This section presents the assessment
findings of the potential air quality impacts on air sensitive uses arising
from the construction and operation of the proposed CKR. Mitigation measures
for construction activities have been recommended and potential environmental
impacts associated with construction dust would be controlled to acceptable
levels. Assessment results have concluded that the predicted cumulative air
quality impacts on all sensitive receivers would comply with the Air Quality
Objectives during the operational phase of the Project.
The air quality impact assessment criteria shall make reference to the Hong Kong Planning Standards and Guidelines (HKPSG), the Air Pollution Control Ordinance (APCO) (Cap.311), and Annex 4 of the Technical Memorandum on Environmental Impact Assessment Process (TM-EIAO).
The APCO (Cap.311) provides the
power for controlling air pollutants from a variety of stationary and mobile
sources and encompasses a number of Air Quality Objectives (AQOs). In addition
to the APCO, the following overall policy objectives are laid down in Chapter 9
of the Hong Kong Planning Standards and Guidelines (HKPSG):
·
Limit
the contamination of the air in Hong Kong, through land use planning and
through the enforcement of the APCO to safeguard the health and well-being of
the community; and
·
Ensure
that the AQO for 7 common air pollutants are met as soon as possible.
Currently, the AQOs stipulate limits on
concentrations for 7 pollutants including sulphur
dioxide (SO2), Total Suspended Particulates (TSP), Respirable Suspended Particulates (RSP), Nitrogen Dioxide
(NO2), Carbon Monoxide (CO), photochemical oxidants, and Lead (Pb). The AQOs are
listed in the table below.
Table 4.1: Hong Kong Air Quality Objectives
(HKAQO)
|
Pollutant |
Limits on Concentration, μg/m3 [1] (ppm in brackets) |
||||
|
1-hr [2] |
8-hr [3] |
24-hr [3] |
3-Month [4] |
Annual [4] |
|
|
Sulphur
Dioxide |
800 (0.3) |
|
350 (0.13) |
|
80 (0.03) |
|
Total
Suspended Particulates |
500
[7] |
|
260 |
|
80 |
|
Respirable
Suspended Particulates [5] |
|
|
180 |
|
55 |
|
Carbon
Monoxide |
30,000 (26.2) |
10,000 (8.7) |
|
|
|
|
Nitrogen
Dioxide |
300 (0.16) |
|
150 (0.08) |
|
80 (0.04) |
|
Photochemical
Oxidants (as ozone) [6] |
240 |
|
|
|
|
|
Lead |
|
|
|
1.5 |
|
Notes:
[1] Measured at 298K and 101.325 kPa.
[2] Not to be exceeded more than three times per
year.
[3] Not to be exceeded more than once per year.
[4] Arithmetic mean.
[5] Respirable suspended
particulates means suspended particulates in air with a nominal aerodynamic
diameter of 10 micrometres or smaller.
[6] Photochemical oxidants are determined by
measurement of ozone only.
[7] Not an AQO but is a criterion for evaluating
air quality impacts as stated in Annex 4 of TM-EIAO.
The Air Pollution Control
(Construction Dust) Regulation specifies processes that require special dust
control. The Contractors are required to
inform the EPD and adopt proper dust suppression measures while carrying out “Notifiable Works” (which requires prior notification by the
regulation) and “Regulatory Works” to meet the requirements as defined under
the regulation.
The
Practice Note on Control of Air Pollution in Vehicle Tunnel published by EPD
provides guidelines on control of air pollution in vehicle tunnel. Guideline
values on tunnel air quality are shown in the following table.
Table 4.2: Tunnel Air Quality Guidelines
|
Pollutant |
Average Time |
Maximum Concentration |
|
|
µg/m3 [1] |
ppm |
||
|
Carbon
Monoxide, CO |
5
minutes |
115,000 |
100 |
|
Nitrogen
Dioxide, NO2 |
5
minutes |
1,800 |
1 |
|
Sulphur
Dioxide, SO2 |
5
minutes |
1,000 |
0.4 |
Notes:
[1] Measured at 298K and 101.325 kPa.
4.3
Construction
Dust Assessment
As discussed in Section
3, construction activities associated with the CKR will be mainly
undertaken underground. However, at-grade construction works are still required
near both tunnel portals (i.e. West and East Portions), and central access/ventilation
shaft in Ho Man Tin, and also a barging facility near Tsing Yi. As such, the
construction dust assessment for the Project is separated into 4 areas, namely the West Portion, Central Portion, East Portion, and Barging Point. With reference to the EIA Study Brief for this Project (ESB-156/2006),
the study area for air quality impact assessment should generally be defined by
a distance of 500m from the boundary of the Project. Figure 4.1.1 to 4.1.4 illustrate the extent of the
study area for construction
dust assessment in West Portion, Central Portion, East Portion, and Barging
Point, respectively.
4.3.2
Ambient
Air Quality Condition
Total suspended particulate (TSP) is of key
concern during the construction phase. Historical TSP monitoring data from the
Air Quality Monitoring Station (AQMS) in Sham Shui Po, Kwun Tong, and Tsuen Wan operated by EPD have been
examined. The latest 5 published years
of air quality monitoring data, i.e. 2007 to 2011 are tabulated in the table below.
The 5-year annual average is adopted as representative background air quality
concentration.
