Table 2 Interim National Water Quality Standards (INWQS).
Parameter | National water quality standards for Malaysia (designated classes) | ||||||
|---|---|---|---|---|---|---|---|
I | IIA | IIB | III | IV | V | ||
Ammoniacal nitrogen | mg/L | 0.1 | 0.3 | 0.3 | 0.9 | 2.7 | > 2.7 |
Oil and grease (mineral) | mg/L | Natural LeveL | 40; N | 40; N | N | – | Level Above IV |
Oil and grease (emulsified) | mg/L | Natural LeveL | 7000; N | 7000; N | N | – | Level Above IV |
Biological oxygen demand | mg/L | 1 | 3 | 3 | 6 | 12 | > 12 |
Chemical oxygen demand | mg/L | 10 | 25 | 25 | 50 | 100 | > 100 |
Dissolved oxygen | mg/L | 7 | 5–7 | 5–7 | 3–5 | < 3 | < 1 |
pH | – | 6.5–8.5 | 6–9 | 6–9 | 5–9 | 5–9 | – |
Total suspended solid | mg/L | 25 | 50 | 50 | 150 | 300 | 300 |
Temperature | OC | – | Normal + 2 °C | – | Normal + 2 °C | – | – |
E-coli | MPN/100 mL | – | – | – | – | – | – |
Turbidity | NTU | 5 | 50 | 50 | – | – | – |
