Water pollution in Nepal

Water pollution through natural processes is insignificant in Nepal. Domestic sewage and industrial effluents are the major contributors of water pollution. Haphazard urbanisation and inadequate sewerage facilities have accelerated the discharge of domestic liquid wastes without any treatment. Almost all the urban areas have no wastewater treatment facilities. The cumulative effects of wastewater discharge have a striking negative impact, particularly, in the rivers flowing through the Kathmandu Valley. The holy river Bagmati is biologically dead due to discharge of such domestic and industrial wasters, particularly in the stretch flowing through urban areas.

Biological contamination is generally noticed in the supplied drinking water as well. Frequent incidence of water-borne diseases indicates the deterioration of the drinking water quality in both urban and rural areas.

Although the contribution of the manufacturing industries to the gross domestic product (GDP) is estimated to be around 10 per cent, most of them discharge the effluents and solid wastes without any treatment. According to the latest Census (1996//97) of industries, the number of establishments and persons engaged in all VDCs were about 1,594 and 92,344 as against 1,963 and 1,04,364 in all Municipalities. Compared to the previous 1991/92 Census, carpet and rugs, garments, bricks, distilleries and printing establishments have decreased in numbers during 1996/97 Census.

With a concentration of 56.76 per cent of total manufacturing establishments, the Central Development Region (CDR) is found to be the most busy region in manufacturing activities. The region shares 70.54 per cent of the total employees, and 73.04 per cent of total wages and salaries. It has also shared 76.04 per cent of the total value added with 66.84 per cent of input and 70.5 per cent of the total output.

In contrast to the CDR, the Far-Western Development Region (FWDR) shares only 3.74 per cent of the total number of manufacturing establishments.

Localised industrial pollution is also on the rise. Wastewater is directly discharged on to the terrestrial and aquatic systems without any treatment. The wastewater generally contains a high load of oxygen demanding wastes, disease causing agents, synthetic organic compounds, plant nutrients, inorganic chemical and minerals, and sediments (Devkota and Neupane, 1994). Total industrial wastes have been estimated at 0.076 million tons of TSP, 8.557 million cubic meter of wastewater, 5.7 thousand tons of BOD, 9.6 thousand tons of TSS and 22 thousand tons of solid wastes. Industrial TSP release in the Kathmandu Valley exceeds the total load discharged in all other development regions. A recent sample survey of 36 industries throughout the Kingdom revealed that the population equivalent (PE) of industrial effluent ranges from 416 to 9,540 (Devkota, 1997; Table 2.8.3). It is generally accepted that local human PE is about 50 gram per day.