Table 4.3: TSP Monitoring Data at Sham Shui Po, Kwun Tong and Tsuen Wan AQMSs (2007-2011)
|
AQMS |
Annual TSP Concentration
(μg/m3) |
|||||
|
2007 |
2008 |
2009 |
2010 |
2011 |
5-year Mean |
|
|
Sham Shui Po |
79 |
81 |
77 |
76 |
79 |
78.4 (98%) |
|
Kwun Tong |
82 |
72 |
70 |
67 |
74 |
73.0 (91%) |
|
Tsuen Wan |
79 |
67 |
63 |
63 |
69 |
68.2 (85%) |
Notes:
% of AQO is provided
in the bracket.
Monitoring results
exceeded AQO are shown as bolded characters.
It is observed from the above table that there were no obvious
trends of TSP concentrations in Sham Shui Po, Kwun Tong and Tsuen Wan. The lowest annual TSP concentrations in these three AQMSs were recorded in 2010.
In consideration of their individual geographical locations, the 5-year
annual TSP averages recorded at Sham Shui Po and Kwun Tong AQMS are adopted as the background TSP
concentrations for the West Portion (i.e. 78.4 µg/m3) and East
Portion (i.e. 73.0 µg/m3) respectively.
For the Central Portion, the average from Sham Shui
Po and Kwun Tong AQMS is adopted (i.e. 75.7µg/m3). The 5-year annual TSP concentration recorded
in Tsuen Wan (i.e. 68.2
µg/m3) is adopted as the background concentration for
the Barging Point.
In accordance with Annex 12 of the
TM-EIAO, Air Sensitive Receivers (ASRs) include domestic premises, hotel,
hostel, hospital, clinic, nursery, temporary housing accommodation, school,
educational institution, office, factory, shop, shopping
centre, place of public worship, library, court of law, sports stadium or
performing arts centre. Any other
premises or places with which, in terms of duration or number of people
affected, has a similar sensitivity to the air pollutants as the aforelisted premises and places are also considered as a
sensitive receiver.
Representative ASRs within a
distance of 500m from the works limit and temporary at-grade work areas
have been identified. These ASRs include both the existing and planned
developments. Existing ASRs are identified by means of reviewing topographic
maps, aerial photos, land status plans, supplemented by site inspections. They
mainly include developed residential buildings with different storey height, educational institution and hotels
etc.
Planned/committed ASRs are
identified by making reference to relevant Outline Zoning Plans (OZP), Outline
Development Plans, Layout Plans and other published plans in the vicinity of
the alignment, including:
·
South
West Kowloon (KPA 20) Outline Zoning Plan (No. S/K20/27);
·
Tsim Sha Tsui (KPA 1) Outline Zoning Plan (No.
S/K1/26);
·
Yau Ma Tei (KPA 2) Outline Zoning Plan (No.
S/K2/21);
·
Ho Man
Tin (KPA 6 & 7) Outline Zoning Plan (No. S/K7/22);
·
Hung Hom (KPA 9) Outline Zoning Plan (No. S/K9/24);
·
Ma Tau Kok (KPA 10) Outline Zoning Plan (No. S/K10/20);
·
Kai Tak (KPA 22) Outline Zoning Plan (No. S/K22/4); and
·
Ngau Tau Kok & Kowloon Bay (KPA 13 & 17) Outline Zoning Plan (No. S/K13/27)
For other planned landuses, the relevant stakeholders have been approached to
obtain latest planning information such as layout and building height.
The locations of the worst representative ASRs for construction
dust assessment are illustrated in Figure 4.1.1 to 4.1.4 and are summarised in the table
below.
Table 4.4: Representative
ASRs for Construction Dust Assessment
|
ASR ID |
Location |
Landuse [1] |
No. of Storey |
Approx. separation distance from works limit (m) |
|
West Portion |
||||
|
W-A1 |
Yau Ma Tei Catholic Primary School (Hoi Wang Road) |
E |
8 |
80 |
|
W-A2 |
Charming Garden Block 12 |
R |
23 |
80 |
|
W-A3 |
Yau Ma Tei Catholic Primary School (Tung Kun Street) |
E |
7 |
<10 |
|
W-A4 |
Prosperous Garden Block 1 |
R |
28 |
<10 |
|
W-A5 |
The Coronation |
R |
30 |
<10 |
|
W-A6 |
Man Cheong Building |
R |
18 |
50 |
|
W-A7 |
Kum Lam Building |
R |
12 |
<10 |
|
W-A8 |
Dickson Building |
R |
18 |
<10 |
|
W-A9 |
Yau Ma Tei Jockey Club Polyclinic |
H |
10 |
<10 |
|
W-A10 |
Alhambra Building |
R |
15 |
<10 |
|
W-A11 |
Hong Kong Community College (HKCC) of PolyU |
E |
19 |
<10 |
|
W-A12 |
Civil Aid Service Headquarter |
GIC |
6 |
20 |
|
W-A13 |
Park Avenue Tower 10 |
R |
35 |
170 |
|
W-A14 |
Charming Garden Block 1 |
R |
22 |
70 |
|
W-A15 |
HKMA David Li Kwok Po College |
E |
8 |
120 |
|
W-P1 |
Reprovisioned Yau Ma Tei Police Station
(Planned) |
GIC |
4 |
<10 |
|
W-P5 |
Hong Kong Red Cross Headquarters (Planned) |
GIC |
- |
<10 |
|
W-P6 |
