209 Research Article ISSN 0973 - 8207 Introduction River Tamirabarani is the only Perennial River in the southern part of Tamil Nadu India. The river was the major source for the potable water supply, irrigational activities, industrial processes etc., to both Tirunelveli and Thoothukudi district peoples with the population of more than 4296261 peoples according to 2001 Census. A common risk identified is the contamination of water resources by water-borne pathogens through coliform contamination ( Murugesan et al., 2004 ). These sources of are classified into nonhuman contamination (natural sources, like migratory and local wildfowl, sheep and cattle, discharges from sewer systems, domestic draining, effluent from dairies, poultry farms, piggeries, and slaughter houses) and human fecal contamination. Most of the rivers have been unmindfully used for the disposal of domestic and industrial effluents far beyond their assimilative capacities (Agarwal and Sharma, 1982). Surface water quality monitoring is one of the important criteria to control and minimize the incidence of pollutant oriented problems and to provide appropriate quality of water for various purposes (Simeonov et al., 2002). The nature and associated potential hazards to health of contamination may be assessed using biological and chemical indicators (Cooper and Danielson, 1997; Isobe et al., 2002; Glassmeyer and Shoemaker, 2005). Currently, coliforms and E. coli are of great importance among bacterial indicators used in water quality definition and health risk (Giannoulis et al., 2005). Excessive amounts of fecal bacteria in sewage and urban run-off have been known to indicate risk of pathogen- Journal of Basic and Applied Biology, 4(1&2), 2010, pp. 209-215 © 2009, by the Centre for Biological Research, Puthalam, 629 602, TN, India DETERMINA DETERMINA DETERMINA DETERMINA DETERMINATION OF W TION OF W TION OF W TION OF W TION OF WATER QUALITY DETERIORA TER QUALITY DETERIORA TER QUALITY DETERIORA TER QUALITY DETERIORA TER QUALITY DETERIORATION USING COLIFORMS TION USING COLIFORMS TION USING COLIFORMS TION USING COLIFORMS TION USING COLIFORMS AS POLLUTION INDICA AS POLLUTION INDICA AS POLLUTION INDICA AS POLLUTION INDICA AS POLLUTION INDICATORS A TORS A TORS A TORS A TORS AT RIVER T T RIVER T T RIVER T T RIVER T T RIVER TAMIRABARANI, T AMIRABARANI, T AMIRABARANI, T AMIRABARANI, T AMIRABARANI, TAMIL NADU, INDIA AMIL NADU, INDIA AMIL NADU, INDIA AMIL NADU, INDIA AMIL NADU, INDIA K. Mophin-Kani and A.G. Murugesan* Manonmaniam Sundaranar University, Sri Paramakalyani Centre of Excellence in Environmental Sciences, Alwarkurichi, Tirunelveli - 627 412. Tamil Nadu, India, E-mail: murugesan@msuniv.ac.in; mophink@yahoo.com; kmophin@gmail.com Abstract: Perennial river Tamirabarani is one among the river which feeds both the southern districts (Tirunelveli and Thoothukudi) of Tamil Nadu, India. Higher urbanization practices along the river basin areas increases the pollutant discharges into the river without any prior treatment which in-turn increases the incidence of water born diseases throughout the basin areas. The present study was planned to study the current bacteriological status of the river basin at 12 different stations for a period of 15 months. The results showed that the sampling stations at urban reaches showed higher incidence of bacterial populations and the content was increased downstream areas when compared with upstream sampling points. Based on the water quality criteria of CPCB, India the quality of the river was classified as class B to class E during the study. Key words: Total coliforms, fecal coliforms, Tamirabarani, water quality monitoring, water born diseases