7
LAND CONTAMINATION
7.1.1
This Section
presents the potential implications of land contamination due to historical and
current land uses within the Project site.
7.1.2
Site appraisal, including desktop review and site
walkover, was conducted to identify the presence of potential land
contamination and assess the potential land contamination impacts within the
Project site. Should any historical or current land contamination
activities and potential land contamination issues be identified in this EIA,
further land contamination assessment would be recommended to be undertaken
prior to the commencement of the construction phase.
7.2
Legislation,
Standards and Guidelines
7.2.1
The following EPD’s guiding documents are referenced
for this land contamination assessment:
·
Annex 19
of the Technical Memorandum on Environmental Impact Assessment Process (Annex
19 of EIAO-TM);
·
Guidance
Note for Contaminated Land Assessment and Remediation (the RBRGs Guidance
Note);
·
Guidance
Manual for Use of Risk-based Remediation Goals for Contaminated Land Management
(the RBRGs Guidance Manual); and
·
Practice
Guide for Investigation and Remediation of Contaminated Land (the Practice
Guide).
7.2.2
The following legislation, documents and guidelines
may cover or have some bearing upon the assessment of contamination and the
handling, treatment and disposal of contaminated materials for this Project:
·
Dangerous
Goods Ordinance (CAP.295);
·
Water
Pollution Control Ordinance (WPCO) (CAP.358);
·
Waste
Disposal Ordinance (WDO) (CAP.354);
·
Waste
Disposal (Chemical Waste) (General) Regulation (CAP.354C); and
·
Code of
Practice on the Packaging, Labelling and Storage of Chemical Wastes.
7.3 Description of the Environment
7.3.1
This Project aims to improve the traffic mobility of
Ming Kum Road, Tsing Wun Road and Lung Mun Road. A pair of elevated slip
roads connecting Tsing Wun Road and Lung Fu Road (LFRSR NB and LFRSR SB), and a
slip road between Tuen Mun Road and Hoi Wing Road (HWRSR) will be built under
this Project. The locations of the LFRSR NB and LFRSR SB, and HWRSR
Project sites and the relevant work limits are shown in Figures 7.1a and 7.1b respectively.
Slip road connecting Tsing Wun Road to Lung Fu
Road (LFRSR NB and LFRSR SB)
7.3.2
As shown in the site location provided in Figure 7.1a, the LFRSR NB and LFRSR SB Project site are located on generally flat
terrain and is mainly bounded by high-rise residential buildings to the
southeast, multi-storey industrial buildings to the northeast, scattered
villages, vegetated land and educational institutions to the west.
Slip road
linking Tuen Mun Road and Hoi Wing Road (HWRSR)
7.3.3 Based
on Figure 7.1b, the HWRSR Project site is located on flat terrain and is mainly
bounded by high-rise residential buildings to the northeast and east,
educational institutions and a community hall to the northwest, a temple to the
southwest, and a vegetated slope to the south.
7.3.4
The Project work limits are shown in Figures 7.1a and 7.1b. The Project would include the construction of at-grade roads,
elevated roads and other associated works where soil excavation would be
anticipated within the Project sites.
3.2.4
The land uses in close vicinity of the three Project sites are urban
residential, industrial use and vehicle road networks. As the land uses
do not rely on the use of groundwater, it is considered that there were no
sensitive receivers located adjacent to or in close proximity to the Project
site from a land contamination assessment point of view.
7.4 Assessment Methodology
7.4.1
Land contamination assessment was undertaken in
accordance with the criteria set out in Annex 19 of the EIAO-TM, as well as
other Guidance Notes, Practice Guide, Guidance Manual and related legislation
as presented in Section 7.2.
