7.
AIR QUALITY IMPACT
Introduction
7.1
The potential air quality impacts associated with the
construction and operation of the proposed Spur Line project are assessed in
this section. In view of the fact that the proposed alignment is relatively
long (7.4km) and will cover areas where existing and future residential
development are clustered, the residents may be prone to potential nuisance due
to the construction works, in particular during the site formation of some
sections of the alignment. However, the air quality impacts due to the
operation of the Spur Line are considered to be minor.
7.2
Construction works associated with the Spur Line
include:
·
A permanent way of a total route length of 7.4 km
between Lok Ma Chau Station and Sheung Shui Station. The alignment of 5 km will
be constructed on viaduct and 1.6 km on cut and embankment. The remaining 0.8
km will be at grade. The project includes construction of the viaducts, rock
cutting and earth embankment. The permanent way will be completed with traction
power supply;
·
Construction of Lok Ma Chau Station: The station
consists of an island platform with future provision for platform screen doors,
two tracks and two concourse levels (one for arriving and one for departing
passengers), KCRC public facilities, staff facilities, and plant and support
facilities;
·
Immigration and customs facilities for Lok Ma Chau
Station: Immigration halls for departing and arriving passengers, non-public
immigration facilities, immigration and custom staff facilities, non-public custom
facilities, security facilities, agricultural and quarantine facilities and
Department of Health facilities;
·
A two level footbridge linking Lok Ma Chau and
Huanggang Stations;
·
Landscaping works and noise barriers where required.
All other mitigation works as agreed in the EIA; and
·
The Dongjiang Raw Water Mains near the existing Sheung
Shui Station have to be diverted. Works need to be carried out during the
Dongjiang supply shut down in December 2001 and 2002 respectively.
7.3
Among the construction works, the most polluting
process from an air quality point of view will be site formation works which
involve a significant amount of earth movement. The air quality impacts from
other processes will be relatively insignificant when compared with the impacts
from site formation. The nuisance from construction vehicle and plant emissions
is likely to be negligible because it is anticipated that the number of these
vehicles and plant will be small for the areas involved.
Air
Quality Assessment Criteria
7.4
The principal legislation regulating air emissions in
Hong Kong are the Air Pollution Control Ordinance (APCO) [Cap. 311] and its
subsidiary regulations. The whole of the territory has been covered by Air
Control Zones. The Hong Kong Air Quality Objectives (AQOs) stipulate maximum
acceptable concentration of air pollutants. The AQOs for hourly, daily and
annual concentrations of four major pollutants are shown in Table 7.1.
Table 7.1
Hong Kong Air Quality Objectives
(AQOs)
Pollutants |
Concentration in Micrograms per Cubic Metre ( |
||
|
Average Time |
||
|
1 hour a |
24 hour b |
1 year c |
Nitrogen
Dioxide (NO2) |
300 |
150 |
80 |
Sulphur
Dioxide (SO2) |
800 |
350 |
80 |
Total
Suspended Particulates (TSP) |
500 e |
260 |
80 |
Respirable
Suspended Particulates (RSP)d |
- |
180 |
55 |
Notes
: Concentrations measured at 298K(25oC) and 101.325kPa (one
atmosphere).
a Hourly
criteria not to be exceeded more than 3 times per year.
b Daily
criteria not to be exceeded more than once per year.
c Arithmetic
means.
d Respirable
suspended particulates means suspended particulates in air with a nominal
aerodynamic diameter of 10 micrometer (ìum) or smaller.
e This
control limit has no statutory basis but is used as a target level for limiting
fugitive dust emissions generated by construction activities.
The Study Area
adjoins the "Special Measures Zone" (SMZ)
detailed in the Deep Bay Guideline (DBG) which is more stringent than the AQO.
For example, TSP and RSP daily average objectives are 180 ìg/m3 and 110 ìg/m3, while annual
average objectives are 80 ìg/m3 and 55 ìg/m3 respectively.
