WHY YOU NEED A BIODIGESTER. 1. The discharge of untreated wastewater on economically important natural resources such as rivers and seas, and their ecosystems leads to their destruction. 2. The inadequate handling and disposal of sewage lead to health problems. 3. Household sewage generated is causing serious pollution of surface and ground waters. 4.The present ‘on-site’ systems of sewage disposal do not provide much in the way of treatment. 5. The extremely high cost of high tech systems (acti