Table 5.8          Modelling Results at Sensitive Receivers

 

Parameters

Predicted Concentration1

Wet Season Without Stratification

Wet Season With Stratification

Dry Season

0.1 m/s

0.5 m/s

0.1 m/s

0.5 m/s

0.05 m/s

0.5 m/s

At Gazetted FCZ 

BOD (mg/L)

1

1

1

1

1

1

SS (mg/L)

12

12

12

12

8

8

TKN (mg/L)

0.278

0.257

0.333

0.268

0.333

0.297

TIN (mg/L)

0.09

0.08

0.11

0.09

0.24

0.23

NH3-N (mg/L)

0.054

0.043

0.081

0.049

0.120

0.101

Unionised Ammonia2

(mg/L)

0.003

0.002

0.004

0.002

0.006

0.005

E. coli (counts per 100 mL)

23

22

25

23

87

85

At Secondary Contact Recreation Subzone at Mo Tat Wan

BOD (mg/L)

1

1

1

1

1

1

SS (mg/L)

12

12

12

12

8

8

TKN (mg/L)

0.275

0.256

0.317

0.263

0.330

0.296

TIN (mg/L)

0.09

0.08

0.10

0.09

0.24

0.23

NH3-N (mg/L)

0.052

0.043

0.073

0.046

0.118

0.101

Unionised Ammonia2

(mg/L)

0.002

0.002

0.003

0.002

0.006

0.005

E. coli (counts per 100 mL)

23

22

25

22

87

85

Note:

1      Background level were included.

2      Unionised ammonia concentration was calculated based on 4.7% of unionised ammonia constituting the total ammonia concentration at 22.4oC, pH 8.1, and salinity of 31.7ppt.