Action / Limit Levels for Air Quality

Parameters

Action Level

Limit Level

24-hour TSP Level in µg/m3

1For baseline level ≤ 200 µg/m3, Action level = (baseline level * 1.3 + Limit level)/2; For baseline level > 200 µg/m3 Action level = Limit level

260 µg/m3

1-hour TSP Level in µg/m3

2For baseline level 384 µg/m3, Action level = (baseline level * 1.3 + Limit level)/2; For baseline level > 384 µg/m3, Action level = Limit level

500 µg/m3

Notes:

1. The Action Level for 24-hour TSP Level:

a) AMS 2 = (71.1*1.3 + 260) / 2 = 176 µg/m3; b) AMS 3C = (56.9*1.3 + 260) / 2 = 167 µg/m3;

c) AMS 6 = (66.4*1.3 + 260) / 2 = 173 µg/m3; d) AMS 7B = (82.3*1.3 + 260) / 2 = 183 µg/m3;

2. The Action Level for 1-hour TSP Level:

a) AMS 2 = (191.5*1.3 + 500) / 2 = 374 µg/m3; b) AMS 3C = (18.2.2*1.3 + 500) / 2 = 368 µg/m3;

c) AMS 6 = (169.2*1.3 + 500) / 2 = 360 µg/m3; d) AMS 7B = (184.2*1.3 + 500) / 2 = 370 µg/m3;

 

 

Action and Limit Levels for Construction Noise

Time Period

Action Level

Limit Level

0700 - 1900 hours on normal weekdays

When one documented complaint is received

75 dB(A) *

Note : If works are to be carried out during restricted hours, the conditions stipulated in the construction noise permit issued by the Noise Control Authority have to be followed.

* Reduce to 70 dB(A) for schools and 65 dB(A) during school examination periods.

 

 

Action and Limit Levels for

Chinese White Dolphin Monitoring – Approach to Define Action Level (AL) and Limit Level (LL)

 

North Lantau Social Cluster

NEL

NWL

Action Level

(STG < 70% of baseline) &

(ANI < 70% of baseline)

(STG < 70% of baseline) &

(ANI < 70% of baseline)

Limit Level

[(STG < 40% of baseline) & (ANI < 40% of baseline)] AND

[ (STG < 40% of baseline) & (ANI < 40% of baseline)]

Remark: For North Lantau Social Cluster, action level will be trigger if either NEL or NWL fall below the criteria; limit level will be triggered if both NEL and NWL fall below the criteria.

 

 

Derived Value of Action Level (AL) and Limit Level (LL) for Chinese White Dolphin Monitoring

 

North Lantau Social Cluster

NEL

NWL

Action Level

(STG < 4.2) & (ANI < 15.5 )

(STG < 6.9) & (ANI < 31.3)

Limit Level

[(STG < 2.4) & (ANI <8.9)] AND [ (STG < 3.9) & (ANI < 17.9)]