Section Title Page
3.1 Introduction________________________________________________________________ 3-1 3.2 Environmental
Legislations, Standards and Guidelines______________________________ 3-1 3.3 Baseline
Condition and Sensitive Receivers_______________________________________ 3-3 3.4 Identification
of Pollution Sources and Assessment Methodology_______________________ 3-6 3.5 Identification,
Prediction and Evaluation of Environmental Impact______________________ 3-20 3.6 Mitigation
of Adverse Environmental Impact_______________________________________ 3-36 3.7 Evaluation
of Residual Impact_________________________________________________ 3-38 3.8 Environmental
Monitoring and Audit_____________________________________________ 3-39 3.9 Conclusion_______________________________________________________________ 3-39 |
Figure 3-1.1 to
3-1.11 Location of Air
Sensitive Receivers and the Assessment Area 3-2.1 to
3-2-11 Location of Potential
Dust Emission Source 3-3.1 to 3-3.17 Location of 30% Active Areas of
Dust Sources Assumed for Tier 2 Assessment 3-4.1a to
3-4.9a Cumulative
Result - Contour of Tier 1 Hourly TSP
Concentration (mg/m3) at 1.5m Above Ground during Construction Phase
(unmitigated) 3-4.1b to 3-4.9b Cumulative Result - Contour of Tier 1 Hourly TSP Concentration
(mg/m3) at 1.5m Above Ground during Construction Phase (mitigated) 3-5.1 to 3-5.17 Cumulative Result - Contour of Tier 2 Hourly TSP
Concentration (mg/m3) at 1.5m Above Ground during Construction Phase
(mitigated) 3-6.1a to
3-6.9a Cumulative
Result - Contour of Tier 1 Daily TSP
Concentration (mg/m3) at 1.5m Above Ground during Construction Phase (unmitigated) 3-6.1b to 3-6.9b Cumulative Result - Contour of Tier 1 Daily TSP Concentration
(mg/m3) at 1.5m Above Ground during Construction Phase (mitigated) 3-7.1 to 3-7.6 Cumulative Result - Contour of Tier 2 Daily TSP Concentration
(mg/m3) at 1.5m Above Ground during Construction Phase (mitigated) 3-8.1a to
3-8.9a Cumulative
Result - Contour of Annual TSP
Concentration (mg/m3) at 1.5m Above Ground during Construction Phase (unmitigated) 3-8.1b to 3-8.9b Cumulative Result - Contour of Annual TSP Concentration (mg/m3) at 1.5m Above Ground during Construction Phase (mitigated) 3-9.1 to 3-9.11
Classifications of Road Types 3-10.1 to
3-10.9 Cumulative
Result - Contour of Hourly NO2
Concentration (mg/m3) at 1.5m Above Ground during Operational Phase (Stability Class D) 3-11.1 to
3-11.9 Cumulative
Result - Contour of Daily NO2
Concentration (mg/m3) at 1.5m Above Ground during Operational Phase (Stability Class D) 3-12.1 to
3-12.9 Cumulative
Result - Contour of Daily RSP Concentration (mg/m3) at 1.5m Above Ground during Operational Phase (Stability Class D) 3-13.1 to
3-13.9 Cumulative
Result - Contour of Hourly NO2
Concentration (mg/m3) at 1.5m Above Ground during Operational Phase (Stability Class F) 3-14.1 to
3-14.9 Cumulative
Result - Contour of Daily NO2
Concentration (mg/m3) at 1.5m Above Ground during Operational Phase (Stability Class F) 3-15.1 to
3-15.9 Cumulative Result - Contour of Daily RSP Concentration (mg/m3) at 1.5m Above Ground during Operational Phase (Stability Class F) 3-16.1 to 3-16.9
Cumulative Result - Contour of Annual NO2
Concentration (mg/m3) at 1.5m Above Ground during Operational Phase 3-17.1 to 3-17.9 Cumulative Result - Contour of Annual RSP Concentration (mg/m3) at 1.5m Above Ground during Operational Phase |
Appendix 3.1a
Details of Dust Emission Sources
for 1-hour and Daily TSP Assessment (Tier 1) 3.1b Details of Dust Emission Sources
for Annual TSP Assessment 3.1c Details of Dust Emission Sources
for 1-hour and Daily TSP Assessment (Tier 2) 3.1d Estimation of Percentage
Active Area for Different Stages of Construction Activities 3.1e Estimation of Total Percentage
Active Area for Hourly, Daily and Annual TSP Assessment 3.1f Estimation of Dust Suppression
Efficiency 3.2 Exhaust Technology Fractions 3.3 Vehicle Population in Years
2018, 2023, 2028 and 2033. 3.4 Diurnal Traffic Pattern, VMT
and Trips in 2018, 2023, 2028 and 2033 3.4-1 Traffic Forecast for 2018,
2023, 2028 and 2033 3.4-2 Road Type and Distance 3.4-3 Trips and VMT for Petrol
Vehicles in 3.4-4 VMT and Trips for 2018, 2023,
2028 and 2033 in the Study Area 3.5 Relative Humidity and
Temperature 3.6 Peak Hour Speed,
Volume/Capacity Ratio and Speed Fractions in 2018, 2023, 2028 and 2033. 3.7a Comparison of Emissions with
Peak and Non-peak Speeds in 2018, 2023, 2028 and 2033 3.7b Calculation of Worst Case
Emission Rates for Different Road Types 3.8 Calculations of the
Composite Emission Factors 3.9a Calculations of the Emission Rates for
Ventilation Shafts and Building 3.9b Selection of Worst Case Hourly Emission for
Calculation of Emission Rates for Ventilation Shafts and Building 3.10a Calculations of Idling Emissions
3.10b Determination of Idling Emission
Factors as Extracted from the Feasibility Study 3.10c Estimation of NOx Composite
Idling Emission Factors |
|
The section presents the assessment of potential
air quality impacts associated with the construction and operational phase of
the proposed BCP and associated facilities in accordance with section
3.2 Environmental Legislations, Standards and Guidelines
3.2.1 Technical Memorandum on Environmental Impact Assessment Ordinance
The criteria and guidelines for evaluating air
quality impacts are laid out in Annex 4 and Annex 12 of the Technical Memorandum
on Environmental Impact Assessment (EIAO-TM),
respectively.
3.2.2 Air Pollution Control Ordinance
The
principal legislation for the management of air quality is the Air Pollution
Control Ordinance (APCO) (Cap 311). The
APCO specifies Air Quality Objectives (AQOs) which stipulate the statutory
limits of air pollutants and the maximum allowable numbers of exceedance over
specific periods. The AQOs are summarized in Table 3.1.
Table 3.1: Hong Kong Air Quality Objectives
|
Concentration
in micrograms per cubic metre (i) |
||||
Pollutant |
Averaging Time |
||||
|
1 hour (ii) |
8 hours (iii) |
24 hours (iii) |
3 Months (iv) |
1 year (iv) |
|
800 |
N.A. |
350 |
N.A. |
80 |
Total Suspended Particulates |
500(vii) |
N.A. |
260 |
N.A. |
80 |
Respirable (v) Suspended Particulates |
N.A. |
N.A. |
180 |
N.A. |
55 |
Nitrogen Dioxide |
300 |
N.A. |
150 |
N.A. |
80 |
Carbon Monoxide |
30000 |
10000 |
N.A. |
N.A. |
N.A. |
Photochemical Oxidants (as Ozone) (vi) |
240 |
N.A. |
N.A. |
N.A. |
N.A. |
Lead |
N.A. |
N.A. |
N.A. |
1.5 |
N.A. |
Legend:
i. Measured at 298K (25oC) and 101.325 kPa (one atmosphere).
ii. Not to be exceeded more than three times per year;
iii. Not to be exceeded more than once per year;
iv. Arithmetic means
v. Respirable suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 10 micrometres and smaller.
vi. Photochemical oxidants are determined by measurement of ozone only.
vii This is not an AQO but a criterion for construction dust impact assessment as stated in Annex 4 of the EIAO-TM.
3.2.3 Air Pollution Control (Construction Dust) Regulation
The Air Pollution Control (Construction Dust) Regulation enacted under the APCO defines notifiable and regulatory works activities that are subject to construction dust control, as listed below:
Notifiable Works:
(a) Site formation
(b) Reclamation
(c) Demolition of a building
(d) Work carried out in any part of a tunnel that is within 100 m of any exit to the open air
(e) Construction of the foundation of a building
(f) Construction of the superstructure of a building or
(g) Road construction work
Regulatory Works:
(h) Renovation carried out on the outer surface of the external wall or the upper surface of the roof of a building
(i) Road opening or resurfacing work
(j) Slope stabilisation work or
(k) Any work involving any of the following activities:
¡ Stockpiling of dusty materials
¡ Loading, unloading or transfer of dusty materials
¡ Transfer of dusty materials using a belt conveyor system
¡ Use of vehicles
¡ Pneumatic or power-driven drilling, cutting and polishing
¡ Debris handling
¡ Excavation or earth moving
¡ Concrete production
¡ Site clearance or
¡
Blasting
Notifiable
works require that advance notice of activities shall be given to
3.2.4 Practice Note on Control of Air Pollution in Vehicle Tunnels
The EPD’s
“Practice Note on Control of Air Pollution in Vehicle Tunnels” controls the air
pollution inside vehicle tunnels. The controlled pollutants and their allowed
concentrations are summarized
in Table 3.2 below.
Table 3.2: Tunnel Air Quality Guidelines
Pollutant |
Averaging Time |
Maximum Concentration (µg/m³)* |
|
5 minutes |
1,000 |
Nitrogen Dioxide |
5 minutes |
1,800 |
Carbon Monoxide |
5 minutes |
115,000 |
* Concentrations at reference conditions of 298K and 101.325kPa.
3.3 Baseline Condition and Sensitive Receivers
The latest
available 5-year average
ambient concentrations of pollutants measured at EPD’s Tai Po Air Quality
Monitoring Station have been taken as the background concentrations for the air
quality assessments, as this Monitoring Station is closest to the Project site
when compared to all other Monitoring Stations. The background level of total suspended particulates (TSP) has been estimated as the 5-year average of the available data from 1
January 2005 to 31 December 2009, and the estimated background TSP level is 66.6µg/m³.. The background levels of nitrogen dioxide (NO2), and respirable
suspended particulates (RSP) have been estimated as the 5-year averages of the data available from 1
July 2005 to 30 June 2010, and the estimated NO2 and RSP background
levels are respectively 50.4µg/m³ and 49.9µg/m³.
It is noted
that the emissions within the Pearl River Delta will be reduced in future years
according to the Mid-term Review Study on Pearl River Delta Regional Air
Quality Management Plan. This will lead to a reduction of the background
concentration of the assessment area, and therefore the
background pollutant levels adopted for this assessment would be on the
conservative side.
In accordance with clause
According to the
planned programme (see Appendix 2.2), the Chuk Yuen
Village Resite will be completed in early 2012 for population intake by early
2013, and construction of this Project will commence in around mid 2013. Therefore the existing
According to the
final report on the "Land Use Planning for the Closed Area” study
(see Section 2.10.6), the
Recommended Development Plan has proposed land use changes in the study
area. In order to assess the potential
impact on the planned village areas of the Closed Area that are within the
assessment area of this BCP Project, three ASRs, namely, KTW6, TF1 and FWW1,
have been identified to represent such planned village development in this
assessment.
