Appendix B
– Action and Limit Levels for Water Quality Monitoring during Post-Trenching Works
|
Parameter (unit) |
Water Depth |
Action Level |
Limit Level |
|
|
|||
|
DO
(mg/L) |
Surface
and Middle |
4.7 |
4 |
|
Bottom |
4.1 |
2 |
|
|
Turbidity
(NTU) |
Depth
average |
17.2 |
18.4 |
|
SS (mg/L) |
Depth
average |
10.2 |
10.7 |
|
|
|||
|
DO
(mg/L) |
Surface
and Middle |
5.0 |
5 |
|
Bottom |
3.3 |
2 |
|
|
Turbidity
(NTU) |
Depth
average |
14.0 |
21.9 |
|
SS (mg/L) |
Depth
average |
6.7 |
7.2 |
|
Ping Chau – PC-I1,
PC-I2 and PC-I3 |
|||
|
DO
(mg/L) |
Surface
and Middle |
4.8 |
4 |
|
Bottom |
2.9 |
2 |
|
|
Turbidity
(NTU) |
Depth
average |
11.2 |
13.0 |
|
SS (mg/L) |
Depth
average |
5.7 |
7.6 |
Notes:
-
For DO, non-compliance of the water quality limits
occurs when monitoring result is lower than the limits.
-
For turbidity and SS, non-compliance of water
quality limits occurs when monitoring result is higher than the limits.