Question

Define water pollution. Describe main sources of water pollution.

Hint:

Categorize sources of pollution into 'point sources' (identifiable sources like a factory drainpipe) and 'non-point sources' (diffused sources like agricultural runoff). This structured approach helps in writing comprehensive answers.

Answer 1

Definition of Water Pollution:
Water pollution is the contamination of water bodies such as rivers, lakes, oceans, aquifers, and groundwater, usually as a result of human activities. It occurs when harmful substances (pollutants) are discharged directly or indirectly into water bodies without adequate treatment to remove them, making the water unfit for its intended uses like drinking, cooking, swimming, or fishing.
Main Sources of Water Pollution:
1. Domestic Sewage: Untreated or inadequately treated wastewater from households, containing human waste, food scraps, and detergents, is a primary source of organic and microbial pollution.
2. Industrial Effluents: Waste discharged from industries like chemical plants, tanneries, and textile mills often contains toxic chemicals, heavy metals (like lead and mercury), and thermal pollution (hot water).
3. Agricultural Runoff: Water flowing from agricultural fields carries fertilizers, pesticides, and herbicides into nearby water bodies, leading to eutrophication (excessive nutrient enrichment) and chemical contamination.
4. Solid Waste: Improper disposal of solid waste and plastics can end up in water bodies, choking aquatic life and leaching harmful chemicals.