9. Land Contamination

9.1 Background

The potential environmental issues associated with land contamination have been reviewed and are presented in this section. The implications of land contamination for the proposed land uses for SIL(E) stations and the associated works areas at the study areas including Hong Kong School of Motoring (HKSM), Citybus Depot, ex-Wong Chuk Hang Estate, Lei Tung Estate, South Horizons and Ap Lei Chau Estate, have been assessed in accordance with the EIA Study Brief (ESB-181/2008).

9.2 Environmental Legislation, Standards and Guidelines

“Guidance Note for Contaminated Land Assessment and Remediation” and “Guidance Notes for Investigation and Remediation of Contaminated Sites of: Petrol filling Stations, Boatyards, and Car Repair/Dismantling Workshops” issued by the Environmental Protection Department (EPD) provide guidance on land contamination assessment. The Guidance Note for Contaminated Land Assessment refers the Risk-based Remediation Goals (RBRGs) as the soil and groundwater contamination criteria. Besides, under the “Guidance Manual for use of Risk-based Remediation Goals for Contaminated Land Management” promulgated by EPD on 15 August 2007, it presents instructions for comparison of soil and groundwater data to the RBRGs levels developed for relevant future land-use scenarios.

Further consideration of contamination issues is provided in Section 3 (Potential Contaminated Land Issues) of Annex 19 “Guidelines for Assessment of Impact on Sites of Cultural Heritage and Other Impacts” of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM).

9.3 Description of the Environment/ Baseline Conditions

9.3.1 Admiralty Station (ADM)

For SIL(E), an Admiralty Station (ADM) is proposed which would be constructed to the east of the existing ISL Admiralty station on Hong Kong Island. The land for the existing area in Admiralty was formed by reclamation in the late 19th or early 20th century.

Over the past decades, the study area has been utilised as commercial uses, open areas, etc with low rise buildings, etc. In the late 70’s, after the commencement of mass transit railway construction, the aforesaid area was used as site office and open areas. Starting from early 90’s, the study area was turned into a public park and underground carpark. The proposed station is going to locate underneath the public park, i.e. Harcourt Garden.

Table 9.1: Land Use History for Future SIL(E) Admiralty Station (ADM)

Date	Ref. no.	Height (ft)	Land Use
11/11/1945	4031	20,000	Low rise buildings
25/5/1949	Y01508	8,600	Low rise buildings
1/2/1963	Y07614	2,700	Open area, low rise buildings
1/1/1969	Y14677	-	Open area, low rise buildings
14/9/1979	26855	4,000	Site office, open area
28/11/1979	27904	4,000	Site office, open area
25/10/1988	A14807	2,000	Site office, open area
2/10/1991	A27674	4,000	Site office, open area
12/5/1992	A30896	4,000	Site office, open area
9/7/1993	A35230	4,000	Harcourt garden under construction, underground carpark
8/10/1993	CN4721	4,000	Harcourt garden and underground carpark
23/6/1997	CN17473	2,000	Harcourt garden and underground carpark
31/10/1998	CN22126	4,000	Harcourt garden and underground carpark
19/5/2006	CW71794	4,000	Harcourt garden and open space

9.3.2 Ocean Park Station (OCP)

The proposed Ocean Park (OCP) Station covers part of the former Hong Kong School of Motoring (HKSM) and a small portion of the existing Citybus Depot (CBD). The HKSM was in operation since 1985 until 2006 and Citybus Ltd. has taken the area to the north of the proposed OCP station in late 90’s as a depot. The remaining HKSM area was then handed over to Ocean Park for further development after HKSM’s closure.

An EIA study for the Ocean Park Development was carried out in accordance with EIA Study Brief No. ESB-125/2005. Land contamination assessment was required as part of the EIA study at the former HKSM site. It was not until late 2006 that the actual site investigation and decontamination works were carried out in the said area.

A post-decontamination confirmation was prepared in accordance with Condition 2.10 of the Environmental Permit EP-249/2006/A and submitted to EPD in April 2007 confirming the completion of all decontamination works in the former HKSM site.

Soon after Citybus Ltd. has taken over part of the area previously used by HKSM, it was turned into a parking area for buses (depot). Based on the desktop studies and site inspection including land use history, questionnaires sent to relevant land users and government departments, the whole area is concrete paved and there was no evidence to show the existence of petrol refilling activities, car/buses maintenance or the presence of underground fuel tanks except that a vehicle washing facility was noted in the CBD site.

