Environmental Permit
No. EP-138/2002
環境許可證編號EP-138/2002
Appendix
A (as referred to in Condition 3.5)
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 removal facilities such as sand traps, silt 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 suitably 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
properly at all times.
(iv)
Earthworks
final surfaces shall be well compacted and the subsequent permanent work or
surface protection shall be carried out immediately after the final surfaces
are formed to prevent erosion caused by rainstorms. Appropriate intercepting
channels shall be provided along the site boundary or at the locations agreed
with the IEC or ET Leader. Rainwater pumped out from trenches or foundation
excavations shall be discharged into storm drains via silt removal facilities.
(v)
Open
stockpiles of construction materials (e.g. aggregates and sand) on site 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.
(vi)
Manholes
(including any newly constructed ones) shall always be adequately covered and
temporarily sealed so as to prevent silt, construction materials or debris from
getting into the drainage system, and to prevent storm run-off from getting
into foul sewers. Discharges of
surface run-off into foul sewers shall always be prevented in order not to
unduly overload the foul sewerage system.
(b) Groundwater
Groundwater pumped out of
wells, etc. for the lowering of ground water level in foundation construction
shall pass through appropriate silt removal facilities before discharge into
storm drains.
(c) General Construction Activities
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. Stockpiling of the excavated
material can be minimised by scheduling the construction programme in a way
that one section of the alignment can be constructed and completed before the
excavation works of the next section commence.