| Value | Category | Cases | Weighted | |
|---|---|---|---|---|
| 1 | Wastewater | 244 | 246 | 
                                                                 
                                    
                                    9.1%
                                 
                                                             | 
                            
                        
                        
                            
                    
| 2 | Dumping site | 143 | 140 | 
                                                                 
                                    
                                    5.1%
                                 
                                                             | 
                            
                        
                        
                            
                    
| 3 | Public restrooms | 2 | 3 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                            
                        
                        
                            
                    
| 4 | Transportation | 6 | 7 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                            
                        
                        
                            
                    
| 5 | Agricultural wastes | 324 | 303 | 
                                                                 
                                    
                                    11.1%
                                 
                                                             | 
                            
                        
                        
                            
                    
| 6 | Industrial activities | 8 | 10 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                            
                        
                        
                            
                    
| 7 | Other | 12 | 10 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                            
                        
                        
                            
                    
| Sysmiss | 1975 | 1997 |