Appendix A (as referred to
in Condition 2.5)
Measures to Mitigate Environmental Impacts due to Site Run-off and
Other Potential Water Pollution During Construction
(a)
Surface Runoff
(i)
Surface
run-off from the construction site shall be directed into adequately designed
sand/silt/grease removal facilities such as sand traps, silt traps, grease
traps and sediment basins before discharge into storm drains. Channels, earth bunds or sand bag
barriers shall be provided on site to properly direct stormwater to such silt
removal facilities.
(ii)
Catchpits
and perimeter channels shall be constructed in advance of site formation works
and earthworks.
(iii)
Silt
removal facilities, channels and manholes shall be maintained with the
deposited silt and grit being removed at least once a week, and at the onset of
and after each rainstorm to ensure that these facilities are functioning at all
times.
(b)
General Construction Activities
(iv)
No
materials which may cause contamination to the Water Gathering Grounds shall be
stored within the Water Gathering Grounds. On-site storage of construction
materials (e.g. aggregates and sand) shall be covered with tarpaulin or similar
fabric during rainstorms. Measures such as providing sand bag barriers shall be
taken to prevent the washing away of construction materials, soil, silt or
debris into any drainage system.
(v)
Use
of chemicals including pesticide, fertilizers, disinfectants, deodourants and
insecticide within the Water Gathering Grounds shall not be allowed unless
otherwise agreed by the Director.
(vi)
At
all parts of all works areas and construction sites, and throughout the full
duration of the construction contract(s), debris and rubbish on site shall be
handled and disposed of to avoid entering the water column and causing water
quality impacts. Temporary on-site storage of excavated materials shall be
covered with tarpaulin or similar fabric during rainstorms. Any washout of construction or
excavated materials should be diverted to the drainage system via sediment
traps.
(vii)
Soil
excavation shall be minimized in rainy seasons. All excavated or filled
surfaces shall be protected from erosion.
-
end -