Appendices
A.	Updated Implementation Schedule of Land Contamination – Construction Phase
B.	Location of Emergency Power Supply System of T2 Building
	B.1 Location of Emergency Power Supply Systems of T2 Building (Overview)
	B.2 Location of Emergency Power Supply System No.2 of T2 Building (Zoom-in View of Northern Section of T2 Building)
	B.3 Location of Emergency Power Supply System No.3, Emergency Power Supply System No.4 and Emergency Power Supply System No.5 of T2 Building (Zoom-in View of Southern Section of T2 Building)
C.	Identified Potential Land Contaminated Source of Emergency Power Supply Systems in SCAP
	C.1 Identified Potential Land Contaminated Source of Emergency Power Supply System No.2 (EPSS2) in SCAP
	C.2 Identified Potential Land Contaminated Source of Emergency Power Supply System No.3 (EPSS3) in SCAP
	C.3 Identified Potential Land Contaminated Source of Emergency Power Supply System No.5 (EPSS5) in SCAP
D.	Indicative Sampling Point Selection of 3,000 L Underground Fuel Tank of EPSS3 in SCAP (i.e. BH5)
E.	Indicative Sampling Point of the Underground Pipeline Trench of EPSS3 in SCAP (ie.BH6)
F.	Structure and Actual Sampling Depth of 3,000 L Underground Fuel Tank of EPSS3 (i.e. BH5)
G.	Actual Sampling Point of the Underground Pipeline Trench of EPSS3 (i.e. BH6)
	G.1 Actual Sampling Point of the Underground Pipeline Trench of EPSS3 (i.e. BH6-S1, BH6-S4, BH6-S5, BH6-S6, BH6-NLTS1)
	G.2 Site Photo Record of Underground Pipeline Trench of EPSS3 at BH6-S2 and BH6-S3 (Photo Record)
H.	Chain-of-Custody Record
I.	Laboratory Testing Results of BH5 and BH6
J.	Site Photo Record of Final Inspection J.1 Site Photo Record of Final Inspection for EPSS2 BH9 (3000L Above-ground Fuel Tank) J.2 Site Photo Record of Final Inspection for EPSS2 HS1 (2 above-ground Emergency generators)
	J.3 Site Photo Record of Final Inspection for EPSS3 BH7 (450 L Above-ground Fuel Tank)
	J.4 Site Photo Record of Final Inspection for EPSS3 BH8 (Above-ground Emergency Generator)
	J.5 Site Photo Record of Final Inspection for EPSS5 HS4 (Above-ground Fuel Tank) and HS5 (Above-ground Emergency Generator)

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 with 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), 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.

Further review on 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 have been undertaken in January 2018 and February 2018 (i.e. fuel tanks and generators within the building). Findings and consideration of assessment results after EIA stage have been summarized in the Supplementary Contamination Assessment Plan (SCAP) being approved in August 2018.

Based on the latest construction programme, decommissioning/ demolition of the Emergency Power Supply Systems No.2 (hereafter referred as EPSS2), Emergency Power Supply Systems No.3 (hereafter referred as EPSS3) and Emergency Power Supply Systems No. 5 (hereafter referred as EPSS5) of T2 building is scheduled to commence in 2^nd Quarter of 2020.

Mott MacDonald Hong Kong Limited (MMHK), as the project’s Environmental Team, was appointed by Airport Authority Hong Kong (AAHK) to prepare the Contamination Assessment Report (CAR) for Terminal 2 EPSS2, EPSS3 and EPSS5 to fulfil part of the SCAP’s recommendation as this CAR only covers three concerned areas. The updated Implementation Schedule of Land Contamination – Construction Phase is provided in Appendix A.

1.2 Scope of this CAR

T2 building of the Hong Kong International Airport comprises northern and southern sections, where each section consists of a number of Emergency Generator Rooms and Fuel Tank Rooms.

The EPSS2 was located at northern section of T2 Building, the set of emergency power supply system comprises above-ground section only. Whereas EPSS3 and EPSS5 were located at southern section of T2 Building. The EPSS3 comprises underground and above-ground section; and for EPSS5, the system comprises above-ground section only.

