STS

Pond

Surface area (m2)

Hydraulic retention time (Days)

Effluent BOD (mg/l)

Effluent faecal coliforms (FC per 100 ml)

Anaerobic pond

A

2220

3

244

5,681,818

Facultative ponds

F1

3024

3

128

645,661

F2

3024

2.7

71

80,506

Maturation ponds

M1

3024

2

44.4

12,985

M2

3360

2.2

26.7

1,932

Constructed Wetland

VSF

465

0.1

24.3

1674

HSSF

1396

0.2

20

195

TOTAL

16,513

13.2