Contents

                                                                                                        

 

8         Land Contamination.. 8-1

8.1     Introduction. 8-1

8.2     Environmental Legislations and Evaluation Criteria. 8-1

8.3     Assessment Approach and Methodology. 8-6

8.4     Description of the Environment 8-9

8.5     Remediation Measures and Validation. 8-29

8.6     Environmental Monitoring & Audit (EM&A) 8-35

8.7     Evaluation of Residual Impact 8-35

8.8     Conclusion. 8-37

 

TABLES

 

Table 8.1 Risk-Based Remediation Goals (RBRGs) for Soil and the Soil Saturation Limit 8-3

Table 8.2 Risk-Based Remediation Goals (RBRGs) for Groundwater and Solubility Limit 8-5

Table 8.3 Summary of Historical Aerial Photographs at the PDA   8-9

Table 8.4 Summary of Historical Aerial Photographs at the Associated Off-site Works Area  8-12

Table 8.5 Land Use Activities and Corresponding Chemicals of Concern at the Proposed Development Area  8-21

Table 8.6 Full List of Chemicals of Concern  8-24

Table 8.7 Post-Restoration Land Uses and the Corresponding RBRGs  8-27

Table 8.8a Potential Soil Remediation Options  8-32

Table 8.8b Potential Groundwater Remediation Options     8-34

 

FIGURES

Figure 8.1        Delineation of Sub-Area 1 to Sub-Area 4 at Fanling Golf Course

Figure 8.2        Notional Layout Plan of Proposed Housing Development at Sub-Area 1

Figure 8.3        Land Use Activities at Sub-Area 1

Figure 8.4        Land Use Activities at Sub-Areas 2 and 3

Figure 8.5        Land Use Activities at Sub-Area 4

Figure 8.6        Land Use Activities Outside the Project Development Area

Figure 8.7        Proposed RBRGs Land Use at Sub-Area 1

Figure 8.8        Proposed RBRGs Land Use at Sub-Areas 2 to 4

 

APPENDIX

Appendix 8.1  Contamination Assessment Plan (CAP)

Appendix 8.2  Geochemical Atlas of Hong Kong – Arsenic in Stream Sediment


8                          Land Contamination

8.1                     Introduction

8.1.1                 This section of the EIA assesses the potential contamination impacts in support of the Project development, to assess whether any surrounding land uses may have and/or are currently impacting the environmental condition of the land. The potential environmental issues related to land contamination have been assessed in accordance with Clause 3.4.8 and Appendix G of the EIA Study Brief and are presented in this section.

8.1.2                 Land contamination refers to an area or a spot of the land that has been polluted by hazardous substances due to historical or current land use activities that may cause hazardous risks or adverse effects to human health and the surrounding environment.

8.1.3                 Contamination is generally the result of past uses or activities on land. It can occur as a result of the improper storage, production or use of petroleum products, improper chemical handling or disposal practices or the placement of contaminated fill on a site. Contamination can also occur when polluted groundwater, dust or hazardous ground gases move from a contaminated site to nearby land.

8.1.4                 The assessment has covered the entire Potential (Proposed) Development Area (PDA) at the Fanling Golf Course (FGC) as well as the footprint of the associated off-site works area, which are located outside the PDA (Figure 8.1).

8.1.5                 The preparation and submission of a Contamination Assessment Plan (CAP) is to satisfy the requirement set out in Appendix G of the EIA Study Brief. The latest version of CAP is presented in Appendix 8.1 with EPD’s endorsement received on 11 May 2022.

8.2                     Environmental Legislations and Evaluation Criteria

8.2.1                 Land contamination assessment will be conducted in accordance with the following environmental legislations, practice guide, guidance note, and guidance manual listed below:

(a)        Sections 3.1 and 3.2 (Potential Contaminated Land Issues) of the 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) set out the general approach and methodology for assessment of land contamination issues, predominantly historical land uses, associated with a project or proposal.

(b)        EPD’s Practice Guide for Investigation and Remediation of Contaminated Land, August 2011 (Practice Guide) presents the standard investigation methods and remediation strategies for the range of potential contaminated sites and contaminants typically encountered in Hong Kong. It sets out the requirements for planning and implementation for the contaminated land investigation, interpretation of the investigation results using the Risk-Based Remediation Goals (RBRGs), outlining the contaminated land assessment, planning and implementation of remediation actions, and reporting the remediation works;

(c)        EPD’s Guidance Note for Contaminated Land Assessment and Remediation, August 2007 (Guidance Note) sets out the requirements for proper assessment and management of potentially contaminated sites that are typically found in Hong Kong. It provides guidelines on how site assessments should be conducted and analysed and suggests practical remediation measures that can be adopted for the remediation of contaminated sites; and

(d)        EPD’s Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management, December 2007 (Guidance Manual) introduces the risk-based approach in land contamination assessment and presents instructions for comparison of soil and groundwater data to the RBRGs for 54 chemicals of concern. The RBRGs were derived to suit Hong Kong’s conditions by following international best practices of adopting a risk-based methodology for contaminated land assessment and remediation. They are designed to protect the health of people who could potentially by exposed to land impacted by any of the above-mentioned chemicals of concern under four broad post-restoration land use categories. In addition, the RBRGs served as the remediation targets if remediation is necessary. The RBRGs for soil and groundwater for the four post-restoration land use categories are presented in Table 8.1 and Table 8.2, respectively.


 

Table 8.1 Risk-Based Remediation Goals (RBRGs) for Soil and the Soil Saturation Limit

Chemical

Risk-Based Remediation Goals for Soil

Soil Saturation 
Limit (Csat) (mg/kg)

Urban Residential (mg/kg)

Rural Residential (mg/kg)

Industrial (mg/kg)

Public Parks (mg/kg)

VOCs

Acetone

9.59E+03

4.26E+03

1.00E+04

1.00E+04

***

Benzene

7.04E-01

2.79E-01

9.21E+00

4.22E+01

3.36E+02

Bromodichloromethane 

3.17E-01

1.29E-01

2.85E+00

1.34E+01

1.03E+03

2-Butanone

1.00E+04

1.00E+04

1.00E+04

1.00E+04

***

Chloroform

1.32E-01

5.29E-02

1.54E+00

2.53E+02

1.10E+03

Ethylbenzene

7.09E+02

2.98E+02

8.24E+03

1.00E+04

1.38E+02

Methyl tert-Butyl Ether

6.88E+00

2.80E+00

7.01E+01

5.05E+02

2.38E+03

Methylene Chloride

1.30E+00

5.29E-01

1.39E+01

1.28E+02

9.21E+02

Styrene

3.22E+03

1.54E+03

1.00E+04

1.00E+04

4.97E+02

Tetrachloroethene

1.01E-01

4.44E-02

7.77E-01

1.84E+00

9.71E+01

Toluene

1.44E+03

7.05E+02

1.00E+04

1.00E+04

2.35E+02

Trichloroethene

5.23E-01

2.11E-01

5.68E+00

6.94E+01

4.88E+02

Xylenes (Total)

9.50E+01

3.68E+01

1.23E+03

1.00E+04

1.50E+02

SVOCs

Acenaphthene

3.51E+03

3.28E+03

1.00E+04

1.00E+04

6.02E+01

Acenaphthylene

2.34E+03

1.51E+03

1.00E+04

1.00E+04

1.98E+01

Anthracene

1.00E+04

1.00E+04

1.00E+04

1.00E+04

2.56E+00

Benzo(a)anthracene

1.20E+01

1.14E+01

9.18E+01

3.83E+01

N/A

Benzo(a)pyrene

1.20E+00

1.14E+00

9.18E+00

3.83E+00

N/A

Benzo(b)fluoranthene

9.88E+00

1.01E+01

1.78E+01

2.04E+01

N/A

Benzo(g,h,i)perylene

1.80E+03

1.71E+03

1.00E+04

5.74E+03

N/A

Benzo(k)fluoranthene

1.20E+02

1.14E+02

9.18E+02

3.83E+02

N/A

bis-(2-Ethylhexyl)phthalate

3.00E+01

2.80E+01

9.18E+01

9.42E+01

N/A

Chrysene

8.71E+02

9.19E+02

1.14E+03

1.54E+03

N/A

Dibenzo(a,h)anthracene

1.20E+00

1.14E+00

9.18E+00

3.83E+00

N/A

Fluoranthene

2.40E+03

2.27E+03

1.00E+04

7.62E+03

N/A

Fluorene

2.38E+03

2.25E+03

1.00E+04

7.45E+03

5.47E+01

Hexachlorobenzene

2.43E-01

2.20E-01

5.82E-01

7.13E-01

N/A

Indeno(1,2,3-cd)pyrene

1.20E+01

1.14E+01

9.18E+01

3.83E+01

N/A

Naphthalene

1.82E+02

8.56E+01

4.53E+02

9.14E+02

1.25E+02

Phenanthrene

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+04*

2.80E+01

Phenol

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+04*

7.26E+03

Pyrene

1.80E+03

1.71E+03

1.00E+04

5.72E+03

N/A

Metals

Antimony

2.95E+01

2.91E+01

2.61E+02

9.79E+01

N/A

Arsenic

2.21E+01

2.18E+01

1.96E+02

7.35E+01

N/A

Barium

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+04*

N/A

Cadmium

7.38E+01

7.28E+01

6.53E+02

2.45E+02

N/A

Chromium III

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+04*

N/A

Chromium VI

2.21E+02

2.18E+02

1.96E+03

7.35E+02

N/A

Cobalt

1.48E+03

1.46E+03

1.00E+04

4.90E+03

N/A

Copper

2.95E+03

2.91E+03

1.00E+04

9.79E+03

N/A

Lead

2.58E+02

2.55E+02

2.29E+03

8.57E+02

N/A

Manganese

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+04*

N/A

Mercury

1.10E+01

6.52E+00

3.84E+01

4.56E+01

N/A

Molybdenum

3.69E+02

3.64E+02

3.26E+03

1.22E+03

N/A

Nickel

1.48E+03

1.46E+03

1.00E+04*

4.90E+03

N/A

Tin

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+04*

N/A

Zinc

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+04*

N/A

Dioxins / PCBs

 

 

 

 

 

Dioxins (I-TEQ)

1.00E-03

1.00E-03

5.00E-03

1.00E-03

N/A

PCBs

2.36E-01

2.26E-01

7.48E-01

7.56E-01

N/A

Petroleum Carbon Ranges

C6 - C8

1.41E+03

5.45E+02

1.00E+04*

1.00E+04*

1.00E+03

C9 - C16

2.24E+03

1.33E+03

1.00E+04*

1.00E+04*

3.00E+03

C17 - C35

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+04*

5.00E+03

Other Inorganic Compounds

Cyanide, free

1.48E+03

1.46E+03

1.00E+04*

4.90E+03

N/A

Organometallics

Tributyltin oxide (TBTO)

2.21E+01

2.18E+01

1.96E+02

7.35E+01

N/A

Notes:

(1)    N/A indicates that RBRG could not be calculated because the toxicity or physical / chemical values were unavailable, or the condition of Henry’s Law Constant > 1.00E-05 was not met for the inhalation pathway.