Refuse Collection Point and street Sleepers’ Shelters (Planned) |
GIC |
4 |
<10 |
|
Central Portion |
||||
|
M-A1 |
Kar Man House, Oi Man Estate |
R |
6 |
<10 |
|
M-A2 |
Carmel on the Hill |
R |
25 |
50 |
|
M-A3 |
SKH Tsoi Kung Po Secondary School |
E |
8 |
10 |
|
M-A4 |
Man Fuk House Block A |
R |
15 |
110 |
|
M-A5 |
Cascades Block A |
R |
18 |
110 |
|
M-A6 |
Ko Fai House, Kwun Fai Court |
R |
9 |
20 |
|
M-A7 |
The Open University of Hong Kong |
E |
12 |
130 |
|
M-A8 |
Kwun Hei Court |
R |
41 |
40 |
|
M-A9 |
Housing Authority Headquarters Block 1 |
GIC |
11 |
<10 |
|
M-A10 |
Ho Man Tin Government Offices |
GIC |
14 |
60 |
|
M-A11 |
Choi Man House, Ho Man
Tin Estate |
R |
42 |
20 |
|
M-A12 |
King Man House, Ho Man Tin Estate |
R |
15 |
210 |
|
M-A13 |
Ho Man Tin Swimming Pool |
P |
- |
10 |
|
M-A14 |
Yee Man house |
R |
41 |
<10 |
|
M-A15 |
Ho Min Tin Estate Service Reservoir Playground |
P |
- |
50 |
|
M-A16 |
Ko Shan Road Park |
P |
- |
80 |
|
M-A17 |
Kiu Wai Mansion |
R |
20 |
370 |
|
M-A18 |
Sun Man House |
R |
24 |
<10 |
|
M-A19 |
Ellery Terrance |
R |
34 |
290 |
|
M-A20 |
Dragon View (Block 1) |
R |
20 |
250 |
|
M-P2 |
Planned Residential Area B (Planned) |
R |
- |
<10 |
|
East Portion |
||||
|
E-A1 |
Hong Kong International Trade and Exhibition Centre |
GIC |
32 |
40 |
|
E-A2 |
EMSD Headquarters |
GIC |
22 |
10 |
|
E-A4 |
Billion Centre |
OU |
45 |
80 |
|
E-A5 |
Kai Fuk Industrial Centre |
I |
9 |
130 |
|
E-A6 |
Grand Watefront |
R |
51 |
<10 |
|
E-A7 |
Chong Chien Court |
R |
13 |
<10 |
|
E-A8 |
Wei Chien Court |
R |
13 |
<10 |
|
E-A9 |
Sino Industrial Plaza |
I |
8 |
<10 |
|
E-A10 |
HSBC Main Treasury |
C |
3 |
30 |
|
E-A11 |
Holy Carpenter Primary School |
E |
6 |
<10 |
|
E-A12 |
United Daily News Centre |
C |
15 |
<10 |
|
E-A13 |
Merit Industrial Centre |
C |
11 |
<10 |
|
E-A14 |
Wyler Gardens |
R |
13 |
<10 |
|
E-P1 [2] |
Site 1B4 – School (Planned) |
E |
10 |
240 |
|
E-P2 [2] |
Site 1I3 – Residential (Planned) |
R |
32 |
90 |
|
E-P3 [2] |
Site 1J1 (Planned) |
GIC |
16 |
170 |
|
E-P4 [2] |
Site 1J3 (Planned) |
GIC |
8 |
20 |
|
Barging Point |
||||
|
TY-A1 |
Grand Horizon Block 6 |
R |
36 |
390 |
|
TY-A2 |
Tai Sang Container and Godown Centre |
I |
15 |
360 |
|
TY-A3 |
Tsing Yi Industrial
Centre Phase 1 |
I |
15 |
380 |
|
TY-A4 |
The Hong Kong Jockey Club International BMX Park |
P |
1 |
300 |
Notes:
[1] R– residential; E – educational; I – Industrial; H – clinic/ home
for the aged/hospital; C – commercial; W – worship; GIC –
government, institution and community; P – Recreational/Park; OU – Other
specified uses (Business)
[2] Based on
the best available information including the implementation plan given in the Legco Paper [CB(1)570/08-09(03)], information from CEDD
etc., the planned ASRs (E-P1, E-P2, E-P3 and E-P4) within the ex-Kai Tak airport area may be concurrent of CKR although the
implementation programme is still yet to be finalised. Hence, these ASRs are
included in the construction dust assessment for a conservative assessment.
4.3.4
Identification of Pollution
Sources and Representative Pollutants
A review on the
construction methodology for various works areas along CKR alignment has been
conducted. In general, construction dust as the representative pollutants, will be potentially generated mainly from the
land-based at-grade construction works including the following activities. According to HKAQO, the 1-hr, 24-hr and
annual concentration would need to be considered. According to Section 13.2.4.3
of USEPA AP-42, most of the particles in fugitive dust have an aerodynamic
diameter of <30 μm. Hence, it is appropriate to adopt Total
Suspended Particulates (TSP) (with aerodynamic diameter ≦30 μm) as the representative pollutant for construction
phase. According to EPD’s Air Quality
Report 2011, the major sources for Respirable
Suspended Particulates (RSP) include power generation, road transport,
etc. Non-combustion sources only
constitute about 14%. Since construction
dust is only one of the sources from non-combustion sources. It is unlikely
that RSP is a representative pollutant for construction dust.
·
Site
clearance;
·
Soil
excavation;
·
Backfilling;
·
Construction
of portals and cut-&-cover tunnel;
·
Temporary
storage, handling and transportation of material at tunnel exit sites;
·
Barging
facilities;
·
Demolition
of existing buildings; and
·
Wind
erosion of open sites.