Air
Sensitive Receivers
7.5
The representative air sensitive receivers (ASRs) that
will be impacted by the Spur Line are mainly rural villages while the remaining
are residential estates around the Sheung Shui Station. They are listed in
Table 7.2. The location of the ASRs is shown in Figure
3.1 of the Noise Assessment Chapter.
7.6
Sheung Shui is a new town containing a number of
residential developments and housing estates such as Choi Po Court, Choi Yuen
Estate, Tai Ping Estate, Sheung Shui Centre, Lung Fung Garden and Tin Ping
Estate. North of the existing Sheung Shui Station is Shek Wu Hui and Sheung
Shui Wai with mainly traditional village houses.
7.7
The areas between Sheung Shui Station and Lok Ma Chau,
are mainly agricultural uses with villages scattered around Kwu Tung, Ho Sheung
Heung and Pak Shek Au. Within the vicinity of the Study Area are ranges of
enterprises including several timber mills, a small scale chemical plant,
several car repair shops, rattan factory, pottery factory, umbrella factory, as
well as food and sauce factories.
7.8
Lok Ma Chau is a boundary control area with restricted
access. Most of the land is for agriculture and fish ponds use with a few
scattered villages.
Table 7.2
Representative Air Sensitive Receivers
ASRs |
Description |
mPD |
No. of
Floor |
1 |
Hong
Kong Taoist Association Tang Hin Memorial Secondary School at Sheung Shui |
9.7 |
6 |
2 |
Sheung
Shui Centre (Block 1) at Sheung Shui |
7.7 |
30 |
3 |
Tong Wu
Mansion at Sheung Shui |
8.8 |
30 |
6 |
Low
rise commercial / residential building at San Fung Avenue at Sheung Shui |
7.6 |
4 |
7 |
Choi Po
Court at Sheung Shui |
9.2 |
30 |
11 |
Village
house at Tsung Pak Long Village |
6.1 |
3 |
13 |
Village
house at Ho Sheung Heung |
5.9 |
1 |
17 |
Village
house at Tong Kok |
7.9 |
3 |
22 |
Village
house at Kwu Tung |
18 |
1 |
23 |
Village
house at Kwu Tung |
23.1 |
1 |
25 |
Village
house at Pak Shek Au |
12 |
1 |
27 |
Village
house at Pak Shek Au |
6.7 |
1 |
28 |
Village
house at Chau Tau |
5.3 |
1 |
31 |
Village
house at Ha Wan Tsuen |
3.2 |
1 |
Baseline Air
Quality
Meteorology and Topography
7.9
The Study Area is situated in the northwest corner of
Hong Kong and falls within the Deep Bay Airshed. There are several hills higher
than 400 m in the Shenzhen area to the northeast (Wutong Mountain and Jigong
Tou Mountain) and two hills to the east (Kai Kung Leng and Tai To Yan) (Figure
7.1).
7.10
Figure 7.2 illustrates the wind
conditions at Lau Fau Shan Station of Hong Kong Observatory which is close
to the Study Area and will be taken as an indication of the conditions that
prevail at the western end of the alignment. During the winter season, the
dominant wind direction is northeasterly. For the rest of the season, 45-50%
of the winds are from the east while about 15-20% come from the southwest
direction[1].
The wind pattern characteristic is the result of the blocking effect of hills
over the western part of the New Territories. Topographic barriers also create
eddies that change the direction and speed of the air.
7.11
In addition to these wind patterns, the Study Area
generally exhibits a limited dispersive capacity because of the occurrence of
an inversion layer in the morning and evening over this area[2].
In other words, the stable layer associated with the inversion layer acts as a
lid thereby trapping the pollutants[3].
Thus the occurrences of frequent and extensive inversions make it very
difficult for the air pollutants to disperse from the Deep Bay area.