Since all
the ASRs except BDG1 are low-rise village houses or playground, three
assessment levels have been adopted, which are 1.5m,
Table 3.3: Representative ASRs Identified for the Assessment
No. |
ASR ID |
Land Use |
Description |
Separation distance from Project Site Boundary (m) |
Construction Phase |
Operational Phase |
1 |
TYHP |
Recreational |
Tsung Yuen Ha Playground |
73.4 |
Ö |
Ö |
2 |
TYH |
Residential |
Tsung Yuen Ha Village House |
49.1 |
Ö |
Ö |
3 |
V1 |
Residential |
Village House near |
9.2 |
Ö |
Ö |
4 |
V2 |
Residential |
Village House near |
19.5 |
Ö |
Ö |
5 |
CY3 |
Residential |
|
56.4 |
Ö |
Ö |
6 |
KL1 |
Residential |
|
46.1 |
Ö |
Ö |
7 |
TKL1 |
Residential |
Ta Kwu Ling Village House 1 |
16.3 |
Ö |
Ö |
8 |
TKL2 |
Residential |
Ta Kwu Ling Village House2 |
8.3 |
Ö |
Ö |
9 |
KTW6* |
Residential |
Kan Tau Wai Village House 6 |
95.8 |
Ö |
Ö |
10 |
TF1* |
Residential |
|
395.2 |
Ö |
Ö |
11 |
FWW1* |
Residential |
Fung Wong Wu Village House 1 |
313.6 |
Ö |
Ö |
12 |
KTW1 |
Residential |
Kan Tau Wai Village House 1 |
62.7 |
Ö |
Ö |
13 |
KTW2 |
Residential |
Kan Tau Wai Village House 2 |
39.7 |
Ö |
Ö |
14 |
KTW4 |
Residential |
Kan Tau Wai Village House 4 |
13.7 |
Ö |
Ö |
15 |
KTW5 |
Residential |
Kan Tau Wai Village House 5 |
34.3 |
Ö |
Ö |
16 |
KTW7 |
Residential |
Planned Village House at |
32.1 |
x |
Ö |
17 |
NYH1 |
Residential |
Nga Yiu Ha Village House 1 |
41.4 |
Ö |
Ö |
18 |
PY1 |
Residential |
|
1.2 |
Ö |
Ö |
19 |
PY3 |
Residential |
|
50.4 |
Ö |
Ö |
20 |
PY6 |
Residential |
|
54.3 |
Ö |
Ö |
21 |
WKS1 |
Residential |
Wo |
25.1 |
Ö |
Ö |
22 |
WKS2 |
Residential |
Wo |
88.6 |
Ö |
Ö |
23 |
WKS3 |
Residential |
Wo |
235.6 |
Ö |
Ö |
24 |
WKS4 |
Residential |
Wo |
33.9 |
Ö |
Ö |
25 |
WKS5 |
Residential |
Wo |
15.6 |
Ö |
Ö |
26 |
WKS7 |
Residential |
Wo |
31.7 |
Ö |
Ö |
27 |
WKS8 |
Residential |
Planned Village House at Wo Keng Shan |
64.3 |
x |
Ö |
28 |
ST1 |
Residential |
|
55.8 |
Ö |
Ö |
29 |
ST2 |
Residential |
|
14.4 |
Ö |
Ö |
30 |
ST3 |
Residential |
|
56.1 |
Ö |
Ö |
31 |
ST4 |
Residential |
|
6.2 |
Ö |
Ö |
32 |
TTW1 |
Residential |
Tai Tong Wu Village House 1 |
13.8 |
Ö |
Ö |
33 |
TTW2 |
Residential |
Tai Tong Wu Village House 2 |
104.3 |
Ö |
Ö |
34 |
TTW3 |
Residential |
Tai Tong Wu Village House 3 |
5.5 |
Ö |
Ö |
35 |
LT1 |
Residential |
Loi Tung Village House 1 |
62.2 |
Ö |
Ö |
36 |
LT2 |
Residential |
Loi Tung Village House 2 |
72.6 |
Ö |
Ö |
37 |
PKT1 |
Residential |
Po |
225.8 |
Ö |
Ö |
38 |
PKT2 |
Residential |
Po |
12.3 |
Ö |
Ö |
39 |
PKT3 |
Residential |
Po |
23.8 |
Ö |
Ö |
40 |
TH1 |
Residential |
|
0.5 |
Ö |
Ö |
41 |
TH4 |
Residential |
|
15.2 |
Ö |
Ö |
42 |
KT1 |
Residential |
|
56.0 |
Ö |
Ö |
43 |
KT2 |
Residential |
|
37.5 |
Ö |
Ö |
44 |
KT3 |
Residential |
|
18.3 |
Ö |
Ö |
45 |
NWP1 |
Residential |
|
3.0 |
Ö |
Ö |
46 |
NWP2 |
Residential |
|
13.9 |
Ö |
Ö |
47 |
NWP3 |
Residential |
|
13.4 |
Ö |
Ö |
48 |
KLH1 |
Residential |
Kau Lung Hang Village House 1 |
60.4 |
Ö |
Ö |
49 |
BDG1 |
-- |
Air Intake Point of |
Within site boundary |
x |
Ö |
Legend: Ö - subject to impact; x - not subject to
impact
*Note: These three ASRs have been identified to
represent the planned village developments as per the Recommended Development
Plan of the final report on the "Land Use
Planning for the Closed Area” study.
3.4 Identification of Pollution Sources and Assessment Methodology
3.4.1.1 Potential Sources of Pollution
The major construction activities of the Project that
would contribute to construction dust impacts include:
·
Excavation/earth
works within the work site areas except the tunnel sections;
·
Road works
involving the realignment and widening of Lin Ma Hang Road in BCP section,
construction of at-grade and viaduct roads in Lin Ma Hang to Frontier Closed
Area section, Ping Yeung to Wo Keng Shan section, Sha Tau Kok Road section and
Fanling section of the Project;
·
Slope works near
the BCP, in Ping Yeung to Wo Keng Shan, near the Tunnel Portal of Sha Tau Kok,
Lau Shui Heung and Tunnel Portal of Fanling section;
·
Site formation
in the BCP; and
·
Construction of
the superstructures such as buildings in the BCP, ventilation shafts near both
ends of the two tunnels, and mid-ventilation building for one of the tunnels.
No
significant fugitive dust emissions would be expected from tunnelling
activities.
3.4.1.2 Air Dispersion Model
The
air pollutant concentrations were assessed in accordance with the Guidelines
for Choice of Models and Model Parameters in Air Quality Assessment published
by
3.4.1.3 Emission Factors
Prediction of dust emissions is based on emissions factors from the USEPA Compilation of Air Pollution Emission Factors
(AP-42), 5th Edition. The emission factor for a typical heavy
construction activity is 2.69 megagrams (Mg)/hectare/month of activities
according to Section
Table 3.4: Assumptions for Calculation of Dust Emission Factors
Activities |
Emission Factors |
Reference |
Heavy construction activities including all above ground and open construction works, excavation and slope cutting works |
2.69 Mg/hectare/month |
Section
13.2.3.3 AP-42, 5th
Edition |
Wind erosion from heavy construction or stockpile areas |
0.85 Mg/hectare/year |
Table 11.9-4 AP-42, 5th
Edition |
Material handling at stockpiles areas |
Emission
Facror = K x 0.0016
x (U/2.2)1.3/(M/2)1.4 kg/Mg where k is
particle size multiplier * U is
average wind spped M is material moisture content |
Section 13.2.4 AP-42, 5th Edition |
* The particle size distribution was made reference to Section 13.2.4 of the USEPA Compilation of Air Pollution Emission Factors (AP-42), 5th Edition .
3.4.1.4 Meteorological Data
The hourly meteorological data for a full year measured
at the Ta Kwu Ling station of Hong Kong Observatory (HKO) in 2008 has been adopted as input to the FDM.
3.4.1.5 Cumulative Impacts
There are a number of identified major concurrent
projects in the vicinity of this Project, the details of which are given in Section 2.10 and Appendix
2.2. Of those concurrent projects, the Regulation
of Shenzhen River (RSR) Stage 4 project and the North East New Territories
(NENT) Landfill Extension project have been considered in the cumulative
construction dust impact assessment. For
the other identified concurrent projects, no sufficient information was
available for assessing the cumulative dust impacts at the time of preparing
this EIA report.
The locations of assumed dust sources of the two
concurrent projects, namely, the RSR Stage 4 project and the NENT Landfill
Extension project, are as shown in Figures
3-2.1, 3-2.2 and 3-2.3. For
the NENT Landfill Extension project, only the portion of the project site
(i.e., the location where capping of the existing landfill will be carried out)
that is within the 500m assessment area of this Project has been taken into
account in the cumulative construction dust impact assessment (see Figure 3-2.3),
and the associated dust emission data as extracted from the approved EIA report
(No.: EIA-133/2007) has been used in the cumulative impact
assessment. For the RSR Stage 4 project,
the latest dust emission data as provided by the Consultants responsible for conducting
EIA of the project have been used in the cumulative impact assessment. The emission inventory and calculation of
emission factors for construction activities of the two concurrent project are detailed in Appendices 3.1a
to 3.1c.
For the North East New Territories New Development
Area, the Widening of Tolo Highway /
3.4.1.6 Modelling Approach
For hourly and daily TSP, a tiered modelling approach has been adopted. A hypothetical Tier 1 screening that assumes 100% active area of construction site with or without dust mitigation measures in place was carried out in order to identify the ASRs which could be subject to significant impacts. However, it should be emphasized that this Tier 1 scenario (i.e. assuming 100% active area for the proposed Project and the two concurrent projects) is a hypothetical one for screening purposes. For the purpose of the Tier 1 screening, the dust mitigation measures, including frequent water spraying and covering of stockpile areas, as detailed in Section 3.6.1.1 have been taken into account when estimating the dust emission rates from the construction activities. Details of the Tier 1 dust sources including their coordinates, dimensions and estimated emission rates are detailed in Appendix 3.1a.
In the course of the Tier 1 screening, the ASRs identified with hourly or daily TSP non-compliance were selected for the subsequent Tier 2 assessment. For these identified ASRs, it is assumed in the Tier 2 assessment that the 30% active areas of this proposed Project and the corresponding active areas of the relevant concurrent project would be located closest to the particular ASRs. The hourly or daily TSP levels at each of these ASRs were then predicted with the dust mitigation measures in place. Under normal circumstances, construction activities for the proposed Project and the concurrent project would likely spread over the whole work sites. As such, assuming the 30% active area of this Project and the corresponding active areas of the relevant concurrent project to be located closest to a particular ASR at any one time during the Tier 2 assessment is a very conservative approach. Details of the Tier 2 dust sources including their coordinates, dimensions and estimated emission rates are given in Appendix 3.1c.
For the assessment of annual TSP concentrations, the active work area over the entire year would be less than that for a typical working hour or a typical working day. On this basis, it is considered that 10% active work area would be a more representative assumption for predicting the annual TSP levels for the proposed Project. Similar to the Tier 1 assessment of hourly and daily TSP, the annual TSP levels were predicted with or without the dust mitigation measures in place. Details of the dust sources for annual TSP assessment including their coordinates, dimensions and estimated emission rates are given in Appendix 3.1b.
The above-mentioned assumed percentages
active work areas for heavy construction activities for hourly, daily and
annual TSP assessment are conservative values when compared to the percentages
active work that are estimated based on Project-specific information, as
detailed in Appendices 3.1d and 3.1e.
For stockpiles, 20% of the stockpiling area is adopted to represent the mitigated dust sources during the assessment as it is recommended in Section 3.6.1.1 that 80% of the stockpiling area is covered by impervious sheets and all dusty materials should be sprayed with water immediately prior to any loading or transfer operation so as to keep the dusty material wet during material handling at the stockpile areas.
For modelling purpose, the entire Project site has been split into 4 areas, namely, (1) BCP, Lin Ma Hang to Frontier Closed Area and Ping Yeung to Wo Keng Shan, up to the north portal of the Cheung Shan tunnel (see Figures 3-1.1 to 3-1.4); (2) Sha Tau Kok section, starting from the south portal of the Cheung Shan tunnel (see Figures 3-1.4 to 3-1.6); (3) Po Kak Tsai section (see Figure 3-1.8); and (4) Fanling section (see Figures 3-1.9 to 3-1.11).
With addition of the TSP background level of 66.6µg/m³, the hourly, daily and annual TSP concentrations at the identified ASRs have been predicted and compared with the TSP criteria of 500μg/m3, 260 μg/m3 and 80 μg/m3 respectively.
3.4.2 Operational Phase
3.4.2.1 Vehicular Emissions
During the operational phase, there would be potential air quality impacts upon the ASRs due to the vehicular emissions from open roads, ventilation shafts, mid-ventilation building as well as kiosks, loading and unloading areas and public transport interchange (PTI) of the BCP. The key air pollutants of concern from vehicle emissions are NO2 and RSP and their levels have been modelled against the relevant criteria (hourly and daily AQOs for NO2; daily AQO for RSP) in 2018, 2023, 2028 and 2033 (i.e. covering 15 years from the commencement of operation of the Project). Details of the emissions, assumptions adopted and assessment approach are presented in Sections 3.4.3 to 3.4.9.
3.4.2.2 Odour from the Proposed Sewage Treatment Works
As detailed in Section 6.6, it is recommended to construct and operate an on-site sewage treatment works at the proposed BCP to treat the sewage to be generated from operation of the BCP and the Chuk Yuen Village Resite. The location of the sewage treatment works is as shown in Figure 3-1.1. During the operational phase, the potential odour impact on nearby ASRs that could be caused by the sewage treatment works has been assessed in Section 3.5.2.2.
3.4.3 Emissions from Open Roads
For the open roads
connecting the BCP, the EMFAC-HK model (v1.2) has been used to determine the
fleet average emission factors and the assumptions and input parameters are presented
in the following sections. The
traffic data used for the assessment, including the hourly traffic flows of 16
vehicle classes at various road links and the speed fractions of various
vehicle classes in all the 4 model years of 2018, 2023, 2028 and 2033 are provided
by the Traffic Consultant, which are presented in the following sections. The traffic forecast data has been submitted
to the Transport Department (TD) for review and TD has made
no adverse comment on the traffic data. The 24-hour traffic patterns together with the
graphical plots are given in Appendix 3.4-1.