(2)    For Dioxins, the clean-up levels in USEPA Office of Solid Waste and Emergency Response (OSWER) Directive of 1998 have been adopted. The OSWER Directive value of 1 ppb for residential use has been applied to the scenarios of “Urban Residential”, “Rural Residential”, and “Public Parks”, while the low end of the range of values for industrial, 5 ppb, has been applied to the scenario of “Industrial”.

(3)    Soil saturation limits for petroleum carbon ranges taken from the Canada-Wide Standards for Petroleum Hydrocarbons in Soil, CCME 2000.

(4)    * indicates a ‘ceiling limit’ concentration.

(5)    *** indicates that the Csat value exceeds the ‘ceiling limit’ therefore the RBRG applies.


Table 8.2 Risk-Based Remediation Goals (RBRGs) for Groundwater and Solubility Limit

Chemical

Risk-Based Remediation Goals for Groundwater

Solubility Limit 
(mg/L)

Urban Residential (mg/L)

Rural Residential (mg/L)

Industrial (mg/L)

VOCs

Acetone

1.00E+04*

1.00E+04*

1.00E+04*

***

Benzene

3.86E+00

1.49E+00

5.40E+01

1.75E+03

Bromodichloromethane 

2.22E+00

8.71E-01

2.62E+01

6.74E+03

2-Butanone

1.00E+04*

1.00E+04*

1.00E+04*

***

Chloroform

9.56E-01

3.82E-01

1.13E+01

7.92E+03

Ethylbenzene

1.02E+03

3.91E+02

1.00E+04*

1.69E+02

Methyl tert-Butyl Ether

1.53E+02

6.11E+01

1.81E+03

***

Methylene Chloride

1.90E+01

7.59E+00

2.24E+02

***

Styrene

3.02E+03

1.16E+03

1.00E+04*

3.10E+02

Tetrachloroethene

2.50E-01

9.96E-02

2.95E+00

2.00E+02

Toluene

5.11E+03

1.97E+03

1.00E+04*

5.26E+02

Trichloroethene

1.21E+00

4.81E-01

1.42E+01

1.10E+03

Xylenes (Total)

1.12E+02

4.33E+01

1.57E+03

1.75E+02

SVOCs

Acenaphthene

1.00E+04*

7.09E+03

1.00E+04*

4.24E+00

Acenaphthylene

1.41E+03

5.42E+02

1.00E+04*

3.93E+00

Anthracene

1.00E+04*

1.00E+04*

1.00E+04*

4.34E-02

Benzo(a)anthracene

N/A

N/A

N/A

N/A

Benzo(a)pyrene

N/A

N/A

N/A

N/A

Benzo(b)fluoranthene

5.39E-01

2.03E-01

7.53E+00

1.50E-03

Benzo(g,h,i)perylene

N/A

N/A

N/A

N/A

Benzo(k)fluoranthene

N/A

N/A

N/A

N/A

bis-(2-Ethylhexyl)phthalate

N/A

N/A

N/A

N/A

Chrysene

5.81E+01

2.19E+01

8.12E+02

1.60E-03

Dibenzo(a,h)anthracene

N/A

N/A

N/A

N/A

Fluoranthene

1.00E+04*

1.00E+04*

1.00E+04*

2.06E-01

Fluorene

1.00E+04*

1.00E+04*

1.00E+04*

1.98E+00

Hexachlorobenzene

5.89E-02

2.34E-02

6.95E-01

6.20E+00

Indeno(1,2,3-cd)pyrene

N/A

N/A

N/A

N/A

Naphthalene

6.17E+01

2.37E+01

8.62E+02

3.10E+01

Phenanthrene

1.00E+04*

1.00E+04*

1.00E+04*

1.00E+00

Phenol

N/A

N/A

N/A

N/A

Pyrene

1.00E+04*

1.00E+04*

1.00E+04*

1.35E-01

Metals

Antimony

N/A

N/A

N/A

N/A

Arsenic

N/A

N/A

N/A

N/A

Barium

N/A

N/A

N/A

N/A

Cadmium

N/A

N/A

N/A

N/A

Chromium III

N/A

N/A

N/A

N/A

Chromium VI

N/A

N/A

N/A

N/A

Cobalt

N/A

N/A

N/A

N/A

Copper

N/A

N/A

N/A

N/A

Lead

N/A

N/A

N/A

N/A

Manganese

N/A

N/A

N/A

N/A

Mercury

4.86E-01

1.84E-01

6.79E+00

N/A

Molybdenum

N/A

N/A

N/A

N/A

Nickel

N/A

N/A

N/A

N/A

Tin

N/A

N/A

N/A

N/A

Zinc

N/A

N/A

N/A

N/A

Dioxins / PCBs

Dioxins (I-TEQ)

N/A

N/A

N/A

N/A

PCBs

4.33E-01

1.71E-01

5.11E+00

3.10E-02

Petroleum Carbon Ranges

C6 - C8

8.22E+01

3.17E+01

1.15E+03

5.23E+00

C9 - C16

7.14E+02

2.76E+02

9.98E+03

2.80E+00

C17 - C35

1.28E+01

4.93E+00

1.78E+02

2.80E+00

Other Inorganic Compounds

Cyanide, free

N/A

N/A

N/A

N/A

Organometallics

Tributyltin oxide (TBTO)

N/A

N/A

N/A

N/A

Notes:

(1)   N/A indicates that RBRG could not be calculated because the toxicity or physical/chemical values were unavailable, or the condition of Henry’s Law Constant>1.00E-05 was not met for the inhalation pathway.

(2)   Water solubilities for Petroleum Carbon Range aliphatic C9-C16 and greater than C16 generally are considered to be effectively zero and therefore the aromatic solubility for C9-C16 is used.

(3)   * indicates a ‘ceiling limit’ concentration.

(4)   *** indicates that the solubility limit exceeds the ‘ceiling limit’ therefore the RBRG applies.

8.2.2                 The methodology for conducting land contamination assessment will be carried out in accordance with the Practice Guide and Guidance Note, with references made from the Guidance Manual.

8.3                     Assessment Approach and Methodology

8.3.1                 A risk-based assessment approach to the investigation of contaminated land is to be conducted to identify any past or present potentially contaminating activities, and to provide the assessment of the extent and nature of site contamination if it exists.

8.3.2                 The following steps have been undertaken to characterise and identify if potential contamination exists or may be present at the development area:

·       Desktop review to investigate the current and past land uses in the PDA for potentially contaminating activities and chemicals, and surrounding area with the aid with historical aerial photographs and maps;

·       History of development applications and approvals for the site;

·       Site inspection to identify the current land uses in the PDA as well as to verify the potential contamination areas and hotspots;

·       Information provided by site representative; and

·       Consideration on the land use changes.

8.3.3                 Desktop review of existing information from historical land contamination Site Investigation, other contamination and environmental reports, and EIA Reports include:

·       Hong Kong Geological Survey Maps (GSMs);

·       Relevant aerial photographs and maps;

·       Relevant Outline Zoning Plans (OZPs);

·       Records of dangerous goods, chemical wastes, chemical spillage/leakage from FSD and EPD;

·       Hong Kong Historic Maps – Reference 1922 (https://www.hkmaps.hk/map.html?1922);

·       Mapping Hong Kong – A Historical Atlas, Government Information Services, 1992;

·       Geochemical Atlas of Hong Kong (Sewell, 1999); and

·       “North East New Territories New Development Areas Planning and Engineering Study – Investigation”, CEDD and PlanD, 2007, EIA Report No. AEIAR-175/2013.

Site Inspection

8.3.4                 Site inspections were conducted for the entire assessment area of the Project as illustrated in Figure 8.1. Site inspection of the FGC and PDA was carried out in May 2020 to validate the initial evaluation of desktop reviews and to identify potential environmental impacts from nearby land uses activities and whether there is any known or potential contamination on neighboring properties.

8.3.5                 Subsequent site inspection was carried out within the boundaries of the associated off-site works area in September 2021, to validate the initial evaluation of desktop reviews and to identify potential environmental impacts from nearby land uses activities and whether there is any known or potential contamination on neighboring properties.

Preparation of Contamination Assessment Plan

8.3.6                 Findings from the desktop review, information requests from governmental departments, geology/hydrogeology of the site, details of the site inspections, and the proposed strategy for sampling and laboratory testing of soil and groundwater (site investigation – SI) are presented in the Contamination Assessment Plan (CAP) as outlined in Appendix 8.1.

8.3.7                 Identification of the chemicals of concern (COCs), areas of potential contamination and the associated impacts, risks or hazards at boundaries of the PDA and associated areas were also identified and discussed in the CAP.

8.3.8                 Sampling locations and sampling depths for soil and groundwater within the PDA have been proposed for SI works in the respective CAP. However, due to site accessibility issues and given the golf course will still be in operation until commencement of construction, undertaking SI works at this EIA stage is not feasible. Further works, including re-appraisal and submission of supplementary CAP(s) are recommended to be conducted in the later stage of the Project. Should there be any changes in land use upon the land has been reverted to Government, the supplementary CAP(s), incorporation of findings of covering the entire assessment area and updated sampling and testing strategy shall be prepared and submitted to EPD for approval. Site Investigation and lab analyses shall commence after the approval of the supplementary CAP(s) by EPD.

8.3.9                 Following the completion of SI works, the SI results should be presented in the Contamination Assessment Report(s) (CAR(s)) for submission to EPD, and if remediation is required, Remediation Action Plan(s) (RAP(s)) shall be prepared with the purpose to set remediation goals and specify remediation monitoring and measurements to monitor remediation progress. The RAP(s) shall be submitted to EPD for approval before the commencement of remediation works.

8.3.10              A Remediation Report (RR) shall be prepared for submission to EPD to demonstrate adequate remediation works have been completed to meet the relevant remediation goals. The content of the RR shall include the description of remediation programme carried out and the remediation monitoring results. The RR shall be submitted to EPD for endorsement. No construction works or development of site should be carried out prior to the endorsement of the RR.


