Question

Which out of the following is NOT a source of water pollution?

• A. Sewage Disposal
• B. Urban run-off
• C. Combustion of coal
• D. Run-off over cultivated lands

Hint:

Pollution source classification:
Water Pollution Sources: Domestic sewage, industrial wastewater, agricultural chemical run-off, urban surface wash.
Air Pollution Sources: Combustion of coal, vehicular emissions, burning of fossil fuels, smelting emissions.

Answer 1

The Correct Option is C

Concept:
Environmental pollution is the contamination of physical and biological components of the earth/atmosphere system to such an extent that normal environmental processes are adversely affected.
Water pollution specifically occurs when undesirable chemical, biological, or physical substances enter water bodies, deteriorating water quality and making it toxic to living organisms.

Step 1: Evaluating Direct Sources of Water Pollution:
Sewage disposal involves domestic wastewater carrying organic matter, toxic pathogens, and detergents directly into water channels.
Urban run-off gathers motor oil, heavy metals, road debris, and municipal litter, discharging them directly into stormwater drains and urban rivers.
Run-off over cultivated lands carries chemical fertilizers, pesticides, herbicides, and insecticides into streams and groundwater reserves, causing eutrophication.
All three options are primary direct sources of aquatic pollution.

Step 2: Evaluating the Combustion of Coal:
Combustion of coal in thermal power plants and factories releases particulate matter, sulfur dioxide ($\text{SO}_2$), nitrogen oxides ($\text{NO}_x$), and carbon dioxide ($\text{CO}_2$) directly into the atmosphere.
Therefore, the combustion of coal is classified primarily as a major source of air pollution.
Final Answer:
Hence, Combustion of coal is NOT a direct source of water pollution.