6.1.1
Potential contaminative workshops have
been identified close to the proposed site boundary of Pak Kong River based on
the findings of the desktop study and site appraisal. As recommended in the EIA
report, further investigation shall be required to determine the presence and
extent of contamination before the construction works taken place at the
concerned areas. The contamination assessment shall be carried out in
accordance with EPD’s ProPECC PN3/94 “Contaminated Land Assessment
and Remediation” and “Guidance Notes for Investigation and Remediation
of Contaminated Sites of Petrol Filling Stations, Boatyards, and Car Repair /
Dismantling Workshops”.
6.1.2
The contaminated sites shall be remediated
before commencement of any construction work at the concerned sites which may
disturb the ground. The duration of remediation shall be taken into account by
the Project Proponent or the Contractor as part of the construction programme.
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.
6.2.1
A preliminary
Contamination Assessment Plan (CAP) has been prepared and included in the EIA
report. The CAP recommended that site investigation shall be conducted for the
potential contaminated areas encroaching upon the proposed drainage works area
of Pak Kong River. As shown in Figure 6.1, two potential zones (SI-1 and
SI-2) have been confined for further investigation due to the presence of two
potential contaminative workshops partially located within the proposed works
area, including Workshop A - Wah Shing Motor Repairing Factory and Workshop
B - Wing Chong Car Repair. The details of further investigation are
presented in Table 6.1.
6.3.1
Due to the possibility of land-use
changes and variable future site conditions caused by different factors such as
weather and business operation, a full site inspection is required by the
future Environmental Team (ET) to review the validity of the preliminary
CAP. The ET shall have suitably
qualified personnel with at least 7 years in land contamination
investigation. The CV of the relevant
personnel shall be submitted to IC(E) and ER for approval before commencement
of land contamination study. The ET
shall base on the findings of the EIA and further detailed site appraisal to
prepare an updated CAP immediately after the site was resumed for this project.
Such updated CAP should be submitted to EPD for approval.
6.3.2
Table 6.1 lists the parameters that shall be analysed and the number of
samples proposed to be taken at each concerned area, according to EPD's
Guidance Notes for Investigation and Remediation of Contaminated Sites, for
reference. All the information given in Table 6.1 (including the number and location of
sampling points and testing parameters) shall be reviewed during the preparation
of CAP.
6.3.3
Upon receipt of EPD’s approval on the
updated CAP, the actual site investigation for land contamination impact
assessment shall be conducted accordingly before any construction work started
at the identified contaminated sites. Soil and groundwater samples shall be
collected and tested as described in the approved CAP to provide site-specific
information for the assessment. The
soil and groundwater sampling and testing work may be carried out by the Contractor
or other drilling contractors under suitable contractual arrangement by the
Project Proponent or ER. The field
sampling work shall be supervised by the ET and audited by the IC(E).
6.3.4
A Contamination Assessment Report
(CAR) shall be prepared by the ET to document the findings of the site investigation.
Interpretation of laboratory testing results in accordance with the ProPECC
Note No. 3/94 and comparison of the findings with relevant standards, such
as the Dutch guidelines or other international practices as appropriate shall
be also included in the CAR.
6.3.5
If land contamination is confirmed, a
Remediation Action Plan (RAP) shall be prepared by the ET and drawn up to
formulate necessary remedial measures, and potential water quality impact to
the river shall be also addressed if necessary in the remediation measures. The
subsequent CAR and RAP shall be endorsed by EPD before implementation of any
remedial technology. The contaminated sites should be remediated before
commencement of any construction work at the concerned sites which may disturb
the ground. The duration of remediation should be taken into account by the
Project Proponent or the Contractor as part of the construction programme.
6.4.1
In the execution of the construction
works, it is expected that any identified contaminated land would be remediated
to the acceptable standards prior to site clearance/excavation works.
Therefore, no significant impact in relation to land contamination would be
anticipated. However, as a precaution, mitigation measures are recommended to
minimise the potentially adverse effects on the health and safety of
construction workers and the impacts arising from the disposal of potentially
contaminated materials. These measures include, but not limited to, the following:
·
Construction workers' potential
contact with contaminated materials should be minimised by using bulk
earth-moving excavator equipment;
·
Exposure to any contaminated materials
should be minimised by wearing appropriate clothing and personal protective equipment
such as gloves and masks (when interacting directly with suspected contaminated
material), providing adequate hygiene and washing facilities and preventing
smoking and eating during such activities;
·
Stockpiling of contaminated excavated
materials on site should be avoided as far as possible;
·
The use of contaminated soil for
landscaping should be prohibited unless there is proper treatment of soil;
·
Vehicles containing any excavated materials
should be suitably covered to limit potential dust emissions or contaminated
wastewater run-off, and truck bodies and tailgates should be sealed to prevent
any discharge during transport or during wet conditions;
·
Only licensed waste haulers should be
used to collect and transport any contaminated material to an appropriate
disposal site and procedures should be developed to ensure that illegal
disposal of waste does not occur;
·
The necessary waste disposal permits
should be obtained, as required, from the appropriate authorities, in
accordance with the Waste Disposal Ordinance (Cap 354), Waste Disposal
(Chemical Waste) (General) Regulation (Cap 35), as required;
·
Records of the quantities of wastes
generated and disposed of should be maintained; and
·
In accordance with good construction
practice, silt traps should be used to reduce the impact to drainage caused by
suspended solids arising from disturbed ground, or any construction materials
such as cement and gravel. Wastewater, surface runoff or extracted groundwater
should be disposed of in accordance with the WPCO.
Table
6.1 Preliminary Contamination
Assessment Plan for Further Investigation of Identified Potential Sites
|
Potential Site
|
Potential Contaminating
Area for SI
|
Workshops within the
Potential Contaminating Areas for SI
|
Current Activities/Uses
|
Potential Contaminants
|
Size/Area of Concern to
this Project
|
Proposed no. of Sampling
Points*
|
Parameters to be Analysed*
|
Remarks
|
|
Site
A
(Pak
Kong River)
|
SI
– 1
|
Workshop
-A
Wah
Shing Motor Car Repairing Factory
|
Long
vehicle parking and maintenance
|
Lubricants, petroleum products, fuels,
battery acid and cleansing solvents.
|
200
m2
|
2
|
BTEX,
TPH,
organic
solvents, lead, copper, chromium, zinc & PAHs.
|
To
be reconfirmed by the environmental team at the construction stage.
.
|
|
Site
B
(Pak
Kong River)
|
SI
– 2
|
Workshop
-B
Wing Cheong Car Repair
|
Repairing
of private vehicles and mini-vans in majority
|
Lubricants, petroleum products, fuels,
battery acid and cleansing solvents.
|
177
m2
|
2
|
BTEX,
TPH,
organic
solvents, lead, copper, chromium, zinc & PAHs.
|
Notes: * Subject to further confirmation/review when
preparing the CAP, and to be endorsed by EPD before the sampling work.
TPH: Total petroleum hydrocarbons: C6 to C36.
BTEX: Benzene, toluene, ethlybenzene
and xylenes.
PAHs: Polycyclic aromatic hydrocarbons