Table 4.1 Hong Kong Air Quality Objectives
Pollutant |
Maximum Average Concentration (µg m-3) (1) |
|||
1-Hour (2) |
8-Hour (3) |
24-Hour (3) |
Annual (4) |
|
TSP |
- |
- |
260 |
80 |
RSP (5) |
- |
- |
180 |
55 |
NO2 |
300 |
- |
150 |
80 |
CO |
30,000 |
10,000 |
- |
- |
1. Measured at 298 K 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 Suspended particulates in air with a nominal aerodynamic diameter of 10 mm or smaller.
Table 4.2 Background Air Quality
Pollutant |
Concentration (mg/m3) (1) |
NO2 |
57 |
SO2 |
19 |
TSP |
95 |
RSP |
56 |
(1) Air Quality in Hong Kong 2000, Environmental Protection Department
Table 4.3 Air Sensitive Receivers
ASR |
Description |
Horizontal Separation from site boundary (m) |
A1 |
Village house near Castle Peak Road |
55 |
A2 |
Village house near Kwu Tung Road |
70 |
A3 |
Village house near Kwu Tung Road |
100 |
A4 |
Village house near Kwu Tung Road |
75 |
A5 |
Village house near Kwu Tung Road |
60 |
A6 |
Village house near San Tin Highway |
30 |
A7 |
Village house near Kwu Tung Road |
75 |
A8 |
Tsing Lung Tsuen |
355 |
A9 |
Village house near San Tin Highway |
135 |
A10 |
Village house near San Tin Highway |
5 |
A11 |
Village house near Tai Fu Tai |
75 |
A12 |
Wing Ping Tsuen |
240 |
A13 |
Tung Chan Wai |
260 |
A14 (1) |
Potential village development |
2 |
A15 (1) |
Proposed development |
220 |
(1) Air sensitive receiver at operation phase only.
· Site clearance and formation;
· Construct retaining wall, boredpile and abutment;
· Cast pilecap and pier;
· Installation of precast concrete road segment; and
· Road pavements and markings.
Table 4.4 TSP Emission Rates for Construction Activities
Location |
Activity |
Emission Rate |
Remarks |
Slip A,E and F (Zone A) |
Material handling |
E = 13.7 mg/s =0.274 mg/s/m |
· Volume of material: 11 m3/day · Moisture content: 25% · Density: 2000 kg/m3 · 50% reduction by water suppression · AP42, Section 13.2.4 |
Excavation |
E = 42.8 mg/s = 0.856 mg/s/m |
· Volume of material: 11 m3/day · Density: 2000 kg/m3 · AP42, Section 11.19.2 |
|
Wind erosion |
E = 1.35 mg/s/m2 |
· 50% reduction by water suppression · AP42, Section 11.9 |
|
Slip B and C (Zone B) |
Material handling |
E = 18.7 mg/s =0.374 mg/s/m |
· Volume of material: 15 m3/day · Moisture content: 25% · Density: 2000 kg/m3 · 50% reduction by water suppression · AP42, Section 13.2.4 |
Excavation |
E = 58.3 mg/s = 1.17 mg/s/m |
· Volume of material: 15 m3/day · Density: 2000 kg/m3 · AP42, Section 11.19.2 |
|
Wind erosion |
E = 1.35 mg/s/m2 |
· 50% reduction by water suppression · AP42, Section 11.9 |
|
Slip D, link bridge and widening castle peak road
(Zone C) |
Material handling |
E = 3.74 mg/s =0.0748 mg/s/m |
· Volume of material: 3 m3/day · Moisture content: 25% · Density: 2000 kg/m3 · 50% reduction by water suppression · AP42, Section 13.2.4 |
Excavation |
E = 11.7 mg/s = 0.233 mg/s/m |
· Volume of material: 3 m3/day · Density: 2000 kg/m3 · AP42, Section 11.19.2 |
|
Wind erosion |
E = 1.35 mg/s/m2 |
· 50% reduction by water suppression · AP42, Section 11.9 |