Table 9.2: Land Use History for Future SIL(E) Ocean Park Station (OCP)

Date	Ref no.	Height (ft)	Land Use
Date	Ref no.	Height (ft)	HKSM site	CBD site
24/4/1949	Y01230	8,000	Farmland, hillside, village houses	Farmland, hillside, village houses
1/2/1963	Y06918	2,700	Farmland, hillside, village houses	Farmland, hillside, village houses
28/1/1976	12832	4,000	Open area	Open area
21/12/1977	20553	4,000	Open area and carpark	Open area and carpark
9/9/1987	A10402	4,000	HKSM	HKSM
20/10/1992	A32589	4,000	HKSM	HKSM
5/12/1993	A37065	4,000	HKSM	HKSM
9/8/2000	CN27613	4,000	HKSM	Citybus depot
19/5/2006	CW71786	4,000	HKSM	Citybus depot

During the construction of OCP station and its associated works, the area which is currently occupied by Citybus Ltd. would be used temporarily as site office and storage of construction material only. Subsequent property development is proposed at the same area but it is outside the scope of this EIA study.

9.3.3 Wong Chuk Hang Station (WCH)

According to the proposed SIL(E), a depot will be built in the area of ex-Wong Chuk Hang Estate close to the future Wong Chuk Hang (WCH) Station.

The construction of Wong Chuk Hang Estate started in 1968 and was completed in 1973. The whole estate consisted of ten blocks which were built in phases over the five year period. It was one of the sixteen “Government Low Cost Housing Scheme” estates built and was the only one of this kind built on Hong Kong Island. The estate was closed in late 2007 for subsequent demolition in 2008.

Table 9.3: Land Use History for Future SIL(E) Wong Chuk Hang Station (WCH)

Date	Ref. no.	Height (ft)	Land Use
24/4/1949	6193	8,000	Hillside, farmland, village houses
2/2/1963	Y6972	2,700	Hillside, farmland, village houses
13/5/1967	Y13197	3,900	Site formation and construction of Wong Chuk Hang Estate
1/1/1968	Y13937	3,000	Wong Chuk Hang Est. under construction
29/1/1976	12832	4,000	Wong Chuk Hang Estate
9/9/1987	A10402	4,000	Wong Chuk Hang Estate
27/9/1988	A14545	4,000	Wong Chuk Hang Estate
20/10/1992	A32591	4,000	Wong Chuk Hang Estate
31/10/1995	CN11691	4,000	Wong Chuk Hang Estate
23/10/1998	CN21061	4,000	Wong Chuk Hang Estate

9.3.4 Lei Tung Station (LET)

The Lei Tung Estate was built in 1987. It consists of eight 34 storey building. It is where the future LET Station locates.

According to the information collected during desktop study, Lei Tung Estate was built on the location around the former Lei Tung Temporary Housing Estate which was demolished in the early 80’s. Both estates cover an area of mainly hillside and farmland on the west side of Ap Lei Chau.

Table 9.4: Land Use History for Future SIL(E) Lei Tung Station (LET)

Date	Ref. no.	Height (ft)	Land Use
13/5/1967	Y13197	3,900	Hillside, farmland
3/5/1982	41911	-	Construction of Lei Tung Estate
27/9/1988	A14548	4,000	Lei Tung Estate
8/10/1993	CN4738	4,000	Lei Tung Estate

9.3.5 South Horizons Station (SOH)

Before South Horizons was built, the whole area was occupied by both the Hong Kong Electric (HEC) Ap Lei Chau Power Plant and Oil Depot of Shell Hong Kong Ltd. The Hong Kong Electric Ap Lei Chau Power Plant was established in 1968 and decommissioned in 1989 leaving only the operations headquarters in Ap Lei Chau. Similarly, the Shell Oil Depot at Ap Lei Chau has been in operation since 1970 and decommissioned in the late 80’s. After the decommissioning, the South Horizons was built in 1992 to 1995 in four phases.

