3.                 Air Quality

3.1              Introduction

3.1.1        This Section of the report presents an assessment of the potential air quality impacts associated with the construction and operation of the NLDFS developments and the CKWLR.  Representative Air Sensitive Receivers (ASRs) have been identified and the potential air quality impacts on these receivers have been evaluated.

3.1.2        Fugitive dust generation from the construction activities is the major concern of potential air quality impact during the construction phase of the proposed developments.  Major air pollutant emissions during operational phase of the Project include vehicular emissions from road networks; industrial emissions from the existing Penny’s Bay Gas Turbine Plant (GTP), the proposed Theme Park at Penny’s Bay such as combustion equipment and fireworks displays, and odour emissions from proposed sewage pumping stations, the Siu Ho Wan Sewage Treatment Works (STW) and the North Lantau Transfer Station (NLTS).  Appropriate mitigation measures have been recommended, where necessary, to ensure that the air quality criteria stipulated in the EIAO TM are met even under the worst case scenarios.  Cumulative air quality impacts with other concurrent projects are also discussed in this Section.  Supplementary information for the air quality assessment are presented in Annex B.

3.2              Evaluation Criteria

3.2.1        The principal legislation for the management of air quality is the Air Pollution Control Ordinance, Cap 311 (APCO).  The entire HKSAR is covered by the Hong Kong Air Quality Objectives (HKAQOs) which stipulate statutory limits of typical air pollutants and the maximum allowable values over specific periods. The HKAQOs are presented in Table 3.2a.

Table 3.2a - Hong Kong Air Quality Objectives (µgm-3) (a)

 

Pollutant

Averaging Time

 

1 Hours (b)

8 Hours (c)

24 Hours (c)

3 Months (d)

1 Year (d)

Total Suspended Particulates (TSP)

-

-

260

-

80

Respirable Suspended Particulates (e) (RSP)

-

-

180

-

55

Sulphur Dioxide (SO2)

800

-

350

-

80

Nitrogen Dioxide (NO2)

300

-

150

-

80

Carbon Monoxide (CO)

30,000

10,000

-

-

-

Lead

-

-

-

1.5

-

Ozone (O3) (f)

240

-

-

-

-

Note:

(a)   Measured at 298K (25°C) and 101.325 kPa (one atmosphere)

(b)   Not to be exceeded more than three times per year

(c)   Not to be exceeded more than once per year

(d)   Arithmetic means

(e)   Respirable suspended particulates are defined as particles suspended in the air with a nominal aerodynamic diameter of 10 mm and smaller

(f)    Photochemical oxidants are determined by measurement of ozone only

 

 

3.2.2        In addition, the EIAO TM stipulates that TSP concentration of 500 mgm-3 measured at 298 K (25 °C) and 101.325 kPa (1 atm) should not be exceeded for construction dust impacts.  Mitigation measures for construction activities specified in the Air Pollution Control (Construction Dust) Regulation should be followed.

3.2.3        Under the Air Pollution Control (Furnaces, Ovens and Chimneys) (Installation and Alteration) Regulations, boilers with total fuel consumption rate more than 25 litres of liquid fuel per hour, 35 kg of solid fuel per hour or 1,150 MJ of gaseous fuel per hour are required to obtain approval from EPD before the installation/alteration of such facilities.

3.2.4        The EIAO TM also stipulates that 5 odour units should be met based on an averaging time of 5 seconds for odour prediction assessment.