Assessment of water quality of a few surface water sources of Kokrajhar District, Assam, India

Abstract

Kokrajhar is one of the important districts of Bodoland Territorial Council, Assam. The topography of the district is uneven. The district is situated on the southern side of the Himalayan plains. The northern part of the district contains dense forests with some of the finest timber varieties like teak (Tectona grandis), sal (Shorea robusta) and other evergreen species of flora. The southern part of the district is almost plain and alluvial agricultural area though there are some forest areas. The district is criss-crossed by a network of rivers consisting of Sonkosh, Damra, Madati, Garufela, Hel, Gangia, Saralbhanga, Samukha, Longa, Gourang, Tarong, etc., flowing from the north towards the Brahmaputra. There are also other water bodies like the Deeplai Beel and a number of wetlands. In this work, an attempt has been made to evaluate the water quality of 6 major rivers (Damra, Madati, Hel, Longa, Gourang, Tarong,) of the district by monitoring the common quality parameters like pH, conductivity, total dissolved solids, turbidity, hardness, bicarbonate, chloride, sulphate, nitrate, phosphate, fluoride, common metals like Ca, Mg, Na, K and trace metals like As, Cd, Cu, Fe, Mn, Ni and Zn. The study has shown important results indicating that even in an under-developed area, water quality problems exist. The results have been explained on the basis of known water-related problems associated with the people living in the area.