7.4.2
A site appraisal, including desktop review and site
walkover, was conducted to identify the potentially contaminating activities
that may pose an adverse impact on the Project sites. Site walkovers were
conducted within the Project sites to review the general site conditions and to
identify any sources of land contamination. For the desktop review, the
following information was reviewed:
· Historical aerial photos from the
Lands Department (LandsD);
· Hong Kong Geological Survey Map
(Series HGM20) – Sheet No. 5 and 6 (1:20,000); and
· Records on dangerous goods (DGs),
chemical wastes, chemical spillage/leakage and fire incidents from the
identified potentially contaminated sites from Environmental Protection
Department (EPD) and Fire Services Department (FSD).
7.5 Identification of Potential Land
Contamination
Desktop Appraisal
Historical Land Uses
7.5.1
A review of past land uses of the Project sites was
conducted by reviewing the relevant historical aerial photographs in the years
between 1963 and 2021 and the available topography map in 1977. The
aerial photographs and topography map in 1977 were obtained from the Surveys
and Mapping Office of LandsD. This review aims to evaluate potential land
contamination implications associated with any land changes within the Project
sites. The historical land uses within the LFRSR Project site and HWRSR
Project site are presented in Table 7.1 and Table 7.2,
respectively. The referenced historical aerial photographs for the LFRSR
Project site and HWRSR Project site are attached in Appendix 7.1a and Appendix
7.1b, respectively. The topography map in 1977 is
attached in Appendix 7.1c for reference.
Table 7.1
Summary of Historical Land Uses at LFRSR NB & LFRSR SB
|
Year
|
Aerial Photo Reference and Date
|
Land Use Observations
|
|
1963
|
63_6389
31 Jan 1963
|
LFRSR
NB & LFRSR SB Project sites and the surroundings were mainly natural
terrains, agricultural lands and sea areas.
|
|
1969
|
69_2452
date not available
|
Site
formation and vehicle roads were developed along the coastline within LFRSR
NB & LFRSR SB Project sites.
|
|
1977
|
19651
5
Dec 1977
|
Based
on the topography map in 1977, sawmills were observed along
the coastline at the south within LFRSR NB & LFRSR SB Project sites.
Sawmills were for cutting timber logs to lumbers.
|
|
1983
|
50894
28 Nov 1983
|
Site
formation was discovered at the east of the LFRSR NB & LFRSR SB Project
sites. Wong Chu Road was developed to cross the Tuen Mun River Channel
and connect Tsing Wun Road and Lung Mun Road. The remaining parts of
LFRSR NB & LFRSR SB Project sites remained unchanged.
|
|
1984
|
55523
24 Jul 1984
|
Construction
of at-grade and elevated vehicle road networks connecting Lung Mun Road, Lung
Fu Road, Tsing Wun Road and Wong Chu Road and associated road access were
observed. The remaining parts of LFRSR NB
& LFRSR SB Project sites remained unchanged.
|
|
1989
|
A18589
6 Oct 1989
|
Road
networks within the LFRSR NB & LFRSR SB Project sites were developed. The
sawmills along the coastline were being demolished.
|
|
1990
|
A24339
3 Dec 1990
|
Reclamation
works commenced at the south of the LFRSR NB & LFRSR SB Project
sites. The sawmills along the
coastline were being demolished.
|
|
1997
|
CN17418
28 May 1997
|
The
roundabout at Lung Mun Road between the residential development Lung Mun
Oasis and Glorious Garden was developed.
|
|
2008
|
CS21786
10
Dec 2008
|
The
construction of Lung Chak Road was completed.
|
|
2014
|
CS48421
22 Jan 2014
|
The
construction of Yip Wong Road was completed.
|
|
2021
|
E128363
18 Jan 2021
|
No
significant change was observed since 2014.
|
Table 7.2
Summary of Historical Land Uses at HWRSR
|
Year
|
Aerial Photo Reference and Date
|
Land Use Observations
|
|
1963
|
63_0454
24 Feb 1963
|
The
HWRSR Project site was mainly located within the natural terrain. The north
part of the HWRSR Project site was located along the coastline of Castle Peak
Bay.
