Table 4.5 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%-ile of baseline data |
4 mg/L except 5mg/L for
FCZ or 1%-ile of baseline data |
|
Bottom |
5%-ile of baseline data |
2 mg/L or 1%-ile of baseline data |
|
|
Turbidity (NTU) |
Depth average |
95%-ile
of baseline data or 120% of upstream control station’s turbidity at the same
tide of the same day |
99%-ile
of baseline or 130% of turbidity
at the upstream control station at the same tide of same day |
|
Suspended Solids (mg/L) |
Depth average
|
95%-ile
of baseline data or 120% of upstream control station’s SS at the same tide of
the same day |
99%-ile
of baseline or 130% of SS at the
upstream control station at the same tide of same day and 10mg/L for WSD
Seawater Intakes |
(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.