Since
excavation and backfilling activities near both ends of the CKR tunnel will
involve large quantities of earthworks and silty
material handling, it is anticipated that there may be dust impact as a result
of these activities if mitigation measures are not implemented. For the tunnel
construction, since all the construction activities, except the cut-&-cover
section, will be undertaken totally underground, dust generated will be confined within the tunnel and no associated
dust impact is therefore anticipated.
Construction
works in the Central Portion will mainly involve construction of the vertical
access shaft for loading of explosives for blasting and the mucking out
location for excavated materials. Dust impact is therefore anticipated.
The current construction methodology has
proposed the barging facilities near Tsing Yi.
Dust emissions due to loading / unloading activities and
truck movement are therefore anticipated.
Appendix 4.1
illustrates the at-grade works area for the
construction of CKR. Dust emissions from concurrent projects and existing
sources would also have potential dust impact on ASRs and the
cumulative impacts have been assessed.
The
tentative commencement year for the construction of CKR is 2015, and would take
approximately 5-6 years for completion. All potential concurrent projects, which
may have cumulative environmental impacts during the construction phase of CKR,
have been identified and they are summarised in the
table below. Figure 1.4 illustrates the locations of these
concurrent projects. The implementation programmes of
these concurrent projects are provided by the respective project proponents.
Where information is not available, they have been made reference to the best
available information such as EIA reports and then confirmed by the respective
project proponents for the
purpose of this EIA.
Table 4.5: Key Concurrent Projects for
Construction Dust Assessment
|
Key Concurrent Projects |
Tentative
Construction Programme |
|
Shatin to Central Link – Tai Wai to Hung Hom Section [1] |
2012-2018 |
|
Kwun Tong Line Extension [2] |
2011-2015 |
|
Trunk Road T2 |
2014/2015- end 2020 |
|
Kai Tak Development |
2009- beyond 2020 |
|
Kai Tak Development – Roads D3A & D4A |
2014-2017 |
|
Express Rail Link – West
Kowloon Terminus [3] |
2010-2015 |
|
Road
Works at West Kowloon |
2011-2014 |
|
Proposed Road Improvement Works
in West Kowloon Reclamation Development Phase I |
2014-2015 |
Notes:
[1] Major civil works will be
completed in 2016
[2] Major civil
works will be completed in 2014
[3] Construction
works in West Kowloon area will be completed in 2014.
Liaisons
with each of the project proponents of the above concurrent projects have been
made in order to obtain the latest available information and details. All the
overlapping construction works within 500m from the project boundary of CKR are
included for cumulative dust impact assessment. Where
appropriate, references are also made to the approved EIA reports to obtain the
details of dust sources. The
following briefly describes each concurrent project:
i)
Shatin to Central Link – Tai Wai to Hung Hom Section (SCL
(TAW-HUH))
SCL
(TAW-HUH) is an approximately
SCL
(TAW-HUH) has commenced its construction in 2012 and is targeted for completion in 2018,
while the major civil construction works will be completed by 2016. It will
therefore be constructed concurrently with the proposed CKR from 2015 to 2016.
Cumulative dust impact is therefore anticipated. All the construction works
within 500m from the CKR project boundary during this period, including site
clearance, ground excavation, cut-&-cover tunnel
section etc., presented in the EIA report for SCL (TAW-HUH) are included in
this assessment.
ii)
Kwun Tong Line Extension (KTE) & associated Essential Public
Infrastructure Works (EPIW)
The
KTE is an approximately 2.6km extension of the existing Kwun
Tong Line from Yau Ma Tei
Station to a new railway station at Whampoa and an interchange with SCL
(TAW-HUH) at Ho Man Tin Station. The KTE includes the construction of the
running line, the proposed Ho Man Tin Station, Whampoa Station and their
associated structures.
The
construction works of KTE has commenced in mid-2011 and is scheduled for
completion in 2015 according to the approved EIA Study “Kwun
Tong Line Extension” (AEIAR-154/2010). In particular, all the major civil works
would be completed by 2014 and only some minor reinstatement works would be
carried out within the first quarter of 2015. Hence, cumulative construction
dust impact from KTE and associated EPIW is not anticipated.
iii)
Trunk
Road T2
Trunk Road T2 is a dual two-lane trunk road of approximately 3.6
km long connecting the CKR and Tseung Kwan O-Lam Tin
Tunnel to
form a new strategic highway network in order to relieve the existing heavily
trafficked road network in the Central and Eastern Kowloon as well as Tseung
Kwan O.
According to the latest implementation programme,
the construction of Trunk Road T2 would likely commence in end 2015 and be completed by end 2020, which would interface with the
construction of CKR. As such, cumulative dust impact during construction is
anticipated.
iv)
Kai
Tak Development
Redevelopment plan for the former Kai Tak
Airport area is proposed to optimise the development
potential of the ex-airport site. It covers a land area of about 328 hectares,
including the ex-Kai Tak Airport and existing
waterfront area at To Kwa Wan, Kowloon Bay etc.
According to the current development plan, the infrastructure works are split
into 7 sub-packages, such as Cruise Terminal Development, Trunk Road T2 etc.
The developments are anticipated to commence in 2009 for completion beyond 2020.