The locations of the captioned emergency power supply systems are shown in Appendix B. The identified potential land contamination sources are listed in Table 1.1 below,

Table 1.1: Identified Potential Land Contamination Source of Emergency Power Supply Systems

Emergency Power Supply System	Potential Land Contamination Source Reference ID	Description	Location
Northern Section
Emergency Power Supply System No.2	Above-ground Section		Please refer to Appendix C
	BH9	A 3,000 L above-ground fuel tank at Fuel Tank Room
	HS1	Two emergency generators at Emergency Generator Room, connecting to the 3,000 L above-ground fuel tank (i.e. BH9)
Southern Section
Emergency Power Supply System No.3	Underground Section
	BH5	A 3,000 L underground fuel tank
	BH6	26 m in-length underground fuel pipelines connecting the 3,000 L underground fuel tank (i.e. BH5) and the 450 L above-ground fuel tank (i.e. BH7)
	Above-ground Section
	BH7	A 450 L above-ground fuel tank at Emergency Generator Room
	BH8	An emergency generator at Emergency Generator Room, connecting to the 450 L above-ground tank (i.e. BH7)
Emergency Power Supply System No.5	Above-ground Section
	HS4	A 1,500 L above-ground fuel tank at Fuel Tank Room
	HS5	An emergency generator at Emergency Generator Room, connecting to the 1,500 L above-ground fuel tank (i.e. HS4)

Layout plans of respective emergency power supply systems included in this CAR are presented in Appendix C.

1.3 Objective

According to the approved SCAP, for the above-ground sections including BH7, BH8, BH9, HS1, HS4 and HS5, final inspection and record checking shall be conducted right before decommissioning/ demolition. While for the underground section including BH5 and BH6, enhanced SI programme shall be conducted along with decommissioning/demolition to confirm no potential land contamination taken place.

For the above-ground sections, decommissioning/ demolition works were scheduled in the 2^nd Quarter of 2020. Final site inspections and record checking were conducted according to the decommissioning/ demolition schedule of respective Emergency Power Supply Systems. Photo records and findings have been included in this CAR. For underground sections, enhanced SI programme for BH5 and BH6 was carried out between June and August 2020.

This CAR for has been prepared to present the findings of final inspections and record checking of the above-ground sections (i.e. BH7, BH8, BH9, HS1, HS4 and HS5), as well as the sampling procedures and laboratory testing of enhanced SI for the underground sections (BH5 and BH6) as described in Section 1.2. Testing results have been interpreted based on the Guidance Manual for Use of Risk Based Remediation Goals (RBRGs) for Contaminated Land Management (Guidance Manual) and detailed in Section 4.

2 Summary of Sampling and Testing Strategy

2.1 Proposed Sampling Method in the SCAP

2.1.1 Proposed Sampling Method of BH5 and BH6

According to the SCAP, grab sampling was proposed for the concerned underground facilities of T2 Building, including BH5 and BH6. The proposed sampling and testing plan including the parameters to be tested, sampling locations and sampling depths are presented in Table 2.1. Sand and soil samples should be grabbed manually during the decommissioning/demolition process of concerned fuel tanks (i.e. BH5) and underground pipeline trench (i.e. BH6). The whole sampling process should be under the supervision of on-site contamination specialist.

Sampling Selection of Underground Fuel Tank (i.e. BH5)

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; and
Soil sample should be collected right underneath concrete chamber of underground fuel tank.

Sampling Selection of Underground Fuel Pipeline (i.e. BH6)

Sand and soil samples should be collected as follows:

· Sand samples should be taken at every curvature of pipeline 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 of BH5 and BH6 extracted from the SCAP are presented in Table 2.2, Appendix D and Appendix E.