Table 9.5: Land Use History for Future SIL(E) South Horizons Station (SOH)

Date	Ref. no.	Height (ft)	Land Use
2/2/1963	Y06856	2,700	Hillside and village houses, farmlands, sea bay
1/1/1969	Y14639	-	Hong Kong Electric Power Plant under construction, Shell Oil Depot under construction
21/12/1977	20557	4,000	Hong Kong Electric Power Plant, Shell Oil Depot, Ap Lei Chau Est. under construction
3/5/1982	41912	-	Hong Kong Electric Power Plant, Shell Oil Depot and Ap Lei Chau Est.
9/9/1987	A10406	4,000	Hong Kong Electric Power Plant, Shell Oil Depot and Ap Lei Chau Est.
12/5/1992	A31015	4,000	Construction of South Horizon, Hong Kong Electric Power Plant, Shell Oil Depot completely removed
8/12/1992	A33525	6,000	South Horizons Phase 4 under construction
8/10/1993	CN4737	4,000	South Horizons and Ap Lei Chau Estate
31/10/1995	CN11690	4,000	South Horizons and Ap Lei Chau Estate

In 1980, a bridge was constructed connecting Aberdeen and Ap Lei Chau and in the same year, the first phase of Ap Lei Chau Estate was completed. The estate was one of the Public Housing Estate built from 1980 to 1982 to accommodate people affected by the major fire in the Aberdeen typhoon shelter.

9.4 Assessment Methodology

In order to identify and evaluate the potential contamination impacts associated with the Study Area, the following tasks have been undertaken:

¡ Desktop study to review the current and historical land uses;

¡ Acquisition of information related to potential land contamination from Environmental Compliance Division of Environmental Protection Department (EPD), Fire Services Department (FSD) and Lands Department; and

¡ Site reconnaissance to identify the existing land uses.

In addition, the following sources of information have been collated and reviewed:

¡ Aerial photos from Lands Department and Geotechnical Engineering Office (GEO);

¡ Ground Investigation (GI) reports from Civil Engineering and Development Department (CEDD) Geotechnical Information library; and

¡ Records and photographs from site visits.

9.5 Identification of Environmental Impact

9.5.1 Admiralty Station (ADM)

The area where future SIL(E) ADM station is located was formed by reclamation and has been used for open space and commercial uses. By the time the construction of mass transit railway started, the area was used for site office as well as open areas. It has been confirmed that there was no activity or industry identified as per the Guidance Manual and Guidance Notes (Section 9.2 refers) within the proposed ADM station area that could potentially result in land contamination.

The corresponding works area and vent shaft/ancillary building locations are located mainly in the vicinity of ADM station, along Queensway, north of Harcourt Road and close to the Hong Kong Park. These areas have been in the past used as commercial and open area/roads/helipad (particularly for those in the vicinity of ADM station) and residential (around Hong Kong Park) purposes. There was no activity or industry identified that could potentially resulted in land contamination and therefore no land contamination is therefore suggested

9.5.2 Ocean Park Station (OCP)

The area south of OCP station was occupied by HKSM prior to handover to Ocean Park in late 2006. The corresponding land remediation works have been carried out as part of the Ocean Park Master Plan Development EIA study. A post-decontamination confirmation was prepared in accordance with Condition 2.10 of Environmental Permit EP-249/2006/A and submitted to EPD in April 2007 confirming the completion of all decontamination works in the former HKSM site.

The required land contamination assessment and remediation for the former HKSM is thus considered complete.

For the area which is currently used by Citybus Ltd, a contamination assessment strategy has been established and revealed no evidence of activities that would potentially result in significant land contamination. However, the existence of a vehicle washing machine was addressed during the desktop study and a prudent approach was adopted to further investigate its land contamination implication.

Other proposed works areas and ventilation building are for the Nam Fung Portal, viaduct and station construction. These areas were farmland, hillside and occupied with village houses in the past which indicate no land contamination issue.

9.5.3 Wong Chuk Hang Station (WCH)

According to the information received from various Government Departments during the contamination assessment stage and land use history, there was no activity or industry inside the ex-Wong Chuk Hang Estate that has contributed to land contamination. In addition, no Dangerous Goods (DG) store or Chemical Waste Store registration were recorded in the said Estate in its life span.

The corresponding works areas in the vicinity are for the construction of station, viaduct and a train depot which were in the past natural hillside, farmland as well as residential areas.

As such, it is considered that land contamination is not an issue for the said area in Wong Chuk Hang.

