Table 2.2 Action and Limit Levels for Marine Water Quality

Parameters	Action	Limit
DO in mg/L (Surface, Middle & Bottom)	Surface and Middle 1 percentile of baseline data; or midway between 5 percentile of baseline data and limit level Bottom 1 percentile of baseline data or midway between 5 percentile of baseline data and limit level	Surface and Middle 4 mg/L Bottom 2 mg/L
SS in mg/L (depth-averaged)	95 percentile of baseline data or 120% of upstream control station's SS at the same tide of the same day	99 percentile of baseline or 130% of upstream control station's SS at the same tide of the same day
Turbidity in NTU (depth-averaged)	95 percentile of baseline data or 120% of upstream control station's Turbidity at the same tide of the same day	99 percentile of baseline or 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.