7.12
Figure 7.3 illustrates wind
conditions at the Hong Kong Observatory's Ta Kwu Ling Station, which is representative
to the eastern part of the Study Area. The prevailing wind direction in the
Study Area is southeasterly, due to the channelling effects of nearby mountain
ridges.
Existing Air Conditions
7.13
There is no baseline air quality data available for
the entire site. EPD's latest data from the air quality monitoring station at
Yuen Long has been used to estimate the ambient air quality over the western
part of the Study Area. According to Air
Quality in Hong Kong (1997), the concentration levels of the NO2,
SO2, TSP and RSP for Yuen Long Station during 1997 are shown in
Table 7.3[4].
Table 7.3
Air Pollutants Concentrations at Yuen Long EPD
Station (1997)
Pollutant |
Concentration in Micrograms per Cubic Metre
(ìg/m3) |
|||||
|
1 hour |
24 hour |
Annual |
|||
|
Maximum |
AQOs |
Maximum |
AQOs |
Maximum |
AQOs |
TSP |
N/A |
500 |
232 |
260 |
103 |
80 |
RSP |
N/A |
N/A |
164 |
180 |
64 |
55 |
NO2 |
202 |
300 |
134 |
150 |
61 |
80 |
SO2 |
310 |
800 |
87 |
350 |
21 |
80 |
Note : N/A means Not Applicable.
7.14
Table 7.3 indicates that the concentrations of NO2
and SO2 are below the AQOs. The short term maximum concentrations of
TSP and RSP are close to the AQOs while the annual average TSP and RSP
concentrations exceed the AQOs.
7.15
The high TSP and RSP levels recorded at EPD's Yuen
Long Station were probably attributed to the intensive construction activities
in the vicinity of the station including works for the Route 3 (Country Part
Section), Village Flood Protection for Yuen Long, Kam Tin & Ngau Tam Mei
(30CD), Drainage Channels for Yuen Long & Kam Tin (43CD and 60CD),
infrastructure provision for Yuen Long South development and the heavy industrial
activities near Shenzhen. In the long term, TSP and RSP levels in the Yuen Long
area are likely to remain high as construction and industrial activities
continue.
7.16
There is no EPD air quality monitoring station within
the eastern part of the Study Area. The closest station is at Tai Po. Although
there are only a small number of industrial establishments, in comparison to
the Tai Po Area, scattered around Sheung Shui, pollutants associated with heavy
industrial activities in Shenzhen are believed to significantly influence air
quality in the Sheung Shui basin. Thus the air quality data from Tai Po Station
is used only as a reference to the general air quality for the eastern section
of the Study Area. According to Environment
Hong Kong (1998), the averaged concentration levels of the NO2,
SO2, TSP and RSP during 1997 at Tai Po Station are tabulated below.
Table 7.4
Air Pollutants Concentrations at Tai Po EPD
Station (1997)
Pollutant |
Concentration in Micrograms per Cubic Metre
(ìg/m3) |
|||||
1 hour |
24 hour |
Annual |
||||
Maximum |
AQOs |
Maximum |
AQOs |
Maximum |
AQOs |
|
TSP |
N/A |
500 |
204 |
260 |
80 |
80 |
RSP |
N/A |
N/A |
153 |
180 |
55 |
55 |
NO2 |
244 |
300 |
138 |
150 |
50 |
80 |
SO2 |
178 |
800 |
54 |
350 |
13 |
80 |
Note : N/A
means Not Applicable.
7.17
The data indicates that the concentrations of NO2
and SO2 were well below AQO. However, long-term and mid-term
averages of TSP and RSP were closed to and just exceeded the AQO respectively.
The high RSP levels were probably due to emissions from traffic utilising the
Fanling Highway and heavy industrial activities on Tai Po Industrial Estate.
These trends are expected to be continued in the short and medium term.