Based on the construction programme
presented in LegCo Papers on Kai Tak
Development (LC Paper No. CB(1)570/08-09(03)), cumulative dust impact is
expected during the interaction with major dusty construction works associated
with the proposed CKR, which will be undertaken in Year 2015. For the purpose of cumulative impact
assessment, construction works which are located within 500m from the site
boundary of CKR with major overlapping construction in Year 2015 are included. Dust emission strengths presented in the
approved EIA Study “Kai Tak Development” (KTD)
(AEIAR-130/2009) are adopted where appropriate.
v)
Kai
Tak Development –Roads D3A & D4A
Road D3A and D4A are both dual 2-lane district distributor roads,
which are 1.4km and 0.1km long respectively, running on the Runway Precinct of
KTD. Road D3A will run along the centre of the Runway Precinct and will replace
the original southern section of Road D3 that runs along the waterfront of the
Runway Precinct. Road D4A is an
extension of Road D4 connecting to the proposed Road D3A. They will serve the Cruise Terminal,
the Tourism Node and the development sites in the Runway Precinct.
The construction of these roads will commence in 2014 tentatively
and will be completed by 2017. However,
the construction site for Road D3A & D4A will be occupied as the barging
facilities for the SCL (TAW-HUH). As such, cumulative dust impact due to the
concurrent activities from the barging facilities has been addressed.
vi)
Express
Rail Link (XRL) – West Kowloon Terminus
The Hong Kong Section of Guangzhou-Shenzhen-Hong Kong Express
Rail Link (XRL) will connect West Kowloon Terminus (WKT) to the Mainland
section of XRL at Hongmian Dao. The XRL will provide
cross-boundary services between stations in Hong Kong, Futian,
Longhua, Humen, Shibi, and other major Mainland cities.
The XRL of approximately
26km long will run as an underground railway in dedicated tunnels from WKT to
the boundary crossing point at Huanggang. Major
construction works in the vicinity of the CKR includes the construction of the
proposed WKT and the cut-&-cover tunnel section near Jordan Road. According
to the approved EIA Study “Hong Kong Section of Guangzhou - Shenzhen - Hong
Kong Express Rail Link” (AEIAR-143/2009), all the construction works in West Kowloon
area is scheduled to be completed by end of 2014. In addition, according to the information presented
in the latest approved VEP application (VEP-377/2012), the proposed concrete
batching plant is located at 500m away from the CKR project boundary and hence
any cumulative impacts are not anticipated to be significant. And the northern
portion of the works area for XRL described in the VEP would have been
completed before the commencement of the CKR construction, which would
therefore not interface with CKR.
vii)
Road
works at West Kowloon
Upon the opening of WKT of the XRL and the future development of
the West Kowloon Cultural District (WKCD), additional traffic capacity and
network restructuring within the West Kowloon Reclamation Area (WKRA) is
required to accommodate the increasing traffic demand. The proposed roads
include Road D1A, Road D1, Lin Cheung Road-Austin Road West Underpass and
upgrading of Austin Road West.
These road works are currently being under construction and are expected to be completed by 2014, which
will therefore not
interface with CKR. As such, cumulative dust impact during construction phase is not anticipated.
It is understood that the extent of the barriers and locations of
the top openings of underpass have been updated in the latest approved VEP
application (VEP-368/2012) since its approved EIA Study
(AEIAR-141/2009). However, the effect of the barrier is only localized. The top openings of the underpasses are
located about 500m away from the Project and the annual pollutant contributions
from these top openings are only insignificant at the nearest identified
ASRs under the CKR EIA. It is therefore considered that the abovementioned changes under this VEP
would have no significant effect on CKR.
viii)
Proposed
Road Improvement Works in West Kowloon Reclamation Development Phase I
The project
is proposed to improve the existing road infrastructure in the West Kowloon
Reclamation Development (WKRD) including the WKCD and WKT etc, and to enhance
its accessibility to
these developments.
It consists of some road widening/improvement works and provision of new link
roads. These works are scheduled to commence in early 2014 and complete in
2015.
Construction works
within 500m from the CKR project boundary are reviewed. According to the latest
information available from its Project Profile (PP-450/2011) and the EIA Study
Brief (ESB-236/2011), construction activities would include some modifications
of bridge structure and construction of road bridges. Given that the
requirements stipulated in the Air Pollution Control (Construction Dust)
Regulation and good site practices for dust control will be implemented by the
Contractor, dust contribution from this project is considered insignificant. In
addition, the nearest ASRs under the CKR Project are W-A12 (Civil Aid Service
Headquarters) and W-P5 (Hong Kong Red Cross Headquarters (Planned)), which are
located about 150m and 200m away from this road improvement works project.
These ASRs are/would be central air-conditioned with fresh air intake at higher
level, dust generated from ground level would not have
significant impact to these nearest ASRs. For ASRs located
further away, potential dust impact would be naturally attenuated to an
insignificant level due to distance. Hence, cumulative
dust impact during construction phase is not anticipated.
There
are 3 existing concrete batching plants (CBPs) within the ex-Kai Tak Airport area, including the Yue
Xiu CBP, Glorious CBP, and Yau
Lee CBP. Based on the latest information, the Yue Xiu CBP, Glorious CBP and the associated sand depot would
cease operation before the commencement of construction of SCL, i.e. 2012. The
operation of Yau Lee CBP, on the other hand, would
have ceased its operation in 2014 before the occupation of the public rental
housing at the same site. Hence, dust
emissions from these CBPs are not anticipated.
According
to the EIA report for SCL (TAW-HUH),
the site next to To Kwa Wan
Station under the SCL project (as shown in Figure 1.3) would be allocated for new CBP under
short-term tenancy. This
potential new CBP has been assessed in the EIA report for SCL (TAW-HUH). It is
considered that the assumptions made in the SCL (TAW-HUH) EIA are the best
available information and are
therefore adopted in this assessment.
