List main sources of water pollution.

Main sources of water pollution are-

● Waste from farms i.e. fertilizers and pesticides. The chemicals in them pollute the water.

● Industries release their waste products directly into the rivers thus degrading water quality. Industries also contribute to thermal pollution as the coolants discharged by them causes a change in the average temperature of water, therby degrading the water quality.

● Disease causing agents like bacteria, viruses and protozoans enter the sewage system. This sewage is ultimately discharged into water bodies like sea