Southern
China
7.18
According to the Air Pollution Index (API) in major
Chinese cities (27th March to 2nd April, 1998; source: China Environmental
Monitoring Centre), Guangzhou was one of the fifteen cities that have moderate
air quality (with API below 100) whereas Beijing, the most polluted city during
the week, registered 259 API points. The dominant pollutant in the Guangzhou,
Shenzhen and Zhuhai areas was found to be nitrogen oxides which are due to the
emission from increased traffic.
Future Air
Quality
7.19
Due to rapid development near the Deep Bay area, both
from the Hong Kong side and the Shenzhen side, it is likely that the air
quality of the area will deteriorate further, particularly if emissions to the
atmosphere from future developments are not properly controlled.
7.20
The proposed development of the Kwu Tung SGA close to
the current Study Area may impact air quality. The findings and recommendations
of the current study should be considered in the evaluation of overall impacts
of the area and the development of suitable mitigation measures in other
studies.
Construction
Impact Assessment
7.21
The principal potential source of air quality impact
arising from the construction of the Spur Line will be fugitive dust. The
temporary dust nuisance, measurable as TSP (Total Suspended Particulates) and
RSP (Respirable Suspended Particulates) would be generated as a result of
construction activities, especially from site formation works where large
quantity of silty material movement will be involved. However, the nuisance
from emission of construction vehicles and plants is likely to be negligible
because it is anticipated that the number of these vehicles and plant will be
relatively small for the area involved.
7.22
The tentative construction programme of the project is
scheduled to be commenced in late 2000 and will be completed in late 2003. Thus
the construction period is about three years. However, it is expected that the
major construction activities that will result in major dust generation will
take place during the site formation of the Lok Ma Chau Station and the cut
slope at Pak Shek Au. Prior to the commencement of the Spur Line construction,
there will be a six months advanced water mains diversion works in early 2000.
7.23
Construction of the line will be fairly
straightforward along the majority of the length of the alignment. The Spur
Line will be constructed on 5 km of viaduct structure, 1.6 km on cut and
embankment and the remaining 0.8 km will be at grade. The proposed Lok Ma Chau
Station will be on elevated structure.
7.24
Potential fugitive dust sources from the construction
of the Spur Line are expected from the following activities:
-
vehicular movement at the haul roads within the works
area and along the track alignment;
-
material handling and stockpiling;
-
precasting and concrete batching plants;
-
wind erosion of unpaved works areas;
-
earthworks in cutting and embankment (Kwu Tung to Pak
Shek Au); and
-
earthworks in excavation and filling for the
foundations and platforms of the Lok Ma Chau Station.
7.25
Since details of the engineering design and the amount
of cut and fill to be generated within the alignment and station sites are not
available in this preliminary design stage, a rough estimate of material
volumes is provided in the following table.
Table 7.5
Material Quantities for the Spur
Line
Construction Activities |
Disposal Quantity (m3) |
Import Quantity (m3) |
Lok Ma Chau Station |
307,000 |
595,000 |
Lok Ma Chau Infrastructure |
6,000 |
4,000 |
Rail Alignment |
119,000* |
267,000 |
*
Approximately half of this material is reusable and can be utilized in the
imported quantity volume.
7.26
During the foundation cutting works associated with
the Lok Ma Chau Station, the dust impacts is expected to be relatively
insignificant as the excavated material of that area will be mainly from fish
ponds which is of high moisture content. Material may be exported transferred to other areas of the
site by road or by barge on Shenzhen River. Given the high moisture
content of the fish pond mud, the dust impacts are likely to be small if
recommended mitigation measures are implemented. As shown in Table 7.5 about
600,000 m3 of fill material will need to be impactedimported, which is likely
to be hydraulic fill from the Pearl River. The river will probably be used as
the route for transportation, thus minimizing the distance for movement of
materials, and also minimizing dust generation. Implementation of appropriate
mitigation measures will help minimize dust generation. If road transportation
is required for import of material, mitigation measures described in this
report will be used to minimize dust impacts. Thus the dust impacts due to the
foundation works on the villages at Lok Ma Chau (ASR 31) will be very limited.
