· Guidance Note for Contaminated Land Assessment and Remediation (Guidance Note) – The Guidance Note sets out the requirements for proper assessment and management of potentially contaminated sites such as oil installations (e.g. oil depots, petrol filling stations), gas works, power plants, shipyards / boatyards, chemical manufacturing / processing plants, steel mills / metal workshops, car repairing / dismantling workshops and scrap yards. In addition, this Guidance Note provides guidelines on how site assessments should be conducted and analysed and suggests practical remedial measures that can be adopted for the clean-up of contaminated sites.

· Practice Guide for Investigation and Remediation of Contaminated Land (Practice Guide) – The Practice Guide outlines typical investigation methods and remediation strategies for the range of potential contaminants typically encountered in Hong Kong.

· Guidance Manual for Use of Risk-based Remediation Goals for Contaminated Land Management (Guidance Manual) – The Guidance Manual introduces the risk based approach in land contamination assessment and present instructions for comparison of soil and groundwater data to the Risk-Based Remediation Goals (RBRGs) for 54 chemicals of concern commonly found in Hong Kong. The RBRGs were derived to suit Hong Kong conditions by following the international practice of adopting a risk-based methodology for contaminated land assessment and remediation and were designed to protect the health of people who could potentially be exposed to land impacted by chemicals under four broad post restoration land use categories. The RBRGs also serve as the remediation targets if remediation is necessary.

7.3 Assessment Methodology

7.3.1.1 Land contamination assessment was carried out according to the abovementioned EIAO-TM, Guidance Note, Practice Guide and Guidance Manual.

7.3.1.2 A site appraisal, including site walkover and desktop review, was conducted to identify the potentially contaminating land uses that may pose adverse impact to the Project. Site walkover was conducted within the Project site to review the general site conditions and to identify any source of land contamination (or ‘hotspots’). For the desktop review, the following information was reviewed:

· Aerial photographs from Survey and Mapping Office of Lands Department;

· Records (if any) on dangerous goods (DGs), chemical wastes, chemical spillage / leakage and fire incidents from Environmental Protection Department (EPD) or Fire Services Department (FSD);

· Site Investigation Report Volume 1 of 3, EDD Contract No. 8/GCO/1983 Pumping Stations in Plover Cove Reservoir and Aqueducts in Tolo Channel Phase II, Enpack (H.K.) Ltd., 1983; and

· Site Investigation Report Volume 2 of 4 Appendix D, Agreement CE/31/82 Pumping Stations at Plover Cove Reservoir & Tolo Channel Aqueduct, Binnie & Partners (Hong Kong), 1984.

7.4 Description of the Environment

7.4.1.1 The proposed Sai O Trunk Sewer Sewage Pumping Station (SPS) is located at the north of Sai O and situated adjacent to the Sai O Offtake and Pigging Station with Hong Kong Baptist Theological Seminary located to the south. The location of the Project site is shown in Figure 2.1.

7.5 Site Appraisal

7.5.1 Review of Historical Land Use

7.5.1.1 A review of aerial photographs has been undertaken to evaluate the likelihood of potential contamination associated with past land uses within the Project site. The development history of the Project site is summarised below and the list of aerial photographs reviewed is shown in Table 7.1. The aerial photographs reviewed are provided in Appendix 7.1.

Table 7.1 Aerial Photographs Reviewed

Year	Height (Feet)	Reference Number of Photograph
1963	3,900	5614
1973	2,800	5450
1985	4,000	65910
1990	2,000	A22615
2000	3,000	CN27797
2015	2,000	CW115773
2019	6,900	E063381C

7.5.1.2 The Project site had been used for cultivation since 1963 and till 1985 when the site was vacated. In 1990, the Project site was entirely covered with vegetation and no significant change in land uses was observed since then. No historical potentially contaminating land uses were identified based on the review of the aerial photographs.

7.5.2 Site Geology

7.5.2.1 Based on the reports mentioned in Section 7.3, the Project site is majorly underlain by 7.5 m to 9 m thick of alluvium / fill / gravel overlaying a layer of mudstone (Grade V rock) / siltstone / sandstone encountered between -4.60 mPD and -5.33 mPD.

7.5.3 Acquisition of Information from Government Departments

7.5.3.1 The EPD and FSD have been contacted for (i) records on any leakage / spillage of chemicals and chemical waste, (ii) records of DGs, (iii) records of Chemical Waste Producer(s) (CWP) and (iv) records of reported fire incidents within the Project site. EPD’s and FSD’s replies on the requests have been received and attached in Appendix 7.2 and Appendix 7.3 respectively. Replies are summarized below.

Environmental Protection Department

7.5.3.2 According to the replies from EPD, there are no spillage / leakage of chemicals at the Project site. Following to the replies from EPD, records of CWP were reviewed on 14 October 2020 at EPD Southorn Centre Office. According to the records reviewed, there are no records of registered CWP within the Project site.

Fire Services Department

7.5.3.3 According to the replies from FSD, there are no records of DGs license, DGs spillage / leakage incidents and fire incidents at the Project site.

7.5.4 Site Walkover

7.5.4.1 Site walkover was conducted on 23 July and 21 November 2020 to ascertain any contaminative issues associated with current land uses and activities within the Project site.

7.5.4.2 The Project site is currently fenced off and inaccessible for detailed site walkover. The Project site is currently owned by the Lands Department and change of land use at the site is not expected prior to commencement of the Project. Based on peripheral site observation, the Project site is a piece of vacant / vegetated land. No potentially contaminating land uses / activities have been identified and no oil stains and / or stressed vegetation have been observed.

7.5.4.3 Photographic records illustrating the current land uses and activities observed during site walkover are provided in Figure 7.1.

7.5.4.4 Site walkover checklist, providing information on site condition and details on site observation, is enclosed in Appendix 7.4.

7.6 Prediction and Evaluation of Land Contamination Impacts

7.6.1.1 Based on the findings of the desktop review and site walkover, no current or historical potentially contaminating land uses / activities were identified within the Project site and therefore, no land contamination impact associated with the Project is anticipated.

7.6.1.2 No further land contamination assessment, including intrusive site investigation (SI) works and submission of Contamination Assessment Plan (CAP), Contamination Assessment Report (CAR) and Remediation Action Plan (RAP), is therefore considered necessary for the Project.

7.7 EM&A Requirements

7.7.1.1 Since land contamination impact is not anticipated, no EM&A requirements are considered necessary for the Project.

7.8 Conclusion

7.8.1.1 Based on the findings of desktop review and site walkover within the Project site, no current or historical potentially contaminating land uses / activities were identified within the Project site and therefore adverse land contamination impact arising from Project is not anticipated. No further land contamination assessment (including SI works and submission of CAP, CAR and RAP) or EM&A requirements are considered necessary for the Project.