| Value | Category | Cases | |
|---|---|---|---|
| 1 | porous cesspit | 90 | 
                                                                 
                                    
                                    34%
                                 
                                                             | 
                                                        
                    
| 2 | Sewage network | 37 | 
                                                                 
                                    
                                    14%
                                 
                                                             | 
                                                        
                    
| 3 | tight cesspit | 110 | 
                                                                 
                                    
                                    41.5%
                                 
                                                             | 
                                                        
                    
| 4 | Other | 28 | 
                                                                 
                                    
                                    10.6%
                                 
                                                             |