| Value | Category | Cases | |
|---|---|---|---|
| 1 | porous cesspit | 118 | 
                                                                 
                                    
                                    41.4%
                                 
                                                             | 
                                                        
                    
| 2 | Sewage network | 43 | 
                                                                 
                                    
                                    15.1%
                                 
                                                             | 
                                                        
                    
| 3 | tight cesspit | 111 | 
                                                                 
                                    
                                    38.9%
                                 
                                                             | 
                                                        
                    
| 4 | Other | 13 | 
                                                                 
                                    
                                    4.6%
                                 
                                                             |