial pit exceeding 1.2 m, with reference to the “Practice Guide
for Investigation and Remediation of Contaminated Land” issued by EPD and
“Guide to Trench Excavations (Shoring Support and Drainage Measures)” issued by
Utilities Technical Liaison Committee of Highway Department and Geotechnical
Engineering Office of Civil Engineering Department.
Grab Sampling for Concerned
Underground Facilities of T2 Building
Grab sampling is proposed for the
locations listed in Table 4.3 as Enhanced
Sampling and Testing plan. Sand and soil samples shall be grabbed manually
during decommissioning/ demolition process of concerned underground
pipeline trench and fuel tanks. The whole sampling process shall be under the
supervision of on-site Contamination Specialist.
Sampling Selection of Underground Fuel Tank
Sand and soil samples should be collected as
follows,
· Sand samples should be collected at
0.5 m, 1.5 m and bottom level inside the concrete chamber of underground fuel
tank;
· Soil sample should be collected
right underneath concrete chamber of underground fuel tank.
Sampling Selection of Underground Fuel
Pipelines
Sand and soil samples should be collected as
follows,
· Sand samples should be taken at
every curvature of pipelines inside the concrete trench;
· Additional sampling points inside
the concrete trench are set depending on length of pipeline segment (from
curvature/connection to curvature):
°
If pipeline segment is ≤10
m, additional sample is considered not required;
°
If pipeline segment is
>10 m and ≤20 m, one sample shall be taken at segment mid-point;
°
If pipeline segment is
>20 m and ≤30 m, samples shall be collected at 2 points which are
evenly spaced with each other and segment ends.
·
Soil samples should be
taken right underneath concrete trench at every curvature.
Sampling point annotation and indicative
sampling point locations are illustrated in Appendix
F and Table 4.1.
Table 4.1: Sampling Point Annotation
of Underground Fuel Pipelines
|
Proposed Sampling Locations |
Annotation of Sampling Point |
Type of Sampling Point (Curvature/ Additional) |
Figure No. |
|
BH2 |
BH2-S1 |
Curvature |
|
|
BH2-S2 |
Curvature |
||
|
BH2-S3 |
Curvature |
||
|
BH2-S4 |
Additional |
||
|
BH2-S5 |
Additional |
||
|
BH2-S6 |
Curvature |
||
|
BH2-S7 |
Additional |
||
|
BH6 |
BH6-S1 |
Curvature |
|
|
BH6-S2 |
Additional |
||
|
BH6-S3 |
Additional |
||
|
BH6-S4 |
Curvature |
||
|
HS3-S1 |
Curvature |
||
|
HS3-S2 |
Additional |
||
|
HS3-S3 |
Curvature |
||
|
HS3-S4 |
Curvature |
||
|
HS3-S5 |
Additional |
||
|
HS3-S6 |
Additional |
||
|
HS3-S7 |
Curvature |
Table 4.2: Sampling and Testing Plan for
Airside Petrol Filling Station, the fuel tank room to the West of CAD Antenna
Farm and Fire Service Facility
|
Proposed Sampling Locations |
Sample Matrix3 |
Parameters to be Tested4 |
Rationale of Sampling |
|||||||||
|
Heavy Metals |
PCRs5 |
VOCs5 |
SVOCs5
|
|||||||||
|
BH111 |
Soil |
0.5 m, 1.5 m, 3.0 m bgs |
Full list |
√ |
√ |
√ |
Assess potential land contamination impact from petrol filling activities |
|||||
|
GW |
If present^ |
Mercury only |
√ |
√ |
√ |
|||||||
|
BH121 |
Soil |
0.5 m, 1.5 m, 3.0 m bgs |
Full list |
√ |
√ |
√ |
Assess potential land contamination impact from petrol filling activities |
|||||
|
GW |
If present^ |
Mercury only |
√ |
√ |
√ |
|||||||
|
BH131 |
Soil |
0.5 m, 1.5 m, 3.0 m below the base of underground fuel tank |
Full list |
√ |
√ |
√ |
Assess potential land contamination impact from underground fuel tanks |
|||||
|
GW |
If present^ |
Mercury only |
√ |
√ |
√ |
|||||||
|
BH141 |
Soil |
0.5 m, 1.5 m, 3.0 m below the base of underground fuel tank |
Full list |
√ |
√ |
√ |
Assess potential land contamination impact from underground fuel tanks |
|||||
|
GW |
If present^ |
Mercury only |
√ |
√ |
√ |
|||||||
|
BH151 |
Soil |
0.5 m, 1.5 m, 3.0 m below the base of underground fuel tank |
Full list |
√ |
√ |
√ |
Assess potential land contamination impact from underground fuel tanks |
|||||
|
GW |
If present^ |
Mercury only |
√ |
√ |
√ |
|||||||
|
Fuel Tank Room to the West of CAD Antenna Farm#, ** |
||||||||||||
|
BH162 |
Soil |
Full list |
√ |
√ |
√ |
Assess potential land contamination impact from the fuel tank |
||||||
|
GW |
If present^ |
Mercury only |
√ |
√ |
√ |
|||||||
|
BH172 |
Soil |
0.5 m, 1.5 m, 3.0 m bgs |
Full list |
√ |
√ |
√ |
Assess potential land contamination impact from the fuel tank |
|||||
|
GW |
If present^ |
Mercury only |
√ |
√ |
√ |
|||||||
|
Fire Training Facility** |
||||||||||||
|
BH182 |
Soil |
0.5 m, 1.5 m, 3.0 m bgs |
Full list |
√ |
√ |
√ |
Assess potential land contamination impact from the above-ground fuel tank |
|||||
|
GW |
If present^ |
Mercury only |
√ |
√ |
√ |
|||||||
Remarks:
1Exact sampling locations will be identified
on-site after decommissioning of petrol filling station.
