Appendix D - Summary of Action and Limit Levels

Table 1 – Action and Limit Levels for 1-hour TSP

Location	Action Level	Limit Level
AMS2	374 mg/m^3	500 mg/m^3
AMS3A*	368 mg/m^3	500 mg/m^3
AMS6	360 mg/m^3	500 mg/m^3
AMS7	370 mg/m^3	500 mg/m^3

Remarks: * Action Level set out at AMS3 Ho Yu College is adopted.

Table 2 – Action and Limit Levels for 24-hour TSP

Location	Action Level	Limit Level
AMS2	176 mg/m^3	260 mg/m^3
AMS3A*	167 mg/m^3	260 mg/m^3
AMS6	173 mg/m^3	260 mg/m^3
AMS7	183 mg/m^3	260 mg/m^3

Remarks: * Action Level set out at AMS3 Ho Yu College is adopted.

Table 3 – Action and Limit Levels for Construction Noise (0700-1900 hrs of normal weekdays)

Location	Action Level	Limit Level
NMS2	When one documented complaint, related to 0700 – 1900 hours on normal weekdays, is received from any one of the sensitive receivers	75 dB(A)
NMS3A		*65 / 70 dB(A)

*Daytime noise Limit Level of 70 dB(A) applies to education institutions, while 65dB(A) applies during school examination period.

Table 4 – Action and Limit Levels for Water Quality

Parameters	Action	Limit
DO in mg L^-1 (Surface, Middle & Bottom)	Surface and Middle 5.0 Bottom 4.7	Surface and Middle 4 .2 (except 5 mg/L for FCZ) Bottom 3.6
SS in mg L^-1 (depth-averaged)	23.5 and 120% of upstream control station's SS at the same tide of the same day	34.4 and 130% of upstream control station's SS at the same tide of the same day and 10mg/L for WSD Seawater intakes
Turbidity in NTU (depth-averaged)	27.5 and 120% of upstream control station's turbidity at the same tide of the same day	47.0 and130% of upstream control station's turbidity at the same tide of the same day

Notes:  

1.   "depth-averaged" is calculated by taking the arithmetic means of reading of all three

depths.

2.   For DO, non-compliance of the water quality limits occurs when monitoring result is lower

than the limits.

3.   For turbidity, SS, non-compliance of the water quality limits occurs when monitoring result

is higher than the limits. 

Table 5(a) 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)]

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.

Table 5(b) 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)]