 

8.4                     Description of the Environment

Review of Historical and Current Information

8.4.1                 Historical information in relation to the PDA and associated off-site works area were reviewed to identify any past land uses which may have caused land contamination, including the review of historical aerial photos between the years 1945 to 2016, in addition to a historic map from 1922. The historical aerial photographs are presented in Appendix A of the CAP (Appendix 8.1). A summary of the findings at the PDA and associated off-site works area are presented in the below Table 8.3 and Table 8.4, respectively.

8.4.2                 Information from relevant governmental departments were also reviewed as presented in Appendix E of the CAP. According to the reply from Fire Services Department (FSD), from the year of 1990 to present, two dangerous goods licenses were held by HKGC for two 7,000L underground storage tanks for petrol and diesel oils that are located outside the PDA. No previous chemical nor dangerous goods leakage and/or spillage was recorded on the FGC.

8.4.3                 Reply from Environmental Protection Department (EPD) in November 2019 stated that no chemical spillage and/or leakage accident has occurred within the PDA in the past 5 years. WSP reviewed the Registry of Chemical Waste Producers (CWPs) in November 2019 and two valid CWPs, namely The Hong Kong Golf Club (golf club activities) and Legend Interiors Ltd. (interior contracting) are present on FGC, but not on the PDA. One invalid CWP, namely Paul Y. Construction & Engineering Co., Ltd. was previously present on FGC for construction works regarding the 2008 Olympic Equestrian Venues (not on the PDA).

8.4.4                 WSP further contacted EPD on the nature of the two valid CWPs in March 2021; the chemical wastes generated from Hong Kong Golf Club include spent lubricating oil, spent acid, and pesticides. Spent paint and spent adhesive were generated from Legend Interiors.

8.4.5                 In retrospect, under a valid CWP held by The Hong Kong Golf Course, the chemical wastes generated include spent lubricating oil, spent acid, and pesticides.

8.4.6                 Reply from Lands Department (LandsD) indicated that the PDA and surrounding areas is permitted for the use of a golf course, club house and ancillary purpose. No information was provided regarding the PDA’s past land uses. There is no record of any reported land contamination regarding the PDA either.

Table 8.3 Summary of Historical Aerial Photographs at the PDA


 

Year

Height (Feet)

Photo Reference Number

Site Description

1922

N/A

HK Maps (extracted from Hong Kong Historic Maps – Reference 1922)

The Proposed Development Area (PDA) already used as a golf course, which is present day ‘Old Course’. “Club House” and “Golf Course” were observed on a printed map. Land use in the surrounding areas include Ping Kong Village which has a settlement history dating back to the Late Ming–Early Qing dynasty (in orange).

1945

20,000

681_4-3117

Fan Kam Road has been established. The PDA remains unchanged serving as a golf course. Agricultural land observed along the eastern side and southwest tip of PDA; settlement of Ping Kong Village shown clearly. The surrounding areas of the PDA are of agricultural use surrounded by dense vegetation and residential (village).

1954

29,200

V81A_550-0046

Additional fairways were constructed between 1945 to 1954 in Sub-Areas 1 to 4. The golf course is more prominent, and the boundary is similar to present day. Some vegetation removal was observed in north of Sub-Area 1 (in turquoise). Site clearance activities observed in yellow where present day Tai Lung Experimental Farm is located.

1961

30,000

F42_625-0029

No change to the land use activities within the PDA. Some structures observed in the area north of Sub-Area 1 (in turquoise). Surrounding areas included agricultural land and residential. Early establishment (a building) of AFCD’s Tai Lung Experimental Farm (in blue) and scattered buildings in present day On Po Village (in yellow) observed.

1969

N/A

1969-1762

Development of fairways in the Fanling Golf Course (Eden Course) in progress. No change to the land use activities within the PDA. The surrounding areas remained as agricultural land.

1973

6,000

CN0625

Development of fairways in the FGC New Course completed. Some site clearance activities observed at present day parking lot in Sub-Area 1.

1974

12,500

10017

No change to the land use activities within the PDA. Surrounding areas remained as agricultural land and residential.

1976

12,500

16328

PDA undergoing changes to create additional fairway located south of present day parking lot in Sub-Area 1. No other development observed in Sub-Area 2 to Sub-Area 4 and no changes to the surrounding areas.

1978

12,500

24505

Completion of the additional fairway and parking lot repaved in Sub-Area 1. No construction activities observed in Sub-Area 2 to Sub-Area 4. Land uses remain unchanged in the surrounding areas.

1983

10,000

52299

The Fanling Pumping Station (constructed in 1983) and associated Substation have been established in Sub-Area 2 of the PDA, in addition to the tennis courts observed in Sub-Area 1. No construction activities are observed in Sub-Area 3 and Sub-Area 4. Scattered temporary structures (present day On Po Village in orange) observed next to southeast border of Sub-Area 2.

1986

10,000

A07957

Private property observed in the northern part of Sub-Area 1. Surrounding areas remain as agricultural land and residential usage.

1992

10,000

A32969

Staff quarters observed in the northern part of Sub-Area 1, whilst no changes to the surrounding areas.

1997

10,000

CN19248

No change to the land use activities within the PDA. Construction of the North District Hospital has been completed.

2008

8,000

CW80471

Removal of vegetation on the tennis court observed. Turf loss in the fairway in Sub-Area 3 observed (in blue). Land use activities surrounding the PDA include residential and agricultural land. A school (Elegantia College) was observed and according to historical sources it was founded in 2002. Site clearance activities observed (in turquoise) north of school site to make way for high-rise residential. According to historical sources, the construction of Tai Lung Veterinary Laboratory (in yellow) commenced in 2000 and completed in 2001.

2016

7,000

E008323C

PDA resembles to present day. Tennis court in Sub-Area 1 is repaved; new greens observed in Sub-Area 3. Surrounding areas are predominately occupied by buildings and structures, consisted of agricultural (Tai Lung Experimental Farm), residential (public housing, hospital, On Po Village and Ping Kong Village). No major changes to the PDA observed from year 2008 to current date.

 

8.4.7                 Review of the aerial photographs revealed that FGC is the first and only occupant since its establishment until present day. Site clearance activities to make way for additional fairways are observed. However, there is an absence of potential contaminating historical land uses such as oil installations, gas works, metal workshops, car repair and dismantling workshops, as having the potential to cause or have caused land contamination. The existing substation will remain and it is not located near to the boundary of proposed works – approximately 51 metres (m) southwest away. No potential land contamination is anticipated from the substation as no development works and/or demolishing the substation is planned.

Table 8.4 Summary of Historical Aerial Photographs at the Associated Off-site Works Area

Year

Height (Feet)

Photo Reference Number

Site Description

1945

20,000

681_4-3117

North of Fan Kam Road

Fanling Highway was observed surrounded by grassland and some densed vegetation. East Rail Line is located further north of Fanling Highway, which according to historical sources, the Sheung Shui Station opened in 1930.

Ping Kong Road and Po Kin Road

The area mainly consisted of farmland and grassland.

1954

29,200

V81A_550-0046

North of Fan Kam Road

No change in land use was observed and remained as a road. Fanling Highway was observed surrounded by grassland

Ping Kong Road and Po Kin Road

A road was observed (Ping Kong Road) and the surrounding area mainly consisted of agricultural land and grassland. Some vegetation and grassland were removed along Ping Kong Road.

1986

10,000

A07957

North of Fan Kam Road

No change in land use was observed and remained as a road.

Ping Kong Road and Po Kin Road

No change in land use. A road was observed extended east to Po Kin Road. According to historical sources, Choi Po Court and Choi Yuen Estate (public housing) were constructed between 1981 and 1985.

1997

10,000

CN19248

North of Fan Kam Road

No change in land use was observed and remained as a road.

Ping Kong Road and Po Kin Road

No change in land use was observed and remained as a road. The North District Hospital was observed and according to historical sources, the hospital opened in 1998.

2016

7,000

E008323C

North of Fan Kam Road

No change in land use was observed and remained as a road. Resembles to present day and site inspection observations.

Ping Kong Road and Po Kin Road

No change in land use was observed and remained as a road. Resembles to present day and site inspection observations.

8.4.8                 Minimal changes to the roads are observed as they have always been a road, and/or removal of vegetation to make new roads. However, there is an absence of potential contaminating historical land uses such as oil installations, gas works, metal workshops, car repair and dismantling workshops at the off-site works area or nearby surrounding areas. There are no potentially contaminating historical land uses observed from the review of aerial photographs.

 

Current and Future Land Use

8.4.9                 The FGC is located on Demarcation District 94 Lot (DD94 942 RP) on Fan Kam Road in Sheung Shui. Partial of the FGC site to the east of Fan Kam Road of about 32 ha is identified as the Potential (Proposed) Development Area (PDA). The boundary of the PDA is an irregular shape and it is delineated into four Sub-Areas to develop in phases. A location map showing the delineation of Sub-Area 1 to Sub-Area 4, and the associated off-site work area is illustrated in Figure 8.1.

8.4.10              Proposed development is planned at Sub-Area 1 for the purpose of public housing site, consisting residential buildings and a school. Figure 8.2 shows the detailed layout of the public housing development at Sub-Area 1.

8.4.11              Under the proposed scheme, future land uses at Sub-Area 2 to Sub-Area 4 will be regarded as open space and recreational area, under “Other Specific Uses”, annotated “Recreation cum Conservation”. Recreational facilities and ancillary facilities would be provided in Sub-Areas 2 to 3. No works would be carried out in Sub-Area 4. Details of such arrangements could be provided in later stage.

8.4.12              The associated off-site infrastructures and utilities (works area) to support the proposed development are located outside the PDA boundary and along existing roads, cycling track and footpath (Figure 8.1). The associated off-site works include the upgrade of the drainage system and laying of sewer to the Shek Wu Hui Sewage Treatment Works.

Existing Environment – PDA

8.4.13              The FGC is divided into two sections – the Old Course and New Course (with coverage of the Eden Course). The FGC is operated by the Hong Kong Golf Club, which has been the occupant since the early 1900s. The PDA comprises Sub-Area 1 to Sub-Area 4, which are located in the Old Course. An overview map of the Hong Kong Golf Club can be referred to Figure 2.1 of the CAP.

