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Wastewater Treatment and Reuse

PYQs

8

Articles

1

Momentum

21

Phase IFoundation

Background

Overview

Essential for sustainable water management, reducing environmental pollution, and addressing water scarcity in urban and industrial sectors. Directly relevant to GS3 (Environment, Infrastructure) and GS1 (Water Resources).

Wastewater treatment involves removing contaminants from sewage and industrial effluents to produce an effluent suitable for discharge or reuse. Wastewater reuse, particularly of treated municipal wastewater, is an increasingly vital strategy for augmenting water supplies, reducing pollution, and promoting a circular economy in water-stressed regions.

Phase IIStatic core

Facts & tables

Key facts

Policy Mandate

BWSSB mandated the use of treated water for non-potable purposes in Bengaluru.

Economic Aspect

Treated water is sold at a nominal cost (₹10 per kilolitre) to encourage adoption.

Adoption Barriers

Challenges in adoption by smaller construction projects and public resistance for uses like swimming pools.

Decentralized Reuse

Efforts to map proximate users for surplus treated water from apartment Sewage Treatment Plants (STPs).

Reference table

Static syllabus anchors

TypeReference
Conceptual areaWaste Management & Water Pollution
Conceptual areaEnvironmental Law & Policy

Reference table

Institutions & roles

BodyRole
Bangalore Water Supply and Sewerage Board (BWSSB)Regulates, promotes, supplies
Confederation of Real Estate Developers’ Associations of India (CREDAI)Advocates for industry adoption
Phase IIIExam lens

Prelims angle

Overview

Prelims angle: Statement-based questions

Prelims angle: Conceptual understanding

Quick revision

  • Treated water reuse augments urban water supply.
  • STPs are central to wastewater treatment infrastructure.
  • Policy mandates (e.g., for construction, pools) drive adoption.
  • Public perception and cost are key barriers.
  • Integration into building codes (National Building Code) is advocated.

High-confidence PYQs

2024Multi-statement analysis, Conceptual understanding

Consider the following materials: 1. Agricultural residues 2. Corn grain 3. Wastewater treatment sludge 4. Wood mill waste Which of the above can be used a...

Environment & EcologyOpen question

With reference to perfluoroalkyl and polyfluoroalkyl substances (PFAS) that are used in making many consumer products, consider the following statements : 1...

Environment & EcologyOpen question
2024Factual recall, Multi-statement analysis

Consider the following materials: 1. Agricultural residues 2. Corn grain 3. Wastewater treatment sludge 4. Wood mill waste Which of the above can be used a...

Environment & EcologyOpen question

With reference to perfluoroalkyl and polyfluoroalkyl substances (PFAS) that are used in making many consumer products, consider the following statements : 1...

Environment & EcologyOpen question
2023Statement-based questions, Conceptual understanding

With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements: 1. Biofilters provide waste treatment by r...

Environment & EcologyOpen question
2018Cause and effect relationships, Multi-statement analysis

Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds? 1. Decreased salinity in the river 2. Pollution of groundwater ...

Environment & EcologyOpen question
2016Multi-statement analysis, Institutional roles and functions

Which of the following are the key features of ‘National Ganga River Basin Authority (NGRBA)’? 1. The river basin is the unit of planning and management. 2...

Environment & EcologyOpen question
2015Statement-based questions, Multi-statement analysis

With reference to bio-toilets used by the Indian Railways, consider the following statements: 1. The decomposition of human waste in the bio-toilets is init...

Environment & EcologyOpen question

With reference to ‘fly ash’ produced by the power plants using coal as fuel, which of the following statements is/are correct? 1. Fly ash can be used in the ...

Environment & EcologyOpen question
2015Statement-based questions, Factual recall

With reference to bio-toilets used by the Indian Railways, consider the following statements: 1. The decomposition of human waste in the bio-toilets is init...

Environment & EcologyOpen question

With reference to ‘fly ash’ produced by the power plants using coal as fuel, which of the following statements is/are correct? 1. Fly ash can be used in the ...

Environment & EcologyOpen question
2013Factual recall

Which one among the following industries is the maximum consumer of water in India?

