Q.Why are the rivers of India polluted, and how can they be made pollution-free?

Rivers in India get polluted from several converging sources. Domestic sewage, often untreated, is the biggest contributor, carrying organic waste and disease-causing pathogens. Industrial effluents from factories add toxic chemicals, heavy metals, and hot water, which kill aquatic life. Agricultural runoff brings in fertilisers and pesticides, causing nutrient overload and algal blooms. On top of this, religious practices like idol immersion and the dumping of solid waste and cremation ashes add to the load, while many cities lack proper sewage treatment plants. …

The rivers of India are not just water bodies; they are living arteries of civilisation, faith, and livelihood. From the Ganga to the Godavari, these rivers sustain hundreds of millions of people. Yet, over the past few decades, they have become open drains for the waste of a rapidly growing nation. The pollution is not a single problem but a web of causes, each feeding the other, and each demanding a different kind of remedy.

The most dominant cause is untreated domestic sewage. Indian cities and towns generate enormous quantities of wastewater, but a large share of it flows directly into rivers without any treatment. The sheer volume of human waste, soap, detergents, and household chemicals overwhelms the natural self-purifying capacity of the rivers. When organic matter decomposes in water, it consumes dissolved oxygen, and fish and aquatic life suffocate. The water turns foul, and the same river that once provided drinking water becomes a carrier of disease.

Industrial pollution is the second major culprit. Factories along riverbanks — tanneries, textile mills, paper plants, chemical units, and sugar mills — discharge their effluents directly into the water. These effluents contain heavy metals like lead, mercury, and chromium, along with acids, dyes, and toxic chemicals. Unlike sewage, which is organic and can be broken down, many industrial pollutants are persistent. They accumulate in the food chain, poison the water for decades, and make it unfit even for irrigation in some stretches. The problem is worsened by the fact that many small-scale industries operate without any effluent treatment plant, either because they cannot afford one or because enforcement is weak.

Agricultural runoff adds a quieter but equally damaging layer. Modern farming uses chemical fertilisers and pesticides in large quantities. When it rains, these chemicals are washed off the fields into nearby streams and rivers. Fertilisers rich in nitrogen and phosphorus cause eutrophication — a process where algae bloom excessively, then die and decompose, depleting oxygen and creating dead zones in the water. Pesticides, meanwhile, are toxic to aquatic organisms and can enter the human body through drinking water and fish consumption.

Religious and cultural practices also contribute, though their share is often overstated in public discourse. Immersion of idols, disposal of flowers, and the release of ashes and offerings add organic and sometimes chemical load to the water. The paints used on idols often contain heavy metals, and the non-biodegradable materials used in decorations persist in the riverbed. While these practices are deeply rooted in tradition, their environmental impact is real, especially when they are concentrated at particular ghats during festivals.

Making rivers pollution-free is not impossible, but it requires a shift from symbolic gestures to systematic action. The first and most fundamental step is to build and operate sewage treatment plants in every town and city that lies on a riverbank. But building the plant is only half the battle — the sewage must actually be collected, the plant must run at full capacity, and the treated water must meet standards before being released. This requires continuous electricity, trained staff, and maintenance budgets, all of which have historically been neglected. …