8.4.14              With reference to Figure 8.1, Sub-Area 1 takes up the northern most portion of the PDA, where the entrance is gated by an outdoor car park. It has an area of approximately 11 ha – which is bordered by Fan Kam Road on the west, North District Hospital and Ching Ho Estate to the north, Ping Kong Road to the east, and Fanling Pumping Station and its associated Substation to the south.

 

8.4.15              Sub-Area 2 is bounded by thick tree foliage extended from Sub-Area 1 and up to the existing access road of On Po on the south side. A number of ecological species of conservation importance were recorded and a man-made pond providing water source for wildlife was observed. The Fanling Pumping Station and its associated substation were also observed.

8.4.16              Sub-Area 3 is bounded by the existing access road leading to On Po Village (residential) in the north; the narrow edge adjacent to the Tai Lung Experimental Farm (agricultural land) in the southeast side of Sub-Area 3. This area is irregular shape consisting of a number of tree clusters at the sides and also in the middle portion of the Sub-Area.

8.4.17              Sub-Area 4 is located in the southernmost tip of the PDA. It is bounded by the boundary of Sub-Area 3 to the site boundary of the PDA. A marsh located on the northeast and a swampy woodland with a rare Chinese Swamp Cypress (Glyptostrobus pensilis) colony in the western portion are identified in Sub-Area 4.  This Sub-Area is considered with high ecological value and therefore, no proposed works are to be carried out in Sub-Area 4. Surrounding areas include the Tai Lung Veterinary Laboratory (a two-storey complex laboratory providing veterinary services) and Tai Lung Experimental Farm (agricultural land) to the east of Sub-Area 4.

8.4.18              Sub-Area 1 is currently surrounded by the golf course, high-rise residential buildings, a hospital, a school and dense vegetation. Sub-Areas 2 and 3 are surrounded by the golf course, scattered villages (Ping Kong and On Po) and dense vegetation. The adjoining areas of Sub-Area 4 include dense vegetation, the Tai Lung Veterinary Laboratory (a two-storey complex laboratory providing veterinary services) and Tai Lung Experimental Farm (agricultural land), located on the east of Sub-Area 4.

Existing Environment – Associated Off-site Works Area

8.4.19              The associated off-site works are located outside the PDA boundary, consist of laying and upgrading existing sewerage and drainage system to support Project development. Details of the existing surrounding environment of contamination assessment area for the associated off-site works area are described below:

Ping Kong Road and Po Kin Road (Drainage System)

8.4.20              The proposed drainage system runs north from Ping Kong Road and extends to east of Po Kin Road, ending at Po Ping Road. The contamination assessment area mainly consist of access road, cycling tracks and pedestrian footpath. Nearby land uses primarily consist of residential buildings, open space and the North District Hospital.

 

8.4.21              Review of historical land uses revealed there is a minimal change to the roads as they have always been a road, and consist of vegetation removal activities to make new roads. The nearby North District Hospital completed its construction in 1998. 

8.4.22              No industrial activity or other land use activities with land contamination potential is identified. Potential contamination at the associated off-site areas of the proposed drainage works is not anticipated.

North of Fan Kam Road (Sewerage System)

8.4.23              The proposed sewerage system runs at the junction of Po Kin Road and extends north on Fan Kam Road towards Fanling Hwy, through the roundabout and cuts into the cycling tracks in the residential neighbourhood consisting of Choi Po Court, Choi Yuk House and Choi Yuen Estate.

8.4.24              Cycling pathways and bike parking areas are observed on the opposite side of Choi Yuen Road and extends to San Wan Road, where the proposed sewerage works end at. The contamination assessment area mainly consist of access road, cycling tracks and pedestrian footpath.

8.4.25              Review of the aerial photographs revealed vegetation on- and off-site have been removed, road and site formation have taken place, with construction of the residential building clusters (Choi Po Court, Choi Yuk House and Choi Yuen Estate) completed between 1981 and 1985.

8.4.26              However, no industrial activity or other land uses activities with land contamination potential is identified. Potential contamination at the associated off-site areas of the proposed sewerage works is not anticipated.

Site Geology

8.4.27              A review of the Geological Map of Hong Kong Web-based Edition – 2006 published by Geotechnical Engineering Office, CEDD indicated that the PDA and associated off-site works area are situated on Tai Mo Shan Formation from the Jurassic period. The stratigraphy primarily consisted of volcanic rocks and lower hills formed of granite. Elevation of the PDA ranges from around 20 to 40 m and is located in a relatively flat and elongated landform.

8.4.28              Multiple Ground Investigations (GI) were conducted previously on the vicinity at the site and the most relevant are listed below:

(a)        Lam Construction Co. Ltd in 1980 (Report No. 2891);

(b)        Gammon (HK) Limited in 1986 (Report No. 48321 and 48322);

(c)        I-P Foundations Limited in 1998 (Report No. 30567); and

(d)        Driltech Ground Engineering in 2014 (Report No. 60803).

8.4.29              A review of the GI reports revealed that the northern PDA (Sub-Area 1) generally consisted of the following strata:

(a)        Completely decomposed granite / volcanic rock or completely weathered pyroclastic rock was encountered throughout the entire borehole depth until termination. This comprised of pink, brown, grey, yellow, dense silt or clay, with occasional rock fragments.

(b)        Colluvium was also encountered at depths of 0 to 12 metres below ground level (mbgl) undertaken by Gammon (HK) Limited in 1986 before the layer of granite. Colluvium comprised of brownish yellow cobbles, gravel and clay.

8.4.30              The area south of PDA (Sub-Area 4) generally consisted of the following strata:

(a)        Tuff was encountered throughout the entire borehole depth until termination. This comprised of grain size ranging from ash, silt, sand to gravel. Occasional quartz and manganese oxide veins were found.

(b)       Colluvium was encountered at the southernmost borehole location, at depths around +33 to +27 metres below Principal Datum (mPD). Colluvium comprised of red, brown and dark grey silty clay.

(c)        Fill was also encountered at the southernmost borehole location, at depths around +35 to +34 mPD.

8.4.31              Based on water level measurements provided in previous GI reports, groundwater in Sub-Area 1 flows towards northeast, and southwest to Sub-Area 2. Groundwater in Sub-Area 4 flows to northwest. There is no information on the site geology in Sub-Area 3. A map showing the locations of previous GI, groundwater flow directions and the strata logs are shown in Appendix C of the CAP. Groundwater level anticipated at Sub-Area 1 with depth ranges from 3.475 to 9.10 mbgl; 1.3 to 2.433 mbgl at Sub-Area 2; and 1.74 to 5.275 mbgl at Sub-Area 4. There is no groundwater information available for Sub-Area 3.

8.4.32              Elevation ranges from around 8.5 to 24.3 m for north of Fan Kam Road off-site works area, with a downward sloping gradient from south to north. The elevation of the off-site works area ranges from around 10.9 to 24.7 m at Ping Kong Road and Po Kin Road with a slight downhill aspect from west to east.

8.4.33              Multiple Ground Investigations (GI) were conducted previously on the vicinity at the site and the most relevant are listed below:

(a)        Terraform-FGS, HKHA 100 of 1998 Stage 2 Study of Slope No. 2SW-A/R28 at Choi Yuen Estate (Report No. 38262);

(b)        Lam Construction Co., Ltd, PWD Contract 613/79 MCA/TPF/81/21 Site Investigation for Fanling Bypass (Report No. 3352);

(c)        Enpack (Hong Kong) Limited, GE/97/13 Fanling/Sheung Shui Development Formation and Servicing in Area 36, Fanling, Ground Investigation (Report No. 28128);

(d)        Chung Shun Boring Eng. Co., Ltd., HKHA Contract No. 20070032 Central Servicing Term Contract for Ground Investigation Works (2007-2009) Public Rental Housing Development at Sheung Shui Area 36 West – Feasibility (Report No. 50647);

(e)        Gammon (Hong Kong) Limited, HKHA Contract No. 98 of 1981 W.O. 181 Shek Wu Hui Area 27c (Report No. 05939 & 04590);

(f)         Gammon (Hong Kong) Limited, Contract 446/81 WOQ 7/2/7.38, Future Increase in Water Supply from China Stage I & II 2200mm Dia. Pipeline from Sheung Shui to Tau Pass (Report No. 03428); and

(g)        Impact Foundations (HK) Ltd., HK-BU-294 Tai Po, Fanling and Shek Wu Hui Development (Report No. 03067A).

8.4.34              The area north of Fan Kam Road generally consisted of the following strata:

(a)        Fill was encountered as the top layer of strata consisting of sand and occasional gravels under the concrete layer, if present. The depths of the fill strata generally reached 2 to 3 mbgl.

(b)        Alluvium was encountered as the layer below fill, or in the case of some boreholes, the first layer of strata where fill was absent. This generally consisted of clay and silty sediment. Alluvium reached the maximum depth of 11 mbgl.

(c)        Completely to highly decomposed granite / volcanic rock was encountered as the bottom layer of strata i.e., below alluvium, until termination depth. This comprised of pink, brown, grey, yellow, dense silt or clay, with occasional rock fragment.

8.4.35              Ping Kong Road and Po Kin Road generally consisted of the following strata:

(a)        Fill as the top layer of strata, ranged a thickness of 1.0 to 2.5 m.

(b)        Alluvium was encountered as the second layer of strata below Fill, on Ping Kong Road, which ranged a thickness of 0.5 to 1.5 m.

(c)        Tuff was encountered as the last layer of strata in all boreholes. This comprised of grain size ranging from ash, silt, sand to gravel. The thickness of Tuff encountered ranged from 37 to 54 m, until termination depth.

(d)        Colluvium was encountered at the southernmost borehole location, at depths around +33 to +27 mPD. Colluvium comprised of red, brown and dark grey silty clay.

(e)        Fill was also encountered at the southernmost borehole location, at depths around +35 to +34 mPD.

8.4.36              Based on water level measurements provided in previous GI reports, groundwater in the off-site works area flows in a north-easterly direction. A map showing the locations of previous GI, groundwater flow directions and the strata logs are also shown in Appendix C of the CAP. Groundwater table depths are approximately 5.5 to 1.8 mbgl for the area north of Fan Kam Road. Groundwater table depths are approximately 4.54 to 2.41 mbgl for Po Kin Road and Ping Kong Road.


 

Findings of Potential Environmental Impacts – PDA

8.4.37              The PDA forms part of an 18-hole golf course, which historically had been a golf course since its establishment and surrounded by agricultural land use. The terrain consists of thick tree foliage around individual open fairways. Other land use activities found within the PDA include an outdoor carpark, tennis court, private properties (houses) and staff living quarters, located in Sub-Area 1 (Figure 8.3).

