Without scheduled desludging, untreated sewage and sludge solids will be released into rivers. This will cause depletion of dissolved oxygen in these rivers, resulting in the death of aquatic life. The large quantities of sludge that settle to the bottom of rivers will also kill off any aquatic plants that contribute oxygen to the rivers. This will cause our rivers to eventually 'die'.
In addition, untreated sewage also poses a threat to public health since it may contain pathogenic bacteria and viruses that cause deadly diseases such as cholera, typhoid and hepatitis A.
All septic tanks need to be desludged on a regular basis, that is once in two years.
The naked eye cannot see the bacteria contained in raw sewage that is released into the waterways.