7.1.1.1
This section presents the potential implications
of land contamination associated with the Project.
·
Annex 19 of Technical Memorandum on
Environmental Impact Assessment Process (EIAO-TM)
·
Guidance
Note for Contaminated Land Assessment and Remediation (Guidance Note) – The
Guidance Note sets out the
requirements for proper assessment and management of potentially contaminated
sites such as oil installations (e.g.
oil depots, petrol filling stations), gas works, power plants, shipyards
/ boatyards, chemical manufacturing / processing plants, steel mills / metal
workshops, car repairing / dismantling workshops and scrap yards. In addition, this Guidance Note provides guidelines on how site assessments should be
conducted and analysed and suggests practical remedial measures that can be
adopted for the remediation of contaminated sites.
·
Practice
Guide for Investigation and Remediation of Contaminated Land (Practice
Guide) – The Practice Guide outlines
typical investigation methods and remediation strategies for the range of
potential contaminants typically encountered in Hong Kong.
·
Guidance
Manual for Use of Risk-based Remediation Goals for Contaminated Land Management
(Guidance Manual) – The Guidance Manual
introduces the risk-based approach in land contamination assessment and present
instructions for comparison of soil and groundwater data to the Risk-Based
Remediation Goals (RBRGs) for 54 chemicals of concern commonly found in Hong
Kong. The RBRGs were derived to suit
Hong Kong conditions by following the international practice of adopting a
risk-based methodology for contaminated land assessment and remediation and
were designed to protect the health of people who could potentially be exposed
to land impacted by chemicals under four broad post restoration land use
categories. The RBRGs also serve as the
remediation targets if remediation is necessary.
7.3.1.1
The Project site covers the existing Fo Tan Nullah (FTN), which is approximately 1.7 km long and
10 m to 35 m wide, located at the centre of Fo Tan
District. The upper portion of the
Project site is surrounded by industrial buildings while residential,
educational institution, and government, institution or community (G/IC)
developments are located in the vicinity of lower portion of the Project
site. The location of the Project is
shown in Figure 2.1. As shown in Figure 2.1, the proposed works under the Project
will not encroach into the nearby industrial buildings in the upper portion of
the Project site.
7.4.1.1
Land contamination assessment was carried
out according to the abovementioned EIAO-TM, Guidance Note, Practice Guide,
Guidance Manual as well as the requirements given in Section 3.4.8 and Appendix
F of the EIA Study Brief.
7.4.1.2 A
site appraisal, including site walkover and desktop review, was conducted to
identify the potentially contaminating activities that may pose adverse impact
to the Project. Site walkover was
conducted within the Project site to review the general site conditions and to
identify any sources of land contamination (or ‘hotspots’). For the desktop review, the following
information was reviewed:
·
Aerial photographs and topographic maps held by
the Lands Department;
·
Hong Kong Geological Survey Map (Series HGM20) –
Sheet No. 7 (1:20,000);
·
Records on dangerous goods, Chemical Waste
Producer, chemical spillage/leakage and fire incidents from the identified
potentially contaminated sites from Environmental Protection Department (EPD)
and Fire Services Department (FSD); and
·
Relevant ground investigation (GI) reports from
the Civil Engineering and Development Department (CEDD) civil engineering
library.
7.4.1.3 If
potentially contaminated land use(s) were identified within the Project site,
the potential land contamination impacts arising from the Project would be
evaluated and appropriate mitigation measures would be recommended. If necessary, Contamination Assessment Plan
(CAP), Contamination Assessment Report (CAR) and Remediation Action Plan (RAP)
would be submitted to EPD for endorsement.
Any contaminated soil and/or groundwater should be treated according to
EPD’s approved RAP. A Remediation Report
(RR), demonstrating adequate remediation, should be submitted to EPD for
endorsement prior to the commencement of any development or redevelopment works
within the Project site.
7.5.1.1 A
review of historical aerial photographs was undertaken to evaluate the
likelihood of potential contamination associated with past land uses within the
Project site. Findings of the review are
summarised in Table 7.1
below and the historical aerial photographs reviewed are provided in Appendix
7.1.
Table 7.1 Aerial Photographs Reviewed
|
Year
|
Reference
of Aerial Photos in Appendix 7.1
(Photo
Reference Number*)
|
Description of Land-Uses and Site
Operation/Activities
|
|
1963
|
AP1
(#1963-5421)
|
The Project site was mainly occupied by
agricultural land, village houses, vegetated land, ponds and
river.
The southeast of the Project site was occupied by open waters.
|
|
1973
|
AP2
(#03232)
|
No significant land use changes were observed
within the Project site.
|
|
1986
|
AP3
(#CN01099)
|
The existing FTN, vacant land / reclaimed land,
gardens / playgrounds, cooked food stalls and public toilet were observed
within the Project site.
Existing Sui Wo Road, Cheung Lek Mei Street, Shan
Mei Street, Tat Yip Lane, garden, playground, cooked food stalls and vacant
land were observed within
the encroached portion of "Industrial (I)" zone.
|
|
1993
|
AP4
(#A34681, #34659)
|
No significant land use changes were observed
within the Project site.
|
|
2003
|
AP5
(#CW47927)
|
No significant land use changes were observed
within the Project site.
|
|
2013
|
AP6
(#CS45459, #CS45509)
|
No significant land use changes were observed
within the Project site.
|
|
2019
|
AP7
(#E064144, #E065829,
#E076790C, #E077223C)
|
No significant land use changes were observed within
the Project site.
|
Note:
* Source of aerial photographs: Survey and
Mapping Office, Lands Department
7.5.2
Site Geology
7.5.2.1 Based
on the HKGS 1:20,000 Geological Map Sheet 7, 2nd Edition (GEO,
2008), the Project site and the hillsides nearby predominantly comprises
coarse-grained biotite granite of Needle Hill Granite of Kwai Chung Suite (Jkt_gc) and medium-grained granite of Sha Tin Granite of
Kwai Chung Suite (Jkt_gm). A layer of colluvium (Qd),
alluvium (Qfa) and marine sand (Qhs)
is recorded as superficial soil.