3.4.3.1 Vehicle Emission Standards
Cross-boundary vehicles
must be registered in Hong Kong and all motor vehicles seeking first registration
in
¡ Diesel vehicles with gross vehicle weight (GVW) of 3.5 tonnes or less: Euro IV by Jan 2007; Euro V not later than 2012 and
¡ Diesel vehicles with GVW of over 3.5 tonnes: Euro IV by Oct 2006, Euro V not later than 2012.
As the EMFAC-HK (v1.2) is incorporated with the Euro V emission standards (or technology group indexes) for only some of the vehicle classes including diesel vehicles with GVW over 3.5 tonnes, the diesel vehicles with GVW of 3.5 tonnes or less could only be modelled as complying with Euro IV emission standards from 2013 onwards (though those vehicles should have fulfilled Euro V standards since then). Nevertheless, the emission results so obtained are on the conservative side.
Emission factors for the following four road types have
been calculated:
·
Road Type 1 - Expressway (Design speed limit:
100kph);
·
Road Type
·
Road Type
·
Road Type 4 - Rural
& Local Roads (Design speed limit: 50kph).
The
four road types are characterized by continuous and interrupted flow with
different design speed limits. It is assumed that there will be continuous
traffic flow in Expressway and Trunk Roads (Road Types 1, 2 & 3) whereas
there will be interrupted flow in Rural & Local Roads (Road Type 4). The
road type classification of individual road links in the study area is as shown
in Figures 3-9.1 to 3-9.11.
Vehicles operating on open roads have been
categorized into 16 vehicle classes according to the Guideline on Modelling Vehicle Emission – Appendix 1,
which is presented in Table 3.5 below:
Table 3.5: Vehicle Classification in the EMFAC-HK Model
Vehicle Class |
Notation in EMFAC-HK Model |
Description |
Gross Vehicle Weight |
MC 1 |
PC+LGV(1) |
Petrol Private Cars & Light Goods Vehicles |
ALL |
MC 3 |
PC+LGV(3) |
Diesel Private Cars & Light Goods Vehicles <=2.5 tonne |
<=2.5ton |
MC 4 |
LGV(4) |
Light Goods Vehicles >2.5-3.5 tonne |
>2.5-3.5ton |
MC 5 |
PLB |
Public Light Buses |
ALL |
MC 6 |
LGV(6) |
Light Goods Vehicles >3.5 tonne |
>3.5ton – 5.5ton |
MC 7 |
HGV(7) |
Medium Goods Vehicles with GVW <15 tonne |
>5.5ton – 15ton |
MC 8 |
HGV(8) |
Medium & Heavy Goods Vehicles with GVW >=15 tonne |
>15ton |
MC 10 |
FBDD |
Double Deck Franchised Buses |
ALL |
MC 11 |
MC |
Motor Cycles |
ALL |
TAXI 3 |
Taxi |
Taxi |
ALL |
TAXI 4 |
PrLB(4) |
Private Light Buses <=3.5 tonne |
<=3.5ton |
TAXI 5 |
PrLB(5) |
Private Light Buses >3.5 tonne |
>3.5ton |
TAXI 6 |
NFB(6) |
Non-franchised Buses <=6.4 tonne |
<=6.4ton |
TAXI 7 |
NFB(7) |
Non-franchised Buses 6.4-15 tonne |
>6.4ton – 15ton |
TAXI 8 |
NFB(8) |
Non-franchised Buses >15 tonne |
>15ton |
TAXI 10 |
FBSD |
Single Deck Franchised Buses |
ALL |
3.4.3.4 Exhaust/evaporation technology fraction
Vehicle
classes are grouped with different exhaust technology indexes and technology
fractions. Each technology group represent a distinct emission control
technologies. Exhaust technology fractions has made reference to “Vehicle
Licensed Number by Age and Technology Group Fractions” updated to year 2008 as
provided by EPD. According to the updated Guideline on Modelling Vehicle Emissions Appendix II – Implementation Schedule of Vehicle
Emission Standards in
3.4.3.5 Vehicle Population
According
to the Guideline on Modelling Vehicle Emissions, the vehicle population has made reference to the latest vehicle age distribution (in
2008) as provided by EPD. There are available data on the overall growths of
broad vehicle types (e.g. overall growth rates for the total population of
private vehicles in different years), however more specific growth rates and
retention rates for vehicles of different age groups could not be identified.
Due to the data limitation, the vehicle age distributions in 2018, 2023, 2028 and
2033 could not be projected, and therefore it is assumed that the vehicle age
distributions in all these 4 model years would be the same as that in 2008, Details
of the input data together with the graphical plots of the vehicle population
in 2008 are provided in Appendix 3.3. While the vehicle age distributions in different
model years are assumed to be unchanged, the traffic forecasts of the study
area in various years (see Appendix 3.4-1) have been taken into
account for estimating the Vehicle Mile-Travelled.
Taxi
With
the implementation of Vehicle Emission Standards, new registration of diesel
taxi was banned in
Private
Light Bus <=3.5 tonne and >3.5 tonne
The
former Environment, Transport and Works Bureau (ETWB) implemented an incentive
scheme to encourage the early replacement of diesel light buses with LPG or
electric ones in 2002. As a conservative
approach, the incentive scheme for light buses has not been considered in this
assessment.
Default values and compositions have been adopted with
reference to in the EMFAC-HK Guideline.
3.4.3.7 Diurnal Variation of Daily Vehicle Mile-Travelled (VMT)
For each vehicle class, the VMT of individual hours is
calculated by multiplying the hourly number of vehicles with the length of the
corresponding road link (in miles). Diurnal (24-hour) traffic pattern has been
provided by Traffic Consultant. The
lengths of individual road links of the connecting road are given in Appendix
3.4-2. The 24-hour VMT values for all vehicle
classes in each of the model years 2018, 2023, 2028 and 2033 together with the
graphical plots are provided in Appendix 3.4-4.
The daily trips were used to estimate the cold start
emissions of the petrol vehicles only. Therefore, trips for vehicles other than petrol type vehicles would be assumed to
be zero. Different road type has different number of trips as follows.
3.4.3.9 Expressway and Trunk Road (Road Types 1, 2 & 3)
Zero trips are assumed in Expressway and Trunk Roads
since there will be no cold start under normal circumstance.
3.4.3.10 Rural and Local Road (Road Type 4)
Trip within study area = (Trip
within HK/VMT within HK) x VMT within study area
Trip within
HK is the default data of EMFAC-HK model.
VMT within HK is the VMT of rural and local roads in
While the number of trips is dependent on
vehicle population, no project-specific vehicle population data can be
identified for the study area according to the Traffic Consultants. However, project-specific VMT has been
estimated based on the traffic forecast in the study area. Moreover, it can be argued that VMT is
related to vehicle population in such a way that a higher vehicle population
would generally result in a higher VMT.
As a result, it has been proposed to estimate the number of trips in the
study area on the basis of the project-specific VMT and the assumption that the
number of trips per VMT in the study area would be similar to the number of
trips per VMT in
3.4.3.11 Hourly Temperature and Relative Humidity Profile
Annual and monthly hourly
average ambient temperature and relative humidity (Appendix 3.5) obtained from HKO’s Ta Kwu Ling meteorological
station in year 2008 have been adopted (with at least 90% valid data) will be adopted. The 24-hour variations of the annual averages
of temperature and relative humidity are presented graphically in Appendix 3.5.
The peak-hour speeds, which are provided by the
Traffic Consultant, are calculated based on the peak traffic flow in each model
year and the volume/capacity ratio of different road types. To calculate the
speed fractions for each vehicle class, the speeds of each road were calculated
and weighed by VMT. For each vehicle class, the VMT of each road link was
grouped into sub-groups with speed interval of 5mph (0 - 5 mph, 5 - 10 mph, 10
- 15 mph, etc.). The speed fraction of
each sub-group was derived by the summation of the total VMT of road link
within this sub-group divided by the total VMT of all road links. The estimated
speed fractions, together with the volume/capacity ratio and the calculation of
peak hour traffic, provided by the Traffic Consultant are given in Appendix 3.6.
3.4.3.13 Worst Case Scenario amongst Peak and Non-peak Hour Speeds of Different Model Years
To determine the worst case emissions within 15 years
after commencement of the Project, emission rates for both peak and non-peak hour
speeds are modelled for years 2018, 2023, 2028 and 2033. By using the VMT for respective years (Appendix 3.4-4), the total emissions of different vehicle classes in
each of the 4 model years have been estimated for both peak and non-peak hour
speeds (Appendix 3.7a). The combination of speed and model year that
would give rise to the highest total daily emissions for each road type is
selected in the assessment as the worst case scenario. Based on the results of comparison (Appendix 3.7a), the worst case nitrogen oxides (NOx) and RSP
emission rates for the following combinations of speeds and model years are
adopted in the assessment:
Road Type |
For NOx Emission Rates |
For RSP Emission Rates |
Local Road & Rural Road |
Peak-hour speed in 2018 |
Peak-hour speed in 2018 |
Trunk Road (50kph) |
Peak-hour speed in 2018 |
Peak-hour speed in 2018 |
Trunk Road (80kph) |
Peak-hour speed in 2018 |
Peak-hour speed in 2018 |
Expressway (100kph) |
Non-peak hour speed in 2018 |
Non-peak hour speed in 2018 |
3.4.3.14 Predicted Emission Factors by EMFAC-HK model
Upon determination of the combination of speeds and
model years that would give rise to the worst case daily emissions as discussed
above, the hour during which the hourly total emissions of all vehicle types as
predicted by the EMFAC-HK model is the largest has then been selected to
represent the worst case emission hour, and the emissions of this worst case
hour are then divided by its corresponding VMT to obtain the worst case emission
factors in grams/vehicle-km, as a conservative approach. Table
3.6 summarizes the results of such worst case emission
factors. Details of
selection of the worst case hours and calculation of the worst case emission
factors are given in Appendix 3.7b.
Table 3.6: Worst Case Emission Factors as Predicted by EMFAC-HK Model
Vehicle Class |
Notation in EMFAC-HK Model |
Worst Case Emission Factors (g/veh-km) |
|||
Expressway (100kph) (Type 1) |
Trunk Road (80kph) (Type 2) |
Trunk Road (50kph) (Type 3) |
Local Road & Rural Road (Type 4) |
||
NOx |
|||||
MC 1 |
PC+LGV(1) |
0.0812 |
0.0749 |
0.0840 |
0.1798 |
MC 3 |
PC+LGV(3) |
0.8294 |
0.5058 |
0.8231 |
0.5086 |
MC 4 |
LGV(4) |
0.2937 |
0.1771 |
0.1725 |
0.1928 |
MC 5 |
PLB |
0.0000 |
0.0859 |
0.0644 |
0.0758 |
MC 6 |
LGV(6) |
2.5908 |
1.6199 |
1.4161 |
1.5964 |
MC 7 |
HGV(7) |
2.9029 |
2.8747 |
2.7458 |
3.0281 |
MC 8 |
HGV(8) |
3.6699 |
3.6387 |
3.4858 |
3.8701 |
MC 10 |
FBDD |
2.5983 |
2.5204 |
2.5768 |
2.6153 |
MC 11 |
MC |
0.8459 |
0.5517 |
0.7414 |
1.3571 |
TAXI 3 |
Taxi |
0.1846 |
0.1570 |
0.1255 |
0.2038 |
TAXI 4 |
PV(4) |
0.0326 |
0.0268 |
0.0000 |
0.0564 |
TAXI 5 |
PV(5) |
0.3055 |
0.1084 |
0.1121 |
0.0628 |
TAXI 6 |
NFB(6) |
1.2621 |
1.1975 |
1.1864 |
1.3027 |
TAXI 7 |
NFB(7) |
2.3861 |
2.3950 |
2.4004 |
2.4091 |
TAXI 8 |
NFB(8) |
2.6986 |
2.6168 |
2.7613 |
2.6872 |
TAXI 10 |
FBSD |
1.7036 |
0.0000 |
0.0000 |
2.7778 |
RSP |
|||||
MC 1 |
PC+LGV(1) |
0.00301 |
0.00134 |
0.00200 |
0.00749 |
MC 3 |
PC+LGV(3) |
0.11848 |
0.05268 |
0.06859 |
0.22604 |
MC 4 |
LGV(4) |
0.02447 |
0.02951 |
0.08626 |
0.09638 |
MC 5 |
PLB |
0.00000 |
0.02864 |
0.06442 |
0.07582 |
MC 6 |
LGV(6) |
0.06132 |
0.07363 |
0.10893 |
0.12280 |
MC 7 |
HGV(7) |
0.12197 |
0.12306 |
0.16950 |
0.18926 |
MC 8 |
HGV(8) |
0.10750 |
0.10566 |
0.13861 |
0.17680 |
MC 10 |
FBDD |
0.02095 |
0.03819 |
0.04295 |
0.11371 |
MC 11 |
MC |
0.06266 |
0.02299 |
0.00000 |
0.05654 |
TAXI 3 |
Taxi |
0.01086 |
0.00872 |
0.01045 |
0.01274 |
TAXI 4 |
PV(4) |
0.01086 |
0.00000 |
0.00000 |
0.00000 |
TAXI 5 |
PV(5) |
0.10183 |
0.05421 |
0.07471 |
0.04184 |
TAXI 6 |
NFB(6) |
0.04352 |
0.02495 |
0.03296 |
0.02714 |
TAXI 7 |
NFB(7) |
0.04772 |
0.04990 |
0.06668 |
0.05019 |
TAXI 8 |
NFB(8) |
0.02444 |
0.02181 |
0.03835 |
0.04479 |
TAXI 10 |
FBSD |
0.00000 |
0.00000 |
0.00000 |
0.00000 |
Note: The emission factors for some combinations of vehicle types and
road types appear as zero because their computed values are too small to be displayed
by the EMFAC model due to the corresponding low VMT values.