8.4.38              As shown in Figure 8.4, the WSD Fanling Pumping Station and the adjoining CLP Fanling P/P Station Substation No. 09905-6 are located in Sub-Area 2. Other land use activities in Sub-Area 2 consisted of tree foliage, open fairways and turf grasses. A man-made pond is located near the lower edge in Sub-Area 2. A paved driveway acting as a divider is located between Sub-Area 2 and Sub-Area 3.

8.4.39              Sub-Area 3 consisted of thick tree foliage, open fairways and turf grasses; tree clusters are located in the middle and long the sides of Sub-Area 3 (Figure 8.4).

8.4.40              Sub-Area 4 consisted of thick tree foliage, open fairways, turf grasses, and two environmental sensitive areas – a marsh and swampy woodland, indicated in Figure 8.5.

8.4.41              With the PDA situated partially on the golf course, the potential contamination is mainly from polluting activities including the historical use and current application of chemicals on the soils – fertilisers, pesticides and herbicides to maintain the health and appearance of the turf grasses, and for pest control management.

8.4.42              In the past, inorganic forms of arsenic were used in pesticides and paint pigment. Historically, use of arsenic-containing pesticides might have left large traces of agricultural land contaminated. Other heavy metal compounds may also pose potential contamination to these lands.

8.4.43              As the FGC was established in 1911 – there is no information on the historical uses of pesticides and herbicides at the golf course (verified and confirmed with the site operator at The Hong Kong Golf Club), and old pesticides persisted in the soil and chemicals may pose a build-up in arsenic and other heavy metals over the years of applying these materials. The legacy of arsenic and other heavy metal compounds in the assessment area cannot be ruled out.

8.4.44              According to the site operator at The Hong Kong Golf Club, an inventory of fertilisers, pesticides and herbicides that are applied at the golf course is maintained. WSP has conducted a review on the inventory list and concluded that all fertilisers and chemicals used at the golf course are organic, branded and of high quality. HKGC confirmed that the pesticides are applied in the golf course soil above the sub-surface drainage system, utilizing best management practices and management systems as outlined in HKGC’s standard operating protocols (SOPs). The guidelines and SOPs describe the procedures used in pesticide application which aim to provide the quality output and uniformity of performance, while reducing accident/spillage occurrences.

 

8.4.45              HKGC also confirmed there were no chemical spillage occurred at the premises and also that the golf course and its employees follow good site practices and a strict set of health and safety policy to ensure safety is incorporated in the working environment.

8.4.46              An inspection of the PDA and surrounding areas was conducted by WSP Land Contamination Specialist on 15 May 2020 to identify the possible land contamination and hotspots. The site inspection was conducted to cover full extent of the FGC footprint and observations on the adjoining properties.

8.4.47              Potentially contaminating land uses such as oil installations, gas works, metal workshops, car repair and dismantling workshops, have the potential to cause or have caused contamination to the land. However, none of these types of land uses were identified on-site and off-site during site inspection. No vehicles maintenance activities were observed anywhere in the PDA during site inspection. WSP did not identify any oil stains and the surface of cart path at the golf course is stain-free and appeared to be well-maintained and not deteriorating. Surrounding nearby land uses include dense vegetation and residential (village), no industrial activity is observed.

8.4.48              The available historical aerial photographs (Appendix A of the CAP) and visual evidence from site inspection (Appendix D of the CAP) have been reviewed thoroughly to evaluate the potential contamination from land use activities. The inventory and photographs of the fertilisers and chemicals used at the golf course, chemical application guidelines and SOPs are provided in Appendix G of the CAP.

8.4.49              Table 8.5 lists the land use types identified at the PDA and the corresponding potential COCs encountered. Current land use activities found within boundaries of Sub-Area 1 can be referred to Figure 8.3. Land use activities found within Sub-Area 2 and Sub-Area 3 can be referred to Figure 8.4. Land use activities within boundaries of Sub-Area 4 can be referred to Figure 8.5.


8.4.50               


Table 8.5 Land Use Activities and Corresponding Chemicals of Concern at the Proposed Development Area

Sub-Area

Type of Activities Based upon Site Inspection in May 2020

Potentially Polluting Activities

Approximate Area

Potential Chemicals of Concern

 

Sub-Area 1

Private properties

Golf course with historical application of fertilisers, pesticides and herbicides

5,958 m2

-        Pesticides and herbicides

-        VOCs / SVOCs

-        Metals (full suite)

-        Dioxins / PCBs

-        PCRs

-        Cyanide

-        TBTO

 

Tennis Court and Staff Quarters

2,432 m2

 

Outdoor car park

10,260 m2

 

Golf course (turf grasses, fairways, teeways and tree foliage)

89,239 m2

 

Total Potentially Contaminated Area in Sub-Area 1#

107,889 m2 / 11 ha

Sub-Area 2

Golf course (turf grasses, fairways, teeways and tree foliage)

Golf course with historical application of fertilisers, pesticides and herbicides

69,161 m(7 ha)

-        Pesticides and herbicides

-        VOCs / SVOCs

-        Metals (full suite)

-        Dioxins / PCBs

-        PCRs

-        Cyanide

-        TBTO

 

Sub-Area 3

85,000 m2  (8.5 ha)

 

Sub-Area 4

50,726 m2  (5.1 ha)

 

Total Potentially Contaminated Area in Sub-Areas 2 to 4

204,887 m2  (20.5 ha)

Total Potentially Contaminated Areas at PDA

32 hectares (ha)

Note: # includes developable and non-developable areas


8.4.51              The WSD Fanling Pumping Station and the adjoining CLP Fanling P/P Station Substation No. 09905-6 are located approximately 51 m southwest from the boundary of Sub-Area 1. Based on the distance of the substation and Sub-Area 1 boundary, potential environmental impact of substation-related contaminants to the soil and/or groundwater is not anticipated. The pumping station and its associated substation will be retained and are not affected by the proposed development. The vicinity of the pumping station and substation are fenced and is inaccessible to the public.

8.4.52              Hazardous substances such as fertilisers and pesticides are applied in the golf course for turf maintenance and pest control. Storage room for the chemicals and fertilisers are located in the New Course outside the PDA (Figure 8.6). Fertilisers are observed being stored in their original packaging (bags, glass or plastic bottles) in a metal shed with locking function. They are stacked on well-treated and even surfaced wooden pallets. Potential contamination generated from surrounding areas (in particular, the chemical and fertiliser storage room) is not anticipated.

8.4.53              The hazardous materials are stored depending on the individual characteristics, they are protected from atmospheric actions, such as rain, sun, winds and moisture, to avoid deterioration and/or spill to cause potential contamination to the ground. The chemical and fertiliser storage room appeared to be well-maintained. Based on site observations, the interview conducted with site operator and review of their internal SOPs, mitigation measures are in place to prevent any chemical leaks or spillage accidents and minimise any chance of contamination. It was also confirmed by the interviewee that no chemical leaks or spillages accidents had ever occurred, and given the distance apart from the chemical storage room (approximately 7 km away from boundary of the PDA), potential contamination generated from these hazardous materials is not anticipated.

8.4.54              The land contamination assessment aims to demonstrate that soil and/or groundwater has not been contaminated by golf course operations and the application of chemicals on the soil, either from current activities or historical uses. Figures 8.7 and 8.8 illustrated the proposed Risk-Based Remediation Goals (RBRGs) restoration land uses at Sub-Area 1, Sub-Areas 2 to 4, respectively.

8.4.55              Based on the observations of other site use activities such as restaurants, clubhouse, residential houses and carpark, no other potential contamination is expected other than from the historical use and current application of fertilisers, pesticides and herbicides for golf course operation, turf maintenance and pest control.

8.4.56              Whereas outside the Sub-Areas, there is no contamination on nearby adjoining properties that will adversely affect the land having regard to the proposed use of housing development. However, any potential design or land use change of the assessment area may result in potential land contamination. Re-appraisal and the submission of supplementary CAP is therefore required if they become part of the land requirement for the proposed development.

Findings of Potential Environmental Impacts – Associated Off-site Works Area

8.4.57              WSP conducted a site inspection at the associated off-site works area on 22 September 2021. Based on the information collected from site inspection and review of available aerial photographs and historical records, no potentially contaminated site activities are identified in the contamination assessment area for the associated off-site works area, or adjoining properties. No hotspots are identified during the site inspection and potential contamination is not anticipated.

8.4.58              Information requests to further identify potential contamination to the associated off-site works area have also been sent to relevant departments of HKSAR Government but no reply has been received as of report writing. The information requests shall be provided in the supplementary CAP. Should any potential contamination issue be identified, the site investigation programme would be reviewed to assess the concerned areas and supplemented in the supplementary CAP.

8.4.59              If there is a footprint change in the associated off-site works area (due to design change or limitation), the entire contamination assessment area for the off-site works, which currently consist of road structure, cycling tracks and footpath, shall also be re-appraised. The re-appraisal is required to ensure any potential contamination activities from land use changes after the approval of this land contamination assessment study, subject to a proper updating review prior to commencement of the construction works.

Chemicals of Concern

8.4.60              Based on the site inspection, potentially polluting activities include the historical and current use of fertiliser, pesticides and herbicides for golf course maintenance and operations. For example, Arsenic could be found in the production of pesticides to control insects and for wood preservation. Other chemical compounds were/are also used in herbicides, pesticides and fertilisers. Noting that various chemicals were applied to the golf course throughout its operating period for more than 100 years, all 54 chemicals of concern (COCs) listed under the Guidance Manual (in addition to the recommended list of pesticides and herbicides) are proposed for testing as a conservative approach. The list of chemicals of concern can be further reviewed during the course of preparation and submission of the supplementary CAP for approval by EPD.

8.4.61              The selection of potential COCs for laboratory analysis to assess contamination level is determined according to the nature of historical and current land use activities. With reference to Table 2.3 of EPD’s Practice Guide, COCs are identified to different types of activities. The full list of COCs are summarised in Table 8.6.

 

8.4.62              The full list of COCs include the volatile organic chemicals (VOCs), semi-volatile organic chemicals (SVOCs), metals, dioxins and polychlorinated biphenyls (PCBs), petroleum carbon ranges (PCRs), other inorganic compounds (free cyanide), and organometallics (TBTO), in addition to the pesticides and herbicides.

