Prevention of Water Pollution

Water pollution is not just a problem of dirty rivers — it is a crisis of mismanagement, weak laws, and public apathy. The textbook makes this clear by tracing pollution from its sources to its consequences, and then examining why existing laws have failed.

The quality of river water in India depends heavily on location. In the upper, less densely populated stretches of the hilly regions, the major rivers generally retain better water quality. Once these rivers enter the plains, the situation changes drastically. Here, river water is used intensively for irrigation, drinking, domestic purposes, and industry. The drains that carry agricultural runoff (containing fertilisers and insecticides), domestic waste (both solid and liquid), and industrial effluents all empty into the rivers.

Pollution levels are not uniform throughout the year. The concentration of pollutants in rivers remains especially high during the summer season, when the flow of water is low. With less water to dilute the waste, the same amount of pollution becomes far more concentrated.

To track this problem, the Central Pollution Control Board (CPCB), working with State Pollution Control Boards, monitors the water quality of national aquatic resources at 507 stations across the country. The data collected from these stations reveals a clear pattern: organic and bacterial contamination continues to be the main source of pollution in rivers.

Some rivers are far worse off than others. The Yamuna river is the most polluted river in the country, particularly between Delhi and Etawah. Other severely polluted rivers include:

• The Sabarmati at Ahmedabad
• The Gomti at Lucknow
• The Kali
• The Adyar
• The Cooum (entire stretches)
• The Vaigai at Madurai
• The Musi of Hyderabad
• The Ganga at Kanpur and Varanasi

Groundwater, too, has not escaped contamination. Pollution of groundwater has occurred due to high concentrations of heavy or toxic metals, fluoride, and nitrates in different parts of the country.