Nepal has been marking the World Water Day every March 22 annually since 1993 as an indication of its efforts to provide safe drinking water and good sanitation. It is now time for the country to publicise its important awareness programmes and lay down some ground rules to maintain the beauty of water resources. A case in point is the Bagmati River Basin Management Plan which aims to make water more beneficial for both people and wildlife. We have always used the water of the Bagmati River to purify ourselves, but today we have reached a point where we have to purify this water. Over the years, huge amounts of chemicals, plastic waste and other non-biodegradable pollutants have disturbed the ecological balance of the Bagmati River and its surroundings. The concern shown by governmental and non-governmental organisations for a clean and green Bagmati is therefore really appreciable.

River and trash

From the late 20th century, river engineering has had environmental concerns which are broader than immediate human benefits. But some river engineering projects like the Bagmati water cleaning project have been concerned exclusively with the restoration or protection of natural characteristics and habitats in different developed countries. The Nepali scenario depicts that this type of approach will soon be a key concern. All the sewerage systems in the Kathmandu valley empty directly into nearby streams. The pollutants fed into the tributary streams have thus rendered the Bagmati useless which now serves only as a wastewater drain. Rapid urbanisation and absence of reliable wastewater treatment facilities are the major causes of river pollution. Drastic measures are required to revive the Bagmati to its original glory. So Nepal needs a new engineering approach to ensure clean and green rivers in Kathmandu. The cleaning approach must target the entire river network and not just certain areas.

In order to implement engineering techniques for sustainable improvement of the quality of water in the rivers, the major contributing factors for pollution must be identified. Waste is a key factor for polluted water, so proper waste management is necessary as the first step. Generally, waste from individual houses are thrown out into the open and also into water sources. The government should focus on a plan to utilise and dispose the waste in the trash-producing house itself. As part of this scheme, a compost pit can be constructed within the house. Segregation of decayable waste for use in the compost pit to produce fertilisers and non-decayable materials for reuse and recycling has tremendous advantages.

Similarly, bioengineering techniques can be implemented for an instant green river approach. This can be done by creating a proper design which helps to control erosion. The design should be aesthetically pleasing, usually self-maintaining and not too expensive. It can also be useful in creating streamside habitats for water life which is an important component for clean and green water. A laboratory designed especially for monitoring the quality of water in the rivers is essential. This will help to make plans for the gradual improvement in the quality of water and spread awareness about the condition of the river and the steps that need to be taken for future improvement.

Cleaning Ganga

We can also learn from case studies around the world, for instance, the Ganga River where innovative technology has been implemented. With the help of William Oswald, an engineering professor at the University of Cal-ifornia at Berkeley, a cost-effective and safe system for cleaning the Varanasi stretch of the Ganga was designed. The process was called an advanced integrated wastewater oxidation pond system. The non-electric wastewater system would store sewage for 45 days in biological oxidation ponds, using bacteria and algae to eliminate pesticides, heavy metals and deadly coli forms, cleansing the entire seven kilometres stretch. The system would not only purify the water, it could also be used to irrigate farmland and grow fish.

In the same way, we can implement innovative ideas after rigorous studies, research and investigation. Conce-ntrating only on the Bagmati and neglecting other rivers such as the Bishnumati, Tukucha and other nearby rivers will not result in a clean Bagmati. This vision must not be limited, and collective action for all the sources must be implemented, which would have a good impact on the environment as a whole.    

Beyond events

Other actions can be considered such as building sewage treatment plants and revamping drains. Pollution sou-rces must be identified and be acted upon accordingly. Some major problems, apart from the ones mentioned above, are haphazard establishment of carpet factories along the river banks, development of new residential zones without sanitation provision and discharge of untreated sewage directly into rivers. The lack of proper rules and regulations for controlling river pollution and non-implementation of existing laws, lack of coordination between government, community and other related agencies and the absence of proper punishment for polluters are also contributing factors.

All these steps combined with rising awareness about the effects of river pollution on the environment and living beings, standardisation of rules and regulations encouraging the public to contribute to water cleaning programmes and abandon polluting practices and limiting activities that harm rivers such as sand mining can have a prompt effect on the clean and green effort. More effective government plans and research for more alternatives must be considered in time. We are on the verge of formulating a constitution, so laws ensuring environmental protection must be proposed. Limiting the activities to occasional media events and to particular areas has no benefits. Our activities should extend to future concerns and must be sustainable.

Bhattarai is an engineer