Table 2.1: Enhanced Sampling and Testing Plan for BH5 and BH6 of Emergency Power Supply System No.3 in T2 Building

Proposed Sampling Locations	Sample Matrix		Sampling Point Annotation	Parameters to be Tested^{1 & 2}				Rationale of Sampling
Proposed Sampling Locations	Sample Matrix		Sampling Point Annotation	Heavy Metals	PCRs³	VOCs³	SVOCs³
BH5⁴	Sand⁵	0.5 m, 1.5 m bgs⁶and bottom level inside the concrete chamber	/	Lead only	ü	BTEX⁷ and MTBE⁸	PAHs⁹	Confirm no diesel leakage from underground fuel tank
	Soil	Right underneath concrete chamber	/	Lead only	ü	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	ü	BTEX⁷ and MTBE⁸	PAHs⁹	Confirm no diesel leakage from underground fuel pipelines
	Soil	Right underneath concrete/brick trench	BH6S1, BH6S4	Lead only	ü	BTEX⁷ and MTBE⁸	PAHs⁹	Confirm no leaked diesel (if any) penetrate the concrete /brick trench

Remarks:

¹ü = testing proposed.

²Having 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.

³PCRs = Petroleum Carbon Ranges; VOCs = Volatile Organic Chemicals; SVOCs = Semi-volatile Organic Chemicals;

⁴Exact sampling locations will be identified on site during the removal of sand/soil during fuel tank and pipelines decommissioning/ demolition.

⁵All sand samples will be collected within the concrete chamber or concrete/brick trench.

⁶bgs = Below Ground Surface.

⁷ BTEX = Benzene, Toluene, Ethylbenzene, and Xylenes.

⁸MTBE = Methyl Tert-Butyl Ether.

⁹Polyaromatic 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.

Table 2.2: Sampling Point Annotation of Underground Fuel Pipeline BH6

Sampling Locations	Sampling Point	Type of Sampling Point (Curvature/ Additional)	Figure No.
Sampling Locations	Sampling Point	Type of Sampling Point (Curvature/ Additional)	Figure No.
BH6	BH6-S1	Curvature	Appendix E
	BH6-S2	Additional
	BH6-S3	Additional
	BH6-S4	Curvature

2.2 Alternative Sampling Method Formulated after Pre-demolition Survey

2.2.1 Alternative Sampling Method of BH5

With the sampling experience of BH1 (for Emergency Power Supply System No.1), deviation between as-built drawing and the actual concrete chamber is expected. It is expected that the fuel tank is fully encased in the concrete chamber. However, the top concrete slab would be located at an uncertain level which would be beneath the surface ground and above the fuel tank. In consideration of the actual site condition and safety reasons, borehole sampling for BH5 was proposed by the Contractor, instead of grab sampling as proposed in the SCAP. Discussion was held between amongst the Contractor, AAHK and the land contamination specialist. It was agreed with the land contamination specialist that the borehole would be undertaken by means of rotary drilling method.

Details of sampling depths was presented in Section 3.1.

2.3 Assessment Criteria

The chemicals of concern (COCs) listed in EPD’s Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management were referred to when proposing the analytical parameters listed in Table 2.1. According to Section 5.3 of the SCAP, categories of Industrial were adopted for evaluating the contamination level of T2 building.

3 Site Investigation

3.1 Sand / Soil Sampling

3.1.1 Underground Fuel Tank BH5

Site investigation works of BH5 was commenced on 29 June 2020 by DrilTech Ground Engineering Limited. Samples were collected at the level of 0.5m and 1.5m below the top slab of the concrete chamber. However, the borehole drill coring process encountered a hard structure when it reached 1.9m below the top concrete slab. In view of the deviation between as-built drawing and the on-site observation, and with the consideration of incurred safety risk, the sampling by rotary drilling method was temporary stopped.

To confirm with the structure encountered at 1.9m below the top concrete slab, an inspection pit was excavated down to 1.9m below ground surface. An inspection was conducted by the land contamination specialist on 24 July 2020.It was found that there was a second concrete slab inside the concrete chamber and the fuel tank was still fully encased in a at least 300 mm thick concrete chamber, with the top concrete slab right beneath the surface ground level and the second concrete slab located at around 1.9 m below the top concrete slab. The structure is illustrated in Appendix F.