|
Stockpile |
Material handling |
E = 36.2 mg/s =0.0302 mg/s/m2 |
· Volume of material: 29 m3/day · Moisture content: 25% · Density: 2000 kg/m3 · 50% reduction by water suppression · AP42, Section 13.2.4 |
Wind erosion |
E = 1.35 mg/s/m2 |
· 50% reduction by water suppression · AP42, Section 11.9 |
Table 4.5 Comparison of Vehicle Emission for Different Scenario Year
Year |
Road |
Segment |
Length (m) |
Traffic Flow (veh/hr) |
Total Emission Rate (g/hr) |
|
NOx |
RSP |
|||||
2007 |
Slip A |
39 |
530 |
501 |
4714 |
706 |
41 |
460 |
828 |
||||
Slip B |
12 |
320 |
307 |
|||
40 |
720 |
327 |
||||
2011 |
Slip A |
39 |
530 |
359 |
3131 |
457 |
41 |
460 |
634 |
||||
Slip B |
12 |
320 |
258 |
|||
40 |
720 |
274 |
||||
2016 |
Slip A |
39 |
530 |
402 |
3462 |
505 |
41 |
460 |
702 |
||||
Slip B |
12 |
320 |
282 |
|||
40 |
720 |
300 |
||||
2022 |
Slip A |
39 |
530 |
456 |
3811 |
556 |
41 |
460 |
792 |
||||
Slip B |
12 |
320 |
282 |
|||
40 |
720 |
321 |
Table 4.6 China Fuel Vehicle Idling Emission Factors
Vehicle Type |
Idling emission factor (g/min-veh) |
|
NOX |
RSP |
|
Passenger Car |
0.21 |
Negligible |
Good Vehicle |
2.1 |
0.06 |
Bus |
2.1 |
0.06 |
· Wind speed: 1 ms-1
· Wind direction: worst case for each receivers
· Stability class: D
· Mixing height: 500 m
· Standard deviation of wind direction: 18 degree
· Surface roughness: 100 cm
· Temperature: 25 oC
Table 4.7 Predicted TSP Concentration at ASR (With Mitigation)
ASR |
TSP Concentration (mg/m3) |
|
1 hr average |
24 average |
|
A1 |
102 |
102 |
A2 |
98 |
98 |
A3 |
99 |
99 |
A4 |
100 |
100 |
A5 |
103 |
103 |
A6 |
109 |
108 |
A7 |
102 |
102 |
A8 |
98 |
98 |
A9 |
100 |
100 |
A10 |
110 |
110 |
A11 |
102 |
102 |
A12 |
100 |
100 |
A13 |
99 |
99 |
Criteria |
500 |
260 |
Note: Background concentration included in the predicted figure.
Cumulative Impacts
Table 4.8 Concurrent Project
Project |
Anticipated Construction Programme |
East Rail Extension – Sheung Shui to Lok Ma Cha Spur Line (KCRC Spur Line) |
December 2002 to September 2006 |
San Tin Eastern Main Drainage Channel (EMDC) |
October 2002 to June 2006 |
Proposed Drainage Channel NTM04 under the Northern NT DMP Study (NTM04) |
October 2005 to October 2009
|
Table 4.9 Predicted NO2 and RSP Concentrations
ASR |
NO2 concentration (mg/m3) |
RSP concentration (mg/m3) |
|
1 hr |
24 hr |
24-hr |
|
A1 |
217 |
121 |
101 |
A2 |
140 |
90 |
78 |
A3 |
129 |
86 |
75 |
A4 |
126 |
85 |
74 |
A5 |
154 |
96 |
82 |
A6 |
265 |
140 |
114 |
A7 |
221 |
122 |
102 |
A8 |
123 |
83 |
75 |
A9 |
215 |
120 |
100 |
A10 |
250 |
134 |
111 |
A11 |
204 |
116 |
97 |
A12 |
117 |
81 |
73 |
A13 |
106 |
77 |
70 |
A14 |
207 |
117 |
98 |
A15 |
108 |
77 |
70 |
AQO |
300 |
150 |
180 |
Note: Background concentrations included in the predicted figure.
· skip hoist for material transport should be totally enclosed by impervious sheeting;
· all stockpiles of aggregate or spoil should be covered and water applied;
[1] Maunsell (May 2000). Environmental Review Report, Drainage Master Plan Study in the Northern New Territories