Dust Emission associated with the
Project
Fugitive
dust impact assessments are carried out based on conservative assumptions of
general construction activities which include the following:
·
Heavy
construction activities including site clearance, ground excavation,
construction of the associated facilities, haul road etc;
·
Wind
erosion of all active open sites;
·
Loading/unloading
from trucks at barging facilities;
·
All
construction activities at all work sites to be undertaken concurrently in
order to assess the worst-case
situation;
·
Construction
working periods of 26 days a month and 12 hours a day from 7:00am to 7:00pm,
except Sundays and public holidays.
The
prediction of dust emissions is based on typical values and emission factors
from United States Environmental Protection Agency (USEPA) Compilation of Air
Pollution Emission Factors (AP-42), 5th Edition. References of the dust
emission factors for different dust generating activities are listed below. Calculation of dust emission factors and locations of dust sources are
given in Appendix 4.1. Detailed descriptions are also discussed in
the following sections.
Table 4.6: References of Dust Emission Factors
for Different Activities
|
Operating Sites |
Activities |
Equations
and Assumptions |
Reference |
|
All construction and excavation sites |
Heavy construction activities including land clearance, ground
excavation, cut and fill operations, construction of the facilities, haul
road, etc |
E = 1.2 tons/acre/month of activity or = 2.69Mg/hectare/month of
activity |
USEPA AP42, S.13.2.3.3 |
|
All construction sites |
Wind Erosion |
E = 0.85 Mg/hectare/yr (24 hour emission) |
USEPA AP42, S.11.9, Table 11.9.4 |
|
Barging facilities and/or any stockpiles |
Loading/Unloading at barging facilities and any stockpile |
k is particle size multiplier U is average wind speed M is material moisture content |
USEPA AP42, S13.2.4 |
Dust emission from construction vehicle movement will generally
be limited within the confined worksites and the emission factor given in AP-42
S.13.2.3.3 has taken this factor into account.
Watering facilities will be provided at every designated vehicular exit
point. Since all vehicles will be washed
at exit points and vehicle loaded with the dusty materials will be covered
entirely by clean impervious sheeting before leaving the construction site,
dust nuisance from construction vehicle movement outside the worksites is
unlikely to be significant.
Dust Emission
associated with the Concurrent Projects / Dust Sources
For the concurrent
projects with overlapping construction works including SCL (TAW-HUH), T2 and
KTD, and the concurrent dust sources from the potential new CBP in ex-Kai Tak airport area, the associated dust emission sources and
emission strength are referenced to the approved EIA Studies for SCL (TAW-HUH)
and KTD.
Dust
impact assessment is undertaken using the EPD approved Fugitive Dust Model
(FDM). It is a well-known Gaussian Plume
model designed for computing air dispersion for fugitive dust sources. Modelling
parameters including dust emission factors, particles size distributions,
surface roughness, etc are referred to EPD’s “Guideline on choice of models and
model parameters” and USEPA AP-42. The
density of dust is assumed to be 2.5g/m3. As discussed in Section
4.3.2, the 5-year annual averaged TSP
concentrations (2007-2011) recorded at Sham Shui
Po and Kwun Tong AQMS are adopted as the background
TSP concentrations of the West Portion (i.e. 78.4 µg/m3) and East
Portion (i.e. 73.0µg/m3)
respectively. For the Central Portion, the average from Sham Shui Po and Kwun Tong AQMS is
adopted (i.e. 75.7µg/m3). The 5-year annual TSP concentration recorded
in Tsuen Wan (i.e. 68.2 µg/m3)
is adopted as the background concentration for the Barging Point. A surface roughness of 100 cm is assumed in
the model to represent the urbanised terrain.
During
daytime working hours (7am to 7pm), it is assumed that dust emissions would be
generated from all dust generating activities and site erosion. During
night-time non-working hours (7pm to 7am of the next day), Sunday and public
holidays, dust emission source would include site erosion only as construction
activities during these hours are ceased.
The
1-hour, 24-hour average and annual TSP concentrations are calculated based on
real meteorological data for Year 2010, including wind direction, wind speed,
temperature and stability collected from the nearest weather stations, i.e.
King’s Park (for West Portion and Central Portion), Kai Tak (for
East Portion), and Tsing Yi (for Barging Point). The mixing height data
from the King’s Park station is also adopted.
Fugitive
dust impacts are modeled for ASR heights at 1.5m, 5m and 10m above ground. Since all the dust generating sources
associated with the Project are at ground level only, these assessment levels
would therefore represent the worst-case scenario. Both the unmitigated and
mitigated scenarios for the project are presented. A
100x100m grid is used to generate pollution contours in order to investigate
the pollutant dispersion.
