(a) Water, a vital element of environment, is polluted in different ways. (complex) People pollute water by throwing waste into it. Fanners use chemicals, fertilizers and insecticides in the fields. (b) When rain and flood wash away some of these chemicals, they get mixed with water. (simple) (c) Mills and factories also pollute water. (passive) (d) Water vehicles pollute rivers by dumping oil, food waste and human waste into them. (compound) (e) Thus water is contaminated by various kinds of waste and filth. (Active)