|
|
1976
|
15703
18 Oct 1976
|
Site
formation and construction of Tuen Mun Road were in progress at the southeast
of the HWRSR Project site.
|
|
1978
|
23890
24 Nov 1978
|
Construction
of Tuen Mun Road within the HWRSR Project site was completed.
|
|
1988
|
A15474
5 Nov 1988
|
Reclamation
of sea and site formation works at the northwest of the HWRSR Project site
were observed.
|
|
1990
|
A22816
1 Oct 1990
|
At
the northwest of the HWRSR Project site, the construction of Hoi Wing Road
was
in progress.
|
|
1991
|
A29291
14 Nov 1991
|
The
construction of Hoi Wing Road and Castle Peak Road (Castle Peak Bay) were
completed at the northwest of the HWRSR Project site.
|
|
2001
|
CW31646
18 Jun 2001
|
No
significant change was observed compared to 1991.
|
|
2011
|
CW92671
11
Dec 2011
|
Retaining
walls at Tuen Mun Road Northbound was observed. The construction of
noise barriers and enclosures for Tuen Mun Road were also observed.
|
|
2021
|
E128906C
18 Jan 2021
|
No
significant change was observed compared to 2011.
|
Site Geology
LFRSR NB & LFRSR SB
7.5.2
The superficial geology of the Project sites generally
comprises fills materials and various Quaternary deposits. According to
the published 1:20,000 Geological Map (Sheet No.5 and 6) and the archival
ground investigation records, the LFRSR NB and LFRSR SB Project sites comprise
fill materials, debris flow, marine sand and alluvium. The rock type to
be encountered is Jurassic Tuen Mun Adesite Member (Jua) under Tuen Mun
Formation. The Tuen Mun Adesite Member comprises fine to coarse grain,
light grey lithic lapilli bearing metatuff.
HWRSR
7.5.3
The superficial geology of the Project sites generally
comprises fills materials and various Quaternary deposits. According to
the published 1:20,000 Geological Map (Sheet No.5 and 6) and the archival
ground investigation records, the HWRSR Project site comprise fill materials
and marine deposits (including marine mud and marine sand). The rock type
to be encountered within the HWRSR Project site is Jurassic Lantau Granite (Jml_gc),
which is coarse-grained biotite granite grey in colour and contains quartz,
plagioclase feldspar and alkali feldspar in roughly equal proportions, as well
as hornblende and biotite.
Record of Chemical Waste Producer
7.5.4
An enquiry was made to the EPD on the chemical waste
producer record of all the Project sites. A visit to the Chemical Waste
Collection Licensing Section of the EPD Territorial Control Office was arranged
on 21 December 2021 and information related to Chemical Waste Producer (CWP)
registered in the Project sites was extracted. Only one valid CWP record
(see Table 7.3) was found in EPD's current and historical CWP
registration. The location of the CWP record is presented in Figure 7.2.
Table 7.3
Record of CWP Registration
|
Location
|
Name
of CWP
|
Description
of the CWP Registration
|
Status
|
|
LFRSR NB
& LFRSR SB
|
Chun Wo Construction and
Engineering Company
|
For DSD’s project DC/2018/09
–
“Rehabilitation of Trunk Sewers in Tuen Mun”
|
Valid
|
7.5.5
Based on the available CWP record from EPD, the CWP
record is associated with the construction of the Drainage Service Department
(DSD)’s project DC/2018/09 – “Rehabilitation of Trunk Sewers in Tuen
Mun”. A site visit was arranged on 29 March 2022 to the DSD’s
construction site. As advised by the DSD’s site representatives, the
DSD’s construction site is divided into two areas, named “Works Area” and “Site
Office” (hereafter “DSD’s Works Area” and “DSD’s Site Office”). The
storage area of chemical waste is located within the “DSD’s Site Office”, which
is outside of the LFRSR NB & LFRSR SB Project sites.
It is expected that any chemical waste storage and/or handling associated with
the CWP record is not anticipated within the LFRSR NB & LFRSR SB Project
sites.