Another site investigation was conducted by land contamination specialist on 20 August 2020. It was found that the lower concrete chamber encasing the fuel tank with an inner depth of 1.25m, with 0.7m void right underneath the second concrete slab. A depth of 0.55m sand was filled from the bottom of the second concrete chamber. Since the actual inner depth of concrete chamber is smaller than those shown in the as-built drawing, as decided by the land contamination specialist, it was considered that 1 undisturbed sand samples collected at 1.0m below the second concrete slab of the concrete chamber was adequate and representative to confirm whether there was land contamination impact caused by the underground fuel tank.

One undisturbed soil sample was collected at 0.5m underneath the bottom concrete slab of the concrete chamber. The entire SI programme was supervised by the land contamination specialist. The actual sampling depths are summarized in Table 3.1 and illustrated in Appendix F. All soil/sand samples were analyzed in accordance with the testing schedules detailed in Table 2.1.

No ground water was observed during sand and soil sampling work of BH5.

Table 3.1: Summary of Sampling Depth of BH5

Sampling Locations	Sampling Depth	Sampling Date
BH5	0.5m below the top concrete slab of the concrete chamber	29 June 2020
	1.5m below the top concrete slab of the concrete chamber	29 June 2020
	1.0m below the second concrete slab of the concrete chamber	20 August 2020
	0.5m underneath the bottom concrete slab of the concrete chamber	20 August 2020

3.1.2 Underground Fuel Pipeline BH6

Soil sampling of BH6 segments was carried out by land contamination specialist on 24 July 2020. Soil samples were collected at sampling points BH6-S1, BH6-S4, BH6-S5, BH6-S6 and BH6-NLTS1. According to site observation, a segment of underground pipeline with 1.3m in length located between BH5 and BH6-S6 are not laid inside the concrete trench, while the underground pipeline running from BH6-S6 to BH7 is laid inside the concrete trench. The actual sampling points and on-site length measurement of the segments of underground pipeline BH6 are illustrated in Appendix G.

BH6 segment between sampling point BH6-S6 and BH7

Based on-site observation, it was found that the concrete trench was filled with concrete rather than sand and no sand samples could be collected inside the concrete trench. Therefore, soil samples were collected at the following sampling points at the depth right underneath the concrete trench, where the curvature of the pipelines located,

● BH6-S1 (Same sampling point proposed in SCAP);

● BH6-S4 (Same sampling point proposed in SCAP);

● BH6-S5 (Newly added according to on-site condition); and

● BH6-S6 (Newly added according to on-site condition).

For indicative sampling points, BH6-S2 and BH6-S3, as no sand samples could be collected at the level of fuel pipelines, the site condition of the concrete trench was examined on-site and the observations are presented in Appendix G. No cracks on the concrete-trench nor oil stains were found in the vicinity of these 2 sampling points. However, due to the safety concerns of excavation at the time of on-site inspection, site photos at the sides and bottom of BH6-S2 and BH6-S3 could not be taken on 24 July 2020. However, with consideration of the site observations as presented in Appendix G and the laboratory testing results of BH6-S1 and BH6-S4, which are at the same segment and near in location, it is confirmed that no diesel leakage from the underground fuel pipelines laid in concrete trench.

To err on a conservative side, additional site photo records at BH6-S2 and BH6-S3 will be provided to EPD after the pipeline at BH6-S2 and BH6-S3 was removed.

No ground water was observed during soil sampling work of BH6-S1, BH6-S4, BH6-S5 and BH6-S6.

BH6 segment between BH5 and sampling point BH6-S6 (No-concrete-trench segment)

To confirm no diesel leakage from underground fuel pipelines from the 1.3m in length no-concrete-trench segment, 1 soil sample was taken right underneath the particular segment (i.e. BH6-NLTS1). Having considered that the sampling point selection strategy in the SCAP (i.e. If pipeline segment is ≤10 m, an additional sample is considered not required), the site observations where no oil stains being found in the vicinity of BH6-NLTS1, and the laboratory testing result for BH6-S6 (no contamination was found) which is near to the location of BH6-NLTS1, 1 sample collected at the depth right underneath the pipeline was deemed to be sufficient to represent and confirm if any diesel leakage from the 1.3m long (as revealed on-site) of no-concrete-trench segment.

