In most parts of Nepal, it has now become a challenge and a desire to see a clean flowing river. Almost all our rivers in urban and rural locations are heavily contaminated with foreign matters and are not suitable for direct usage.

Due to the flow of pollutants into water bodies without any treatment to remove dangerous substances, lakes, rivers, and groundwater become increasingly contaminated with contaminants. Water pollution has a direct negative impact on aquatic life, humans, and ecosystems as a whole.

Below you will discover the ten most significant causes of water pollution in Nepal. Behold, and see if you are someone who has been contributing to the contaminated water in Nepal.

1. Unmanaged Sewage and Wastewater

Sewage - Nepal water pollution
Sewage Overflow of Lalitpur, Nepal (source)

Improper sewage disposal is increasingly becoming a serious global concern. The waste goes somewhere each time we flush, either to a sewage treatment facility or to waterways, where the residual sewage is deposited.

Household waste, factory waste, and agricultural waste are all dumped into rivers and lakes. This waste can take the form of liquid waste, trash, or sewage. The toxic substances leaking from this trash have the potential to destroy marine life. 

Sewage and wastewater include harmful chemicals, bacteria, and diseases. The germs and bacteria discovered in that wastewater cause disease in humans and animals indiscriminately and hence are a source of health problems in numerous parts of Nepal.

2. Dumping Waste Materials on the River Beds

As unplanned urbanization takes a toll in Nepal, the dumping of waster matters around the river beds has significantly increased over the past years. Most water sources are heavily polluted by solid waste, converting the river beds into dumping ground. 

These unauthorized and harmful dumps contain household waste products such as plastic, food matters, aluminum, glass, styrofoam, etc.

Over time these waste matters get deposited deep in the water, taking a very long time to self-degrade. Hence, these waste matters are more likely to stay in our water sources forever or at least for an extensively long time.

3. Acid Rain

Acid rain is a type of water pollution caused by pollution in the air. Acid rain occurs when acidic particles in the atmosphere combine with water vapor.

Acid rain has various ecological effects, primarily on lakes and streams. It raises the acidity of the water, causing more aluminum to be absorbed from the soil, which is carried into the water.

Nitrogen oxides and Sulphur dioxides are emitted into the atmosphere when humans burn fossil fuels. Sulphuric and nitric acid are formed when these pollutants react with water, oxygen, and other substances in the air.

Winds may spread these acidic compounds through the atmosphere and over hundreds of miles. When acid rain hits the ground, it forms runoff water, enters water sources, and sinks deep into the soil.

4. Industrial Waste Disposal

River - water pollution Nepal
Polluted Bagmati river of Kathmandu (source)

Industrial pollutants and wastewaters contaminate all sources of fresh water. These industrial wastes are poisonous to the organisms that consume the water, whether directly or indirectly. Paper mills, steel plants, textile and sugar industries are among the other significant sources of wastewater. 

Distilleries, followed by paper mills, are the primary sources of pollution in terms of organic load. Both large and small-scale sectors contribute to water pollution.

Many large-scale enterprises claim to have established expensive treatment and disposal equipment, yet they are frequently out of operation.

Water pollution is caused by industrial sites all over the world, and more so in Nepal. Waste materials are frequently thrown into surrounding rivers and lakes.

Lead, asbestos, petrochemicals, and even mercury are all found in industrial trash. All of these compounds are extremely dangerous to humans as well as marine life.

5. Improper Agricultural Practises and Fertilizer Deposition

Farmers frequently employ chemicals and pesticides to protect their crops from bacteria and insects. These pollutants can affect animals, plants, and humans when they seep into groundwater.

Furthermore, when it rains, the chemicals mingle with the precipitation and pours into rivers and streams. This phenomenon is especially true during those hard monsoon seasons.

Even though Nepal’s irrigation infrastructure has grown significantly, no steps have addressed the high acidity water problem.

Another significant source of water pollution is flood-plain farming. During the monsoons, the fertilizers and pesticides used on these swaths of land are inevitably washed into rivers.

6. Flood, Landslides, and Soil Erosions

Flood - water pollution Nepal
Effect of flood 2020 in Myadi River (source)

We have been made aware of the potentially catastrophic event of landslides and soil erosion sending toxins to surface waters. Most silt is transported from the landslide to the river during high-flow periods (summer).

The suspended sediment flows through the river system in suspension, deposition, and re-suspension pulses throughout many natural events.

Many water delivery systems have been destroyed as a result of the increase in floods and landslides. The drinking water has been heavily contaminated in Butwal, Hetauda, Jhapa, and Rautahat districts in Nepal. 

7. Social and Religious Practises

Festival - water pollution Nepal
Mother’s day (mata tirtha aunsi) celebration in Matatirtha pond (source)

Our river waters are also polluted by religious faith and societal practices. Cattle and other animal carcasses are thrown into rivers. On the riverbanks, bodies are burned.

Bodies that have been partially burned are also thrown into the river. All of this is performed out of religious belief and following old rites.