7.5.6
In view of the above, with no chemical waste storage
and/or handling within the LFRSR NB & LFRSR SB Project sites based on the
CWP record, no land contamination issue at the LFRSR NB & LFRSR SB Project
sites is anticipated.
Record of Chemical Spillage Incidents
7.5.7
Letters were sent to the EPD and Fire Service
Department (FSD) on the records of chemical spillage incidents and chemical
leakage for all the Project sites (see Appendix 7.2). Based on the replies from EPD and FSD, no records of chemical
spillage incidents and chemical leakage were found within all the Project
sites.
Record of Fire Incidents
7.5.8
A letter was sent to the FSD on the records of
Dangerous Goods (DGs) and records of reported fire incidents at the Project
sites (see Appendix 7.2). Based on the reply from FSD, there were no DG license records
identified within all the Project sites. Yet,
eight fire incidents were reported within all the Project sites. Table
7.4 below presents the incident records provided by FSD. The
locations of the fire incidents are shown in Figure 7.3.
Table 7.4
Record of Fire Incidents from FSD
|
Incident
ID
|
Date
|
Project
Site Involved
|
Approximate
Address
|
Type
of Incident
|
|
1
|
4 October 2019
|
LFRSR NB
& LFRSR SB
|
Near Lamppost AD0417B,
Lung Mun Road
|
Vehicle Fire
|
|
2
|
29 April 2020
|
HWRSR
|
Near Lamppost DD2121,
Near Castle Peak Road
|
Vehicle Fire
|
|
3
|
5 May 2020
|
HWRSR
|
Near On Ting Estate,
Tuen Mun Road
|
No.2 Fire Alarm
|
|
4
|
15 October 2020
|
LFRSR NB
& LFRSR SB
|
Near Lamppost AD0409,
Near Lung Mun Road
|
No.1 Fire Alarm
|
|
5
|
15 December 2020
|
LFRSR NB
& LFRSR SB
|
Near Lamppost AD0422,
Near Lung Mun Road
|
No.1 Fire Alarm
|
|
6
|
19 December 2020
|
LFRSR NB
& LFRSR SB
|
Near Lamppost AD0409,
Near Lung Mun Road
|
No.1 Fire Alarm
|
|
7
|
20 April 2021
|
LFRSR NB
& LFRSR SB
|
Near Lamppost AD0395,
Lung Mun Road
|
No.1 Fire Alarm
|
|
8
|
5 June 2021
|
LFRSR NB
& LFRSR SB
|
Near Lamppost AD0395,
Lung Mun Road
|
No.1 Fire Alarm
|
7.5.9
Based on the FSD’s records, there were five “No.1 Fire
Alarm” fire incidents and one vehicle fire incident reported within the LFRSR
NB & LFRSR SB Project site in the last two years. Although those fire
incidents were within the Project sites, they were minor fire cases in terms of
extinguishing resources allocated by FSD. No burnt stains remained nearby
the locations of “No.1 Fire Alarm” incidents. The vehicle fire incident
was properly extinguished by FSD and no oil or burnt stains remained on the
road. It is not expected to pose any potential land contamination issues
to the LFRSR NB & LFRSR SB Project sites.
7.5.10 One “No.2 Fire Alarm” fire incident reported near On Ting Estate was a
vehicle fire incident. The vehicle fire incident was properly
extinguished by FSD and no oil or burnt stains remained on the road. As
the fire incident location is situated more than 500m to the north of the HWRSR
Project site (refer to Figure 7.3), the fire incident is not expected to pose any potential land
contamination issues to the HWRSR Project site.
7.5.11 One vehicle fire incident was reported within the HWRSR Project
site. The vehicle fire incident was properly extinguished by FSD and no
oil or burnt stains remained on the road. The fire incident is not
expected to pose any potential land contamination issues to the HWRSR Project
site.
