The world is facing an acute shortage of clean and safe freshwater. What are the alternative technologies which can solve this crisis? Briefly discuss any three such technologies citing their key merits and demerits.
Approach · directive: “what / discuss”
What it asks · Name alternative water technologies and evaluate three of them with merits and demerits.
The question has 2 parts — answer each
- What: the alternative technologies that can address the freshwater crisis
- Discuss any three of them with their key merits and demerits
Open with · Freshwater is a small share of Earth's water, and demand, pollution and climate change are shrinking what is usable.
Cover
- Options: desalination, wastewater recycling, atmospheric water generation, managed aquifer recharge, rainwater harvesting, fog harvesting, solar stills.
- Desalination (reverse osmosis): reliable coastal supply, as in Chennai's plants; but energy-intensive, costly, and brine harms marine life.
- Wastewater recycling: tertiary treatment for industry, farms and even drinking; cuts pollution and demand; needs investment and public acceptance.
- Atmospheric water generators: draw water from humid air, useful off-grid; high energy use, low output and humidity dependence.
- Managed aquifer recharge: cheap, stores water underground; depends on geology and clean recharge water.
- Cross-cutting: pair technology with pricing, leak control and renewable power to keep costs and emissions down.
Close with · No single technology suffices; a portfolio with conservation and reuse at its core offers the most sustainable path.
Add value (verified)
- WHO/UNICEF (2025): 1 in 4 people worldwide still lack safely managed drinking water. WHO — 1 in 4 people globally still lack access to safe drinking water (26 Aug 2025) ↗“Despite gains since 2015, 1 in 4 – or 2.1 billion people globally – still lack access to safely managed drinking water”
Question: UPSC's CS (Main) 2024, GS Paper III — paper ↗. Approach: Minimalist IAS, checked 30 Sept 2026 (how we verify) — UPSC publishes no model answers. ·
Model answer · 234 words (UPSC limit 250) · Minimalist IAS
Freshwater is a small share of Earth's water and most of it is locked in ice; WHO and UNICEF report that 1 in 4 people still lack safely managed drinking water, as pollution and climate change shrink the usable supply.
Alternative technologies
- Desalination, wastewater recycling, atmospheric water generation, managed aquifer recharge, rainwater harvesting, fog harvesting and solar stills — each suited to particular geographies.
Desalination (reverse osmosis)
- Merits: drought-proof supply for coastal cities, as at Chennai's Minjur and Nemmeli plants (100 MLD each); proven at scale.
- Demerits: energy-intensive and costly per litre; brine and chemicals harm marine life; membranes need imports and skilled upkeep.
Wastewater recycling
- Merits: tertiary treatment turns sewage into water for industry, farms and even drinking (Singapore's NEWater); cuts both demand and river pollution; Bengaluru sends treated water to fill Kolar's tanks.
- Demerits: high capital and energy cost, pathogen and micro-pollutant risks if standards slip, and public reluctance to accept reuse.
Atmospheric water generation
- Merits: draws potable water from humid air, useful for off-grid, coastal and disaster settings without pipelines.
- Demerits: heavy power use, low output and dependence on humidity make it unsuitable for arid regions at scale.
Cross-cutting lessons
- Technology works only with pricing, leak control, renewable power and reuse mandates that keep costs and emissions down.
No single technology suffices; a portfolio anchored in conservation and reuse, with desalination as a coastal backstop, offers the most sustainable way out.
Written by Minimalist IAS from facts checked at source (how we verify). UPSC publishes no model answers: compare your structure and coverage with this, then write your own.