---
title: "Water and air pollution in Nepal"
subject: "Technology, Environment and Society"
chapter: 5
key: "semester_7/technology_environment_and_society:water-air-pollution-nepal"
source: https://www.bctengineer.com/q/semester_7/technology_environment_and_society/water-air-pollution-nepal
site: BCT Engineering
---

# Water and air pollution in Nepal

Technology, Environment and Society · Chapter 5: Water and Air Pollution

- Asked in: 2072 Kartik, 8 marks
- Video: [How Bad Is Nepal’s Air Pollution? EXPLAINED](https://www.youtube.com/watch?v=F8QqCcyfMTg) — Sanjay Silwal Gupta
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/technology_environment_and_society/water-air-pollution-nepal
- Whole chapter: https://www.bctengineer.com/md/semester_7/technology_environment_and_society/chapter-5

## Question

Discuss the severity of water and air pollution problem in Nepal? Give your plans to solve this problem effectively and in short time.

## Short answer

Water pollution is severe: urban rivers are sewers, microbial contamination, arsenic in Terai, industrial effluents. Air pollution: high PM2.5 in Kathmandu and Terai, indoor smoke. Short-term solutions: enforce vehicle emission tests, pave roads, ban open burning, issue air alerts, test and chlorinate water, stop river dumping, and fine violators.

## Answer

**Water pollution** is the contamination of water by sewage, chemicals, pathogens or sediment that makes it unsafe for use; **air pollution** is the presence of harmful gases and particles in the atmosphere. Both are among the most serious environmental and health problems in Nepal.

#### Severity of water pollution in Nepal
1. **Urban rivers turned into sewers** – the Bagmati, Bishnumati and Dhobi Khola in Kathmandu receive untreated sewage and solid waste; dissolved oxygen is near zero in the dry season.
2. **Microbial contamination** – many piped and tanker supplies contain faecal coliform; outbreaks of cholera, typhoid and diarrhoea occur every monsoon.
3. **Arsenic in Terai groundwater** above the national standard (50 µg/L) in districts such as Nawalparasi, Rautahat and Bara.
4. **Iron, manganese, ammonia and nitrate** in Kathmandu valley and Terai groundwater.
5. **Industrial effluent** – tanneries, distilleries, dyeing and paper mills in industrial corridors discharge directly into rivers.
6. **Agro-chemicals and sediment** in rivers and wells.

#### Severity of air pollution in Nepal
1. **Kathmandu valley** – PM2.5 often many times the WHO guideline in winter and spring due to vehicles, road dust, brick kilns and waste burning, made worse by the bowl-shaped valley and temperature inversion.
2. **Terai cities** (Birgunj, Biratnagar, Bhairahawa) – industrial emissions and cross-border haze from the Indo-Gangetic plain.
3. **Indoor air pollution** – about half of households still cook with firewood, harming mainly women and children.
4. **Health burden** – air pollution is among the leading risk factors for death in Nepal (respiratory and heart disease, lung cancer).
5. **Other effects** – flight delays, damage to heritage, black carbon speeding snow melt.

#### Plans to solve the problem effectively and in a short time
**Short-term (1–2 years, quick wins)**
- Strict vehicle emission testing; remove vehicles older than 20 years from the valley.
- Finish and pave dug-up roads; sprinkle water; cover construction sites and trucks.
- Ban and fine open burning of waste; daily waste collection.
- Air quality alerts and school closures on hazardous days; masks for vulnerable groups.
- Test drinking water sources; chlorinate supplies; household treatment (boiling, filters, chlorine) during the monsoon.
- Stop direct dumping of waste into rivers; enforce existing effluent standards with fines.

**Medium-term (3–5 years)**
- Electric public buses and incentives for electric vehicles and induction cooking, using Nepal's hydropower.
- Convert all brick kilns to cleaner zig-zag technology.
- Complete sewer interceptors and wastewater treatment plants along the Bagmati (Bagmati Action Plan).
- Arsenic-safe deep tube wells and community treatment plants in the Terai.
- Effluent treatment plants in industrial estates.

