Table 3.2d Action and Limit
Levels for Water Quality
Parameter (unit) |
Water Depth |
Action Level |
Limit Level |
Dissolved Oxygen (mg/L) (surface, middle, bottom) |
Surface and Middle |
5.0 |
4.2 except 5 for FCZ |
Bottom |
4.7 |
3.6 |
|
Turbidity (NTU) |
Depth average |
27.5 and 120% of upstream control station’s turbidity
at the same tide of the same day |
47.0 and 130% of turbidity at the upstream control
station at the same tide of same day |
Suspended Solids (mg/L) |
Depth average |
23.5 and 120% of upstream control station’s SS
at the same tide of the same day |
34.4 and 130% of SS at the upstream control station at
the same tide of same day and
10mg/L for WSD Seawater Intakes |
Note:
(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 limit occurs when monitoring result is lower that the limit.
(3) For SS & turbidity
non-compliance of the water quality limits occur 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.
(5) The 1%-ile
of baseline data for dissolved oxygen (surface and middle) and dissolved oxygen
(bottom) are 4.2mg/L and 3.6mg/L respectively.