2.1.1.1
The EIA study of this Project
concluded that, with the implementation of the dust suppression measures
stipulated in the Air Pollution Control (Construction Dust) Regulation, good
site practices and proposed mitigation
measures, adverse dust impact would not be anticipated at the Air Sensitive
Receivers (ASRs) as shown in Figure 2.1 in the vicinity of the construction sites. As such, dust monitoring
is not recommended.
2.1.1.2
However, weekly site audits are
recommended to ensure that appropriate dust control measures are properly
implemented and good construction site practices are adopted throughout the
construction period.
2.1.1.3
Air quality monitoring during
the operation phase of this Project is considered not necessary as the proposed
drainage works would not expected to generate any air quality impacts to the
adjacent identified ASRs.
2.2.1.1
Air Sensitive Receivers (ASRs)
have been identified in accordance with Annex 12 of the EIAO-TM, which includes
domestic premises, hotels, hostels temporary housing accommodation, hospitals,
medical clinics, educational institutions, offices, factories, shops, shopping
centres, places of public worship, libraries, court of law or performing arts centre.
2.2.1.2
The existing ASRs are
identified with reference to the latest information provided on the survey
maps, topographic maps, aerial photos, land status plans and confirmed by
various site surveys undertaken. The planned ASRs are also identified with reference
to the latest published Ngong Ping Outline Zoning Plan (OZP) No. S/I-NP/6.
2.2.1.3
The relevant authorities have
been approached as far as practicable so as to obtain the latest information on
planning applications, layout and building height, etc. The major planned uses
in the vicinity of the area include different land uses including Village Type,
Development, Residential, Government, Institution or Community, Open Space,
Recreation and Other Specified Uses.
2.2.1.4
With reference to the EIA Study
Brief, the Study Area for the air quality impact assessment has been defined as
a distance of 500 metres from the boundary of the Project Area and the
assessment has included all relevant air sensitive receivers which may be
potentially affected by the Project within this Study Area.
2.2.1.5
The existing ASRs are the
village houses, other specified uses such as
Table 2.1 Representative
Air Sensitive Receivers
|
ASR |
Location |
Landuse [1] |
No. of Storeys |
Assessment Height (above ground level) |
Horizontal Distance to the Proposed
Drainage Works (m) |
|
ASR1 |
Columbarium of |
-- |
1 |
1.5m |
21 |
|
ASR2 |
|
OU |
2 |
1.5m |
23 |
|
ASR3 |
Village House No. 68 |
GB |
2 |
1.5m |
37 |
|
ASR4 |
Village House No. 65 |
GB |
2 |
1.5m |
31 |
|
ASR5 |
Village House No. 49A |
GB |
2 |
1.5m |
8 |
|
ASR6 |
Village House No. 40 |
V |
2 |
1.5m |
20 |
|
ASR7 |
Luen Sin Tong |
V |
2 |
1.5m |
12 |
|
ASR8 |
Village House No. 34 |
V |
2 |
1.5m |
20 |
|
ASR9 |
Village House |
V |
2 |
1.5m |
4 |
|
ASR10 |
|
GIC |
2 |
1.5m |
15 |
Note: [1] -- – No zoning, OU – Other Specified Uses
(Cable Car Terminal), GB – Green Belt, V – Village Type Development, GIC –
Government, Institution or Community.
2.3.1.1
Specific mitigation measures (Appendix A) have been assumed in the modelling to reduce the dust generation
from the Project to within the 1-hour (500µgm-3), 24-hour (260µgm-3)
and Annual (80µgm-3) criteria at ASRs, and have been applied for
both the short-term Tier 1 and annual TSP predictions. The specific mitigation comprises watering of
exposed soil areas in active works areas and paved haul roads every two hours
for 12 hours a day to reduce dust emissions by 91.7%, with reference to the
“Control of Open Fugitive Dust Sources” (USEPA AP-42). The amount of water to
be applied would be 0.25L/m2.
2.3.1.2
In addition to the mitigation
mentioned above, under the auspices of the Air Pollution Control (Construction
Dust) Regulation, the Contractor will be required to ensure that dust control
measures stipulated in the Regulation should be implemented control dust
emissions. The dust control measures detailed below shall also be incorporated
into the Contract Specification where practicable as an integral part of good
construction practice:
(i)
Use of regular watering to
reduce dust emissions from exposed site surfaces and unpaved roads,
particularly during dry weather;
(ii)
Use of frequent watering for
particularly dusty construction areas and areas close to ASRs;
(iii)
Side enclosure and covering of
any aggregate or dusty material storage piles to reduce emissions. Where this
is not practicable owing to frequent usage, watering shall be applied to
aggregate fines;
(iv)
Open stockpiles shall be
avoided or covered. Prevent placing dusty material storage piles near ASRs;
(v)
Tarpaulin covering of all dusty
vehicle loads transported to, from and between site locations;
(vi)
Establishment and use of
vehicle wheel and body washing facilities at the exit points of the site;
(vii)
Imposition of speed controls
for vehicles on unpaved site roads, 8 km per hour is the recommended limit;
(viii)
Routing of vehicles and
position of construction plant should be at the maximum possible distance from
ASRs;
(ix)
Every stock of more than 20
bags of cement or dry pulverised fuel ash (PFA) should be covered entirely by
impervious sheeting or placed in an area sheltered on the top and the 3 sides;
(x)
Cement or dry PFA delivered in
bulk should be stored in a closed silo fitted with an audible high level alarm
which is interlocked with the material filling line and no overfilling is
allowed; and
(xi)
Loading, unloading, transfer,
handling or storage of bulk cement or dry PFA should be carried out in a
totally enclosed system or facility, and any vent or exhaust should be fitted
with an effective fabric filter or equivalent air pollution control system.
2.4.1.1
The implementation of regular
site audits aims to ensure the mitigation measures recommended in the EIA
report to be properly undertaken during the construction phase of this Project.
It can also provide an effective control
of any mal-practices and, therefore, achieve the continual improvement of the environmental
performance on-site.
2.4.1.2
Inspections of the construction
activities and works sites and works areas should be conducted by the
Contractor at least on a weekly basis to ensure the mitigation measures to be properly
implemented.
2.4.1.3
Site audits should be carried
out by the Engineer, ET and Contractor, and should be based on the mitigation
measures for the air pollution control as recommended in Appendix A. In the event that the
recommended mitigation measures are not fully or properly implemented, the
Contractor should report the deficiency to the Engineer and ET. The appropriate action will need to be taken
by the Contractor:
(i)
Investigate the problems and
causes;
(ii)
Discuss a remedial and
corrective proposal with the ER and ET;
(iii)
Take action according to the
action notes agreed with the ER;
(iv)
Implement the remedial and
corrective action immediately;
(v)
Re-inspect the site conditions
upon the completion of the remedial and corrective action; and
(vi)
Record the event.