Introduction

India is facing an acute river pollution crisis these days. Nearly all of the country's major rivers are burdened with immense amounts of municipal sewage, industrial effluents, solid waste and other harmful substances. Pollution, moreover, is spreading fast. According to a recent report by the Indian government's Central Pollution Control Board, the number of polluted rivers rose from 121 in 2009 to 275 in 2015, while the number of polluted river stretches more than doubled during the same period, increasing from 150 to 302. ¹ A primary example for the extent of this crisis is the Ganges. Banaras, Kanpur and other riparian cities discharge over 2,600 million litres of sewage into the river daily. Most of this is raw sewage, since existing sewage treatment plants handle only a fraction of the total amount and are often inadequately operated. Additionally, tanneries, oil refineries, paper mills, pharmaceutical and other industries discharge 290 million litres of often highly toxic industrial wastes. Agricultural runoff (containing pesticide and fertiliser residues), solid waste, and waste generated in connection with religious worship count among the many other sources of pollution. ² At the same time, the river's ability to regenerate itself steadily diminishes, as water levels keep dropping due to over-extraction and the construction of countless dams. ³ Consequently, the Ganges – officially declared as India's ‘national river’ by Prime Minister Manmohan Singh in 2008 – has turned into one of most polluted rivers in the world.