7.27
For the construction of other superstructure of the
station, a relatively small amount of disposal and filling material will be
involved, estimated to be 6,000 m3 and 4,000 m3
respectively. Construction of various government control offices such as
Immigration and Customs facilities, security facilities, agricultural and
quarantine facilities and Department of Health facilities involve only minor
cutting and filling of materials. It is anticipated that the dust impacts to
the sensitive receivers will not be significant. Any materials dropped on
sealed roads will need to be cleaned up immediately to prevent any dust
nuisance.
7.28
Widening the Boundary Patrol/Control Road to serve as
emergency vehicle access for Lok Ma Chau Station is required. The major
potential construction impact due to this road widening including the
associated drains, sewers and water distribution mains in the Lok Ma Chau
Boundary Crossing Area is the dust arising from breaking up the existing road
surface. Construction of drains, culverts, sewers and water distribution mains
will require excavation of trenches. Laying this new infrastructure will be
conducted section by section; thus the quantity of the excavated material will
only be stockpiled at each local works area. The duration of stockpiling will
be as short as possible as most of the material will be used as backfill
material for the open cut trenches. Leveling, compacting and resurfacing of the
new roads will not involve significant movement of materials; hence dust
impacts will be insignificant. However, proper watering of exposed dirt should
be undertaken throughout the construction phase to ensure that the cumulative
impacts of these and other concurrent works such as Shenzhen River Regulation
Phase III and San Tin MDC East Channel, comply with the AQO at all times.
7.29
A foot bridge connecting the Huanggang Station and Lok
Ma Chau Station will accommodate the smooth passenger flow upon the
commissioning of Spur Line. Percussive piling will be required to provide foundations
for the foot bridge. As the construction activities involve minor cutting and
filling of materials, it is anticipated that the dust impacts to the sensitive
receivers will not be significant.
7.29Lok Ma Chau
falls within the area bordered by the "Special Measures
Zone" (SMZ) of the Deep Bay Guideline (DBG) which is more stringent than
AQOs. Therefore, strict dust mitigation measures must be implemented. If human
sensitive receivers are adequately protected, other wildlife species, such as
birds, will also be protected.
7.30
For the construction of the rail alignment, the
disposal volume of excavated material is estimated to be about 162,000 58,500 m3
while the imported filling materials will be 126,000 208,500 m3,
which is expected to be hydraulic fill from the Pearl River. Construction
activities for viaduct sections involve excavation during site preparation,
construction of foundations by bored piling and construction of the viaduct
deck. The dust levels associated with the viaduct construction will be
relatively small as the viaduct deck is likely to be pre-cast. It is likely
that excavated materials will be disposed off-site by dump truck and hence haul
road dust is anticipated. Proper watering of exposed dirt will be undertaken
throughout the construction phase so that dust generation is minimised and
compliance with the AQOs can be achieved at the representative air sensitive
receivers at all times.
7.31
The cutting at Pak Shek Au is likely to be carried out
with a bulldozer with ripper. Dust problems are unlikely, providing mitigation
measures are implemented to suppress dust.
7.32
According to the preliminary design information,
precast yard and concrete batching plants will be required for the construction
of the Spur Line. Storage of the raw materials and material handling at the
precast yard and concrete batching plants are identified as potential fugitive
dust sources. The locations of precast yard and concrete batching plants are
proposed at Kwu Tung. According to the Air
Pollution Control (Specified Processes) Regulations, concrete
crushing/batching plants with an annual output exceeding 5000a site capacity greater than 50
tonnes will be considered a specified process and require a licence to be
operated. Under this regulation, an Air Pollution Control Plan for the batching
plant will be prepared in an effort to control the fugitive dust. Thus,
operation of concrete batching plant must comply with the strict dust controls
so as to reduce the potential dust impact on the nearby sensitive receivers at Kwu
Tung and Pak Shek Au.
