River pollution occurs when pollutants are not removed from sewage and are discharged into the river. River water is a very important source of freshwater required to sustain life. We need a constant supply of fresh water for drinking, cooking and washing. Animals living near the river, as well as fishes and aquatic plants, also depend on clean river water.

       When heavy rainfall occurs, pollutants accumulated within the boundaries of the catchment area may be washed into river channels. These pollutants include a variety of agrochemicals like fertilizers and insecticides.

       Waste water containing cleaning detergents, oil and other pollutants like industrial waste may be discharged into the river channel through our drainage systems. Industrial waste may contain sulfur, resulting in increasing the acidity of the river water. Sometimes, rubbish such as plastic bags and bottles, are also washed into the river channel.

Answer the questions below:

1. When does river pollution occur?

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2.    What is the important role of fresh water to humans and animals?

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3.    What happens when heavy rainfall occurs in a polluted area?

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4.    How may waste water be discharged into the river?

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5.    What is the effect of industrial waste on the environment?

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