No ground water was observed during soil sampling work of BH6-NLTS1.

The actual sampling points and on-site length measurement of the particular segment of underground pipeline BH6 are summarized in Table 3.2 and illustrated in Appendix G. All soil samples were analyzed in accordance with the analysis schedules detailed in Table 2.1.

Table 3.2: Summary of Sampling Point of BH6

Sampling Locations	Sampling Point	Type of Sampling Point (Curvature/ Additional/ No-concrete-trench Segment)	Sampling Date
Sampling Locations	Sampling Point		Sampling Date
BH6	BH6-NLTS1	No-concrete-trench Segment	24 July 2020
	BH6-S1	Curvature	24 July 2020
	BH6-S4	Curvature	24 July 2020
	BH6-S5	Curvature	24 July 2020
	BH6-S6	Curvature	24 July 2020

3.1.3 Additional Photo Record Upon Demolition Works

To err on a conservative side, additional site photo records at the sides and bottom of BH6-S2 and BH6-S3 will be submitted to EPD upon the demolition work at these locations to reaffirm the conclusion drawn in Section 3.1.2 that there was no diesel leakage from the underground fuel pipe.

In case that sign of diesel leakage is spotted during the demolition works, agreement from EPD shall be sought for sampling strategy and subsequent SI shall be arranged in accordance with the agreed sampling plan. A CAR should be submitted to EPD and if remediation is required, a Remediation Action Plan and Remediation Report will also be prepared.

3.2 Decontamination Procedures

Before excavation/ sampling, all equipment in contact with the ground were thoroughly decontaminated between each excavation and sampling event to minimise the potential for cross contamination. The equipment should be decontaminated by steam cleaning or high-pressure hot water jet, then washed by phosphate-free detergent and finally rinsed by distilled water. During decontamination procedures and sampling, disposable latex gloves were worn to prevent the transfer of contaminants from other sources.

3.3 Quality Assurance (QA) / Quality Control (QC) Procedure

3.3.1 QA/QC Procedure

The soil samples taken were placed in sample containers provided by the HOKLAS laboratory. Sufficient sample size was collected for the laboratory analysis. Samples were marked with sampling date, sampling identification number and sampling depth with appropriate chain-of-custody form. Collected samples were then stored in a cool box at a temperature between 0^oC and 4^oC and transported to the laboratory immediately after completion of the sampling.

The chain-of-custody records are given in Appendix H.

3.3.2 QA/QC Analysis

In this enhanced SI programme, QA/QC samples were collected in accordance with the frequency proposed in the SCAP as follows, with a Chain of Custody protocol adopted:

● One equipment blank per 20 samples for full suite analysis*;

● One field blank per 20 samples for full suite analysis*;

● One duplicate sample per 20 samples for full suite analysis*; and

● One trip blank per trip for the analysis of volatile parameters^#.

Note:

* For the purposes of this enhanced SI programme, the following parameters were tested in a ‘full suite analysis’ –

· Heavy Metals: Lead only.

· PCRs: C6-C8; C9-C16; C17-C35.

· VOCs: Benzene, Toluene, Ethylbenzene, Xylenes and Methyl Tert-Butyl Ether.

· SVOCs: 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.

^# For the purposes of this Project, the following parameters were tested in the analysis of ‘volatile parameters’ – Benzene, Toluene, Ethylbenzene, Xylenes, Methyl Tert-Butyl Ether and C6-C8.

The duplicate, equipment blank and field blank samples were collected on 29 June 2020 during the sampling for BH5.

The laboratory results for QA/QC samples are presented in Appendix I.