2Exact sampling
locations will be identified on site after the removal of the fuel tank.
3 bgs = Below Ground
Surface; GW = groundwater.
4ü = testing proposed.
5 PCRs = Petroleum Carbon Ranges;
VOCs = Volatile Organic Chemicals; SVOCs = Semi-volatile Organic Chemicals;
^ Samples will only be
collected if groundwater is encountered during SI works.
#The sampling and testing plan for Airside Petrol
Filling Station and fuel tank room to the West of CAD Antenna Farm are
extracted from Table 4.2 of the Approved CAP.
* Testing
protocol shall be reviewed subject to the result of detailed design review.
Details are provided in Section 4.1.3.
**Testing protocol shall be reviewed after the site
re-appraisal prior to commencement of SI works. Details are provided in Section
4.1.1 and Section 4.2.1 respectively.
Table 4.3: Enhanced Sampling and
Testing Plan for T2 Building
|
Proposed Sampling Locations |
Sample Matrix |
Sampling Point Annotation |
Parameters to be Tested1
& 2 |
Rationale of Sampling |
|||||||
|
Heavy
Metals |
PCRs3 |
VOCs3 |
SVOCs3 |
||||||||
|
Northern Section |
|||||||||||
|
BH14 |
Sand5 |
0.5 m, 1.5 m bgs6and bottom level inside the concrete
chamber |
/ |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no diesel leakage from underground fuel tank |
|||
|
|
Soil |
Right underneath concrete chamber |
/ |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no leaked diesel (if any) penetrate the concrete chamber |
|||
|
BH24 |
Sand5 |
At the level of fuel pipelines |
BH2S1 - BH2S7 |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no diesel leakage from underground fuel pipelines |
|||
|
|
Soil |
Right underneath concrete/brick trench |
BH2S1, BH2S2, BH2S3,
BH2S6 |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no leaked diesel (if any) penetrate the concrete /brick trench |
|||
|
Southern Section |
|||||||||||
|
BH54 |
Sand5 |
0.5 m, 1.5 m bgs6 and bottom level inside the concrete
chamber |
/ |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no diesel leakage from underground fuel tank |
|||
|
|
Soil |
Right underneath concrete chamber |
/ |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no leaked diesel (if any) penetrate the concrete chamber |
|||
|
BH64 |
Sand5 |
At the level of fuel pipelines |
BH6S1 - BH6S4 |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no diesel leakage from underground fuel pipelines |
|||
|
|
Soil |
Right underneath concrete/brick trench |
BH6S1, BH6S4 |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no leaked diesel (if any) penetrate the concrete /brick trench |
|||
|
HS34 |
Sand5 |
At the level of fuel pipelines |
HS3S1 - HS3S7 |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no diesel leakage from underground fuel pipelines |
|||
|
|
Soil |
Right underneath concrete/brick trench |
HS3S1, HS3S3, HS3S4, HS3S7 |
Lead only |
√ |
BTEX7 and MTBE8 |
PAHs9 |
Confirm no leaked diesel (if any) penetrate the concrete /brick trench |
|||
Remarks:
1 ü = testing proposed.
2 Having reviewed the potentially polluting
activities of the site (use of diesel fuel) and S2.4.3 of Practice Guide, it is
recommended to analyse the key COCs (i.e. Lead, PCRs, BTEX, MTBE and PAHs) of
“Petrol Filling Station” which is the most relevant land use type for the case
of T2. The concerned diesel tanks and pipelines are used for storage and
transfer of diesel fuel only and only diesel fuel is used for the generator. It
is noted BTEX, MTBE and Lead present in gasoline but unlikely to be found in diesel
fuel.
3 PCRs = Petroleum Carbon Ranges; VOCs =
Volatile Organic Chemicals; SVOCs = Semi-volatile Organic Chemicals;
4 Exact sampling locations will be identified on
site during the removal of sand/soil during fuel tank and pipelines
decommissioning/ demolition.
5 All sand samples will be collected within the
concrete chamber or concrete/brick trench.
6 bgs = Below Ground Surface.
7 BTEX = Benzene, Toluene, Ethylbenzene, and
Xylenes.
8 MTBE = Methyl Tert-Butyl Ether.
9 Polyaromatic hydrocarbons (PAHs) in the RBRGs
include, acenaphthene, acenaphthylene, anthracene, benzo(a)anthracene,
benzo(a)pyrene, benzo(b)fluoranthene, benzo(g,h,i)perylene,
benzo(k)fluoranthene, chrysene, dibenzo(a,h)anthracene, fluoranthene, fluorene,
indeno(1,2,3-cd)pyrene, naphthalene, phenanthrene and pyrene.