Study of some water quality parameters of Kolong riverine system of Nagaon, India Imdadul Islam Khan and Arup Kumar Hazarika Department of Zoology, Cotton College, Guwahati, India Abstract The study was carried out for a period of two seasons (Pre-monsoon) and that of the (Post-monsoon) in the year 2011. Samples of water from two sites of the River Kolong in Nagaon District of Assam, India, were analysed. The physico chemical parameters such as pH, conductivity (EC), Alkalinity, Total suspended solids (TSS), Hardness, Chloride, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD) and COD etc were evaluated. The river is subjected to severe domestic and sewage pollution at two selected sites of Nagaon town, Assam, India. At sampling site I and II physicochemical parameters were not found to be within the safe limits of drinking water as prescribed by World Health Organization W.H.O. (1984). The present studies indicate increase in water pollution levels in the River Kolong due to discharge of various types of waste water, sewage and effluents. Keywords : Physioco-chemical parameter, Kolong river, Nagaon district, sewage and effluents. E ISSN : 2277-1697 1. Introduction One of the most critical problems of developing countries is improper management of vast amount of wastes generated by various anthropogenic activities. More challenging is the unsafe disposal of these wastes into the ambient environment. Water bodies especially freshwater reservoirs are the most affected. This has often rendered these natural resources unsuitable for both primary and/or secondary usage (Fakayode, 2005). Wastes entering these water bodies are both in solid and liquid forms. These are mostly derived from Industrial, agricultural and domestic activities. As a result, water bodies which are major receptacles of treated and untreated or partially treated industrial wastes have become highly polluted. The resultant effects of this on public health and the environment are usually great in magnitude. These include endangering of aquatic resources and other commercially important marine flora and fauna. The outbreaks of water-borne diseases like cholera, hepatitis, gastro-enteritis, etc, are possible health effects of polluted water (Adesina, 1986; Frontiers, 1996; Jhingan, 1997; Brown et al., 2008). Contributing to the menace of indiscriminate discharges of industrial effluents in receiving water bodies is the improper disposal of domestic wastes, particularly in urban centres of most developing countries. Presently, open and indiscriminate dumping of solid wastes in drainages and riverbanks is one of the most critical problems facing the city of Ibadan (Omoleke, 2004). This practice contributes significantly to environmental degradation caused by incessant flooding in most parts of the different cities allover the globe in recent times. Other notable effects of this practice include proliferation of insects, aesthetic nuisance, Corresponding author : hazarikacotton@sify.com The Clarion Volume 1 Number 2 (2012) PP 121-129 The Clarion International Multidisciplinary Journal