3.4.3.15 Inputs of Caline4 Model
The composite fleet emission factors for the road links
have been calculated by using the worst case emission factors in Table 3.6 and the peak hour traffic flow and vehicle
composition in the year with the highest traffic forecast. Details of the calculations of the composite
emission factors for each road link are provided in Appendix 3.8.
The worst case meteorological conditions input to the
Caline4 model for the assessment are as follows:
¡ Wind speed: 1 m/s
¡ Wind direction: worst case
¡ Stability Class: D (day-time) and F (night-time)
¡ Wind variability: 12° (day-time) and 6° (night-time)
¡ Surface roughness: 1m
¡ Mixing height: 500m
Since the Calline4 model can predict hourly
pollutant concentrations only, the 24-hour pollutant concentrations are
calculated as 0.4 x (1-hour concentration) according to the Screening
Procedures for Estimating the Air Quality Impact of Stationary Source
(EPA-454/R-92-019). The annual pollutant levels are calculated by averaging the
concentrations predicted by running the Caline4 model on an hour-to-hour basis
with the full year of hourly meteorological data at HKO’s Ta Kwu Ling station
in 2008. It is also assumed that
NO2 is taken as 20% of NOx.
The pollution levels at the ASRs have included
those predicted by Caline4 and the background levels. The assessment levels of
1.5m, 5m and 10m above ground are assumed for all ASRs, except using actual
height for the air intake point for the BCP.
3.4.4
Emission from Ventilation Shafts and
The Project
consists of two vehicle tunnels – one short tunnel (Cheung Shan tunnel section)
with a length of about 0.9 km (Figures 3-1.4) and one
long tunnel (Lau Shui Heung tunnel section) with a length of about
¡ Hourly meteorological data in 2008 as measured at HKO’s Ta Kwu Ling station.
¡ Discharge parameters such as dimensions, discharge flow/velocity and temperature in accordance with the ventilation system design
¡ Pollutant emission rates, which are calculated based on the worst case emissions obtained from EMFAC-HK (see Table 3.6), the linear lengths of the tunnels and traffic flow
As confirmed by the Engineer,
the ventilation systems have been designed to operate continuously to extract
all emissions from within the tunnels for discharge to the atmosphere via the ventilation
shafts at tunnel portals and the mid-ventilation building (for long
tunnel). The designed splits of emissions are summarized
as follows.
¡ For the long tunnel, 22% of the vehicle emissions inside the tunnel will be removed from the mid-ventilation building, while the remaining 33% and 45% of the emissions will be discharged from the ventilation shafts near Fanling (Figure 3-1.9) and Sha Tau Kok Road – Wo Hang (Figure 3-1.6), respectively.
¡ For the short tunnel, 43% of the emissions inside the tunnel will be discharged from the ventilation shaft at the southern portal while the remaining 57% of the emission will be discharged from the ventilation shaft at the northern portal (Figures 3-1.4).
Based on the above designed
split of emissions, the Engineer has accordingly developed the preliminary
design of the ventilation shafts/building including the locations, numbers and
specifications of the fans for each of the tunnels, which will form parts of
the key requirements for the subsequent detailed design.
As a conservative approach,
it is assumed that the total hourly emission rates of ventilation shafts and
mid-ventilation building (for the long tunnel) throughout each of the 4 model
years would be the same as the emission rates estimated based on the
aforementioned worst case emissions. The calculation of emission rates at the
ventilation shafts/building, as well as the relevant dimension and
specifications are provided in Appendices
3.9a
and 3.9b.
3.4.5 Emission from Tunnel Portals
As confirmed by the Engineer, all the emissions within both tunnels are designed to be extracted by the ventilation shafts and mid-ventilation building (for the long tunnel), and therefore there will be no emission from all tunnel portals. Hence, modelling of tunnel portal emissions is not required in this assessment.
3.4.7 Emission from kiosks, loading and unloading areas and PTI
The emissions from kiosks, loading and unloading (L&UL)
areas and PTI have been considered as idling emissions. The worst-case forecast
of numbers of idling vehicles in kiosks, L&UL and PTI in peak hour as
provided by the Traffic Consultant are provided in Table 3.7. The composite
NOx and RSP idling emissions factors of different vehicle types are
extracted respectively from the Feasibility Study[1] and the approved
EIA for Improvement to San Tin Interchange[2] ,and are as
summarized in Table 3.8. The average lengths of goods vehicle,
coach/bus and passenger car/taxi are assumed to be
Table 3.7: Forecast of Idling Vehicles in Kiosks, L&UL and PTI in Peak Hour
Location |
Vehicle Type |
Level (m AGL) |
Total Idling Time in an Hour (veh-minutes)(a) |
Equivalent No. of Idling Vehicles in an Hour(b) |
PTI |
Bus |
0 |
30 |
0.5 |
Green Mini Bus (GMB) |
0 |
12 |
0.2 |
|
Taxi |
0 |
2880 |
48 |
|
L&UL: Cross-Boundary Coach
Boarding Area (to |
Cross-Boundary Coach |
10 |
1392 |
23.2 |
L&UL: Cross-Boundary Coach
Boarding Area (to PRC) |
Cross-Boundary Coach |
10 |
348 |
5.8 |
Kiosks (to |
Coach (3 Channels) |
10 |
50 per channel |
0.8 per channel |
Passenger Car/taxi (3 Channels) |
10 |
205 per channel |
3.4 per channel |
|
Goods Vehicle (9 Channels) |
0 |
602 per channe) |
10.0 per channel |
|
Kiosks (to PRC) |
Coach (3 Channels) |
10 |
50 per channel |
0.8 per channel |
Passenger Car/taxi (3 Channels) |
10 |
171 per channel |
2.9 per channel |
|
Goods Vehicle (9 Channels) |
0 |
602 per channel |
10.0 per channel |
Notes:
(a)
The total idling
time in an hour was estimated by the Traffic Consultant based on the total
number of vehicles that would idle in each location in the hour multiplied with
the corresponding idling time (in minutes) of the vehicle.
(b)
The equivalent number
of idling vehicles in an hour is equal to the total idling time in an hour divided
by 60 minutes. In other words, it is the
equivalent number of vehicles that were idling in each location for the entire
hour.
Table 3.8: Idling Emissions from Kiosks, L&UL areas and PTI
|
||
1.317 |
||
The composite
NOx idling emission factors adopted in the Feasibility Study were estimated
based on the implementation of emission standards (as of July 2005) and vehicle
population distribution (as of 2003) available at the time of completing the Study
(see Appendix 3.10b). In view of
the updated implementation schedule of emission standards (as of June 2010) and
the latest available vehicle population data (as of 2008), it is necessary to
accordingly update the NOx idling emission factors as detailed below.
Based on Tables II.3-20 to II.3-27 and Tables II.3-46
to II.3-50, Appendix 2 of the “Road Tunnels: Vehicle Emissions and Air Demand
for Ventilation” published by the Permanent International Association of Road
Congresses (PIARC) in November 2004 (see the Attachment to Appendix 3.10b), the NOx idling emission factors of relevant
vehicle types for different Euro emission standards are as follows:
Emission Standard |
NOx Idling
Emission Factor for Heavy Goods Vehicle (g/h-veh) |
NOx Idling
Emission Factor for Private Car (g/h-veh) |
Pre-Euro |
73.0 |
1.00 |
Euro I |
61.3 |
1.00 |
Euro II |
40.8 |
0.38 |
Euro III |
27.5 |
0.27 |
Euro IV |
18.0 |
0.14 |
According to Tables II.3-22, II.3-24, II.3-26 and II.3-51, Appendix 2 of the above-mentioned publication by PIARC (see the Attachment to Appendix 3.10b), all the above NOx idling emission factors for heavy goods vehicles should be adjusted by a mass factor of 2.5 to account for the vehicle mass variation whereas the NOx idling emission factors for private cars should be adjusted by the aging factors of 3 for Euro I; 1.82 for Euro II and 2 for Euro III. As the aging factor for Euro IV private cars is not provided in the PIARC publication, it is assumed to be the same as that for Euro III, i.e., 2. The adjusted emission factors therefore become:
Emission Standard |
Adjusted NOx
Idling Emission Factor for Heavy Goods Vehicle (g/h-veh) |
Adjusted NOx
Idling Emission Factor for Private Car (g/h-veh) |
Pre-Euro |
182.50 |
1.00 (no adjustment needed) |
Euro I |
153.25 |
3.00 |
Euro II |
102.00 |
0.69 |
Euro III |
68.75 |
0.54 |
Euro IV |
45.00 |
0.28 |
Based EPD’s published vehicle population data in 2008 and EPD’s updated Guideline on Modelling Vehicle Emissions, Appendix II – Implementation Schedule of Vehicle Emission Standards in Hong Kong (June 2010), the estimated population distributions of heavy goods vehicles and private cars complying with various Euro emission standards in the assessment year of 2018 can be estimated and the results are as follows:
Emission Standard |
% of
Population of Heavy Goods Vehicle |
% of
Population of Private Car |
Pre-Euro |
0.2% |
0.2% |
Euro I |
0.9% |
0.1% |
Euro II |
8.7% |
0.5% |
Euro III |
26.3% |
8.2% |
Euro IV |
31.9% |
47.4% |
Euro V |
31.9% |
43.6% |
Details of the population distribution
estimation are given in Appendix
3.10c.
With the adjusted NOx idling emission factors and the estimated
population distribution in 2018, the composite NOx idling emission factors for
heavy goods vehicle and private car have been calculated by taking the
population-weighted average of the corresponding emission factors (see Appendix
3.10c). Since there is no NOx idling emission factor
for Euro V engines in the PIARC publication, it is conservatively assumed to be
the same as that for Euro IV engines for the purpose of calculating the
composite emission factors. Finally, with
reference to the Feasibility Study, the composite emission factors are
multiplied by the factors of 1.05 and 1.3 to respectively account for the
From the above, it can be seen that the composite emission
factor for heavy goods vehicle (i.e., 1.308 g/min-veh) estimated based on the
latest vehicle population and implementation schedule is very close to (only about
1% below) the corresponding factor used in the Feasibility Study (i.e., 1.317
g/min-veh). For the estimated composite emission
factor for passenger cars (i.e., 0.007 g/min-veh), as it is substantially lower
than the factor used in the Feasibility Study (i.e., 0.2 g/min-veh), the factor
used in the Feasibility Study is adopted in this EIA in order to be
conservative. Therefore, despite the
updated vehicle population and implementation schedule of emission standards, the
composite NOx idling emission factors of the Feasibility Study for both heavy
goods vehicle and private car (see Table 3.8) remain applicable and have been adopted for this
EIA.
During the detailed design stage, it is proposed to explore the feasibility and arrangement for administrative measures whereby vehicle idling emissions could be reduced within the BCP area, for example, administrative means to encourage switching off engines while waiting. Nevertheless, as a conservative approach, the effects of such administrative measures (if any) are not taken into account in the modelling exercise.
3.4.8 Cumulative Impacts
There are a number of identified major concurrent
projects in the vicinity of this Project, the details of which are given in Section 2.10 and Appendix 2.2. The
concurrent projects that are considered to have cumulative impacts on the
identified ASRs during the operational phase of this Project are the North East
New Territories New Development Area (including Fanling Bypass) and the
Widening of Tolo Highway /
Within the
The layout of the Shenzhen BCP
as provided by the Shenzhen Authority (深圳市建築工務署) has been used in the cumulative impact
assessment. However, as information
about the emission sources of the Shenzhen BCP is not available, it is assumed
that they are similar to those of the BCP on
According to the information
provided by the Shenzhen Authority, it is planned to commence the EIA for the
Shenzhen BCP in the 4th quarter of 2010 and to complete the EIA in 6 to 9
months. Therefore, information regarding
the vehicular emissions from Luo Sha Road and Luo Fong Road in Shenzhen for
assessing the associated air quality impact is currently not available (though
it may probably be available in the 1st or 2nd quarters of 2011, subject to the
scope of that EIA). Due to the unavailability
of such information for carrying out the EIA of this BCP Project, quantitative
assessment of the cumulative air quality impacts due to traffic emissions from
the proposed connecting roads of this Project and the two Roads in Shenzhen
cannot be made. Nevetheless, it is
proposed to adopt the following qualitative approach to review the potential
air quality impacts that may arise from the two Roads in Shenzhen.
