Water Pollution: Contamination of water with the substances harmful for life is called water pollution. 

Causes of water pollution: 

(a) Water becomes polluted when industrial waste, garbage, polythene and other waste mixes with water.

(b) Dirty water of rural drains mixes with pond water and rivers.

(c) Washing clothes, bathing, washing utensils, dumping garbage, giving bath to animals, dispose of solid and liquid waste, cleaning of vehicles in ponds and rivers make water polluted.

(d) Pesticides and chemical fertilizers used increase growth of crops when reaches to rivers along with rain water they become polluted.

(e) Polluted water makes oceanic water polluted. Atomic test domestic oceans, radiations of these explosions make oceanic water polluted.

Effect of water pollution:

Solid waste deposited in water make water polluted. This polluted water contains various, microbes, fungi, parasites etc. Such water can cause infections and diseases like Cholera, diarrhea, skin diseases etc. Polluted water decreases the supply of oxygen to aquatic plants and animals, it puts an adverse effect on their growth. Hence their number is decreasing day-by-day. Polluted water makes soil polluted, it decreases its fertility. Oil refineris, paper industries, textile and sugar industries emit chemicals in which poisonous substances like – lead, arsenic, fluoride are present. These mixes with soil and produce toxicity in animals and plants. Hot water expelled by electric plants and industries, increases the temperature of ponds and put an adverse effect on aquatic life. Pesticides and insecticide dissolved water reach to the underground and makes it polluted.

Measures to control water pollution: 

(a) Waste from the industries should not disposed in rivers. 

(b) According to the laws passed by the government these wastes should be treated in treatment of plants and then should be drained. These laws should be followed strictly. 

(c) Atomic explosions should be banned in oceans.

(d) Washing clothes, bathing of animals, washing utensils in rivers should be banned.

(e) Solid and liquid waste should not be passed near banks of rivers and ponds.

(f) Water supply sources should be checked and cleaned regularly.

(g) Domestic waste should be dumped at right place in options.

(h) At every rural and tehsil level water purifier plants should be installed so pollutants from water should be removed.