Question

River Yamuna is polluted near Delhi due to: 
1. Water animals 
2. Rivers joining it
3. Discharge of untreated sewage 
4. Thermal plant on its bank 

Answer 1

Correct Answer - Option 3 : Discharge of untreated sewage 

The correct answer is Discharge of untreated sewage.

• Untreated sewage refers to wastewater which contains harmful waterborne pathogens and bacteria and which has not yet gone through a sewage treatment plant.
• Water pollution is a major environmental issue in India. The largest source of water pollution in India is untreated sewage.
• Other sources of pollution include agricultural runoff and unregulated small scale industry.
• Irrigation canals whisk away clean water soon after the rivers reach the plains, denying water to flow in the river downstream.
• What flows into the river is water trickling in from small insignificant streams and drains carrying untreated sewage and effluents.
• The river-turned drain flow downstream with little or no freshwater unless a large river augments the depleted flows.
• As the quantity of fresh water in the river is negligibly small, pollution either from urban and rural areas, industries or even natural forms of pollution can not get diluted and its ill effects are not reduced.
• The Yamuna has almost no water at Tajewala in Haryana where the Eastern Yamuna Canal and the Western Yamuna Canal abstract all the water for irrigation.