On Feb 26 2014, I along with my classmate with our faculty teacher Maya Prasad Bhatta went for the environmental monitoring of Bagmati River (a holy river of Nepal) from its origin to its outlet within Kathmandu Valley. Bagmati, a holy river of Nepal flows through the Kathmandu Valley originated from Shivapuri range of hills with total catchment area of 14384 sq.km.. The Bagmati River is the principal river of the Bagmati Basin (ca. 3640km2) in central Nepal. The river is fed by springs and monsoon rainfall, originates in the north of Valley and drains across the Mahabharat Range to the Gangetic plain. The Basin transacts three distinct latitudinal physiographic zones (Mountain, Siwalik and Terai) of the Nepal Himalayas. Water pollution today is one of the most serious environmental issues all over the world. Pollution of water is responsible for a very large number of mortalities and incapacitations in the world. Human activities creates vast amount of various waste and pollutants which leads to the deterioration on the both quality and quantity of water resource.

 

The Bagmati Basin currently faces a number of serious environmental and ecological challenges. Rapid population growth due to massive migration to the urban areas, unmanaged urbanization, unscientific agricultural practice, industrialization, lack of proper sewage disposal are causes of water pollution. Basin headwaters at Kathmandu contributed to water quality deterioration with regional consequences on the aquatic ecosystem and on the health of the downstream sub-basin?s user groups as well as degradation of the natural resources.

 

The observations made during the field along the Bagmati River are.

1. In upstream, the water was found to be in pristine state, free of anthropogenic discharge with the discharge rate of 0.14m³s^-1.

2. Velocity of water was found to be 0.2 ms^-1 which is higher than in downstream.

3. Water in upstream though mixed with tremendous amount of organic load from forest litters in to the river system due to elevation/slope, has high DO (dissolved oxygen) i.e.(7.16-0.24 mg/l) than that of water in downstream.

4. Physical disintegration rate of soil and fresh minerals into soil so high pH.

5. Anthropogenic activities due to human population are mainly responsible for the organic matter dynamics and inorganic chemistry in river system of Bagmati within Kathmandu valley.

6. Pollution of water in downstream, where water was flowing as black drain, offensive for olfactory organ due to conversion of sulphur into sulphide.

7. The whole scenario of river system is destroyed by drains, waste deposition, foul smell, untreated disposal of sewage through the canals caused deterioration of water quality.

8. Because of the heavy input of sewers and other organic wastes into the water, concentration of DO was found to be 0.5-2 mg/l lower than that of upstream as oxygen is consumed in decomposition of organic waste.

9. The non-biodegradable wastes as plastics, tins, wrappers, bottles cause the blockage of the drainage system.

10. The bubbles at ,Thapathali, Teku, Dhobighat area river side is the fact that shows the presence of hydrogen sulphide (H₂S or HS) which indicates the zero aquatic life and high microbial activities  in water.

11. Schools build near the river bank not more that 20 meter distance from the bank can cause health hazard for the children.

12. The monitoring and evaluation measures for Bagmati protection as Bagmati Action Plans are not successful at implementation.

The organic load and sewer input in different places from Sundarijal to downstream are shown in table below:

(Observed on 26 Feb 2014)

 

Bagmati River is found to be polluted by 68% organic waste deposition, plastics, tins, inorganic chemicals and many other wastes. This is the major problem in the city as it is facing the problem of water pollution along with the soil quality degradation and the air pollution due to H₂S production in the river as decrease in dissolved oxygen plus increase in TOC AND TON these days due to rapid population growth.  By controlling the organic waste deposition or drainage disposal after proper treatment,i.e. (Tertiary treatment, Activited Sludge method), the water can be reversed from waster to usable once again, thus the beauty of our holy Bagmati river can be revived and the immerging water pollution along with soil and air pollution near bagmati river area can be minimized not instantly but surely.

So, The river system can maintained through following process. (Listed from the group discussion between classmates in the college)

1. Public awareness to the people living alongside Bagmati river as Jorpati, Sinamangal, Guheshwori, Thapathali, Kupondol, Teku, and Balkhu.

2. The waste water should be drained after regular treatment process.

3. The number of treatment plant shall be increased for the proper disposal of Waste water into the river.

4.  Proper landfill system away from Bagmati river periphery.

5. Afforestation in the banks of the riverside.

6. Proper act and legislation shall be implemented for the protection of the river. i.e setting of ambient river quality standard.

7. Cooperation from the local peoples participation is vital.

8. Commitment shall be performed by government and the public for the protection and cleaning of Bagmati.