7.33
The remaining construction activities are not expected
to produce any dust nuisance to the air sensitive receivers. Landscaping areas
within the Spur Line alignment will not involve significant movement of earth
materials; hence dust impacts are expected to be insignificant.
7.34
Proper dust suppression measures, as stipulated by Air Pollution Control (Construction Dust)
Regulation, are always required when handling exposed dirt throughout the
construction phase to ensure that the compliance of AQOs is achieved at the
ASRs. For example, proper watering of exposed dirt will need to be undertaken
throughout the construction phase so that dust generation is minimised and
compliance with the AQOs can be achieved at the representative ASRs.
7.35
Despite the three years construction period of the
Spur Line, the cumulative dust impacts as a result of concurrent construction
activities both within the Study Area and surrounding areas are not expected to
be significant provided that proper dust suppression measures are implemented.
They are highlighted below.
Dust
Mitigation Measures
7.36
The following dust control measures as part of good
construction practice should be incorporated in the Contract Specification and
implemented to minimise dust nuisance to within acceptable levels arising from
the works:
(i) The
Contractor shall undertake at all times to prevent dust nuisance as a result of
his activities. Effective dust suppression measures as are necessary should be
installed to minimize air quality impacts, at the boundary of the site and at
any sensitive receivers.
(ii) The
Contractor shall frequently clean and water the site to minimise fugitive dust
emissions.
(iii) Effective
water sprays shall be used during the delivery and handling of all raw sand and
aggregate, and other similar materials, when dust is likely to be created and
to dampen all stored materials during dry and windy weather.
(iv) Watering of
exposed surfaces shall be conducted as often as possible depending on the
circumstances.
(v) Areas
within the site where there is a regular movement of vehicles shall have an
approved hard surface, be kept clear of loose surface materials and / or
regularly watered.
(vi) Where dusty
materials are being discharged to vehicle from a conveying system at fixed
transfer point, a three-sided roofed enclosure with a flexible curtain across
the entry shall be provided. Exhaust fans shall be provided for this enclosure
and vented to a suitable fabric filter system.
(vii) The Contractor
shall confine haulage and delivery vehicles to designated roadways inside the
Site. If in the opinion of the Engineer, any motorised vehicle is causing dust
nuisance, the Engineer may require that the vehicle be restricted to a maximum
speed of 15 km per hour while within the Site.
(viii) Wheel washing
facilities shall be installed and used by all vehicles leaving the Site. No
earth, mud, debris, dust and the like shall be deposited on public roads. Water
in the wheel cleaning facility shall be changed at frequent intervals and
sediments shall be removed regularly. The Contractor shall submit details of
proposals for the wheel cleaning facilities to the Engineer prior to
construction of the facility. Such wheel washing facilities shall be usable
prior to any earthworks excavation activity on the Site. The Contractor shall
provide a hard-surfaced road between any washing facility and the public road.
(ix) Stockpiles
of sand and aggregate greater than 20 m3 shall be enclosed on three
sides, with walls extending above the pile and 2 m beyond the front of the
pile.
(x) Chemical
wetting agents shall only be used on completed cuts and fills to reduce wind
erosion.
(xi) All site
vehicular exhausts should be directed vertically upwards or directed away from
ground.
7.37
In addition, based on the Air Pollution Control (Construction Dust) Regulation, any works
involved regulatory work, such as stockpiling, loading and unloading of dusty
materials, shall take precautions to suppress dust nuisance. Examples of dust
suppression methods are:
- the
working area of any excavation or earth moving operation shall spray with water
or a dust suppression chemical immediately before, during and immediately after
the operation so as to maintain the entire surface wet;
- exposed
earth shall be properly treated by compaction, turfing, hydroseeding,
vegetation planting or sealing with latex, vinyl, bitumen or other suitable
surface stabiliser within six months after the last construction activity on
the construction site or part of the construction site where the exposed earth
lies; and
- any
stockpile of dusty materials shall be either covered entirely by impervious
sheeting or placed in an area sheltered on the top and 3 sides; and sprayed
with water or a dust suppression chemical so as to maintain the entire surface
wet.
