Physical, biological and chemical parameters of river water samples at the same period of time as the survey
| Waste point | |||
|---|---|---|---|
| −1 km | +1 km | Sering | |
| *NTU, nephelometric turbidity unit; †MPN/100ml, most probable number/100 ml; ‡COD, chemical oxygen demand; §BOD, biological oxygen demand. | |||
| Physical and biological: | |||
| Temperature (°C) | 29 | 29 | 29 |
| Total suspended solid (mg/l) | 15 | 14 | 11 |
| Turbidity (NTU)* | 15.9 | 18.5 | 14.2 |
| Coliform MPN/100ml† | 8 | 9 | 10 |
| Faecal coliform MPN/100ml† | Nil | Nil | 6 |
| Chemical: | |||
| pH | 5.8 | 5.8 | 6.0 |
| Total N as NH3 | 0.28 | 0.31 | 0.25 |
| Nitrite | 0.01 | 0.01 | 0.01 |
| Nitrate | 0.3 | 0.3 | 0.2 |
| Phosphate | 0.01 | 0.01 | 0.01 |
| Alkalinity | 10.0 | 8.5 | 8.2 |
| Ca hardness | 2.5 | 2.1 | 2.5 |
| Chloride | 4.52 | 4.96 | 4.62 |
| Residual Cl2 | Nil | Nil | Nil |
| COD‡ | 19 | 18 | 14 |
| BOD§ | 4 | 3 | 4 |