Table 8.6 Full List of Chemicals of Concern

Pesticides and herbicides (Total Pesticides)[1]

Total pesticides consist of organochlorine pesticides, organophosphorus pesticides and triazine pesticides, with details listed below:

Organochlorine pesticides –alpha-BHC, beta-BHC, gamma-BHC, delta-BHC, Heptachlor, Aldrin, Heptachlor epoxide, cis-hlordane, Endosulfan 1, trans-Chlordane, Dieldrin, 4.4`-DDE, Endrin, Endosulfan 2, 4.4`-DDD, Endrin aldehyde, Endosulfan sulfate, 4.4`-DDT, Endrin ketone, Methoxychlor, Cypermethrins(total), Hexachlorobenzene (HCB)

Organophosphorus pesticides – Dichlorvos, Monocrotophos, Dimethoate, Diazinon, Chlorpyrifos-methyl, Parathion-methyl, Malathion, Fenthion, Chlorpyrifos, Parathion, Pirimphos-ethyl, Chlorfenvinphos (E), Chlorfenvinphos (Z), Bromophos-ethyl, Fenamiphos, Prothiofos, Ethion, Carbophenothion, Azinphos Methyl

Triazine pesticides – Atrazine, Simazine

 

VOCs

Acetone, Benzene, Bromodichloromethane, 2-Butanone, Chloroform, Ethylbenzene, Methyl- tert-Butyl Ether, Methylene Chloride, Styrene, Tetrachloroethene, Toluene, Trichloroethene, Xylenes (total)

 

SVOCs

Acenaphthene, Acenaphthylene, Anthracene, Benzo(a)anthracene, Benzo(a)pyrene, Benzo(b)fluoranthene, Benzo(g,h,i)perylene, Benzo(k)fluoranthene, bis-(2-Ethylhexyl)phthalate, Chrysene, Dibenzo(a,h)anthracene, Fluoranthene, Fluorene, Hexachlorobenzene, Indeno(1,2,3-cd)pyrene, Naphthalene, Phenanthrene, Phenol, Pyrene

 

Metals (full suite)

Antimony, Arsenic, Barium, Cadmium, Chromium III, Chromium VI, Cobalt, Copper, Lead, Manganese, Mercury, Molybdenum, Nickel, Tin, Zinc

 

Dioxins / PCBs

Dioxins, PCBs

PCRs

Petroleum Carbon Ranges: C6 to C8, C9 to C16, and C17 to C35

Other Inorganic Compounds

Cyanide (free)

Organometallics

TBTO

 

Natural Occurrence of Arsenic-Containing Soil

8.4.63              Arsenic is a naturally occurring element that is found on earth’s crust and in combination with either inorganic or organic substances to form many different compounds. Inorganic arsenic compounds are commonly found in soils, sediments, weathered rocks and groundwater. If the presence of naturally occurring arsenic-containing soil exists at a site, it will pose potential environment and human health risk

8.4.64              As the PDA is inaccessible and given the golf course will still be in operation until the land has been reverted to Government in Year 2023, undertaking site investigation works to determine the actual land contamination impact is not feasible at this stage. The assessment of whether naturally occurring arsenic or due to anthropogenic activities with appropriate mitigation measures will be provided following the SI results.

8.4.65              That being said, a review of the Geochemical Atlas of Hong Kong (Sewell, 1999 / Appendix 8.2) was conducted to evaluate the likelihood of presence of naturally occurring arsenic within the PDA.  The review result shown that the proposed public housing and school site located in northern part of the PDA (Sub-Area 1) have relatively lower arsenic levels (in stream sediments) between 28 to 58ppm. The remaining portions of the PDA (Sub-Areas 2 to 4) have arsenic level ranging from 58 to 306 ppm. With reference to Appendix 8.2 and the approved EIA report of North East New Territories New Development Areas (Register no.: AEIAR-175/2013), the entire PDA is unlikely to have high level of naturally occurring arsenic-containing soil.

8.4.66              If elevated concentration of arsenic is identified from the SI results, further assessment would be conducted to review whether the elevated concentration is due to natural sources or anthropogenic activities.  If the elevated concentration of arsenic is confirmed due to natural sources instead of anthropogenic activities, it may require the consideration for adopting mitigation measures to reduce the risk of public health due to possible exposure pathways of the naturally occurring arsenic based on established international practices, including any codes of practices and guidelines applicable to Hong Kong with suitable reference to the approved EIA report of North East New Territories New Development Areas.

8.4.67              Such consideration of mitigation measures with justifications on the scope, approach and methodology should be documented in a form of submission to EPD, this may include an Arsenic Assessment Plan (AAP) or health impact assessment.

Land Use Classifications

8.4.68              According to EPD’s Guidance Manual, there are four different post-restoration land use classifications typically applied in Hong Kong’s setting, where the contaminated land may result in a risk occurring to human health and/or the environment. Examples of post-restoration land uses and the most appropriate RBRGs are as follows:

·       Urban residential – sites located in an urban area where main activities involve habitation by individuals. The typical physical setting is high-rise residential building situated in a housing estate where amenity facilities such as landscaped yards and children playground. The receptors are residents who stay indoors most of the time, if not for a short duration each day where they may come in direct contact with soil at landscaping or play areas within the estate.

·       Rural residential – Sites located in a rural area where main activities involve habitation by individuals. These sites typically have village-type houses or low-rise residential blocks surrounded by open space. The receptors are rural residents who stay at home and spend some time each day outdoor engaging in gardening works or participating in light sport activities. The degree of contact with soil under the rural setting is more than urban setting in terms of the intensity and frequency of contact.

·       Industrial – any sites where activities involve the manufacturing, chemical or petrochemical processing, storage or raw materials, transport operations, energy production or transmission. Receptors include those at sites where part of the operation is carried out directly on the subject land and the workers are more likely to be exposed to the soil than those working in multi-storey factory buildings.

·       Public parks – receptors include individuals and well-being who frequent parks and play areas where there is contact with soil in lawns, walkways, gardens and play areas. Parks are considered to be predominately hard covered with limited areas of landscaped soil. Furthermore, buildings are unlikely to be constructed in public parks.

8.4.69              The current plan at present is that proposed development is planned at Sub-Area 1 for the purpose of a school site and public housing site (Figure 8.7). The public housing site is made up of a few high-rise buildings, social welfare facilities, public transport interchange (PTI), amenity areas, footpaths and access roads. The remediation target will adopt the most stringent set of RBRGs to ensure the entire public housing site is suitable for its intended use – in this case, “Urban Residential” or “Rural Residential”, whichever more stringent will be applied to the public housing site (i.e., Sub-Area 1) to ensure the remediated soil can be reused off-site or otherwise disposed of in a safe manner.

8.4.70              Under the current proposed scheme, future land use at Sub-Area 2 will be regarded as open space and recreation, under “Other Specific Uses”, annotated “Recreation cum Conservation”. Recreational facilities and ancillary facilities (with minimal new structure/change to existing site conditions) to support the open space consisting of a 1-storey building is to be provided in the northern edge of Sub-Area 2 (Figure 8.7) – in this case, “Urban Residential” or “Rural Residential”, whichever more stringent will be applied to this area. “Public Park” will be applied to the remaining areas in Sub-Area 2 as only tree transplanting is expected and the excavated soil from tree transplanting activities will be reused on-site.

8.4.71              Sub-Areas 3 and 4 will be utilised as open space and recreation, under “Other Specific Uses”, annotated “Recreation cum Conservation”. “Public Park” land use scenario will be applied to Sub-Areas 3 and 4. No development will be undertaken at Sub-Area 3 other than to preserve existing trees and maintain ecological value. Excavated soil at Sub-Area 3 generated from tree transplanting activities will also be reused on-site.

8.4.72              Sub-Area 4 will be utilised as open space and recreation, under “Other Specific Uses”, annotated “Recreation cum Conservation”. No proposed work is to be carried out in Sub-Area 4.

8.4.73              The corresponding RBRGs of future land uses for each Sub-Area can be referred to Figures 8.7and 8.8, with details provided in Table 8.7. The proposed sampling point for each respective grid can be referred to Figures 4.1 and 4.2 in the CAP (Appendix 8.1):  

Table 8.7 Post-Restoration Land Uses and the Corresponding RBRGs

Land Use

Corresponding RBRGs Land Use

Grid IDs

Sub-Area 1

(Figure 8.7)

 

Public housing site made up of:

-       high rise residential buildings

-       social welfare facilities

-       public transport interchange (PTI)

-       amenity areas

-       footpaths and access roads

School site (special school)

Urban residential or

Rural residential, whichever more stringent

1-1 to 1-51

Sub-Area 2

(Figure 8.7 and Figure 8.8)

Open space made up of:

-      recreational facilities and ancillary facilities (with minimal new structure/change to existing site conditions)

Urban residential or

Rural residential, whichever more stringent

 

2-1 to 2-9

Open space made up of:

-       recreational facilities

-       tree transplanting

Public parks

2-10 to 2-31

Sub-Area 3

(Figure 8.8)

Open space made up of:

-       recreational facilities

-       tree transplanting

Public parks

3-1 to 3-41

Sub-Area 4

(Figure 8.8)

Open space

(no works to be carried out in Sub-Area 4)

Public parks

4-1 to 4-26

                   

Site Investigation

8.4.74              Potentially contaminated areas due to anthropogenic activities have been identified in Section 8.4 based on site appraisal and site inspection. A general approach following the grid pattern to identify the representation of the extent will be adopted. The SI sampling strategy is based on the assumptions that the fertilisers, pesticides and herbicides are applied on the greens throughout the golf course, above the sub-surface drainage system. No hotspots were identified in the entire assessment area during site inspection. Details of the proposed SI works are discussed in the CAP given in Appendix 8.1.

8.4.75              Given the golf course will still be in operation until the commencement of construction, undertaking SI works at this EIA stage is not feasible. As there may be potential changes in land use activities upon the land has been reverted to Government, it is recommended that the Project Proponent’s appointed consultant conduct site re-appraisal to assess the latest site condition and to update the sampling and testing plan presented in the CAP. Supplementary CAP(s), reporting the latest site condition, locations of hotspots and updated sampling and testing plan for the sites, should be submitted to EPD for approval at the later stage of the Project. Based on the assumption that the PDA resumes in Year 2023, the tentative schedule for the Land Contamination Assessment can be found as follow:

Task

Tentative Date

Supplementary CAP(s)

Q2 2023

Site Investigation Works[1]

Q3 2023

Submission of CAR and RAP (if required)

Q4 2023

Submission of RR (if required)

TBD

Note:

[1] Arsenic Assessment Plan (AAP) will be prepared and submitted to EPD after site investigation (if required).