A
summary of modelling parameters adopted in the
construction dust assessment are given in the table below:
Table 4.7: Modelling Parameters in FDM
|
Parameters |
Input |
Remark |
|
Particle
size distribution |
1.25um = 7% 3.75um =
20% 7.5um = 20% 12.5um =
18% 22.5um =
35% |
Reference
from S13.2.4.3 of USEPA AP-42 |
|
Background
Concentration |
78.4µg/m3
(West Portion) 75.7µg/m3
(Central Portion) 73.0µg/m3
(East Portion) 68.2µg/m3 (Barging Point) |
5-year
annual averaged value recorded at Sham Shui Po,
Kwun Tong, and Tsuen Wan
AQMS |
|
Modeling
mode |
Flatted
terrain |
- |
|
Meteorological
data |
Real
meteorological data recorded in 2010 |
West
Portion & Central Portion (King’s Park meteorological data) East
Portion (Kai Tak meteorological data) Barging Point (Tsing Yi
meteorological data) |
|
Anemometer
Height |
King’s Park
: 25m Kai Tak : 13m Tsing Yi : 10m |
Elevation
of anemometer : +90mPD (King’s Park) +16mPD
(Kai Tak) +43mPD (Tsing Yi) Ground
level of anemometer : +65mPD (King’s Park) +3mPD
(Kai Tak) +33mPD (Tsing Yi) |
|
Surface
Roughness |
100cm |
- |
|
Emission
period |
General
construction activities during daytime working hours (7 am to 7 pm) Wind
erosion during both day-time (7am to 7pm) and night-time (7pm to 7am of the
next day) |
- |
|
Assessment
height |
1.5m, 5m
and 10m |
- |
It is
understood that construction activities (except at the Barging Point) will not
be taken place on the entire work sites at the same time, but to be undertaken
at moving multiple work fronts spread across the work sites. The active areas
on each work sites could be best estimated based on the construction method,
construction programme and number of operating
plants. Based on the engineering information presented in the Appendix 4.2, it is estimated that the hourly percentage of
active area are in the range of 1.0% to 7.4%, while the annual percentage of
active areas are in the range of 0.8% to 5.5%. As a conservative assessment, it
is assumed that the hourly and annual percentage active areas are 15% and 6%
respectively.
For
short-term 1-hour and 24-hour assessment, construction activities and plants
would neither be taken place on the entire work site/work area at the same time
nor be concentrated in certain areas of the site close to ASRs at any time
during construction period. Notwithstanding this, a conservative “Two Tiers”
assessment approach has been adopted. An initial screening test, namely “Tier 1
Screening Test” has been undertaken. The Tier 1 screening test is conservative
and has represented the worst case situation, whereby all the worksites would
be active (i.e. 100%).
The
purpose of the Tier 1 screening test is to identify
the potentially affected areas where construction dust may accumulate.
The hot spot areas identified in the Tier 1 assessment have been subsequently
assessed by a more focused Tier 2 test, for which it is assumed that the hourly active works areas (i.e. 15%) for the nearby construction sites are positioned closest to the potentially
worst affected ASRs, while the active
areas for
all other construction
sites located
relative further away from the ASRs remain at 100% as per Tier 1. Thus, the Tier 2 assessment is also very
conservative as it assumes that all works activities with the associated plants in the nearby construction sites would be
undertaken in the closest proximity to the potentially affected ASRs at the
same time, which as mentioned
above would not occur in reality.
For the
long-term annual concentration assessment, as mentioned above that all the
active construction activities would likely be moving work fronts spreading
across the whole works site. On this basis, it is assumed that the dust emissions would
be distributed across the whole area of each site to reasonably represent this
mode of construction works (i.e. a
correction factor of 0.06 is applied to the total dust emission rate for
prediction of annual concentration).
4.3.9
Assessment
Results (Unmitigated)
The maximum unmitigated Tier 1 1-hour, 24-hour and annual cumulative TSP concentrations at each representative ASR have been assessed and are presented in the tables below. Exceedances of the relevant AQOs are predicted at most of the ASRs. Hence, mitigation measures are therefore required to reduce the dust impact. Figure 4.2.1 to 4.2.12 illustrate the contours for the cumulative unmitigated 1-hour, 24-hour and annual TSP concentrations in West Portion, Central Portion, East Portion, and Barging Point.
Table 4.8: Predicted Unmitigated Tier 1 Cumulative 1-hour and
24-hour TSP Concentrations at Various Heights above Ground (Including
