The Ganges is the local sewer.
I’d read a long time ago that efforts were made to clean up the Ganges. Now I read that those efforts are failed. This excerpt from Wikipedia gives one a sense of how things are going on this idyllic waterway:
Varanasi, a city of one million people that many pilgrims visit to take a “holy dip” in the Ganges, releases around 200 million liters of untreated human sewage into the river each day, leading to large concentrations of fecal coliform bacteria.[137] According to official standards, water safe for bathing should not contain more than 500 fecal coliforms per 100 ml, yet upstream of Varanasi’s ghats the river water already contains 120 times as much, 60,000 fecal coliform bacteria per 100 ml.[139][140]
After the cremation of the deceased at Varanasi’s ghats, the bones and ashes are immersed into the Ganges. However, in the past thousands of uncremated bodies were thrown into the Ganges during cholera epidemics, spreading the disease. Even today, holy men, pregnant women, people with leprosy or chicken pox, people who have been bitten by snakes, people who have committed suicide, the poor, and children under 5 are not cremated at the ghats but are left to float free, to decompose in the waters. In addition, those who cannot afford the large amount of wood needed to incinerate the entire body, leave behind many half-burned body parts