TBD – to be determined: remediation programme subject to contamination extent and remediation method(s) chosen

8.4.76              Results obtained from the site investigation and related activities will be documented in the Contamination Assessment Report (CAR). If land contamination is confirmed, a Remediation Action Plan (RAP) will be developed to formulate viable remedial measures to set remediation goals, this includes the outline of methods for remediation, treatment and handling of the contaminated material, equipment, verification and confirmation sampling and testing and other monitoring and audit requirements and equipment decontamination procedure.


 

8.5                     Remediation Measures and Validation

8.5.1                 The collected soil and/or groundwater samples shall be screened against the RBRGs developed for the 54 COCs under EPD’s Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management which were selected on the basis that either they are known to occur in typical Hong Kong environment, or are in use locally. The list of COCs presented in the CAP can be further reviewed during the course of preparation and submission of the supplementary CAP for approval by EPD. For those COCs that fall outside the list of 54 chemicals, international standards may be referred to set appropriate standard and/or remediation goals, which would be determined in the supplementary CAP to be submitted at detailed design stage for agreement with EPD.

8.5.2                 If the levels of contamination exceed relevant remediation goals and need to be remediated in order for the development area to be suitable for the intended land use, remediation objectives of rural and urban residential (whichever is more stringent), and public parks classifications will be adopted to ensure the contaminants will not pose an unacceptable risk to human health or to the environment.

8.5.3                 In the case of contamination levels exceeding the rural and urban residential (whichever more stringent), and public parks RBRGs, remediation works following a remediation plan is required. The remediation plan is based on the findings from assessment of site contamination having regard to the proposed use of the site. Remediation plans will be fit for purpose, with the level of detail in the plan responding to the scale, complexity and risks of the proposed remediation works. Remediation plans will be prepared in accordance with EPD’s Practice Guide, Guidance Note and Guidance Manual.

8.5.4                 Remediation plans will be documented in the form of a Remediation Action Plan (RAP), which will require EPD’s agreement before commencement of any remediation works. The RAP provides comparison on a variety of soil and/or groundwater remediation methods, procedures and plans to be implemented to reduce risks to acceptable levels for the proposed use, and identify the appropriate remediation methods suitable for site-specific conditions and the contaminants requiring remediation. The remediation methods will be compared based on the following criteria:

·       Site characteristics (i.e., site hydrogeology, soil and groundwater chemical characteristics);

·       Site constraints (i.e., available space, surrounding areas);

·       Nature and level of contamination;

·       Extent and area of contamination;

·       Cost effectiveness;

·       Experience and expertise requirement; and

·       Time available to carry out remediation works.

8.5.5                 Several potential remediation options for the 54 COCs identified in the Guidance Manual, in addition to pesticides and herbicides, for soil and groundwater, are reviewed based on literature research and provided in Table 8.8a and Table 8.8b, respectively. In some situations, it may be necessary to combine two or more of these techniques in order to arrive at a more economical and effective treatment. The success of remediation process relays on the proper selection, design and operation of the remediation technology, which should be selected based on the contaminant and soil characteristics. But above all, landfill disposal directly cannot be adopted due to leachate of contaminants and limited space in Hong Kong. The remedial options for soil and/or groundwater will be available and are subject to further review upon the COCs identified in the supplementary CAP and presented in the RAP if contamination is identified.

8.5.6                 In particular, objectives of the RAP are to:

·       Set remediation objectives and goals;

·       Formulate optimal and cost-effective mitigation and remedial measures for the contaminants identified in the contamination assessment;

·       Specify remediation monitoring and measurements to monitor remediation progress and to confirm completion of the remediation (i.e., validation); and

·       Propose good handling practices for the contaminated materials during all stages of the remediation works and appropriate disposal measures.

8.5.7                 Above all, the content of the RAP should include:

·       Background information (i.e., background of the project, regulatory and other requirements, summary of site history, and contamination sources);

·       A summary of site investigation findings, nature, levels and extent of contamination on site;

·       The objectives of the RAP, goals and remediation targets;

·       The proposed remediation actions (i.e., general description of the remediation methods, treatment and handling, equipment, verification and confirmation sampling and testing, other monitoring and audit requirements, and equipment decontamination procedure);

·       An implementation schedule for remediation with appropriate actions and milestones. The criteria to be used to assess the effectiveness of the remediation activities should be included; and

·       A health and safety section in the RAP to include health and safety risks identification and control measures required during the remediation, monitoring and measurement activities.

8.5.8                 Remediation works will be carried out upon agreement of the RAP, and a notice of completion must include a validation that states whether the remediation objectives have been achieved and whether any further remediation work or restrictions on land use. This validation is documented in the Remediation Report (RR). The RR should describe the works carried out and observations made during the work. It must assess the results of post-remediation observations, testing and outcomes against the remediation objectives stated in the RAP. Where the targets have not been achieved, reasons for this must be stated and additional site work proposed to ensure the original objectives will be achieved.

8.5.9                 The content of the RR should include:

·       Background information (i.e., background of the project, regulatory and other requirements, future land use of the site and land use classifications assessed, and the summary of the on-site contamination);

·       Description of the remediation programme carried out (i.e., additional investigation, pilot testing, remediation, monitoring and measurements, and decommissioning of plants and equipment);

·       Remediation monitoring results (i.e., field measurements and observations, samples laboratory test results, QA/QC results);

·       Soil disposal records and certification by the Independent Checker (if applicable); and

·       Conclusions, recommendations and other supplementary information.


Table 8.8a Potential Soil Remediation Options[2]

Remediation Category

Remediation Method

Type of Contaminants

Description

Applicability

Limitations

Physical-chemical

Cement Solidification / Stabilisation

Inorganic compounds, including radionuclides, heavy metals.

 

Ex-situ immobilisation technique treats contaminated soil by mixing soil with binding agents.

·       Applicable to soils

·       Solidification has been used on certain contaminated site in Hong Kong and demonstrated as a successful treatment method for inorganic contaminated soil.

·       The effectiveness reduces with the presence of organic contaminants

·       Large boulders may hinder the mixing process. Soil sorting is necessary before the treatment taken place

·       The process may result in volume increase

·       Pilot test is required to set the appropriate ratio of cement to soil for complete immobilisation

Physical-chemical

Soil Vapour Extraction (SVE), also referred to as in-situ Soil Venting

Effective to petroleum hydrocarbons such as PCRs.

In-situ bioremediation method that make use of indigenous bacteria to degrade contaminants. The bacteria activities will be enhanced by inducing air flow and adding nutrients if necessary.

·       Applicable to soils

·       Suitable for remediation in built up areas as the wells can be placed between and below buildings.

·       Applicable to large sites.

·       Equipment can be installed easily.

·       Vapour emissions can be controlled.

·       Usually applied for cases with large area of organic contaminated soil

·       May induce air emission to the sensitive receivers

·       Large space is required

·       Generally utilised to remove the more volatile petroleum products such as gasoline and aviation fuel. It can also be used to reduce the mobility and hazard of diesel, kerosene, and some heating oils by removing the more volatile fractions from the soil

Physical-chemical

Soil Washing / Flushing

Inorganic compounds, including radioactive contaminants, heavy metals, PCBs, VOCs, SVOCs, free cyanide, fuels and pesticides

Water-based process for scrubbing soils ex-situ to remove contaminants.

·       Applicable to coarse-grained organic or inorganic-contaminated soils

·       Required further treatment and disposal for residual

·       Complex waste mixtures make formulating washing fluid difficult

·       Effectiveness of soil washing treatment depends on the soil particle size. Fine soil particle may require a polymer in addition to be removed from the washing fluid

·       Maybe less cost-effective

Biological

Biopiling / Bioremediation

Non-halogenated volatiles and semi-volatiles, fuel hydrocarbons, residues of coke and some pesticides, and organometallic compounds (TBTO).

Bioremediation method that bacteria grow in the piled contaminated soil and degrade the waste into harmless products.

·       Applicable and most cost-effective for large volumes of contaminated soil.

·       Vapour emission can be controlled as it can be designed to be a closed system.

·       Effective method to utilise microbes and plants to eliminate the pesticide residues

·       Large space is required for biopile construction

·       Time-consuming as it usually takes one year

Biological

Bioventing

Petroleum products including gasoline, jet fuels, kerosene and diesel fuel. Non-halogenated solvents, some pesticides and wood preserves, among other organic compounds.

In-situ bioremediation process that promotes aerobic biodegradation of organic contaminants in soil by providing oxygen to existing soil microorganisms.

·       Proven successful in remediating soils contaminated by petroleum hydrocarbons, non-chlorinated solvents, some pesticides and other organic compounds

·       Low levels of humidity and permeability may limit bioventing efficiency

·       Effectiveness of the process may be affected by the soil moisture content

Biological

Phytoremediation[3]

Radionuclides, hydrophobic organic compounds, BTEX, PAHs, organometallic compounds (TBTO), heavy metals and pesticides.

Bioremediation process that uses various types of plants to remove, transfer, stabilise, and/or destroy contaminants in the soil and groundwater.

·       Applicable to soils, groundwater and surface water

·       The contaminating material should be present within the root zone to be accessible to the roots

·       Large space is required to grow plants

·       Time-consuming as it usually takes one year

Remediation Category

Remediation Method

Type of Contaminants

Description

·       Applicability

·       Limitations

Thermal

Thermal Incineration

Explosives and residues, particularly chlorinated hydrocarbons, PCBs and dioxins, free cyanide, semi-volatiles, and pesticides.

Utilises flame and high temperature to cause the organic and some of the metal wastes to be converted from solids or liquids into hot gases.

·       Applicable to soils

 

·       High energy costs

·       Volatile metals such as arsenic, cadmium, chromium, lead and mercury are not destroyed by the combustion, thus being some of them present in the ashes or released in the gases

·       Require residual management for inorganic materials

Thermal

Thermal Desorption

All types of organic contaminants. The target contaminants include SVOCs, PAHs, PCBs, heavy metals and pesticides.

Utilises heat to increase the volatility of contaminants such that they can be removed (separated) from the solid matrix (typically soil, sludge or filter cake).

