| Value | Category | Cases | |
|---|---|---|---|
| 1 | Wastewater network | 1989 |
67.2%
|
| 2 | Tight cesspit | 308 |
10.4%
|
| 3 | Porous cesspit | 353 |
11.9%
|
| 4 | Others | 176 |
5.9%
|
| 5 | 136 |
4.6%
|