For
For
3.4.9 Calculation of Total Concentration
The cumulative pollution levels at the identified
ASRs during the operational phase have been calculated by adding up the
contribution of emissions from all the major open roads within the 500m
assessment area of the Project in Hong
Kong and from idling vehicles in kiosks/L&UL/PTI of the BCPs on both Hong
Kong and Shenzhen sides which are predicted by the Caline4 model; the emissions
from ventilation building/shafts which are predicted by the ISCST3 model as
well as the background concentrations (50.4 μg/m3 for NO2 and 49.9 μg/m3 for
RSP). The assessment levels of
3.5 Identification, Prediction and Evaluation of Environmental Impact
For the purpose of Tier 1 screening, the predicted hourly TSP concentrations at all identified ASRs are summarized in Tables 3.9 to 3.12 for unmitigated scenario and Tables 3.13 to 3.16 for mitigated scenario. For clarity, the ASRs are split into four groups: (1) near the BCP, Lin Ma Hang to Frontier Closed Area and Ping Yeung to Wo Keng Shan; (2) Sha Tau Kok, (3) Po Kak Tsai, and (4) Fanling. The Tier 1 contours of cumulative hourly TSP levels at 1.5m AGL are shown in Figures 3-4.1a to 3-4.9a and Figures 3-4.1b to 3-4.9b for respectively the unmitigated and mitigated scenarios..
Table 3.9: Predicted Cumulative Hourly Average TSP Concentration in near the BCP, Lin Ma Hang to Frontier Closed Area and Ping Yeung to Wo Keng Shan (Tier 1 – Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TYHP |
4018 |
3975 |
3096 |
TYH |
4876 |
4639 |
3338 |
V1 |
9270 |
6870 |
3845 |
V2 |
6177 |
4845 |
3242 |
CY3 |
3531 |
3091 |
2216 |
KL1 |
4444 |
4456 |
3690 |
TKL1 |
3802 |
3870 |
3307 |
TKL2 |
4943 |
3600 |
3091 |
KTW6 |
3586 |
3646 |
3122 |
TF1 |
2209 |
2348 |
2139 |
FWW1 |
2877 |
3061 |
2760 |
KTW1 |
3336 |
3267 |
2563 |
KTW2 |
3931 |
3660 |
2625 |
KTW4 |
4710 |
3305 |
2111 |
KTW5 |
2373 |
2040 |
1589 |
NYH1 |
1636 |
1564 |
1310 |
PY1 |
2870 |
2104 |
1225 |
PY3 |
1911 |
1894 |
1544 |
PY6 |
2084 |
1897 |
1382 |
WKS1 |
2177 |
1881 |
1329 |
WKS2 |
1653 |
1306 |
1149 |
WKS3 |
1160 |
1186 |
1011 |
WKS4 |
2787 |
2375 |
1370 |
WKS5 |
2570 |
2159 |
1602 |
WKS7 |
3529 |
2230 |
1853 |
Note: Bold
value: The predicted value exceeds the 1-hour average
Table 3.10: Predicted
Cumulative Hourly Average TSP Concentration in Sha Tau Kok (Tier 1– Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
ST1 |
1042 |
1001 |
735 |
ST2 |
1426 |
1267 |
906 |
ST3 |
2910 |
2533 |
1608 |
ST4 |
2822 |
2244 |
1584 |
TTW1 |
4340 |
1996 |
1159 |
TTW2 |
2518 |
2157 |
1216 |
TTW3 |
4445 |
2407 |
1246 |
LT1 |
2204 |
1645 |
1254 |
LT2 |
1914 |
1786 |
1287 |
Note:
Bold value: The predicted value exceeds the 1-hour average
Table 3.11: Predicted
Cumulative Hourly Average TSP Concentration in
ASRs |
1.5m AGL |
|
10m AGL |
PKT1 |
490 |
456 |
318 |
PKT2 |
1048 |
816 |
379 |
PKT3 |
891 |
684 |
311 |
Note: Bold value: The predicted value exceeds the 1-hour average
Table 3.12: Predicted
Cumulative Hourly Average TSP Concentration in Fanling (Tier 1 – Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TH1 |
4825 |
2320 |
1482 |
TH4 |
3154 |
3066 |
2319 |
KT1 |
3680 |
3081 |
1676 |
KT2 |
3555 |
2432 |
1355 |
KT3 |
5290 |
3366 |
1825 |
NWP1 |
5465 |
4120 |
2233 |
NWP2 |
5309 |
4508 |
2785 |
NWP3 |
5129 |
2634 |
1497 |
KLH1 |
5030 |
3872 |
2117 |
Note: Bold value: The predicted value
exceeds the 1-hour average
Table 3.13: Predicted Cumulative Hourly Average TSP Concentration in near the BCP, Lin Ma Hang to Frontier Closed Area and Ping Yeung to Wo Keng Shan (Tier 1 – Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TYHP |
569 |
562 |
447 |
TYH |
673 |
640 |
470 |
V1 |
1133 |
871 |
547 |
V2 |
770 |
684 |
473 |
CY3 |
479 |
421 |
345 |
KL1 |
572 |
574 |
487 |
TKL1 |
496 |
505 |
448 |
TKL2 |
668 |
496 |
417 |
KTW6 |
491 |
497 |
433 |
TF1 |
320 |
337 |
312 |
FWW1 |
403 |
426 |
390 |
KTW1 |
447 |
438 |
356 |
KTW2 |
558 |
519 |
384 |
KTW4 |
660 |
469 |
312 |
KTW5 |
377 |
333 |
247 |
NYH1 |
278 |
268 |
226 |
PY1 |
444 |
323 |
211 |
PY3 |
301 |
298 |
251 |
PY6 |
380 |
308 |
231 |
WKS1 |
468 |
384 |
255 |
WKS2 |
324 |
309 |
242 |
WKS3 |
238 |
243 |
216 |
WKS4 |
457 |
403 |
265 |
WKS5 |
436 |
383 |
271 |
WKS7 |
533 |
352 |
302 |
Note: Bold
value: The predicted value exceeds the 1-hour average
Table 3.14: Predicted
Cumulative Hourly Average TSP Concentration in Sha Tau Kok (Tier 1– Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
ST1 |
199 |
193 |
157 |
ST2 |
251 |
229 |
180 |
ST3 |
450 |
399 |
274 |
ST4 |
438 |
360 |
271 |
TTW1 |
643 |
327 |
214 |
TTW2 |
397 |
348 |
221 |
TTW3 |
657 |
382 |
225 |
LT1 |
355 |
279 |
227 |
LT2 |
316 |
298 |
231 |
Note: Bold
value: The predicted value exceeds the 1-hour average
Table 3.15: Predicted
Cumulative Hourly Average TSP Concentration in
ASRs |
1.5m AGL |
|
10m AGL |
PKT1 |
176 |
167 |
132 |
PKT2 |
318 |
260 |
147 |
PKT3 |
279 |
226 |
130 |
Table 3.16: Predicted
Cumulative Hourly Average TSP Concentration in Fanling (Tier 1 – Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TH1 |
708 |
370 |
257 |
TH4 |
485 |
472 |
370 |
KT1 |
554 |
473 |
283 |
KT2 |
537 |
385 |
240 |
KT3 |
770 |
511 |
304 |
NWP1 |
794 |
613 |
359 |
NWP2 |
773 |
665 |
433 |
NWP3 |
749 |
413 |
259 |
KLH1 |
736 |
579 |
343 |
Note: Bold
value: The predicted value exceeds the 1-hour average
The Tier 1 screening results have identified that with the mitigation
measures in place 20 ASRs would potentially be subject to adverse dust impacts,
i.e., exceedance of the 1-hour TSP criterion.
These ASRs were then selected to undergo the Tier 2 assessment, the
results of which are as shown in Table 3.17. The locations of 30% active areas of the dust
emission sources assumed to be closest to the identified ASRs are shown in Figures 3-3.1 to 3-3.17. It can be seen that the Tier 2 results at all
the selected ASRs would comply with the 1-hour TSP criterion (500 μg/m3).
The Tier 2 contours of cumulative hourly TSP levels at such ASRs at 1.5m AGL (mitigated) are shown in Figures 3-5.1 to 3-5.17.
Table 3.17: Predicted Cumulative Hourly Average TSP Concentration at Selected ASRs (Tier 2 – Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TYHP |
260 |
222 |
156 |
TYH |
249 |
230 |
170 |
V1 |
300 |
289 |
230 |
V2 |
303 |
287 |
222 |
KL1 |
194 |
185 |
171 |
TKL1 |
184 |
170 |
159 |
TKL2 |
303 |
178 |
153 |
KTW2 |
315 |
270 |
177 |
KTW4 |
485 |
282 |
156 |
WKS7 |
201 |
148 |
102 |
TTW1 |
315 |
186 |
127 |
TTW3 |
268 |
173 |
122 |
TH1 |
361 |
228 |
163 |
KT1 |
321 |
274 |
166 |
KT2 |
396 |
288 |
156 |
KT3 |
462 |
283 |
153 |
KLH1 |
415 |
333 |
197 |
NWP1 |
409 |
309 |
179 |
NWP2 |
344 |
301 |
207 |
NWP3 |
472 |
259 |
170 |
3.5.1.2 Daily TSP Levels
For the purpose of Tier 1 screening, the predicted daily TSP concentrations at all identified ASRs are summarized in Tables 3.18 to 3.21 for unmitigated scenario and Tables 3.22 to 3.25 for mitigated scenario.. The Tier 1 contours of cumulative daily TSP levels at 1.5m AGL are shown in Figures 3-6.1a to 3-6.9a. and Figures 3-6.1b to 3-6.9b for respectively the unmitigated and mitigated scenarios.