All testing parameters were not detected (below the limit of reporting) in all blank samples obtained, except Total Petroleum Hydrocarbons (TPH) C17 – C35 of equipment blank is in mild detected level. Given that the same testing parameters (C17 – C35) in the sand and soil samples are below the limit of reporting, therefore, it is considered that the testing results of sand and soil samples are reliable. QA/QC procedures for sample collection and preparation are considered acceptable.

4 Interpretation of Laboratory Testing Results

4.1 Sand/Soil Contamination

4.1.1 Underground Fuel Tank BH5

A total of 3 sand samples and 1 soil sample were collected at BH5 for laboratory testing. The testing results are summarised in Table 4.1 and the testing reports are presented in Appendix I. The testing results of all parameters indicated that all sand/ soil samples from BH5 were below the value of RBRGs for Industrial.

Table 4.1: Laboratory Testing Results of Sand and Soil Samples at BH5

Chemical	Concentration (mg/kg)
Chemical	BH5 (0.5 m below the top concrete slab of the concrete chamber)	BH5 (1.5 m below the top concrete slab of the concrete chamber)	BH5 (1.0m below the second concrete slab of the concrete chamber)	BH5 (0.5m underneath the bottom concrete slab of the concrete chamber)	RBRGs for Industrial
Heavy Metals
Lead	8	7	4	7	2290
PCRs
C6 - C8	<5	<5	<5	<5	C6 - C8: 10,000 C9 - C16: 10,000 C17 - C35: 10,000
C9 - C16	<200	<200	<200	<200
C17 - C35	<500	<500	<500	<500
VOCs
Benzene	<0.2	<0.2	<0.2	<0.2	9.21
Toluene	<0.5	<0.5	<0.5	<0.5	10,000
Ethylbenzene	<0.5	<0.5	<0.5	<0.5	8,240
Xylenes (Total)	<2.0	<2.0	<2.0	<2.0	1,230
Methyl tert-Butyl Ether	<0.2	<0.2	<0.2	<0.2	70.1
SVOCs
Naphthalene	<0.500	<0.500	<0.500	<0.500	453
Acenaphthylene	<0.500	<0.500	<0.500	<0.500	10,000
Acenaphthene	<0.500	<0.500	<0.500	<0.500	10,000
Fluorene	<0.500	<0.500	<0.500	<0.500	10,000
Phenanthrene	<0.500	<0.500	<0.500	<0.500	10,000
Anthracene	<0.500	<0.500	<0.500	<0.500	10,000
Fluoranthene	<0.500	<0.500	<0.500	<0.500	10,000
Pyrene	<0.500	<0.500	<0.500	<0.500	10,000
Benz(a)anthracene	<0.500	<0.500	<0.500	<0.500	91.8
Chrysene	<0.500	<0.500	<0.500	<0.500	1140
Benzo(b)fluoranthene	<0.500	<0.500	<0.500	<0.500	17.8
Benzo(k)fluoranthene	<0.500	<0.500	<0.500	<0.500	918
Benzo(a)pyrene	<0.500	<0.500	<0.500	<0.500	9.18
Indeno(1.2.3.cd)pyrene	<0.500	<0.500	<0.500	<0.500	91.8
Dibenz(a.h)anthracene	<0.500	<0.500	<0.500	<0.500	9.18
Benzo(g.h.i)perylene	<0.500	<0.500	<0.500	<0.500	10,000

4.1.2 Underground Fuel Pipeline BH6

A total of 5 soil samples were collected at BH6 for laboratory testing. The testing results are summarised in Table 4.2 and the testing reports are presented in Appendix I. The testing results of all parameters indicated that all soil samples from BH6 were below the value of RBRGs for Industrial.

