9.1
Water
Quality Parameters
9.1.1A This
Contract does not involve marine works such as dredging and reclamation, only
land-based construction works are anticipated. With proper implementation of recommended
mitigation measures and with the conducting of regular site audits to ensure
proper implementation of the mitigation measures and for compliance checking,
no adverse water quality impact would be expected. No water quality monitoring
will be undertaken for the Contract.
9.1.1
9.1.2
Prior
to the commencement of the construction work, a detailed site drainage
management plan should be submitted to EPD. The plan should cover measures to
minimize all potential water quality impact arising from the surface runoffs of
all the related constructions.
9.1.3
9.1.3A The guidelines outlined in the Practice Note for
Professional Persons Environmental Consultative Committee (ProPECC),
Construction Site Drainage (PN 1/94) should be adopted to control construction
site runoff. Mitigation measures to minimise water quality impacts from
construction site runoff and wastewater and sewage generated from construction
activities are:
n
Provision
of site drainage systems over the entire construction site with sediment
control facilities. Regular inspection and maintenance of the site drainage
systems are required to ensure proper and efficient operation at all times.
n
Sedimentation
tanks or package treatment systems are required to treat the large amount of
sediment-laden wastewater generated from foundation construction work, wheel
washing, site runoff. Any construction activities that
generate wastewater with high concentrations of suspended solids (SS)
should also be collected to these facilities for proper treatment prior to
disposal. Treated wastewater can be reused for vehicle washing, dust
suppression and general cleaning. Bentonite slurry used in bore-pile
construction should be reconditioned and reused to minimise the disposal volume
of the used slurry.
n
The
construction programme should be properly planned to avoid soil excavation in
rainy seasons. Exposed stockpiles of excavated soils or construction materials
should be covered with tarpaulin or impervious sheets to avoid release of
pollutants into the drainage channels.
n
Sewage
generated from site toilets and canteen should be collected using a temporary
storage system. Chemical toilets should be provided at different locations for
use by the workers on site. Licensed waste collectors should be employed for
collection and disposal of the sewage. The drainage system for collection of
wastewater generated from canteen, if any, should be equipped with grease trap
capable of providing at least 20 minutes retention during peak flow.
n
Wheel
washing facilities should be installed at all site entrances/exits.
n
An
emergency plan should be developed by the contractors to deal with accidental
spillage of chemicals.
9.1.4
Upon completion of the HKLR / HKBCF development,
stormwater drainage systems would be completed to collect stormwater generated
from the whole area including new roads. Sewage generated from the HKBCF
development would be treated on site to fulfil effluent limit for discharge.
Additional mitigation measures would not be required.
9.1.5
Not applicable
9.1.6
Not applicable
9.1.7
Not applicable
9.1.8
Not applicable
9.1.9
Not applicable
9.2
Monitoring
Equipment
Not
applicable
9.3
Laboratory
Measurement / Analysis
Not
applicable
9.4
Monitoring
Locations
Not
applicable
9.5
Baseline
Monitoring for Water Quality
Not
applicable
9.6
Efficiency
of Silt Curtain and Cage Curtain
Not
applicable
9.7
Post-construction
Monitoring
Not
applicable
9.8
Impact
Operational Phase Monitoring
Not
applicable
9.9
Event
and Action Plan
Not
applicable
9.10
Mitigation
Measures
9.10.1
The EIA Report has recommended construction and
operational phase mitigation measures. All the prepared mitigation measures are
summarized in the EMIS as shown in Appendix B.