Table 3.18: Predicted Cumulative Daily Average TSP Concentration in near the BCP, Lin Ma Hang to Frontier Closed Area and Ping Yeung to Wo Keng Shan (Tier 1 – Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TYHP |
619 |
576 |
431 |
TYH |
631 |
606 |
478 |
V1 |
2592 |
1991 |
1151 |
V2 |
1993 |
1737 |
1215 |
CY3 |
1051 |
954 |
778 |
KL1 |
628 |
634 |
577 |
TKL1 |
538 |
544 |
486 |
TKL2 |
819 |
592 |
482 |
KTW6 |
519 |
524 |
465 |
TF1 |
362 |
381 |
369 |
FWW1 |
343 |
359 |
340 |
KTW1 |
1022 |
1028 |
889 |
KTW2 |
998 |
937 |
751 |
KTW4 |
1294 |
956 |
679 |
KTW5 |
514 |
463 |
417 |
NYH1 |
383 |
375 |
356 |
PY1 |
846 |
633 |
414 |
PY3 |
499 |
488 |
412 |
PY6 |
547 |
511 |
401 |
WKS1 |
620 |
549 |
380 |
WKS2 |
420 |
416 |
351 |
WKS3 |
234 |
246 |
236 |
WKS4 |
722 |
639 |
448 |
WKS5 |
731 |
612 |
424 |
WKS7 |
506 |
447 |
375 |
Note: Bold value: The predicted value exceeds the daily average
Table 3.19: Predicted Cumulative Daily Average TSP Concentration in Sha Tau Kok (Tier 1 – Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
ST1 |
249 |
246 |
210 |
ST2 |
335 |
315 |
250 |
ST3 |
424 |
388 |
290 |
ST4 |
540 |
436 |
289 |
TTW1 |
895 |
633 |
399 |
TTW2 |
555 |
499 |
336 |
TTW3 |
915 |
573 |
352 |
LT1 |
439 |
364 |
292 |
LT2 |
391 |
379 |
309 |
Note:
Bold value: The predicted value exceeds the daily average
Table 3.20: Predicted
Cumulative Daily Average TSP Concentration in
ASRs |
1.5m AGL |
|
10m AGL |
PKT1 |
103 |
102 |
94 |
PKT2 |
146 |
132 |
108 |
PKT3 |
147 |
128 |
102 |
Table 3.21: Predicted Cumulative Daily Average TSP Concentration in Fanling (Tier 1 – Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TH1 |
1475 |
648 |
381 |
TH4 |
576 |
447 |
293 |
KT1 |
632 |
582 |
422 |
KT2 |
938 |
752 |
447 |
KT3 |
1023 |
787 |
541 |
NWP1 |
1124 |
722 |
421 |
NWP2 |
831 |
724 |
576 |
NWP3 |
1213 |
812 |
488 |
KLH1 |
1509 |
1262 |
782 |
Note: Bold
value: The predicted value exceeds the daily average
Table 3.22: Predicted Cumulative Daily Average TSP Concentration in near the BCP, Lin Ma Hang to Frontier Closed Area and Ping Yeung to Wo Keng Shan (Tier 1 – Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TYHP |
137 |
131 |
114 |
TYH |
140 |
136 |
120 |
V1 |
362 |
293 |
202 |
V2 |
316 |
281 |
212 |
CY3 |
201 |
187 |
162 |
KL1 |
134 |
137 |
130 |
TKL1 |
129 |
124 |
119 |
TKL2 |
162 |
133 |
118 |
KTW6 |
121 |
122 |
116 |
TF1 |
105 |
107 |
106 |
FWW1 |
101 |
103 |
99 |
KTW1 |
190 |
191 |
172 |
KTW2 |
192 |
183 |
157 |
KTW4 |
235 |
187 |
148 |
KTW5 |
131 |
123 |
112 |
NYH1 |
112 |
106 |
103 |
PY1 |
176 |
142 |
112 |
PY3 |
124 |
122 |
112 |
PY6 |
134 |
126 |
110 |
WKS1 |
149 |
139 |
114 |
WKS2 |
122 |
122 |
112 |
WKS3 |
100 |
102 |
99 |
WKS4 |
169 |
158 |
130 |
WKS5 |
169 |
152 |
125 |
WKS7 |
129 |
121 |
111 |
Note: Bold
value: The predicted value exceeds the daily average
Table 3.23: Predicted Cumulative Daily Average TSP Concentration in Sha Tau Kok (Tier 1 – Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
ST1 |
93 |
92 |
87 |
ST2 |
105 |
102 |
93 |
ST3 |
117 |
112 |
97 |
ST4 |
135 |
118 |
97 |
TTW1 |
185 |
147 |
112 |
TTW2 |
134 |
126 |
104 |
TTW3 |
185 |
140 |
107 |
LT1 |
119 |
109 |
97 |
LT2 |
111 |
109 |
100 |
Table 3.24: Predicted
Cumulative Daily Average TSP Concentration in
ASRs |
1.5m AGL |
|
10m AGL |
PKT1 |
76 |
76 |
74 |
PKT2 |
87 |
83 |
77 |
PKT3 |
88 |
83 |
76 |
Table 3.25: Predicted Cumulative Daily Average TSP Concentration in Fanling (Tier 1 – Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TH1 |
266 |
148 |
111 |
TH4 |
138 |
121 |
99 |
KT1 |
147 |
140 |
116 |
KT2 |
188 |
162 |
121 |
KT3 |
203 |
169 |
131 |
NWP1 |
222 |
161 |
118 |
NWP2 |
172 |
162 |
140 |
NWP3 |
235 |
173 |
124 |
KLH1 |
271 |
236 |
167 |
Note: Bold
value: The predicted value exceeds the daily average
The Tier 1
screening results have identified that with the mitigation measures in place 4 ASRs
would potentially be subject to adverse dust impacts, i.e., exceedance of the daily
TSP criterion. The ASRs were then
selected to undergo the Tier 2 assessment, the results of which are as shown in
Table 3.26. The locations
of 30% active areas of the dust emission sources assumed to be closest to the
identified ASRs are shown in Figures 3-3.7, 3-3.8, 3.3.12, 3.3.13, 3.3.16 and 3.3.17. It can be
seen that the Tier 2 results at the selected ASR would comply with the daily
TSP criterion (260 μg/m3). The Tier 2 contours of cumulative daily
TSP levels at such ASRs at 1.5m AGL (mitigated) are shown in Figures 3-7.1 to 3-7.6.
Table 3.26: Predicted Cumulative Daily Average TSP Concentration at Selected ASRs (Tier 2 – Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
V1 |
103 |
101 |
96 |
V2 |
130 |
119 |
104 |
TH1 |
163 |
97 |
83 |
KLH1 |
158 |
138 |
105 |
3.5.1.3 Annual TSP Levels
The predicted
annual TSP concentrations are summarized in Tables 3.27 to 3.30 for unmitigated scenario and Tables 3.31 to 3.34 for mitigated scenario.
It can be seen that with the mitigation measures in place the annual TSP
concentrations at all ASRs would comply with the corresponding AQO (80 μg/m3).
The contours of cumulative annual TSP levels at 1.5m AGL (mitigated) are shown in Figures 3-8.1a to 3-8.9a and Figures 3-8.1b to 3-8.9b for respectively the unmitigated and mitigated
scenarios.
Table 3.27: Predicted Cumulative Annual Average TSP Concentration in near the BCP, Lin Ma Hang to Frontier Closed Area and Ping Yeung to Wo Keng Shan (Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TYHP |
74 |
74 |
73 |
TYH |
75 |
75 |
74 |
V1 |
108 |
101 |
90 |
V2 |
87 |
86 |
82 |
CY3 |
76 |
76 |
74 |
KL1 |
84 |
83 |
80 |
TKL1 |
85 |
82 |
78 |
TKL2 |
83 |
79 |
76 |
KTW6 |
75 |
75 |
74 |
TF1 |
71 |
72 |
71 |
FWW1 |
71 |
71 |
71 |
KTW1 |
77 |
77 |
76 |
KTW2 |
85 |
83 |
80 |
KTW4 |
89 |
85 |
80 |
KTW5 |
79 |
77 |
75 |
NYH1 |
75 |
74 |
73 |
PY1 |
85 |
81 |
76 |
PY3 |
73 |
73 |
72 |
PY6 |
78 |
77 |
75 |
WKS1 |
83 |
80 |
75 |
WKS2 |
78 |
77 |
75 |
WKS3 |
68 |
68 |
68 |
WKS4 |
82 |
79 |
75 |
WKS5 |
87 |
82 |
75 |
WKS7 |
73 |
72 |
70 |
Note: Bold value: The predicted value exceeds the annual average
Table 3.28: Predicted Cumulative Annual Average
TSP Concentration in Sha Tau Kok (Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
ST1 |
68 |
68 |
68 |
ST2 |
70 |
70 |
69 |
ST3 |
74 |
73 |
71 |
ST4 |
79 |
77 |
74 |
TTW1 |
78 |
76 |
73 |
TTW2 |
78 |
78 |
76 |
TTW3 |
94 |
88 |
81 |
LT1 |
70 |
70 |
69 |
LT2 |
70 |
70 |
70 |
Note:
Bold value: The predicted value exceeds the annual average
Table 3.29: Predicted Cumulative Annual Average
TSP Concentration in
ASRs |
1.5m AGL |
|
10m AGL |
PKT1 |
67 |
67 |
67 |
PKT2 |
73 |
70 |
68 |
PKT3 |
68 |
67 |
67 |
Table 3.30: Predicted Cumulative Annual Average TSP Concentration in Fanling (Unmitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TH1 |
69 |
69 |
68 |
TH4 |
69 |
69 |
68 |
KT1 |
68 |
68 |
68 |
KT2 |
68 |
68 |
68 |
KT3 |
69 |
69 |
68 |
NWP1 |
72 |
71 |
69 |
NWP2 |
71 |
70 |
68 |
NWP3 |
73 |
71 |
69 |
KLH1 |
68 |
68 |
68 |
Table 3.31: Predicted Cumulative Annual Average TSP Concentration in near the BCP, Lin Ma Hang to Frontier Closed Area and Ping Yeung to Wo Keng Shan (Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TYHP |
68 |
68 |
68 |
TYH |
68 |
68 |
68 |
V1 |
72 |
71 |
70 |
V2 |
69 |
69 |
69 |
CY3 |
68 |
68 |
68 |
KL1 |
69 |
69 |
68 |
TKL1 |
69 |
69 |
68 |
TKL2 |
69 |
68 |
68 |
KTW6 |
68 |
68 |
68 |
TF1 |
67 |
67 |
67 |
FWW1 |
67 |
67 |
67 |
KTW1 |
68 |
68 |
68 |
KTW2 |
69 |
69 |
69 |
KTW4 |
70 |
69 |
68 |
KTW5 |
68 |
68 |
68 |
NYH1 |
68 |
68 |
68 |
PY1 |
69 |
69 |
68 |
PY3 |
68 |
68 |
67 |
PY6 |
68 |
68 |
68 |
WKS1 |
69 |
69 |
68 |
WKS2 |
68 |
68 |
68 |
WKS3 |
67 |
67 |
67 |
WKS4 |
69 |
69 |
68 |
WKS5 |
70 |
69 |
68 |
WKS7 |
68 |
67 |
67 |
Table 3.32: Predicted Cumulative Annual Average TSP Concentration in
Sha Tau Kok (Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
ST1 |
67 |
67 |
67 |
ST2 |
67 |
67 |
67 |
ST3 |
68 |
68 |
67 |
ST4 |
69 |
68 |
68 |
TTW1 |
68 |
68 |
68 |
TTW2 |
68 |
68 |
68 |
TTW3 |
71 |
70 |
69 |
LT1 |
67 |
67 |
67 |
LT2 |
67 |
67 |
67 |
Table 3.33: Predicted Cumulative Annual Average TSP Concentration in
ASRs |
1.5m AGL |
|
10m AGL |
PKT1 |
67 |
67 |
67 |
PKT2 |
68 |
67 |
67 |
PKT3 |
67 |
67 |
67 |
Table 3.34: Predicted Cumulative Annual Average TSP Concentration in Fanling (Mitigated)
ASRs |
1.5m AGL |
|
10m AGL |
TH1 |
67 |
67 |
67 |
TH4 |
67 |
67 |
67 |
KT1 |
67 |
67 |
67 |
KT2 |
70 |
67 |
67 |
KT3 |
68 |
68 |
67 |
NWP1 |
67 |
67 |
67 |
NWP2 |
68 |
67 |
67 |
NWP3 |
71 |
70 |
68 |
KLH1 |
67 |
67 |
67 |
3.5.2 Operational Phase
3.5.2.1 Vehicular Emissions
During the
operational phase, the predicted hourly and daily NO2 as well as
daily RSP concentrations at all the identified ASRs are presented in Tables 3.35 and 3.36 for stability class D and stability class F
respectively. The predicted annual NO2 and RSP
concentrations at all ASRs are presented in Table 3.37. The contours of cumulative hourly NO2,
daily NO2 and daily RSP levels at 1.5m AGL are given respectively in Figures 3-10.1 to 3-10.9, Figures 3-11.1 to 3-11.9 and Figures 3-12.1 to 3-12.9 for stability class D whereas the similar sets of
contours for stability class F are given in
Figures
3-13.1 to 3-13.9, Figures 3-14.1 to 3-14.9 and Figures 3-15.1 to 3-15.9. The contours for annual NO2 and RSP
concentrations at 1.5m AGL are given respectively in Figures 3-16.1 to 3-16.9 and Figures 3-17.1 to 3-17.9. As discussed
earlier, the predicted results have included the background pollutant levels
and the cumulative impacts of the following emissions:
¡
Open roads on the
¡
Idling vehicles in kiosks/L&UL/PTI from the
BCPs of both
¡ Ventilation building/shafts of the vehicle tunnels.