Table 4.2: Laboratory Testing Results of Soil Samples at BH6

Compound	Concentration (mg/kg)
	BH6-NLTS1	BH6-S1	BH6-S4	BH6-S5	BH6-S6	RBRGs for Industrial
Heavy Metals
Lead	62	76	209	71	104	2290
PCRs
C6 - C8	<5	<5	<5	<5	<5	C6 - C8: 10,000 C9 - C16: 10,000 C17 - C35: 10,000
C9 - C16	<200	<200	<200	<200	<200
C17 - C35	<500	<500	<500	<500	<500
VOCs
Benzene	<0.2	<0.2	<0.2	<0.2	<0.2	9.21
Toluene	<0.5	<0.5	<0.5	<0.5	<0.5	10,000
Ethylbenzene	<0.5	<0.5	<0.5	<0.5	<0.5	8,240
Xylenes (Total)	<2.0	<2.0	<2.0	<2.0	<2.0	1,230
Methyl tert-Butyl Ether	<0.2	<0.2	<0.2	<0.2	<0.2	70.1
SVOCs
Naphthalene	<0.500	<0.500	<0.500	<0.500	<0.500	453
Acenaphthylene	<0.500	<0.500	<0.500	<0.500	<0.500	10,000
Acenaphthene	<0.500	<0.500	<0.500	<0.500	<0.500	10,000
Fluorene	<0.500	<0.500	<0.500	<0.500	<0.500	10,000
Phenanthrene	<0.500	<0.500	<0.500	<0.500	<0.500	10,000
Anthracene	<0.500	<0.500	<0.500	<0.500	<0.500	10,000
Fluoranthene	<0.500	<0.500	<0.500	<0.500	<0.500	10,000
Pyrene	<0.500	<0.500	<0.500	<0.500	<0.500	10,000
Benz(a)anthracene	<0.500	<0.500	<0.500	<0.500	<0.500	91.8
Chrysene	<0.500	<0.500	<0.500	<0.500	<0.500	1140
Benzo(b)fluoranthene	<0.500	<0.500	<0.500	<0.500	<0.500	17.8
Benzo(k)fluoranthene	<0.500	<0.500	<0.500	<0.500	<0.500	918
Benzo(a)pyrene	<0.500	<0.500	<0.500	<0.500	<0.500	9.18
Indeno(1.2.3.cd)pyrene	<0.500	<0.500	<0.500	<0.500	<0.500	91.8
Dibenz(a.h)anthracene	<0.500	<0.500	<0.500	<0.500	<0.500	9.18
Benzo(g.h.i)perylene	<0.500	<0.500	<0.500	<0.500	<0.500	10,000

5 Final Inspection and Record Checking Findings

5.1 General

According to Section 3.2.5 of the SCAP, it is recommended that final inspection and record checking should be conducted right before decommissioning/ demolition of the concerned above-ground fuel tank and the above-ground emergency generator for respective Emergency Power Supply Systems to ensure no contaminative activities during the period from the time of preparation of SCAP till the decommissioning. Summary of final inspection and record checking are given in ensuing paragraphs. Photo records of final inspections are presented in Appendix J.

5.1.1 Final Inspection and Record Checking Findings

5.1.1.1 Emergency Power Supply System No.2

Final Inspection

The above-ground fuel tank (i.e. BH9) and emergency generator (i.e. HS1) of EPSS2 were disconnected in late-May 2020. As advised by the contractor, the fuel inside EPSS2 was removed in late-June 2020. Hence the final inspection of the BH9 and HS1 was conducted on 8 July 2020. During our final inspection, BH9 and HS1 were at the same locations as for the time of preparation of SCAP in 2018. Both facilities were mounted on intact concrete floor with no oil stain observed, and no oil stain was observed inside the drip tray of the above-ground fuel tank (BH9). In addition, bund wall was provided in the access of the fuel tank room.

The fuel pipelines running through BH9 and HS1 were buried by sand inside a concrete and brick trench at floor level. Two sections of the pipelines were checked by removing the chequer plate cover and no sign of leakage was observed. Photo records of final inspections are presented in Appendix J1 and Appendix J2.

Record Checking

Available monthly maintenance records of the BH9 and HS1 from the time of SCAP preparation (i.e. March 2018) to February 2020 (month of last maintenance) were checked. No abnormality on fuel re-filling record was observed and no fuel tank leakage was recorded. It is concluded that there was no fuel leakage for the above-ground facilities BH9 and HS1 from the time of SCAP preparation till decommissioning/ demolition.