Concurrent
Construction Activities
7.38
The major
concurrent construction activities are shown in Table 6.14 of the water
chapter. In brief, the construction activities include Shenzhen River Training
Phase III, San Tin Eastern Main Drainage Channels; Fanling, Sheung Shui &
Hinterland Main Drainage Channels, Lok Ma Chau Control Point Expansion Project.
As each construction project must and will implement the adequate dust mitigation measures, the
cumulative impacts of these projects together with Spurline project are
expected to be within the acceptable levels.
Operational
Impact Assessment
Vehicular
Emission
7.39
There are no major air quality impacts associated with
the operation of the Spur Line as only Electric Multiple Units (EMU), which
would not emit atmospheric pollutants, are to be used. It is proposed that used
air inside the station will be removed through ventilation facilities which are
expected to be limited and no adverse air quality impacts to nearby ASRs are expected.
7.40
Ventilation fans and air ventilation systems should be
provided to ensure sufficient local air movement within the station concourse.
Smoke extraction vents should also be provided in the event of fire. The vents
for all ventilation systems should be directed away from nearby sensitive
receivers.
7.41
As such, none of the areas will likely be subject to
adverse air quality due to the operation of the Spur Line.
7.42
The additional
traffic flow around the station at Sheung Shui Station as a result of the Spur
Line is expected to be minimal as passengers will generally reach the station
on foot or by public transport. No more trains than at present will pass through
Sheung Shui Station; some trains will simply be diverted onto Spur Line. Works
vehicles are not expected to increase significantly above present traffic
flows.
7.43
The road leading to Lok Ma Chau
station is a restricted access road, for which a permit is required to cross
into the Closed Border area. The road will be widened within the Closed Border
Area for use as an Emergency Vehicle Access (EVA) route. Vehicles will
therefore continue to be restricted in this area, and the additional traffic
due to the presence of the station will be minimal. No public access to the
station will be permitted.
Summary and
Recommendations
Construction Dust Impact
7.44
The construction dust impact assessment has identified
Air Sensitive Receivers (ASRs) within the Study Area. It has also identified
those works that have potential to generate substantial dust impact to the nearby
ASRs.
7.45
The transportation of earth material by trucks over
haul road is likely to be the dominant dust generation during the site
formation of the construction stage. With the implementation of the recommended
dust suppression measures and backed up by a proper designed EM&A
programme, the construction of Spur Line should comply with the Air Quality
Objectives.
Operational
Air Quality Impact
7.46
Air quality impacts arising from the operational phase
of the Spur Line are not considered to be of concern as limited potential
sources have been identified. No adverse residual impacts due to the Spur Line
are anticipated.
Environmental
Monitoring & Audit (EM&A) Requirements
7.47
Dust impacts during the construction phase can be
easily mitigated through implementation of standard mitigation measures and
good house keeping practices.
7.48
However,
if the proposed mitigation measures for dust during construction are not fully
implemented, it is likely that some nearest sensitive receivers would suffer
unacceptable impact. It is therefore recommended that an EM&A programme in
respect of dust issues is carried out at two locations. The first location is
at Lok Ma Chau due to the proximity to the “Special Strategic Measures Zone” of
Deep Bay. The second location is Pak Shek Au where some sensitive receivers are
very close to the construction areas.
[1] Royal Observatory Hong Kong,
1981: A Preliminary Report on the Meteorological Conditions in the Deep Bay
Area.
[2] Royal Observatory Hong Kong, 1984: Meteorological
Assessment of Atmospheric Transport Condition in the Deep Bay Airshed.
[3] Roland, B.S. (1988): An Introduction to Boundary Layer
Meteorology, Kluwer Academic Publishers, p.666.
[4] EPD 1998 : Environment Hong Kong
1998, Hong Kong Government