Table 3.35: Predicted Cumulative Hourly and Daily NO2 and Daily RSP concentrations for Stability Class D
|
Hourly NO2 Concentration (μg/m3) |
Daily NO2 Concentration (μg/m3) |
Daily RSP Concentration (μg/m3) |
||||||||
|
(Criterion: 300 μg/m3) |
(Criterion: 150 μg/m3) |
(Criterion: 180 μg/m3) |
||||||||
ASRs |
1.5m AGL |
5m AGL |
10m AGL |
1.5m AGL |
5m AGL |
10m AGL |
1.5m AGL |
5m AGL |
10m AGL |
||
TYHP |
121 |
120 |
116 |
76 |
76 |
74 |
55 |
55 |
54 |
||
TYH |
125 |
123 |
120 |
78 |
77 |
76 |
55 |
55 |
55 |
||
V1 |
132 |
130 |
124 |
81 |
80 |
78 |
56 |
56 |
56 |
||
V2 |
118 |
117 |
114 |
76 |
75 |
74 |
55 |
55 |
55 |
||
CY3 |
97 |
97 |
97 |
67 |
67 |
67 |
53 |
53 |
53 |
||
KL1 |
97 |
97 |
97 |
67 |
67 |
66 |
53 |
53 |
53 |
||
TKL1 |
91 |
91 |
91 |
65 |
64 |
64 |
53 |
53 |
53 |
||
TKL2 |
87 |
87 |
87 |
63 |
63 |
63 |
52 |
52 |
52 |
||
KTW6 |
84 |
84 |
84 |
62 |
62 |
62 |
52 |
52 |
52 |
||
TF1 |
78 |
78 |
79 |
59 |
59 |
59 |
51 |
51 |
51 |
||
FWW1 |
75 |
76 |
76 |
58 |
58 |
58 |
51 |
51 |
51 |
||
KTW1 |
101 |
101 |
101 |
68 |
68 |
68 |
53 |
53 |
53 |
||
KTW2 |
130 |
129 |
127 |
80 |
80 |
79 |
56 |
56 |
55 |
||
KTW4 |
134 |
133 |
130 |
82 |
81 |
80 |
56 |
56 |
55 |
||
KTW5 |
140 |
138 |
135 |
84 |
83 |
82 |
56 |
56 |
55 |
||
KTW7 |
83 |
83 |
83 |
61 |
61 |
61 |
52 |
52 |
52 |
||
NYH1 |
124 |
123 |
121 |
77 |
77 |
76 |
55 |
54 |
54 |
||
PY1 |
167 |
162 |
149 |
95 |
93 |
87 |
57 |
57 |
56 |
||
PY3 |
96 |
96 |
95 |
66 |
66 |
66 |
53 |
53 |
53 |
||
PY6 |
117 |
116 |
114 |
74 |
74 |
73 |
54 |
54 |
54 |
||
WKS1 |
99 |
98 |
97 |
67 |
67 |
66 |
53 |
53 |
53 |
||
WKS2 |
85 |
85 |
85 |
61 |
61 |
61 |
52 |
52 |
52 |
||
WKS3 |
99 |
99 |
99 |
67 |
67 |
67 |
53 |
53 |
53 |
||
WKS4 |
102 |
95 |
92 |
69 |
66 |
64 |
53 |
53 |
52 |
||
WKS5 |
107 |
106 |
103 |
70 |
70 |
69 |
53 |
53 |
53 |
||
WKS7 |
106 |
105 |
103 |
70 |
70 |
69 |
53 |
53 |
53 |
||
WKS8 |
132 |
131 |
129 |
80 |
80 |
79 |
55 |
55 |
55 |
||
ST1 |
65 |
65 |
66 |
55 |
55 |
55 |
51 |
51 |
51 |
||
ST2 |
69 |
69 |
70 |
57 |
57 |
57 |
51 |
51 |
51 |
||
ST3 |
75 |
75 |
76 |
59 |
59 |
59 |
52 |
52 |
52 |
||
ST4 |
79 |
79 |
79 |
60 |
60 |
60 |
52 |
52 |
52 |
||
TTW1 |
81 |
80 |
79 |
62 |
61 |
61 |
52 |
52 |
52 |
||
TTW2 |
77 |
76 |
75 |
60 |
60 |
59 |
52 |
52 |
52 |
||
TTW3 |
81 |
79 |
74 |
61 |
60 |
59 |
53 |
52 |
51 |
||
LT1 |
77 |
77 |
76 |
60 |
60 |
60 |
52 |
52 |
52 |
||
LT2 |
78 |
77 |
76 |
61 |
60 |
60 |
52 |
52 |
52 |
||
PKT1 |
68 |
68 |
69 |
55 |
55 |
55 |
51 |
51 |
51 |
||
PKT2 |
68 |
68 |
68 |
55 |
55 |
55 |
51 |
51 |
51 |
||
PKT3 |
67 |
67 |
68 |
54 |
54 |
54 |
51 |
51 |
51 |
||
TH1 |
109 |
105 |
103 |
72 |
70 |
69 |
54 |
54 |
54 |
||
TH4 |
107 |
107 |
107 |
71 |
71 |
71 |
54 |
54 |
54 |
||
KT1 |
115 |
114 |
111 |
74 |
73 |
72 |
54 |
54 |
54 |
||
KT2 |
115 |
114 |
113 |
74 |
74 |
73 |
54 |
54 |
54 |
||
KT3 |
128 |
126 |
122 |
79 |
79 |
77 |
56 |
56 |
56 |
||
NWP1 |
137 |
135 |
128 |
83 |
82 |
79 |
57 |
57 |
56 |
||
NWP2 |
152 |
150 |
144 |
89 |
88 |
86 |
58 |
58 |
58 |
||
NWP3 |
116 |
115 |
112 |
75 |
74 |
73 |
55 |
55 |
55 |
||
KLH1 |
118 |
118 |
117 |
75 |
75 |
75 |
57 |
57 |
57 |
||
BDG1 (at 35m AGL) |
- |
- |
90 |
- |
- |
62 |
- |
- |
52 |
||
Table 3.36: Predicted Cumulative Hourly and Daily NO2 and Daily RSP concentrations for Stability Class F
|
Hourly NO2 Concentration (μg/m3) |
Daily NO2 Concentration (μg/m3) |
Daily RSP Concentration (μg/m3) |
||||||||
|
(Criterion: 300 μg/m3) |
(Criterion: 150 μg/m3) |
(Criterion: 180 μg/m3) |
||||||||
ASRs |
1.5m AGL |
5m AGL |
10m AGL |
1.5m AGL |
5m AGL |
10m AGL |
1.5m AGL |
5m AGL |
10m AGL |
||
TYHP |
172 |
168 |
158 |
96 |
95 |
91 |
59 |
58 |
58 |
||
TYH |
183 |
179 |
168 |
101 |
100 |
95 |
59 |
59 |
58 |
||
V1 |
229 |
223 |
206 |
120 |
117 |
111 |
64 |
64 |
63 |
||
V2 |
201 |
197 |
187 |
108 |
107 |
103 |
62 |
62 |
61 |
||
CY3 |
158 |
157 |
153 |
91 |
91 |
89 |
57 |
57 |
57 |
||
KL1 |
165 |
164 |
160 |
94 |
93 |
92 |
59 |
58 |
58 |
||
TKL1 |
154 |
153 |
150 |
90 |
89 |
88 |
58 |
57 |
57 |
||
TKL2 |
146 |
146 |
143 |
87 |
86 |
85 |
57 |
57 |
57 |
||
KTW6 |
138 |
137 |
135 |
83 |
83 |
82 |
56 |
56 |
56 |
||
TF1 |
120 |
119 |
118 |
76 |
76 |
75 |
55 |
55 |
55 |
||
FWW1 |
116 |
116 |
115 |
75 |
74 |
74 |
55 |
54 |
54 |
||
KTW1 |
170 |
169 |
165 |
96 |
96 |
94 |
58 |
58 |
58 |
||
KTW2 |
207 |
205 |
200 |
111 |
110 |
108 |
61 |
61 |
61 |
||
KTW4 |
192 |
190 |
186 |
105 |
104 |
102 |
59 |
59 |
59 |
||
KTW5 |
193 |
192 |
187 |
105 |
105 |
103 |
59 |
59 |
59 |
||
KTW7 |
135 |
134 |
132 |
82 |
82 |
81 |
56 |
56 |
56 |
||
NYH1 |
170 |
168 |
164 |
96 |
95 |
94 |
58 |
58 |
57 |
||
PY1 |
210 |
205 |
193 |
112 |
110 |
105 |
61 |
60 |
60 |
||
PY3 |
125 |
124 |
120 |
78 |
77 |
76 |
55 |
55 |
55 |
||
PY6 |
152 |
151 |
147 |
88 |
88 |
87 |
57 |
57 |
56 |
||
WKS1 |
124 |
124 |
122 |
77 |
77 |
76 |
55 |
55 |
55 |
||
WKS2 |
107 |
107 |
106 |
70 |
70 |
70 |
54 |
54 |
53 |
||
WKS3 |
134 |
134 |
132 |
81 |
81 |
80 |
55 |
55 |
55 |
||
WKS4 |
122 |
116 |
111 |
76 |
74 |
72 |
55 |
54 |
54 |
||
WKS5 |
122 |
119 |
125 |
76 |
75 |
78 |
54 |
55 |
54 |
||
WKS7 |
140 |
138 |
135 |
83 |
83 |
81 |
56 |
56 |
55 |
||
WKS8 |
193 |
191 |
186 |
105 |
104 |
102 |
59 |
59 |
59 |
||
ST1 |
87 |
87 |
87 |
64 |
64 |
63 |
52 |
52 |
52 |
||
ST2 |
97 |
96 |
97 |
68 |
68 |
67 |
53 |
53 |
53 |
||
ST3 |
101 |
101 |
102 |
69 |
69 |
69 |
53 |
53 |
53 |
||
ST4 |
91 |
90 |
90 |
65 |
65 |
65 |
53 |
53 |
52 |
||
TTW1 |
99 |
98 |
93 |
69 |
68 |
66 |
54 |
54 |
53 |
||
TTW2 |
83 |
82 |
80 |
63 |
62 |
61 |
52 |
52 |
52 |
||
TTW3 |
96 |
92 |
85 |
67 |
66 |
63 |
53 |
53 |
52 |
||
LT1 |
92 |
91 |
88 |
66 |
66 |
65 |
54 |
54 |
53 |
||
LT2 |
91 |
90 |
87 |
66 |
66 |
64 |
54 |
54 |
54 |
||
PKT1 |
90 |
90 |
90 |
63 |
63 |
63 |
53 |
53 |
53 |
||
PKT2 |
89 |
89 |
89 |
63 |
63 |
63 |
52 |
52 |
52 |
||
PKT3 |
88 |
88 |
88 |
62 |
62 |
62 |
52 |
52 |
52 |
||
TH1 |
122 |
129 |
126 |
77 |
80 |
78 |
56 |
56 |
55 |
||
TH4 |
138 |
138 |
137 |
84 |
83 |
83 |
58 |
58 |
57 |
||
KT1 |
146 |
144 |
138 |
86 |
85 |
83 |
57 |
57 |
57 |
||
KT2 |
143 |
142 |
138 |
85 |
85 |
83 |
57 |
57 |
56 |
||
KT3 |
156 |
153 |
142 |
91 |
90 |
85 |
59 |
59 |
59 |
||
NWP1 |
172 |
168 |
159 |
97 |
95 |
92 |
61 |
60 |
59 |
||
NWP2 |
184 |
181 |
173 |
102 |
101 |
98 |
60 |
60 |
59 |
||
NWP3 |
136 |
135 |
129 |
83 |
82 |
80 |
57 |
57 |
57 |
||
KLH1 |
146 |
146 |
144 |
87 |
86 |
86 |
61 |
60 |
60 |
||
BDG1 (at 35m AGL) |
- |
- |
87 |
- |
- |
61 |
- |
- |
52 |
||
Table 3.37: Predicted Cumulative Annual NO2 and RSP concentrations
|
Annual Average NO2 Concentration (μg/m3) |
Annual Average RSP Concentration (μg/m3) |
||||||
|
(Criterion: 80 μg/m3) |
(Criterion: 55 μg/m3) |
||||||
ASRs |
1.5m AGL |
5m AGL |
10m AGL |
1.5m AGL |
5m AGL |
10m AGL |
||
TYHP |
57 |
55 |
55 |
51 |
51 |
51 |
||
TYH |
61 |
60 |
58 |
53 |
52 |
52 |
||
V1 |
59 |
58 |
57 |
54 |
53 |
52 |
||
V2 |
55 |
55 |
54 |
52 |
52 |
52 |
||
CY3 |
55 |
55 |
55 |
51 |
51 |
51 |
||
KL1 |
55 |
54 |
54 |
51 |
51 |
51 |
||
TKL1 |
54 |
54 |
54 |
51 |
51 |
51 |
||
TKL2 |
54 |
54 |
54 |
51 |
51 |
51 |
||
KTW6 |
53 |
53 |
53 |
51 |
51 |
51 |
||
TF1 |
53 |
53 |
53 |
51 |
51 |
51 |
||
FWW1 |
56 |
56 |
55 |
51 |
51 |
51 |
||
KTW1 |
61 |
60 |
59 |
53 |
53 |
52 |
||
KTW2 |
63 |
62 |
59 |
54 |
54 |
53 |
||
KTW4 |
60 |
59 |
58 |
54 |
53 |
53 |
||
KTW5 |
55 |
55 |
55 |
52 |
52 |
52 |
||
KTW7 |
57 |
56 |
56 |
51 |
51 |
51 |
||
NYH1 |
67 |
64 |
60 |
54 |
53 |
52 |
||
PY1 |
67 |
64 |
60 |
55 |
54 |
53 |
||
PY3 |
60 |
59 |
58 |
52 |
52 |
52 |
||
PY6 |
58 |
58 |
57 |
52 |
52 |
52 |
||
WKS1 |
61 |
60 |
57 |
52 |
52 |
51 |
||
WKS2 |
57 |
57 |
56 |
51 |
51 |
51 |
||
WKS3 |
52 |
52 |
52 |
50 |
50 |
50 |
||
WKS4 |
63 |
60 |
57 |
52 |
52 |
51 |
||
WKS5 |
63 |
61 |
57 |
53 |
52 |
51 |
||
WKS7 |
55 |
54 |
53 |
51 |
51 |
51 |
||
WKS8 |
53 |
53 |
53 |
51 |
51 |
51 |
||
ST1 |
52 |
52 |
52 |
50 |
50 |
50 |
||
ST2 |
52 |
52 |
52 |
50 |
50 |
50 |
||
ST3 |
52 |
52 |
52 |
51 |
51 |
50 |
||
ST4 |
52 |
52 |
52 |
51 |
51 |
51 |
||
TTW1 |
54 |
54 |
53 |
51 |
51 |
51 |
||
TTW2 |
55 |
55 |
54 |
51 |
51 |
51 |
||
TTW3 |
57 |
56 |
55 |
52 |
51 |
51 |
||
LT1 |
52 |
52 |
52 |
50 |
50 |
50 |
||
LT2 |
53 |
53 |
52 |
50 |
50 |
50 |
||
PKT1 |
51 |
51 |
51 |
50 |
50 |
50 |
||
PKT2 |
51 |
51 |
51 |
50 |
50 |
50 |
||
PKT3 |
51 |
51 |
51 |
50 |
50 |
50 |
||
TH1 |
54 |
54 |
54 |
51 |
51 |
51 |
||
TH4 |
54 |
54 |
53 |
51 |
51 |
51 |
||
KT1 |
55 |
55 |
55 |
51 |
51 |
51 |
||
KT2 |
55 |
55 |
55 |
51 |
51 |
51 |
||
KT3 |
57 |
57 |
56 |
51 |
51 |
51 |
||
NWP1 |
66 |
65 |
63 |
53 |
53 |
53 |
||
NWP2 |
72 |
69 |
64 |
55 |
54 |
53 |
||
NWP3 |
65 |
65 |
63 |
54 |
54 |
53 |
||
KLH1 |
57 |
57 |
56 |
52 |
52 |
51 |
||
BDG1 (at 35m AGL) |
- |
- |
52 |
- |
- |
51 |
||
As indicated
in the above Tables, the predicted
hourly, daily and annual NO2 as well as daily and annual RSP
concentrations at all ASRs are in compliance with the corresponding AQOs. The
maximum hourly NO2, daily NO2 and daily RSP levels are respectively
229 μg/m3, 120 μg/m3 and 64 μg/m3
as predicted at V1. The maximum annual NO2
and annual RSP are respectively 72 μg/m3 and 55 μg/m3
as predicted at NWP2.
