(i) What are the two main causes of river water pollution?

(ii) What can be the role of each individual in controlling water pollution?

• Pesticides and fertilisers: The excessive use of fertilisers and pesticides in the farms have resulted in the pollution of many river systems especially in the northern plains. The run-off of the polluted water from the farms to the rivers has caused many river systems to be highly polluted.

• Industrial waste: The industries always discharge their highly polluted water into the local water bodies. This discharge of the untested industrial waste is also a major source of water pollution, especially in the cities. Oil spills are also another major source of industrial pollution.

• Improper waste disposal: The improper disposal of waste and the disposal of plastic waste in water bodies can also result in water pollution. The disposal of plastic waste in the water bodies can result in clogging and the flow of water will be disrupted.

• Mining and other extraction: The extraction of natural resources from the surface of the earth can result in the pollution of the water bodies nearby. The extraction process can result in the generation of certain chemicals, thereby polluting the water bodies.

(ii)

The water resources are being exploited at an increasing rate across the country. When the rivers enter the plains and deltas, the excessive use of water for agricultural purposes has resulted in the depletion of water table. The overuse of fertilisers and pesticides has resulted in the pollution of the major river systems. Man legal measures have been taken by the government to control water pollution in the country. It includes the enactment of various acts and laws including the Water (Prevention and Control of Pollution) Act 1974, the Environment Protection Act 1986 and the Water Cess Act, 1977. The individuals can also contribute to controlling water pollution. Some important measures that can be taken are:

• Recycle and reuse: Lesser quality water can be reused and recycled for other uses. The water after bathing and washing can be used for gardening. This would conserve the better quality of water for drinking and other purposes. It can also be expanded to industrial areas. The water of lesser quality can be used in industries for cooling and fire fighting. This will help in the conservation of freshwater resources.

• Watershed management: It focuses on the replenishment and the efficient utilisation of groundwater resources. It involves the prevention of runoff and storage and recharge of groundwater through the participation of the society. Haryali, Neeru-Meeru and Arvary Pani Sansad are some schemes of watershed management.

• Rainwater harvesting: Rainwater harvesting is the method to collect and store rainwater for various uses. It is also used to recharge groundwater aquifers. It has been in practice for a long time using different methods. Recharging the groundwater through ponds, lakes and canals and building harvesting plants in homes are some of them.