Site Walkover
7.5.12 Site walkovers were conducted on 23 December 2021, 29 March 2022 and 3
April 2022 to observe all the Project sites' land conditions and identify signs
of potential land contamination. Site walkover
checklists are provided in Appendix 7.3.
LFRSR NB & LFRSR SB
7.5.13 Based on the findings of site walkovers, the LFRSR NB & NFRSR SB
Project sites are mainly occupied by non-contaminating land uses including Lung
Fu Road, Lung Mun Road, Tsing Wun Road, pedestrian access roads, vegetated land
and trees (see Photos 1 to 6 in Appendix
7.4a). A construction site for DSD’s project
DC/2018/09 – “Rehabilitation of Trunk Sewers in Tuen Mun” is observed within
LFRSR NB & LFRSR SB Project sites.
7.5.14 On 29 March 2022, a site visit was conducted for the construction site
for DSD’s project DC/2018/09 – “Rehabilitation of Trunk Sewers in Tuen
Mun”. As advised by the DSD’s site representative, the DSD’s construction
site is divided into “DSD’s Works Area” and “DSD’s Site Office”. The “DSD’s
Works Area” is within the LFRSR NB & LFRSR SB Project sites and undergoing
the construction works; whilst the “DSD’s Site Office” is outside of the LFRSR
NB & LFRSR SB Project sites. Only construction equipment and
materials are temporarily stored in the “DSD’s Works Area”, as advised by the
site representative during the site visit.
Neither storage/ handling of hazardous chemicals nor equipment repair/
maintenance activities were anticipated at the “DSD’s Works Area” within the LFRSR NB & LFRSR SB Project sites (see Photos
7 to 11 in Appendix 7.4a). No potentially contaminating land activities and issues were
identified within the “DSD’s Works Area” during the site walkover.
HWRSR
7.5.15 Based on the findings of site walkovers, the HWRSR Project site is
mainly occupied by non-contaminating land uses including a small portion of Hoi
Wing Road, Castle Peak Road (Castle Peak Bay), Tuen Mun Road and street
vegetation including trees (see Photos 17 to 18 in Appendix 7.4b). No potentially contaminating land uses or activities were
observed in the HWRSR Project site during the site walkover.
7.5.16 During another site visit on 3 April 2022, a temporary site office under
Civil Engineering and Development Department (CEDD)’s Contract No.GE/2019/10 –
“Landslip Prevention and Mitigation Programme, 2017, Package D, Landslip
Prevention and Mitigation Works” (Tuen Mun 6SW-A/R84 Slope) were observed on
the pedestrian road within the HWRSR Project site. Some plastic fences
were placed surrounding the CEDD’s site office. As advised by the site
representative, the temporary site office is only for office uses only.
Neither storage/ handling of hazardous chemicals nor equipment repair/
maintenance activities are anticipated within the HWRSR Project site (see
Photos 19 to 20 in Appendix 7.4b). No potentially land contamination activities and issues were
identified within the CEDD’s site office during the site walkover.
Summary
7.5.17 During the site walkovers, all Project sites are well paved with
concrete, except for the DSD’s works area at the LFRSR NB & LFRSR SB
Project sites was bare land with vegetation. Neither storage/ handling of
hazardous chemical and chemical waste nor equipment repair/ maintenance
activities were observed within all Project sites. No evidence of oil
stains or chemical leakages/ spillages was observed. Besides, no
potential land contamination facilities, such as underground fuel oil storage
tanks, underground oil pipelines, chemical and chemical waste storage areas,
dangerous goods stores, wastewater treatment facilities and transformer rooms
at all Project sites. Also, no signs of obvious/ suspected contamination
such as abnormal odour and/or distressed vegetation were observed or notified
at all Project sites.
