| Value | Category | Cases | |
|---|---|---|---|
| 1 | porous cesspit | 113 | 
                                                                 
                                    
                                    41.2%
                                 
                                                             | 
                                                        
                    
| 2 | Sewage network | 38 | 
                                                                 
                                    
                                    13.9%
                                 
                                                             | 
                                                        
                    
| 3 | tight cesspit | 112 | 
                                                                 
                                    
                                    40.9%
                                 
                                                             | 
                                                        
                    
| 4 | Other | 11 | 
                                                                 
                                    
                                    4%
                                 
                                                             |