| 指标 | 水质分类标准 | |||||
| Ⅰ类 | Ⅱ类 | Ⅲ类 | Ⅳ类 | Ⅴ类 | 劣V类 | |
| COD (mg/L) | ≤15 (0~15) | ≤15 (0~15) | ≤20 (15~20) | ≤30 (20~30) | ≤40 (30~40) | >40 |
| NH3-N (mg/L) | ≤0.15 (0~0.15) | ≤0.5 (0.15~0.5) | ≤1.0 (0.5~1.0) | ≤1.5 (1.0~1.5) | ≤2.0 (1.5~2) | >2.0 |
| TP (mg/L) (湖泊，水库) | ≤0.01 (0~0.01) | ≤0.025 (0.01~0.025) | ≤0.05 (0.025~0.05) | ≤0.10 (0.05~0.10) | ≤0.20 (0.10~0.20) | >0.20 |