What is water pollution?

Water pollution is the contamination of water, i.e. changing of the physical, chemical or biological properties of water or the emission of sewage or industrial discharge. It includes the introduction of any solid, liquid or gaseous pollutant into water (either directly or indirectly) which would make water toxic and injurious to the health of the public or for domestic, commercial, agricultural or other important purposes or be unsafe and harmful to the life and health of plants, animals and aquatic organisms^{(( Section 2(e), The Water (Prevention and Control of Pollution) Act, 1974.))}.

Causes of water pollution include:

i. Solid water pollutant. For example, plastic waste, metals, food and animal remains.

ii. Liquid water pollutant. For example, sewage, human waste and industrial waste water.

iii. Gaseous water pollutant. For example, methane, carbon dioxide, sulphur dioxide, nitrogen oxide.