5.1.1.2 Emergency Power Supply System No.3

Final Inspection

The above-ground fuel tank (i.e. BH7) and emergency generator (i.e. BH8) of EPSS3 were decommissioned in early-April 2020. Final inspection of the BH7 and BH8 was conducted on 1 April 2020. During our final inspection, BH7 and BH8 were at the same locations as for the time of preparation of SCAP in 2018. The above-ground fuel tank (BH7) was surrounded by concrete curb and no oil stain was observed inside its drip tray, and the emergency generator (BH8) was mounted on intact concrete floor with no oil stain observed.

The fuel pipelines running through BH7 and BH8 were buried by sand inside a concrete and brick trench at floor level. Two sections of the pipelines were checked by removing the chequer plate cover and no sign of leakage was observed. Photo records of final inspections are presented in Appendix J3 and Appendix J4.

Record Checking

Available monthly maintenance records of the BH7 and BH8 from the time of SCAP preparation (i.e. March 2018) to March 2020 (month of last maintenance) were checked. No abnormality on fuel re-filling record was observed and no fuel tank leakage was recorded. It is concluded that there was no fuel leakage for the above-ground facilities BH7 and BH8 from the time of SCAP preparation till decommissioning/ demolition.

5.1.1.3 Emergency Power Supply System No.5

Final Inspection

The above-ground fuel tank (i.e. HS4) and emergency generator (i.e. HS5) of EPSS5 were decommissioned in late-May 2020. Final inspection of the HS4 and HS5 was conducted on 25 May 2020. During our final inspection, HS4 and HS5 were at the same locations as for the time of preparation of SCAP in 2018. Both facilities are mounted on intact concrete floor with no oil stain observed, and no oil stain was observed inside the drip tray of the above-ground fuel tank (HS4). In addition, curb wall was provided in the access of the fuel tank room.

The fuel pipelines running through HS4 and HS5 were buried by sand inside a concrete and brick trench at floor level. Two sections of the pipelines were checked by removing the chequer plate cover and no sign of leakage was observed. Photo records of final inspections are presented in Appendix J5.

Record Checking

Available monthly maintenance records of the HS4 and HS5 from the time of SCAP preparation (i.e. March 2018) to February 2020 (month of last maintenance) were checked. No abnormality on fuel re-filling record was observed and no fuel tank leakage was recorded. It is concluded that there was no fuel leakage for the above-ground facilities HS4 and HS5 from the time of SCAP preparation till decommissioning/ demolition.

6 Conclusion

Enhanced SI programme have been conducted for the underground sections, BH5 and BH6, during June to August 2020. During the enhanced SI programme, a total of 3 sand samples and 6 soil samples were collected and testing of CoCs was undertaken. The testing results indicated that all the samples at BH5 and BH6 were below the RBRGs standard for industrial. Based on the sample testing results, it is considered that there are no land contamination issues at the BH6, including the segment running through BH6-S2 and BH6-S3 as per the site photo record taken at BH6-S2 and BH6-S3. To sum up, it is considered that there are no land contamination issues at BH5 and BH6, therefore remediation works are not required.

To err on a conservative side, additional site photo records at the sides and bottom of BH6-S2 and BH6-S3 will be submitted to EPD upon the demolition at these two specific sampling points to reaffirm the conclusion drawn in Section 3.1.2 that there was no diesel leakage from the underground fuel pipes. In case that sign of diesel leakage is spotted during the demolition works, agreement from EPD shall be sought for sampling strategy and subsequent SI shall be arranged in accordance with the agreed sampling plan. A CAR should be submitted for the subsequent SI work and if remediation is required, a Remediation Action Plan and Remediation Report will also be prepared for submission to EPD.

Final inspection and record checking were conducted right before decommissioning/ demolition of the above-ground section of EPSS2 (i.e. BH9 and HS1), EPSS3 (i.e. BH7 and BH8) and EPSS5 (i.e. HS4 and HS5). According to the inspection and record checking results, it is concluded that there was no contaminative activities during the period from the preparation of SCAP till decommissioning/demolition of the above-ground facilities .