The Ganges river basin is one of the most fertile and densely populated regions in the world and covers an area of 1,080,000 km2 (400,000 square miles). The river flows through 29 cities with population over 100,000; 23 cities with population between 50,000 and 100,000, and about 48 towns.[6] A large proportion of the waste in the Ganges is from this population through domestic usage like bathing, laundry and public defecation.
Industrial wasteCountless tanneries, chemical plants, textile mills, distilleries, slaughterhouses, and hospitals contribute to the pollution of the Ganges by dumping untreated waste into it.[7] Industrial effluents are about 12% of the total volume of effluent reaching the Ganges. Although a relatively low proportion, they are a cause for major concern because they are often toxic and non-biodegradable.[2]Religious eventsDuring festival seasons, over 70 million people bathe in the Ganges over a few weeks[8] to cleanse themselves from their sins.
Some materials like food, waste or leaves are left in the Ganges for ritualistic reasons.[9]DamsBuilt in 1854 during the British colonization of India, the Haridwar dam has led to decay of the Ganges by greatly diminishing the flow of the river. The Farakka Barrage was built originally to divert fresh water into the Bhagirathi River but has since caused an increase of salinity in the Ganges, having a damaging effect on the ground water and soil along the river.[6] The barrage has caused major tension between Bangladesh and India. The government of India has planned about 300 dams on the Ganges and its tributaries in the near future despite a government-commissioned green panel report that has recommended scrapping 34 of the dams citing environmental concerns.