Environment & EcologyOpen question

Topic timeline

Waste Management & Water PollutionEnvironmental Law & Policy
Prelims 2013· Factual recall

Which one among the following industries is the maximum consumer of water in India?

Open question
Prelims 2015· Statement-based questions, Multi-statement analysis

With reference to bio-toilets used by the Indian Railways, consider the following statements: 1. The decomposition of human waste in the bio-toilets is init...

Open question

With reference to ‘fly ash’ produced by the power plants using coal as fuel, which of the following statements is/are correct? 1. Fly ash can be used in the ...

Open question
Prelims 2015· Statement-based questions, Factual recall

With reference to bio-toilets used by the Indian Railways, consider the following statements: 1. The decomposition of human waste in the bio-toilets is init...

Open question

With reference to ‘fly ash’ produced by the power plants using coal as fuel, which of the following statements is/are correct? 1. Fly ash can be used in the ...

Open question
Prelims 2016· Multi-statement analysis, Institutional roles and functions

Which of the following are the key features of ‘National Ganga River Basin Authority (NGRBA)’? 1. The river basin is the unit of planning and management. 2...

Open question
Prelims 2018· Cause and effect relationships, Multi-statement analysis

Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds? 1. Decreased salinity in the river 2. Pollution of groundwater ...

Open question
Prelims 2023· Statement-based questions, Conceptual understanding

With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements: 1. Biofilters provide waste treatment by r...

Open question
Prelims 2024· Multi-statement analysis, Conceptual understanding

Consider the following materials: 1. Agricultural residues 2. Corn grain 3. Wastewater treatment sludge 4. Wood mill waste Which of the above can be used a...

Open question

With reference to perfluoroalkyl and polyfluoroalkyl substances (PFAS) that are used in making many consumer products, consider the following statements : 1...

Open question
Prelims 2024· Factual recall, Multi-statement analysis

Consider the following materials: 1. Agricultural residues 2. Corn grain 3. Wastewater treatment sludge 4. Wood mill waste Which of the above can be used a...

Open question

With reference to perfluoroalkyl and polyfluoroalkyl substances (PFAS) that are used in making many consumer products, consider the following statements : 1...

Open question

Bengaluru: Treated water sales up, but not yet at summer levels 

06 Aug 2026 · Wastewater treatment and reuse are critical for urban water security, involving STPs and policy mandates, but face hurdles in public acceptance and widespread implementation.

Read article

Related topics

Current topic

Wastewater Treatment and Reuse

Practice writing on this topic

UPSC has asked 8 linked questions on Wastewater Treatment and Reuse in Mains. Write an answer to one — and get it evaluated.

See Mains PYQsEvaluate an answer

UPSC Prelims PYQs on Wastewater Treatment and Reuse

Practice official previous year questions asked by UPSC related to this concept.

With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements: 1. Biofilters provide waste treatment by r...

2023·Environment & Ecology
Solve

With reference to bio-toilets used by the Indian Railways, consider the following statements: 1. The decomposition of human waste in the bio-toilets is init...

2015·Environment & Ecology
Solve

Consider the following materials: 1. Agricultural residues 2. Corn grain 3. Wastewater treatment sludge 4. Wood mill waste Which of the above can be used a...

2024·Environment & Ecology
Solve

Which one among the following industries is the maximum consumer of water in India?

2013·Environment & Ecology
Solve

With reference to ‘fly ash’ produced by the power plants using coal as fuel, which of the following statements is/are correct? 1. Fly ash can be used in the ...

2015·Environment & Ecology
Solve

Which of the following are the key features of ‘National Ganga River Basin Authority (NGRBA)’? 1. The river basin is the unit of planning and management. 2...

2016·Environment & Ecology
Solve

With reference to perfluoroalkyl and polyfluoroalkyl substances (PFAS) that are used in making many consumer products, consider the following statements : 1...

2024·Environment & Ecology
Solve

Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds? 1. Decreased salinity in the river 2. Pollution of groundwater ...

2018·Environment & Ecology
Solve

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