These actions contaminate river water and harm the quality of water. Another environmentally hazardous habit is mass swimming in a river during religious holidays.

When thousands of individuals take a ‘holy dip’ simultaneously, the biochemical oxygen demand (BOD) increases dramatically.

Offerings from a puja must also be dipped in a river, according to religious traditions. People are increasingly immersing offerings in plastic bags in sacred rivers and streams. Plastic bags are incredibly hazardous and contribute to the river’s pollutant burden.

8. Direct Marine Dumping

The quantity and quality of river water are at worrying levels along most of the river’s path through the valley, particularly during the dry season. The Bagmati River’s water quality issues are exacerbated by a large amount of dumped waste matter.

Likewise, the Kathmandu valley’s surface and subsurface water quality have been seriously impacted by the haphazard dumping of solid debris in the Bishnumati River.

The river water and shallow wells had excessively high conductivity and significant nitrate, nitrite, and COD levels. In water, different objects take different amounts of time to degrade:

  • It takes two weeks for cardboard to deteriorate
  • Newspapers deteriorate in six weeks.
  • Photodegradable packaging degrades after six weeks.
  • The foam takes fifty years to dissolve, while styrofoam takes eighty years.
  • Aluminum takes two hundred years to degrade.
  • It takes four hundred years for plastic packaging to disintegrate.
  • We don’t know how long the glass takes to deteriorate because it takes so long.

9. Global Warming and Climate Change

In terms of water contamination, rising temperatures as a result of global warming are a big worry. Water temperatures are rising as a result of global warming, which kills aquatic species. When much marine life dies, the water supply is severely polluted, worsening the problem.

Droughts, rising water temperatures, and solid and violent downpours are becoming more common due to climate change. The quality of our drinking may be affected as an outcome of such climatic extremities.

Bacteria and viruses thrive in these new settings and can cause a variety of ailments when they come in touch with humans. 

Bacteria, viruses, and protozoa can contaminate drinking water, resulting in epidemics and illnesses like diarrhea. It is not a surprise that many parts of Nepal suffer from Malaria, Cholera, and Typhoid outbreaks soon after a severe flood or landslide.

10. Excessive extraction of water

Groundwater is the world’s largest source of drinkable and pure water. Only exploiting groundwater in several world regions, especially where surface water supplies are scarce, can fulfill domestic, agricultural, and industrial water requirements.

Water in the ground is compared to money in a bank account by the United States Geological Survey. There will be account supply issues if cash is withdrawn quicker than new money is deposited. Pumping water out of the ground expeditious than it is recharged poses significant problems in the long run.

Such problems are very prominent in urban locations of Nepal, where people have excessively opted for deep-water boring to access water for daily use.

Day by day, the water is getting less and more and more unclean for everyday usage. Similarly, rivers in the Himalayan and mountainous regions contain an abundance of water in the upper areas.

When they reach the plains, though, they are dehydrated. Irrigation canals divert clean water from rivers when they arrive at the flatlands, preventing water from flowing downstream.

Therefore, excessive underground water usage and unmanaged irrigation canals have devoid of clean water supply to a significant number of people in both urban and rural areas.

11. Unplanned extraction of sand from rivers

sand mining - water pollution nepal
Tippers stationed on the banks of Kaligandaki for loading sand and stones in Tanahun (source)

Unplanned extraction of sand from rivers continues to increase as unplanned urbanization and industrialization progress. Sand mining is exerting enormous strain on Nepal’s rivers and creeks, and it has the potential to destroy the neighboring landscape and ecosystem. 

Modifications in the geometry of streams, rivers, and wetlands, disturbances to aquatic ecosystems, groundwater levels, and water quality degradation directly affect excessive sand mining.

The mining sector has a variety of implications on marine biodiversities, such as first-hand poisoning. Sand mining further leads to a decrease in the species and density of fish in excavated regions and disruptions in the riverfront ecosystem.

Exceptionally high quantities of pollutants such as arsenic, sulfuric acid, and mercury can permeate across a large region of shallow or underground water and impact consumers’ health.

To Wrap Up

Water pollution is a big problem worldwide, and it has resulted from numerous daily human activities. It can devastate the health and economy of the entire world, including the natural ecosystem.

If we are to outlast on Earth, we must have access to water, to be more specific, “clean and pollution-free water’. We are all well aware of the extent to which we humans have harmed the Earth by polluting it to the core. According to many reports, two-thirds of the world will face water shortages by 2025.

And if the same trend continues, Nepal will undoubtedly fall on the list despite being among the richest in freshwater resources. Countries such as Laos, Cambodia, and Thailand are also not safe from water exploitation.

(Last Updated on December 27, 2021 by Sadrish Dabadi)

Shradha Bhatta holds a Bachelors’s Degree in Social Work along with a Post-graduate degree in Project Management from Georgian College in Canada. Shradha enjoys writing on a variety of topics and takes pleasure in discovering new ideas. She likes traveling and spending time with nature. She is a very people-person who loves talking about climate change and alerting people to go green!