| Value | Category | Cases | |
|---|---|---|---|
| 1 | porous cesspit | 108 | 
                                                                 
                                    
                                    39.3%
                                 
                                                             | 
                                                        
                    
| 2 | Sewage network | 39 | 
                                                                 
                                    
                                    14.2%
                                 
                                                             | 
                                                        
                    
| 3 | tight cesspit | 114 | 
                                                                 
                                    
                                    41.5%
                                 
                                                             | 
                                                        
                    
| 4 | Other | 14 | 
                                                                 
                                    
                                    5.1%
                                 
                                                             |