Appendix C              Environmental Action and Limit Levels

 

Action and Limit Levels for 24-hour TSP

 

Monitoring Station

Action Level (mg/m3)

Limit Level (mg/m3)

AM1

177.4

260

AM2

205.0

260

 

Action and Limit Levels for 1-hour TSP

 

Monitoring Station

Action Level (mg/m3)

Limit Level (mg/m3)

AM1

311.2

500

AM2

368.6

500

 

Action and Limit Levels (Leq) for Construction Noise

 

Time Period

Action Level

Limit Level

NMC1

NMC2

NMC3

0700 – 1900 hours on normal weekdays

When one documented complaint is received from any one of the sensitive receivers

75

70/65*

70/65*

0700 – 2300 hours on public holidays including Sundays and

1900 – 2300 hours on all days

Subject to requirements stipulated in future Construction Noise Permits

2300 – 0700 on all days

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

 

Action and Limit Levels for Water Quality

 

Parameters

Action

Limit

DO in mg/L

(Surface & Middle, Bottom)

Surface & Middle

5.4 mg/L

Bottom

5.2 mg/L

Surface & Middle

4.0 mg/L

Bottom

2.0 mg/L

SS in mg/L

(depth-averaged)

17.7 mg/L and 120% of upstream control station's SS at the same tide of the same day

20.5 mg/L and 130% of upstream control station's SS at the same tide of the same day

Turbidity in NTU

(depth-averaged)

9.6 NTU and 120% of upstream control station's Turbidity at the same tide of the same day

10.8 NTU and 130% 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 and SS, non-compliance of the water quality limits occurs when monitoring result is higher than the limits. 

                  4.   All the figures given in the table are used for reference only and the EPD may amend the figures whenever it is considered as necessary.