·       Thermal desorption has varying degrees of effectiveness against the full spectrum of organic contaminants

·       Thermal methods can be particularly useful for dense nonaqueous phase liquids (DNAPLs) or light nonaqueous phase liquids (LNAPLs)

·       Effectiveness depends on the contaminant

·       Clay, silty soils and high humic content soils increase reaction time as a result of binding of contaminants. Highly abrasive feed potentially can damage the processor unit

 

 


 

Table 8.9b Potential Groundwater Remediation Options [4] [5]

Remediation Category

Remediation Method

Type of Contaminants

Description

Applicability

Limitations

Chemical

In-situ chemical oxidation and chemical reduction

Depends on contaminant and method chosen but applicable to metals, PCRs, PAHs, PCBs, dioxins, VOCs / SVOCs and pesticides

 

Groundwater is treated in place without extraction from the aquifer. In situ treatment technologies can destroy, immobilize or remove contaminants

·       Applicable to soil and groundwater

·       Site specific – depends on the contaminant present and method chosen

·       Very specialised contractors required

·       Chemical methods require the handling of large quantity of hazardous oxidising chemicals

·       Some COCs are resistant to oxidation

Physical

Containment

Metals

Applicable for containing contamination in groundwater in place, avoids need for pump and treat.

·       Applicable to soil and groundwater

·       In-situ treatment technologies such as chemical oxidation and chemical reduction, and permeable reactive barriers

·       Long-term monitoring and maintenance required

·       Treatment in the future cannot be ruled out

·       This method does not lessen toxicity, mobility, or volume of hazardous wastes, but does mitigate migration

Physical

Permeable Reactive Barrier

Metals, PCRs, PAHs, PCBs, dioxins, free cyanide, VOCs / SVOCs and pesticides

Groundwater is treated in place without extraction from the aquifer

·       Water flows through reactive material to reduce contamination levels and risk to receptors down stream of site

·       Applies to relatively shallow aquifers

·       Effectiveness of the treatment is influenced by groundwater chemistry / flow rate, ground geochemistry, site topography, seasonal changes in hydrogeological conditions

Physical

Pump and Treat

Metals, PCRs, PAHs, PCBs, dioxins, free cyanide, VOCs / SVOCs and pesticides

Extract and convey groundwater to an above-ground treatment system to remove the contaminants

·       Most common clean up method to remove contaminants from groundwater

·       Also applicable to plumes in groundwater

·       Above-ground treatment system required

Biological

Phytoremediation[6]

Radionuclides, hydrophobic organic compounds, BTEX, PAHs, organometallic compounds (TBTO), heavy metals and pesticides.

Bioremediation process that uses various types of plants to remove, transfer, stabilise, and/or destroy contaminants in the soil and groundwater.

·       Applicable to soils, groundwater and surface water

·       The contaminating material should be present within the root zone to be accessible to the roots

·       Large space is required to grow plants

·       Time-consuming as it usually takes one year


8.6                     Environmental Monitoring & Audit (EM&A)

8.6.1                 The land contamination assessment examined the potential contaminative land use within the assessment area and their potential impacts to future land use. As the golf course would still in operation and the development will only commence in stages from 2024 to 2033, further works is recommended to be conducted upon the land has been reverted to Government in Year 2023. Further works include site re-appraisal and a supplementary CAP covering the whole assessment area and submitted to EPD for approval. Preparation and submission of CAR/RAP for EPD’s approval after obtaining SI results. If contaminated soil and/or groundwater are identified, remediation works should be carried out upon EPD’s approval on the RAP.

8.6.2                 Mitigation measures as outlined in the future RAP agreed by EPD shall be implemented throughout the remediation works. The EM&A requirements shall be carried out in the form of regular site inspection to ensure the recommended mitigation measures are properly implemented and findings of the audit shall be reported in the EM&A reports.

8.6.3                 Given that any contaminated soil and/or groundwater would be remediated prior to Project development, there is no land contamination issue anticipated during the operation phase. As such, EM&A during operation phase for land contamination is not necessary.

8.7                     Evaluation of Residual Impact

8.7.1                 Land contamination assessment shall be carried out to uncover potential environmental issues and, if necessary, carry out remediation works before the development so as to prevent environmental risks arising in the future.

8.7.2                 Potential land contamination at the PDA is expected to be from the historical use and current application of fertilisers, pesticides and herbicides on turf grasses, fairways and teeways. Site investigation works involving sampling and testing of soil and/or groundwater are presented in the CAP (Appendix 8.1). Further works, including site re-appraisal and submission of a supplementary CAP is required upon the land has been reverted to Government to ascertain if potential contamination exists and the extent of contaminants.

 

8.7.3                 SI shall commence after the land has been reverted to Government and approval of the supplementary CAP is obtained from EPD. Following the completion of SI, the testing results shall be presented in the CAR and where a need for remediation is identified, a RAP consisting of remediation objectives and goals, proposed remediation actions, verification and confirmation sampling and testing, and other monitoring and audit requirements, shall be prepared and submitted to EPD for agreement prior to the commencement of the remediation works.

8.7.4                 Upon completion of the remediation, a RR shall be prepared and submitted to EPD to demonstrate that the remediation work is adequate and is carried out in accordance with the approved CAR and RAP. Information such as soil treatment, disposal records (including trip tickets), confirmatory sampling results, photographs and, if applicable, certification of independent checker should be included in the aforesaid RR. No construction activities or development of the site shall be carried out prior to EPD’s endorsement of the RR.

8.7.5                 With the establishment and implementation of the CAP and the supplementary CAP, to define the nature, extent and degree of contamination; together with results from site investigation to provide sufficient information for the development of the CAR and/or RAP, no adverse residual impacts are anticipated from the construction and operation of Project activities as the land contamination assessment and remediation would be completed before the commencement of any construction works.


 

8.8                     Conclusion

8.8.1                 This chapter examined the potential land contamination impacts at the Proposed Development Area (PDA), and the associated off-site works area. The land contamination assessment consisted of detailed desktop reviews, site inspections, the proposed site investigation, recommended further works and their potential impacts to land users during construction and operation phases.

8.8.2                 The land contamination assessment follows a risk-based screening approach to the investigation of contaminated land, in order to identify any past or present potentially contaminating activities and to provide the assessment of the extent and nature of site contamination if it exists.

8.8.3                 If the levels of contamination need to be remediated for the development area to be suitable for the intended land use, remediation objective of rural and urban residential (whichever more stringent) at Sub-Area 1 and Sub-Area 2 (partial), and public parks classifications at Sub-Area 2 to Sub-Area 4 will be adopted to ensure the contaminants will not pose an unacceptable risk to human health or to the environment.

8.8.4                 Sampling strategy with details on representative sampling and analysis for determination of the nature and extent of the actual contamination conditions of soil and/or groundwater at the PDA are proposed in the CAP (Appendix 8.1).

8.8.5                 As the FGC will remain in operation until the land is handed over to the Project Proponent, further works are proposed to be carried out upon the land has been reverted to Government in Year 2023. Further works, including re-appraisal and supplementary CAP, are recommended to be conducted in the later stage of the Project. The supplementary CAP, incorporation of findings of covering the entire assessment area and updated sampling and testing strategy shall be prepared and submitted to EPD for approval. Site investigation and lab analyses shall commence after the approval of the supplementary CAP by EPD.

8.8.6                 Following the completion of SI works, the SI results shall be presented in the Contamination Assessment Report (CAR) for submission to EPD. If remediation is required, Remediation Action Plan (RAP) shall be prepared with the purpose to set remediation goals and specify remediation monitoring and measurements to monitor remediation progress. The RAP shall be submitted to EPD for approval before the commencement of remediation works.

 

8.8.7                 A Remediation Report (RR) shall be prepared for submission to EPD to demonstrate adequate remediation works have been completed to meet the relevant remediation goals. The content of the RR shall include the description of remediation programme carried out and the remediation monitoring results. The RR shall be submitted to EPD for endorsement. No construction works or development of site shall be carried out prior to the endorsement of the RR.

8.8.8                 Land contamination assessment and remediation shall be completed prior to the development of the Project. If deemed necessary, the contaminated sites shall be remediated before commencement of any construction works which may disturb the ground. In all cases, contaminated soil remediation, treatment or disposal must be managed in an environmentally sound manner, including compliance with all relevant legislation and Government requirements.

8.8.9                 If elevated concentration of arsenic is identified from the SI results, further assessment would be conducted to review whether the elevated concentration is due to natural sources or anthropogenic activities.  If the elevated concentration of arsenic is confirmed due to natural sources instead of anthropogenic activities, it may require the consideration for adopting mitigation measures to reduce the risk of public health due to possible exposure pathways of the naturally occurring arsenic based on established international practices, including any codes of practices and guidelines applicable to Hong Kong with suitable reference to the approved EIA report of North East New Territories New Development Areas (Register no.: AEIAR-175/2013).

8.8.10              Such consideration of mitigation measures with justifications on the scope, approach and methodology to be adopted in the health impact assessment shall be submitted to EPD for agreement prior to commencement of assessment.

8.8.11              However, as the PDA is inaccessible and given the golf course will still be in operation until the land has been reverted to Government in Year 2023, undertaking SI works to determine the actual land contamination impact is not feasible. The assessment of whether naturally occurring arsenic or due to anthropogenic activities with appropriate mitigation measures is not available at this stage and will be provided following SI results.

8.8.12              Remediation options for the land contamination assessment are discussed in Section 8.5. The remediation method adopted will be based upon results of the site investigation, and views from the relevant authorities would be sought for the remediation technologies that are not included in the Practice Guide.

8.8.13              The establishment and implementation of the supplementary CAP, CAR and/or RAP will minimise potential adverse impacts to the environment arise from land contamination and site remediation activities. No adverse residual impacts are anticipated from the construction and operation of Project activities.


 



[1] Source: Full list of pesticides and herbicides available for analysis provided by ALS Technichem (HK) Pty Ltd (HOKLAS-accredited)

[2] Teresa Castelo-Grande, Paulo A. Augusto, Paulo Monteiro, Angel M. Estevez & Domingos Barbosa (2010): Remediation of soils contaminated with pesticides: a review, International Journal of Environmental Analytical Chemistry, 90:3-6, 438-467.

[3] Views from relevant authorities (i.e., WPG/EPD) would be sought and presented in the Remediation Action Plan (RAP) if remediation is required; and subject to EPD’s agreement.

[4] Remediation Methods Applied in Overseas Cases, extracted from Table 4.2 of EPD’s Practice Guide for Investigation and Remediation of Contaminated Land.

[5] How Superfund Addresses Groundwater Contamination, USEPA <https://www.epa.gov/superfund/how-superfund-addresses-groundwater-contamination>.

[6] Views from relevant authorities (i.e., WPG/EPD) would be sought and presented in the Remediation Action Plan (RAP) if remediation is required; and subject to EPD’s agreement.