Background Concentration)
|
ASR ID |
Location |
1-hour TSP Concentrations at Various Height (μg/m3) |
24-hour TSP Concentrations at Various Height (μg/m3) |
||||
|
1.5m |
5m |
10m |
1.5m |
5m |
10m |
||
|
West Portion |
|
|
|
|
|
|
|
|
W-A1 |
Yau Ma Tei
Catholic Primary School (Hoi Wang Road) |
2289 |
1972 |
1127 |
440 |
406 |
294 |
|
W-A2 |
Charming Garden Block 12 |
2512 |
2076 |
1083 |
417 |
395 |
308 |
|
W-A3 |
Yau Ma Tei
Catholic Primary School (Tung Kun Street) |
2620 |
2175 |
1405 |
474 |
446 |
364 |
|
W-A4 |
Prosperous Garden Block 1 |
3410 |
2654 |
1506 |
748 |
608 |
437 |
|
W-A5 |
The Coronation |
4833 |
2094 |
1087 |
903 |
502 |
321 |
|
W-A6 |
Man Cheong Building |
1818 |
1604 |
972 |
407 |
345 |
246 |
|
W-A7 |
Kum Lam Building |
4791 |
3146 |
1768 |
692 |
448 |
320 |
|
W-A8 |
Dickson Building |
5081 |
3534 |
1816 |
886 |
418 |
296 |
|
W-A9 |
Yau Ma Tei
Jockey Club Polyclinic |
2148 |
2023 |
1464 |
481 |
467 |
383 |
|
W-A10 |
Alhambra Building |
5102 |
3420 |
1723 |
843 |
625 |
402 |
|
W-A11 |
Hong Kong Community College (HKCC) of PolyU |
4317 |
2405 |
1231 |
841 |
621 |
364 |
|
W-A12 |
Civil Aid Service Headquarter |
2785 |
2228 |
1165 |
913 |
706 |
382 |
|
W-A13 |
Park Avenue Tower 10 |
1071 |
1061 |
857 |
225 |
228 |
205 |
|
W-A14 |
Charming Garden Block 1 |
1300 |
1284 |
1010 |
304 |
301 |
254 |
|
W-A15 |
HKMA David Li Kwok Po College |
1646 |
1551 |
1083 |
339 |
328 |
264 |
|
W-P1 |
Reprovisioned Yau Ma Tei Police Station
(Planned) |
Note [1] |
2576 |
1250 |
Note [1] |
757 |
450 |
|
W-P5 |
Hong Kong Red Cross Headquarters (Planned) |
1465 |
1356 |
1017 |
317 |
308 |
252 |
|
W-P6 |
Refuse Collection Point and street
Sleepers’ Shelters (Planned) |
3308 |
2524 |
1361 |
560 |
502 |
366 |
|
Central Portion |
|
|
|
|
|
|
|
|
M-A1 |
Kar Man House, Oi
Man Estate |
1584 |
1033 |
467 |
327 |
251 |
150 |
|
M-A2 |
Carmel on the Hill |
702 |
579 |
328 |
190 |
176 |
139 |
|
M-A3 |
SKH Tsoi Kung Po Secondary School |
2441 |
1179 |
568 |
413 |
277 |
145 |
|
M-A4 |
Man Fuk House Block A |
925 |
726 |
360 |
280 |
244 |
163 |
|
M-A5 |
Cascades Block A |
1053 |
874 |
457 |
178 |
167 |
133 |
|
M-A6 |
Ko Fai House, Kwun
Fai Court |
1888 |
993 |
371 |
320 |
223 |
146 |
|
M-A7 |
The Open University of Hong Kong |
763 |
686 |
444 |
147 |
142 |
122 |
|
M-A8 |
Kwun Hei Court |
708 |
614 |
362 |
147 |
137 |
113 |
|
M-A9 |
Housing Authority Headquarters Block 1 |
2247 |
1339 |
619 |
351 |
251 |
144 |
|
M-A10 |
Ho Man Tin Government Offices |
1210 |
795 |
404 |
342 |
276 |
164 |
|
M-A11 |
Choi Man House, Ho Man Tin Estate |
540 |
512 |
373 |
132 |
132 |
121 |
|
M-A12 |
King Man House, Ho Man Tin Estate |
364 |
361 |
300 |
96 |
96 |
93 |
|
M-A13 |
Ho Man Tin Swimming Pool |
3421 |
1360 |
566 |
639 |
355 |
171 |
|
M-A14 |
Yee Man house |
618 |
565 |
375 |
113 |
112 |
106 |
|
M-A15 |
Ho Min Tin Estate Service Reservoir Playground |
1668 |
1014 |
505 |
224 |
194 |
152 |
|
M-A16 |
Ko Shan Road Park |
334 |
326 |
261 |
102 |
102 |
97 |
|
M-A17 |
Kiu Wai
Mansion |
386 |
374 |
298 |
94 |
94 |
91 |
|
M-A18 |
Sun Man House |
440 |
413 |
304 |
108 |
106 |
98 |
|
M-A19 |
Ellery Terrance |
447 |
432 |
331 |
109 |
108 |
101 |
|
M-A20 |
Dragon View (Block 1) |
476 |
457 |
345 |
137 |
134 |
118 |
|
M-P2 |
Planned Residential Area B (Planned) |
3433 |
1224 |
486 |
642 |
315 |
173 |
|
East Portion |
|
|
|
|
|
|
|
|
E-A1 |
Hong Kong International Trade and Exhibition Centre |
Note [2] |
4311 |
2641 |
Note [2] |
601 |
387 |
|
E-A2 |
EMSD Headquarters |
Note [2] |
3820 |
2274 |
Note [2] |
543 |
433 |
|
E-A4 |
Billion Centre |
3058 |
2625 |
1730 |
616 |
581 |
444 |
|
E-A5 |
Kai Fuk Industrial Centre |
2273 |
2125 |
1575 |
507 |
501 |
411 |
|
E-A6 |
Grand Watefront |
3064 |
2011 |
1377 |
723 |
482 |
296 |
|
E-A7 |
Chong Chien Court |
4380 |
3449 |
1779 |
379 |
340 |
273 |
|
E-A8 |
Wei Chien Court |
6114 |
3832 |
2080 |
890 |
462 |
308 |
|
E-A9 |
Sino Industrial Plaza |
3274 |
3232 |
2503 |
344 |
349 |
310 |
|
E-A10 |
HSBC Main Treasury |
3367 |
3246 |
2434 |
411 |
389 |
297 |
|
E-A11 |
Holy Carpenter Primary School |
2344 |
2279 |
1789 |
354 |
329 |
281 |
|
E-A12 |
United Daily News Centre |
3382 |
3253 |
2419 |
370 |
352 |
285 |
|
E-A13 |
Merit Industrial Centre |
2847 |
2490 |
1500 |
300 |
280 |
236 |
|
E-A14 |
Wyler Gardens |
4972 |
3765 |
1927 |
497 |
426 |
317 |
|
E-P1 |
Site 1B4 – School (Planned) |
1547 |
1462 |
1232 |
195 |
192 |
178 |
|
E-P2 |
Site 1I3 – Residential (Planned) |
2494 |
2270 |
1507 |
239 |
229 |
202 |
|
E-P3 |
Site 1J1 (Planned) |
1676 |
1615 |
1240 |
209 |
211 |
194 |
|
E-P4 |
Site 1J3 (Planned) |
3512 |
2729 |
1407 |
317 |
283 |
227 |
|
Barging Point |
|
|
|
|
|
|
|