| Value | Category | Cases | |
|---|---|---|---|
| 1 | porous cesspit | 84 | 
                                                                 
                                    
                                    32.3%
                                 
                                                             | 
                                                        
                    
| 2 | Sewage network | 36 | 
                                                                 
                                    
                                    13.8%
                                 
                                                             | 
                                                        
                    
| 3 | tight cesspit | 125 | 
                                                                 
                                    
                                    48.1%
                                 
                                                             | 
                                                        
                    
| 4 | Other | 15 | 
                                                                 
                                    
                                    5.8%
                                 
                                                             |