9.5.4 Lei Tung Station (LET)

Based on the desktop review, it is unlikely that land contamination is an issue at Lei Tung Estate since it was built on natural hillside and farmland without any indication of industrial activities in the past.

Works areas are also required for the construction of the station, tunnel, site office and storage of construction materials in the vicinity. Similarly, no issue in land contamination could be concluded based on the past land uses.

9.5.5 South Horizons Station (SOH)

The desktop study has indicated that the proposed location of the SOH station is over the former oil depot of Shell Hong Kong Ltd. Land use and other environmental information was acquired from the past users and various Government Departments.

It was considered likely that the original ground condition of the former oil depot has been significantly disturbed by the South Horizons construction works including excavation and filling. Nevertheless, contaminated soil may be present on this site and a site investigation strategy was therefore proposed.

Besides, part of the SOH station is inside a cavern while the remaining part is to be constructed by cut and cover along Yi Nam Road. The corresponding works areas and ventilation building are mostly concentrated in the vicinity of SOH station except for the one at Lee Wing Street on the south side of Ap Lei Chau which is located on reclaimed land.

Based on the assessment, no land contamination implication is therefore suggested in these areas

9.6 Prediction and Evaluation of Environmental Impact

9.6.1 Construction Phase

Desktop review has been carried out for the 6 respective sites. Based on the review, we have summarized the results in Table 9-6.

Table 9.6: Potential Contamination for each Study Area

Site	Desktop Studies	Potential for Land Contamination	Site Investigation	Corresponding RBRGs Land Use Scenario
ADM	No industries identified in accordance with the GM* and GN*	Unlikely	NO – no SI was proposed	N/A
CBD	No indication of contaminating industries/activities except for the existence of a vehicle washing facility	Anticipated significance is low	YES – less intensive SI was proposed for CBD site and has been completed in June and July 2009	Industrial
HKSM	The area has been decontaminated during the EIA study for Ocean Park Development (Study Brief No. ESB-125/2005)	Unlikely	NO – no SI was proposed	N/A
WCH	No industries identified in accordance with the GM* and GN*	Unlikely	NO – no SI was proposed	N/A
LET	No industries identified in accordance with the GM* and GN*	Unlikely	NO – no SI was proposed	N/A
SOH	Possible spillage/ leakage/ migration of fuel/ oil	Anticipated significance is low	YES – less intensive SI was proposed and has been completed in December 2008, June and July 2009	Industrial

Out of the six sites shown in Table 9-6, insignificant land contamination implication was considered for four of them, i.e. Admiralty, Ocean Park (former HKSM), Wong Chuk Hang and Lei Tung sites. For the SOH station at Yi Nam Road, its location is on the former oil depot before the existence of residential estate. Moreover, the original ground condition could have been seriously disturbed during the construction of residential estate. Nevertheless, less intensive sampling strategy was proposed for the SOH station.

For the CBD site, the existence of vehicle washing facility has been addressed in the desktop review and a prudent approach has been adopted in further investigating the presence of land contamination. As such, less intensive sampling strategy was also proposed for the area.

The sampling strategy used during SI followed the principles of the Environmental Protection Department Guidance Manual and Guidance Notes as described in Section 9.2. Soil samples were obtained at a maximum depth of 3m using the “trial pit” method from each of the sampling locations (Figures 9.1 and 9.2). Three (3) samples per trial pit were taken vertically from typical depths of 0.5m, 1.5m and 3.0m below ground level in accordance with the Contamination Assessment Plan (CAP) (Appendix 9.1). At the same time, ground condition for each trial pit was logged accordingly. The samples were tested for a range of heavy metals, BTEX, VOCs and SVOCs by an HOKLAS laboratory, ALS Technichem (HK) Pty Ltd. All testing results is summarized in Table 9-7.

In the above table, all laboratory results were well below the respective RBRGs “Industrial” criteria indicating an acceptable environmental quality in terms of anticipated impact to future land users.

9.6.2 Operation Phase

During the operation phase, it is expected that defined procedures in handling chemicals for the operation of a depot and railway station would be implemented as part of MTRCL company’s policy. As such, no land contamination implication is therefore considered.

