Untreated sewage is the leading cause of water pollution, contributing to diseases like diarrhea cholera, and typhoid. Rivers like the Godavari and Krishna are heavily polluted., Septic tank effluent, if discharged directly into the sea without proper treatment, can introduce pathogens (bacteria, viruses), nutrients (nitrates, phosphates), and other pollutants into the marine environment. severe sewage management crisis, driven by rapid urbanization, inadequate infrastructure, and poor maintenance.