The river flows through 100 cities with populations over 100,000, and 97 cities and 48 towns with populations between 50,000 to 100,000. A large proportion of sewage water with higher organic load in the Ganges is from this population through domestic water usage. Because of the establishment of a large number of industrial cities on the bank of the Ganges like Kanpur, Prayagraj/Allahabad, Varanasi and Patna, countless tanneries, chemical plants, textile mills, distilleries, slaughterhouses, and hospitals prosper and grow along this and contribute to the pollution of the Ganges by dumping untreated waste into it. One coal-based power plant on the banks of the Pandu River, a Ganges tributary near the city of Kanpur, burns 600,000 tons of coal each year and produces 210,000 tons of fly ash. The ash is dumped into ponds from which a slurry is filtered, mixed with domestic wastewater, and then released into the Pandu River. Fly ash contains toxic heavy metals such as lead and copper. The amount of parts per million of copper released in the Pandu before it even reaches the Ganges is thousand times higher than what is there in the uncontaminated water.

Industrial effluents are about 12 percent 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. Despite being a lifeline of millions of people staying along its course Ganga is steadily getting sick for many reasons; some due to apathy of people and some due to natural phenomena. Lifeline of a large number of Indians and a spiritual mooring for a large number of Hindus not only in India but all over the world, Ganga is reckoned as one of the most polluted river in the world today. Some of the important reasons are discussed in succeeding paragraphs.

Sewage from many cities along the river’s course, industrial waste especially from the tanneries and religious offerings wrapped in non-degradable plastics, add large amounts of pollutants to the river as it flows through densely populated areas. During festival season immersion of idles having large amount of plastic and chemicals further add to the pollution of the water. The River is also used for throwing the half burnt dead bodies and animal carcass which add to the pollution of the water. During Monsoon when river water invades the flood plains, the pesticides and chemical manures used in the fields located near the river course; further contaminate the water.

Despite the ongoing campaign against the open defecation, the fact remains that the flood plains are still used by a large number of people as areas for defecating. Feces thus generated find way into the river water. Case in point is the state at Varanasi. The levels of fecal coliform bacteria from human waste in the river near Varanasi, the most ancient living city of the world and a very sacred seat of Hindu faith, today is said to be more than a hundred times that of the Indian government’s stated official limit. It is because Varanasi is a city of over 1.2 million people and is visited by a large number of pilgrims to take holy dip in the Ganges. Such a heavy concentration of human beings releases around 200 million litres of untreated human sewage into the river each day, leading to large concentrations of fecal coliform bacteria. Story is same with other cities and human concentrations located on the banks of River.

A large number of small streams join the river during her journey in the mountains, however over a period of time, due to increasing pressure of the population, people have settled next to these small streams and thus the flow of these streams into the main course of the river gets blocked. Such activities reduce the supply of fresh water into the river rendering its quality getting further degraded.

Large scale deforestation in the catchment areas further reduces soil’s capacity to arrest flow of water and accentuates silt getting carried with the water. Global warming is resulting into faster melting of glacier (22 meters/year) and that will result into increasing instances of floods in the monsoon and increasing reduced flow of water in the main stream of the river in years ahead.