As shown in Figure 3.17.2, three
patches of the land near KTW1, KTW2 and KTW4 are within the annual RSP criterion
line where the annual AQO for RSP would be exceeded. However, there are currently no ASRs in these
patches of land. As these areas are
within the Ta Kwu Ling North Development Permission Area (DPA), the relevant
government authority has been notified about the potential air quality issues
of the areas, which will be taken into account when developing the Outline
Zoning Plan (OZP) for the DPA. Therefore,
presence of ASRs within such affected areas would be avoided in future.
Similarly, it can be seen from Figure
3.17.3 that other three patches
of the land near NYH1, PY1 and PY6 are within the annual RSP criterion line
where the annual AQO for RSP would be exceeded.
However, there are currently no ASRs in these patches of land. According to the Ping Che & Ta Kwu Ling
OZP, these areas are intended for either agricultural or green belt use and development
of such sensitive uses as village houses in these areas will require planning
approval by relevant government authority, which has been notified about the
potential air quality issues of the areas.
Therefore, presence of ASRs within these affected areas would be avoided
in future.
From Figures 3.16.9 and 3.17.9, two patches of the land on the south and north
sides of NWP2 are within the annual NO2/RSP
criteria lines where the annual AQOs for NO2/RSP would be
exceeded. However, there are currently
no ASRs in these patches of land. According to the Kau Lung Hang OZP, the
affected area on the south side of NWP2 is intended for open storage use and
is, based on site inspection, currently paved and used for storage
facilities. As such, it is very unlikely
to have ASRs in this affected area in future.
The other affected area on the north side of NWP2 is zoned as green belt
based on the OZP and there are currently underground drainage facilities in the
area. Therefore,
future development of such sensitive uses as village houses in the area would
very unlikely be allowed. On the north
side of NWP3, there is another patch of land within the annual NO2/RSP criteria
lines.
However, as this area is a part of the government land on hillside and
has not been zoned for any specific land uses, there are no existing ASRs and
presence of future ASRs in the area would be avoided through the planning
process.
3.5.2.2 Odour from the Proposed Sewage Treatment Works
As can be seen from Figures 3-1.1 and 3-1.2, ASRs BDG1, TYHP, TYH and V1 are relatively closer to the sewage treatment works at the BCP than the other ASRs and would be subject to potential odour impact. However, all these 4 ASRs are at a buffer distance of at least 490 m from the sewage treatment works. In addition, the following odour containment and control measures will be provided for the treatment works:
(a) The treatment works will be totally enclosed. Negative pressure ventilation will be provided within some of the enclosures to avoid any fugitive odorous emission from the treatment works. In addition, the tanks will be connected to deodorisation facilities directly to eliminate the odour problem.
(b) Further odour containment will be achieved by using air-tight cover to cover or confine the sewage channels, sewage tanks, and equipment with potential odour emission. Where covers are used, the trapped gases would be collected by air handling equipment for containing and directing odorous gases to treatment systems.
(c) The gravity sewers, equalization and sludge holding tanks will be designed with suitable sewer distance and retention time to prevent sewage septicity.
(d) Deodorisation facilities by chemical, biological or physical methods (e.g. adsorption by activated carbon) with a minimum odour removal efficiency of 95% will be provided to treat potential odorous emissions from the treatment plant including sewage channels / tanks, filter press and screening facilities so as to minimize any potential odour impact to the nearby ASRs.
With the large buffer distance and the above odour containment and control measures in place to substantially confine and reduce the potential odour emissions at sources, it is anticipated that there would not be significant odour impact on the nearby ASRs.
3.6 Mitigation of Adverse Environmental Impact
3.6.1 Construction Phase
To ensure compliance with the TSP criteria during the construction phase, the relevant requirements stipulated in the Air Pollution Control (Construction Dust) Regulation and good practices for dust control should be implemented to reduce the dust impact. The dust control measures are detailed as follows.
3.6.1.1 General Dust Control Measures
Dust emissions could be suppressed by regular water
spraying on site. In general, water spraying twice a day could reduce dust
emission from active construction area by 50%. However, for this Project, more
frequent water spraying, i.e., 8 times a day (or about once every 1.5 hours for
12 hours per day), is required for heavy construction activities and slope cutting activities
at all active works area, except the active works area in Po Kak Tsai (see Figure 3-1.8),
in order to achieve a higher dust suppression efficiency of 87.5% to reduce the
dust impacts to acceptable levels. For the active works area in Po Kak Tsai, a
water spraying frequency of 4 times a day (or about once every 3 hours for 12
hours per day) would be adequate to achieve a dust suppression efficiency of
75% to mitigate the dust impacts to acceptable levels. Heavy construction activities include construction
of buildings or roads, drilling, ground
excavation, cut and fill operations (i.e., earth moving), etc. The dust suppression efficiencies were estimated
by making reference to the “Control of Open Fugitive Dust Sources Final Report”
published by USEPA, as detailed in Appendix 3.1f.
For stockpiling activities, it is recommended that 80% of the stockpiling area should be covered by impervious sheets and all dusty materials should be sprayed with water immediately prior to any loading or transfer operation so as to keep the dusty material wet during material handling at the stockpile areas.
It is anticipated that the number of construction trucks
approaching and leaving the works sites would be limited. The speed of the
trucks within the site should be controlled to about
With implementation of the above dust mitigation measures,
it has been assessed in Section 3.5.1 that
the predicted hourly TSP (Tier 2), daily TSP (Tier 2) and annual TSP
concentrations at all the identified ASRs would comply with the corresponding TSP
criteria (i.e., respectively 500μg/m3, 260μg/m3 and 80μg/m3).
3.6.1.2 Best Practices for Dust Control
In addition to implementing the recommended dust control measures mentioned above, it is recommended that the relevant best practices for dust control as stipulated in the Air Pollution Control (Construction Dust) Regulation should also be adopted to further reduce the construction dust impacts of the Project. These best practices include:
¡ Good site management is important to help reducing potential air quality impact down to an acceptable level. As a general guide, the Contractor should maintain high standard of housekeeping to prevent emission of fugitive dust. Loading, unloading, handling and storage of raw materials, wastes or by-products should be carried out in a manner so as to minimize the release of visible dust emission. Any piles of materials accumulated on or around the work areas should be cleaned up regularly. Cleaning, repair and maintenance of all plant facilities within the work areas should be carried out in a manner minimizing generation of fugitive dust emissions. The material should be handled properly to prevent fugitive dust emission before cleaning.
Disturbed Parts of the Roads
¡ Each and every main temporary access should be paved with concrete, bituminous hardcore materials or metal plates and kept clear of dusty materials; or
¡ Unpaved parts of the road should be sprayed with water or a dust suppression chemical so as to keep the entire road surface wet.
Exposed Earth
¡ Exposed earth should be properly treated by compaction, hydroseeding, vegetation planting or seating with latex, vinyl, bitumen within six months after the last construction activity on the site or part of the site where the exposed earth lies.
Loading, Unloading or Transfer of Dusty Materials
¡ All dusty materials should be sprayed with water immediately prior to any loading or transfer operation so as to keep the dusty material wet.
Debris Handling
¡ Any debris should be covered entirely by impervious sheeting or stored in a debris collection area sheltered on the top and the three sides.
¡ Before debris is dumped into a chute, water should be sprayed so that it remains wet when it is dumped.
Transport of Dusty Materials
¡ Vehicle used for transporting dusty materials/spoils should be covered with tarpaulin or similar material. The cover should extend over the edges of the sides and tailboards.
Wheel washing
¡ Vehicle wheel washing facilities should be provided at each construction site exit. Immediately before leaving the construction site, every vehicle should be washed to remove any dusty materials from its body and wheels.
Use of vehicles
¡ Immediately before leaving the construction site, every vehicle should be washed to remove any dusty materials from its body and wheels.
¡ Where a vehicle leaving the construction site is carrying a load of dusty materials, the load should be covered entirely by clean impervious sheeting to ensure that the dusty materials do not leak from the vehicle.
Site hoarding
¡ Where a site boundary adjoins a road, street, service lane or other area accessible to the public, hoarding of not less than 2.4m high from ground level should be provided along the entire length of that portion of the site boundary except for a site entrance or exit.
Blasting
¡ The areas within 30m from the blasting area should be wetted with water prior to blasting.
3.6.2 Operational Phase
3.6.2.1 Vehicular Emission
Since there will
be no exceedance of the 1-hour, 24-hour and annual AQOs for NO2 and the
24-hour and annual AQOs for RSP at all the ASRs, no mitigation measure is
required during the operational phase.
3.6.2.2 Odour from the Proposed Sewage Treatment Works
With the large buffer distance (over 490m) and the odour containment and control measures in place to substantially confine and reduce the potential odour emissions at sources (see Section 3.5.2.2), it is anticipated that the sewage treatment works would not have significant odour impact on the nearby ASRs. Hence, no further mitigation measure is required.
3.7 Evaluation of Residual Impact
3.7.1 Construction Phase
With implementation of the recommended mitigation measures as well as the relevant control
requirements as stipulated in the Air
Pollution Control (Construction Dust) Regulation, no adverse residual impacts are
predicted at all the ASRs during the construction phase.
3.7.2.1 Vehicular Emission
Since there will
be no exceedance of the 1-hour, 24-hour and annual AQOs for NO2 and the
24-hour and annual AQOs for RSP at all the ASRs, no adverse residual impacts are
predicted during the operational phase.
3.7.2.2 Odour from the Proposed Sewage Treatment Works
With the large buffer distance (over 490m) and the odour containment and control measures in place to substantially confine and reduce the potential odour emissions at sources (see Section 3.5.2.2), no adverse residual impacts due to the sewage treatment works are anticipated during the operational phase.
3.8 Environmental Monitoring and Audit
3.8.1 Construction Phase
Regular dust monitoring is
considered necessary during the construction phase of the Project and regular
site audits are also required to ensure that the dust control measures are
properly implemented. Details of the environmental monitoring and audit (EM&A)
programme will be presented in the stand-alone EM&A Manual.
3.8.2 Operational Phase
Since it has been assessed
that there will be no adverse air quality impacts due to vehicular emissions or
odour from the sewage treatment works during the operational phase, EM&A is
considered not necessary.
With implementation of the recommended mitigation measures as well as the relevant control requirements as stipulated in the Air Pollution Control (Construction Dust) Regulation, no exceedance of the TSP criteria is predicted at all the ASRs during the construction phase.
No adverse impacts are predicted during the operational phase of the Project.
[1] Planning Study on
Liantang/Heung Yuen Wai Cross-boundary Control Point and its Associated
Connecting Roads in
[2] Improvements to San Tin Interchange – EIA (EIA-093/2004)
[3] The
“GB17691-2005” document can be found from the website of the Vehicle Emission
Control Centre of Ministry of Environmental Protection,