In the recent past, due to rapid progress in communications and commerce, there has been a swift increase in the urban areas along the river Ganga, As a result the river is no longer only a source of water but is also a channel, receiving and transporting urban wastes away from the town. Today, one third of the country's urban population lives in the towns of the Ganga basin. Out of the 2,300 towns in the country, 692 are located in this basin, and of these, 100 are located among the river bank itself.
The belief the Ganga river is “holy” has not, however prevented over-use, abuse and pollution of the river. All the towns along its length contribute to the pollution load. It has been assessed that more than 80 percent of the total pollution load (in terms of organic pollution expressed as biochemical oxygen demand (130D, arises from domestic sources, i.e. from the settlements along the river course. Due to over-abstraction of water for irrigation in the upper regions of the river, the dry weather flow has been reduced to a trickle. Rampant deforestation in the last few decades, resulting in topsoil erosion in the catchment area, has increased silt deposits which, in turn, raise the river bed and lead to devastating floods in the rainy season and stagnant flow in the dry season. Along the main river course there are 25 towns with a population of more than 100,000 and about another 23 towns with populations above 50,000. In addition there are 50 smaller towns with populations above 20,000. There are also about 100 identified major industries located directly on the river, of which 68 are considered as gro.ly polluting. Fifty-five of these industrial units have complied with the regulations and installed effluent treatment plants (ETPs, a. legal proceedings are in progress. for the remaining unit. The natural assimilative capacity of the river is severely stressed.
Principal sources of pollution of the Ganga River can be characterized as follows:-
• Domestic and industrial wastes which are going into the river.
• Solid garbage thrown directly into the river.
• Non-point sources of pollution from agricultural run-off containing, residues of harmful pesticides and fertilizer.
• Animal carcasses and half-burned and unburned human corpses thrown into the river.
• Defecation on the banks by the low-income people.
• Mass bathing and ritualism, paradigms.