3

3 aIR qUALITY.. 1

3.1 Introduction. 2

3.2 Environmental Legislation, Policies, Plans, Standards and Criteria. 2

3.3 Description of the Environment 2

3.4 Sensitive Receivers. 3

3.5 Identification of Environmental Impacts. 3

3.6 Mitigation of Adverse Environmental Impacts. 3

3.7 Evaluation of Residual Impacts. 3

3.8 Environmental Monitoring and Audit 3

3.9 Conclusion. 3

3 aIR qUALITY

3.1 Introduction

3.1.1 This section presents an air quality impact assessment for DP4 Project under the Wan Chai Development Phase II project. Potential construction dust impact is expected to be less. In view of the project nature, no adverse air quality impact during the operation phase would be anticipated. Thus, this section would only focus on assessing air quality impact due to construction and removal of temporary typhoon shelter.

3.2 Environmental Legislation, Policies, Plans, Standards and Criteria

3.2.1 The criteria for evaluating air quality impacts and the guidelines for air quality assessment are set out in Annex 4 and Annex 12 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM).

Air Quality Objective & EIAO-TM

3.2.2 The Air Pollution Control Ordinance (APCO) provides the statutory authority for controlling air pollutants from a variety of sources. The Hong Kong Air Quality Objectives (AQOs), which must be satisfied, stipulate the maximum allowable concentrations of certain pollutants over specific periods. The relevant AQOs are listed in Table 3.1.

Table 0.1 Hong Kong Air Quality Objectives

Notes:

(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.

(6) Photochemical oxidants are determined by measurement of ozone only.

3.2.1 The EIAO-TM stipulates that the hourly TSP level should not exceed 500 gm-3 (measured at 25oC and one atmosphere) for construction dust impact assessment. Standard mitigation measures for construction sites are specified in the Air Pollution Control (Construction Dust) Regulations.

3.2.2 In accordance with the EIAO-TM, odour level at an air sensitive receiver should meet 5 odour units based on an averaging time of 5 seconds for odour prediction assessment.

3.3 Description of the Environment

Baseline Conditions

3.3.1 The study area is in Causeway Bay. The nearest EPD air quality monitoring stations are in Central and Central/Western. The annual average concentrations of the pollutants measured at EPD’s Central / Western and Central air quality monitoring stations in 2006 adjacent to the WDII development area are summarised in Table 3.2.

Table 3.2 Annual Average Concentrations of Pollutants in 2006

Pollutant	Annual Average Concentration in 2006 (mg m^-3)	Monitoring Stations
CO	862	Central
NO₂	54	Central / Western
RSP	53	Central / Western
TSP	78	Central / Western

3.4 Sensitive Receivers

3.4.1 The study area is within 500m from the project boundary. The study area of air quality assessment is shown in Figure 3.1. The Air Sensitive Receivers (ASRs) including domestic premises, commercial buildings, educational institutions, and recreational and leisure facilities have been identified for air quality impact assessment.

3.4.2 The identified representative ASRs within 500m of DP4 Project study area are listed in Table 3.3 and the corresponding locations are shown in Figures 3.2.

Table 3.3 Details of Representative Air Sensitive Receivers

ASRs	Section	Location	Existing / Planned Land Use	No. of floors
A44	Causeway Bay	Sino Plaza	Commercial	33
A45	Causeway Bay	World Trade Centre	Commercial	34
A46	Causeway Bay	Excelsior Hotel	Commercial	28
A47	Causeway Bay	Riviera Mansion	Residential	15
A48	Causeway Bay	Marco Polo Mansion (northern façade)	Residential	15
A49	Causeway Bay	Marco Polo Mansion (eastern façade)	Residential	15
A50	Causeway Bay	Royal Hong Kong Yacht Club	Recreation	3
A51	Causeway Bay	Police Officers Club (Tennis Courts)	Recreation	0
A52	Causeway Bay	Police Officers Club (Bowling Green)	Recreation	0
A53	Causeway Bay	Police Officers Club	Recreation	3
A54	Causeway Bay	Bowling Green, Victoria Park	Recreation	0
A55	Causeway Bay	Victoria Park Public Swimming Pool	Recreation	0
A56	Causeway Bay	Viking Garden	Residential	25
A57	Causeway Bay	Victoria court	Residential	18
A58	Causeway Bay	Mayson Garden	Residential	24
A59	Causeway Bay	Gorden House	Residential	15
A60	Causeway Bay	Belle House	Residential	24
A61	Causeway Bay	Citicorp Centre	Commercial	36
A62	Causeway Bay	Hoi Tao Building	Residential	30
A63	Causeway Bay	Victoria Centre	Residential	30
A64	Causeway Bay	Seaview Estate	Industrial/commercial	13
A65	Causeway Bay	Harbour Heights	Residential	44
A66	Causeway Bay	Whitfield Road Rest Garden	Recreation	0

3.5 Identification of Environmental Impacts

3.5.1 Dredging and rock filling are the major construction works. As dredging is marine based activity, dust nuisance from this construction activity is not anticipated. Regarding the rock filling, the materials to be used for filling would not be fine particles. The filling period would be last for two months and the ASRs are located far away from the work site. Therefore, insignificant dust impact is expected on the ASRs during construction of temporary typhoon shelter.

3.5.2 Potential marine traffic emissions from the dredgers would be expected. However, only two dredgers would be operated at the work site, the associated emission should be limited. Under normal operation, equipment with proper maintenance is unlikely to cause significant dark smoke emissions and gaseous emissions are expected to be minor. Thus, the AQOs are not expected to be exceeded. Notwithstanding, plant should be regularly maintained to minimise emissions.

3.5.3 The removal of temporary typhoon shelter would be commenced from late December 2015 to end February 2016. In view of marine based activities, short-term period of construction works and large separate distance between the ASRs and the work site, no adverse dust impact would be expected during removal of temporary typhoon shelter. In accordance with the construction programme, there is no other construction activity to be operated concurrently within 500m study area of DP4, no cumulative impact is anticipated.

3.6 Mitigation of Adverse Environmental Impacts

3.6.1 No adverse air quality impacts at the ASRs are expected during construction and removal of temporary typhoon shelter. However, requirements of the Air Pollution Control (Construction Dust) Regulation shall be adhered to during the construction period. In addition, the operated dredgers should be regularly maintained to minimise emissions.

3.7 Evaluation of Residual Impacts

3.7.1 No adverse residual air quality impact would be expected with the implementation of proposed mitigation measures.

3.8 Environmental Monitoring and Audit

3.8.1 Acceptable air quality impact would be expected at the ASRs during construction phase, air quality monitoring is not recommended but regular site audit is required to ensure that the dredgers are regularly maintained.

3.9 Conclusion

3.9.1 Negligible dust impact and emission impact would be expected during construction and removal of temporary typhoon shelter. Air quality monitoring is therefore not required.