**Long-term and supporting**
- Land-use planning, green belts and satellite towns.
- Continuous monitoring networks for air and water with public data.
- Health education through schools and FCHVs.
- Clear roles for federal, provincial and local governments under the Environment Protection Act 2076.
- Regional cooperation on cross-border haze.

Quick results come from enforcing existing rules and fixing visible sources (dust, burning, old vehicles, untreated water); lasting results need investment in clean transport and sewage treatment.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the condition of the Bagmati, Bishnumati and Dhobi Khola in Kathmandu?
   A. Clean with high dissolved oxygen
   B. Used only for drinking
   C. Receive untreated sewage and solid waste, with dissolved oxygen near zero in the dry season
   D. Treated with sewage plants everywhere
   Answer: C. These rivers have turned into sewers receiving untreated sewage and waste, so DO is near zero in the dry season. (Key point: Condition of urban rivers)

2. Which is a short-term (1-2 years) quick win?
   A. Complete all metro systems
   B. Build new hydropower plants
   C. Strict vehicle emission testing, paving dug-up roads, banning open burning and testing and chlorinating water
   D. Convert all kilns later in the long term
   Answer: C. Short-term actions enforce existing rules and fix visible sources like old vehicles, dust, burning and untreated water. (Key point: Short-term water and air actions)

3. Which measure belongs to the medium-term (3-5 years) plan?
   A. Air quality alerts only
   B. Hand washing campaigns only
   C. Fines for open burning
   D. Electric public buses, zig-zag kilns, Bagmati sewer interceptors and treatment plants, arsenic-safe deep wells
   Answer: D. Larger investments such as electric buses, cleaner kilns, interceptors with treatment plants and deep wells need 3-5 years. (Key point: Medium-term measures)

4. How does the answer say quick and lasting results are achieved?
   A. Quick results come from enforcing existing rules and fixing visible sources; lasting results need investment in clean transport and sewage treatment
   B. Quick results come from new laws only
   C. Lasting results need no investment
   D. Only masks give lasting results
   Answer: A. Enforcement and fixing dust, burning, old vehicles and untreated water give fast gains, while clean transport and sewage treatment give lasting ones. (Key point: Quick versus lasting results)

## Related in Technology, Environment and Society

- [Severity of indoor air pollution in Nepal](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Aindoor-air-pollution-severity) — Technology, Environment and Society, chapter 5
- [Inorganic water pollution in Nepal](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Ainorganic-water-pollution-nepal) — Technology, Environment and Society, chapter 5
- [Indoor air pollution in Nepal and counter measures](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Aindoor-air-pollution-nepal) — Technology, Environment and Society, chapter 5
- [Short note: Technology and water/air pollution](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Atechnology-water-air-pollution) — Technology, Environment and Society, chapter 5
- [Indoor air pollution and Kathmandu air problems](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Aindoor-air-kathmandu-health) — Technology, Environment and Society, chapter 5
- [Air pollution: causes, effects and mitigation](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Aair-pollution-causes-mitigation) — Technology, Environment and Society, chapter 5, asked 3×

## Related in other subjects

- [Research article on air pollution in Kathmandu](https://www.bctengineer.com/question.md?key=semester_5%2Fcommunication_english%3Aresearch-article-air-pollution-kathmandu) — Communication English, chapter 10, asked 3×
- [Air pollution, pollutants, sources and remedies](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Aair-pollution-sources-remedies) — Engineering Chemistry, chapter 3
- [Water quality parameters and Nepal drinking water standards](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Anepal-drinking-water-quality-standards) — Environment and Pollution Control, chapter 4
- [Sources, effects and remedies of water pollution](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollution-sources) — Engineering Chemistry, chapter 3, asked 2×