9.7 Mitigation of Adverse Environmental Impact

9.7.1 Construction Phase

Mitigation measures are proposed for handling of the contaminated materials (if any) in order to minimize:

¡ The potentially adverse effects on the health and safety of construction workers; and

¡ The impacts arising from the disposal of potentially contaminated materials

The following measures are for contaminated material excavation and transportation:

¡ To minimize the chance for construction workers’ to come into contact with contaminated materials, bulk earth-moving excavation equipment should be employed;

¡ Contact with contaminated materials can be minimised by wearing appropriate clothing and personal protective equipment such as gloves and masks (especially when interacting directly with contaminated material), provision of washing facilities and prohibition of smoking and eating on site;

¡ Stockpiling of contaminated excavated materials on site should be avoided as far as possible;

¡ The use of contaminated soil for landscaping purpose should be avoided unless pre-treatment was carried out;

¡ Vehicles containing any excavated materials should be suitably covered to reduce dust emissions and/or release of contaminated wastewater;

¡ Truck bodies and tailgates should be sealed to stop any discharge;

¡ Only licensed waste haulers should be used to collect and transport contaminated material to treatment/disposal site and with the implementation of tracking system to avoid fly tipping;

¡ Speed control for trucks carrying contaminated materials should be carried out;

¡ Observe all relevant regulations in relation to waste handling, such as Waste Disposal Ordinance (Cap 354), Waste Disposal (Chemical Waste) (General) Regulation (Cap 354) and obtain all necessary permits where required; and

¡ Maintain records of waste generation and disposal quantities and disposal arrangements.

9.7.2 Operation Phase

During operation phase, it is anticipated that defined procedures in handling chemicals are to be implemented as part of MTRCL company policy. As such, all relevant operational procedures shall be strictly followed to avoid land contamination.

9.8 Evaluation of Residual Impact

Based on the desktop review and available site investigation results for land contamination assessment of the Project, no contaminated land issue has been revealed and hence, no land remediation action is proposed at this stage.

As such, the residual impact in relation to land remediation is considered not an issue at this stage.

9.9 Environmental Monitoring and Audit

9.9.1 Construction Phase

In view of the desktop review results and the Site Investigation Results, bulk excavation of soil for land remediation is not expected. As such, any environmental monitoring in relation to land remediation is not required.

On the other hand during construction phase, land contamination monitoring could be carried out in the form of regular site inspection. All related procedures and facilities in handling or storage of chemicals and chemical wastes should be audited regularly to make sure they are in order and intact and reported in the EM&A reports as such.

9.9.2 Operation Phase

During operation phase, regular audits are expected in the form of company’s internal and external audits. All the procedures in handling chemicals and chemical wastes would then be audited against company policies, regulations and international standards. Subsequent audit results would be reported in the corresponding audit reports.

9.10 Conclusion

9.10.1 Construction Phase

The land contamination assessment has been carried out which included a review of historical/current land uses, desktop review and site inspection. Other relevant information was also collected from related Government Departments during the assessment exercise.

All results have indicated insignificant contaminated land issue at ADM, WCH and LET sites. For OCP site, no similar issue was identified as land remediation had been carried out in the area south of OCP station (the former HKSM area) during another EIA study. For the area north of OCP station, i.e. the existing CBD, there was no evidence to show any sign of past activities that would potentially contributed to significant land contamination. As a result of the existence of a vehicle washing machine, a prudent approach in further site investigation was adopted and soil sampling strategy was proposed.

For the SOH site, it was where the former HEC Power Station and Shell Oil Depot located before South Horizons. Land contamination could be an issue due to the operation of the power plant as well as oil depot. Despite the aforesaid, it was believed the whole ground condition could have had seriously disturbed during the construction of South Horizons. As such, less intensive site investigation strategy was proposed.

SI was conducted in December 2008, June and July 2009 for the SOH and OCP stations where soil samples from five sampling locations were taken for laboratory analysis. Subsequent results have indicated the “Chemicals of Concern” (COC) of all locations at both SOH and OCP stations were well below their respective RBRGs “Industrial” criteria. Details of sampling and testing results are contained in the Contamination Assessment Report (CAR) in Appendix 9.2.

In view of the desktop review results and the Site Investigation Results, the significance of contamination to be low in the stations footprints as well as the concerned areas to the north and south OCP station. Bulk excavation of soil for land remediation is therefore not expected at this stage.

9.10.2 Operation Phase

During the operation phase, it is expected that defined procedures in handling chemicals for the operation of a depot and railway station will be implemented as part of the MTRCL’s policy. As such, no land contamination implication is anticipated.