7.5.2.2
Based on available Ground Investigation (GI)
records, generally 0.2 m to 14 m thick of fill layer with silt to gravel
sized was encountered on the top of the Project site. A layer of marine deposits (typically clay to
silt) with thickness ranging from 0.2 m to 12 m was found below the fill
layer. Approximately 1.5 m to 13.2 m
thick of alluvium (typically silt to gravel) was identified below the marine
deposits. Besides, a layer of colluvium
(typically clay and silt) with thickness up to 8.35m was also encountered below
the marine deposits/alluvium.
7.5.2.3 Saprolite
encountered typically comprised highly to completely decomposed granite with
thickness ranging from 0.75 m to 30 m.
The inferred rockhead level varies from -46.44mPD to +58.99mPD. The weathering profile generally appeared to
become deeper towards the southeast. The
bedrock was typically described as moderately strong to strong, moderately to
slightly decomposed granite.
7.5.3
Acquisition of Information from Government
Departments
7.5.3.1
The EPD and FSD were contacted for (i) records
of any spillage / leakage of chemicals, (ii) records of Dangerous Goods (DG)
and (iii) records of Chemical Waste Producer(s) (CWPs) within the Project site.
7.5.3.2
EPD and FSD’s replies on the request have been
received and attached in Appendix 7.2. The information is summarised below.
Environmental Protection
Department
7.5.3.3
Based on the reply given by EPD on 18 September 2020,
there is no record of spillage / leakage of chemical wastes or chemicals within
the Project site.
7.5.3.4
Further to the EPD’s reply, visit to EPD’s Southorn Centre Office was undertaken on 14 October 2020 to
review the available CWP records. No CWP
records were found within the Project site.
Fire Services Department
7.5.3.5
Based on the reply from FSD on 21 September
2020, no records of DG license, fire incidents or incidents of spillage / leakage
of DG were found within the Project site.
7.5.4
Site Walkover
7.5.4.1
Site walkover was conducted on 14 August 2020 to
investigate any contaminative issues associated with current land uses and
activities within the Project site.
Findings of the site walkover, including the photographic records and
site layout plan, are shown in Figure 7.1 and Figure 7.2. Site walkover checklist is provided in Appendix
7.3.
7.5.4.2
The Project site covers the existing FTN (nullah
/ box culvert / polder), Shan Mei Street Children’s Playground, Shan Mei Street
Sitting-out Area, Kwei Tei Street Garden,
Kwei Tei Street Public
Toilet, Fo Tan Cooked Food Market (East), vacant
land, footpaths, cycling track, bridges, a vacated first aid station at Shing
Mun River Promenade, and sections of Shing Mun River Channel, Yuen Wo Road,
Shan Mei Street, Sui Wo Road, Cheung Lek Mei Street, Kwei
Tei Street and Tat Yip Lane. Based on the site walkover, no chemical / oil
storage or stressed vegetation were observed within the Project site. The concrete paved ground was noted to be in
good condition with no oil stains observed.
No potentially contaminating land uses / activities were observed during
the site walkover.
7.5.4.3
According to the draft Sha Tin Outline Zoning
Plan (OZP) No. S/ST/35, part of the Project site was identified as
"Industrial (I)" zone.
However, the encroached portion only consists of
Shan Mei Street Children’s Playground, Shan Mei Street Sitting-out Area, Fo Tan Cooked Food Market (East), Sui Wo Road,
Shan Mei Street, Cheung Lek Mei Street, Tat Yip Lane, vacant land and
footpaths. Based on the site walkover,
no chemical / oil storage or stressed vegetation were observed within the
encroached portion. The concrete paved
ground was noted to be in good condition with no oil stains observed. No potentially contaminating land uses / activities
were observed during the site walkover.
Given the above, no potential land contamination issues within the
encroached portion of the "Industrial (I)" zone were observed.
7.6
Prediction and Evaluation of Environmental Impacts
7.6.1.1
Based on the findings of site appraisal, the
Project site has been occupied by non-contaminating land uses (e.g. the existing nullah, gardens / playgrounds /
sitting-out areas, cooked food stalls, vacant land, footpaths, cycling tracks,
bridges, a vacated first aid station and roads) and no potentially contaminating
activities were observed. Therefore, no adverse land contamination impact
arising from the Project is anticipated and mitigation measures are considered
not necessary. No further site
investigation (SI) works at the Project site is required.
7.7
Evaluation of Residual Impacts
7.7.1.1
As land contamination impacts are not
anticipated for the Project, no residual impacts are expected.
7.8
Environmental Monitoring and Audit
7.8.1.1
Based on the site appraisal, no land
contamination impacts are anticipated for the Project. No environmental monitoring and audit programme
would be required during construction or operational phase.
7.9.1.1
A site
appraisal, in the form of desktop review and site walkover, was conducted from
August 2020 to February 2021 to identify any current/historical potentially
contaminating and uses within the Project site.
7.9.1.2
Based
on the findings of the site appraisal, no adverse land contamination impact
arising from Project is anticipated. No
further SI works at the Project site is required.