
River water sample was collected at five different locations in Gundaru river, Tirumangalam. Then these samples were tested for pH factor. It showed neutral pH and electrical conductivity. The water sample was also analysed for color, dissolved oxygen and BOD. The examined river water contained chloride, calcium, phosphorus, sulfate, potassium, total solids and nitrogen. The soil samples were collected from five different places near Gundaru river basin. The colony forming units were countable and maximum in first three sites and minimum in the next two sites. The first three sites namely Arukannu bridge, Santhapettai and Near Girls school were very much contaminated with sewage water and the other two sites namely Sengapadai and Sonnaisamy bridge were not so much contaminated with sewage water. In MPN method, it was found that the sewage enteric organisms are present in Gundaru River. Molecular techniques were used in estimating the phylogenetic relatedness of 15 bacterial species isolated.