7.6
Prediction
and Evaluation of Environmental Impacts
7.6.1
With reference to the aerial photos and topography
maps reviewed from the Survey and Mapping Office of LandsD, all of the Project
sites were in undeveloped status (i.e. natural terrain, agricultural land and
part of the Castle Peak Bay) in 1963 and before. Those Project sites were
formed and gradually developed as the present. Based on the available
topography map in 1977 and related aerial photos, sawmills were observed along
the south of the coastline within LFRSR NB & LFRSR SB Project sites since
1977 and they were demolished in 1990. These sawmills were used for cutting
timber logs into lumbers and no potential contamination activities were
expected. No historical potential land contamination activities were
identified within all Project sites. Details of the aerial photos were
discussed in Section 7.5.1 and presented in Appendice 7.1a and
7.1b, and the topography map in 1977 is presented in Appendix 7.1c.
7.6.2
Based on the available CWP records from EPD, one valid
CWP record was found associated with the DSD’s construction site which is
partially located in the LFRSR NB & LFRSR SB Project sites. The exact
chemical waste storage area is located outside of the LFRSR NB & LFRSR SB
Project sites. Based on the CWP record, it is expected that any chemical
waste storage/ handling is not anticipated within the LFRSR NB & LFRSR SB
Project sites. Details of the CWP records were presented in Table 7.3
and discussed in Sections 7.5.4 to 7.5.6. Moreover, further
to the response from EPD and FSD, there are no records of chemical spillage
incidents and chemical leakage incidents within all Project Sites. The
responses from these government departments were provided in Appendix 7.2.
7.6.3
Referring to the responses from FSD, no DG licence
records were identified within all Project sites. Yet, eight fire
incidents were reported within all Project sites. Those fire incidents
were minor fire cases in terms of extinguishing resources allocated by
FSD. No burnt stains and no oil and/or burnt stains remained at and/or
nearby the locations. In this connection, those reported fire incidents
are not expected to pose any potential land contamination at the Project
sites. Details of the incident records were presented in Table 7.4
and Appendix 7.2 and discussed in Sections 7.5.7 to 7.5.11.
7.6.4
In addition, according to the site walkovers, the
majority of the area of all Project sites comprises concrete paved vehicle road
networks and pedestrian access. DSD’s Works Area and CEDD’s site office
were identified at the LFRSR NB & LFRSR SB Project sites and HWRSR Project
site, respectively. No potential contamination activities (e.g. handling
of hazardous chemical/ chemical waste and repair/ maintenance activities) and
no potential land contamination facilities (e.g. aboveground/ underground fuel
oil storage tank and oil pipeline, chemical and chemical waste storage area,
dangerous goods store, wastewater treatment facility and transformer room) were
observed at all three Project sites. Also, no signs of obvious/ suspected
contamination such as abnormal odour and/or distressed vegetation were observed
at all of the Project sites. Therefore, no potential land contamination
activities and facilities were identified in all three Project sites.
Details of the site walkovers were discussed in Sections 7.5.12 to
7.5.16, while site walkover checklists and photos are presented in Appendices
7.3 and 7.4.
7.6.5
In view of the above, no potential land contamination
activities and facilities were identified within the Project sites.
Therefore, it is considered that the land contamination impact associated with
the Project is not anticipated. Further site investigation and mitigation
measures are considered not necessary.
7.7 Evaluation of Residual Impacts
7.7.1
No land contamination impacts are anticipated for the
Project. Thus, no residual impacts are expected.
7.8 Environmental Monitoring and Audit
7.8.1
No land contamination impacts are anticipated for the
Project. Thus, environmental monitoring and audit for the Project are not
required.
7.9.1 A desktop appraisal and site walkover were carried out to identify any
potential land contamination activities and facilities within all Project
sites.
7.9.2
Further to the discussion in Section
7.6, based on the findings of the desktop appraisal (including a
review of historical aerial photos, request for information from related
government departments and site walkovers), no potentially contaminating activities and facilities were identified
within all the Project sites. Therefore, no adverse environmental impact
in respect of land contamination is anticipated. Further SI works and
mitigation measures are deemed not necessary for the Project.