CHAPTER ONE
INTRODUCTION
Natural water whether surface ground water, river, ocean or lakes contains variety of micro-organisms. The sanitary quality of drinking water is affected by both variety and number of micro-organisms. The sanitary quality of drinking water is affected by both Variety and number of micro-organisms available. River is fit for drinking if its does not contain any micro-organism that are pathogenic to man. The WHO (1958) published the international standard for drinking water, in it water for consumption should be free from pathogenic organisms. According to Howel (1994). He defined bacterial gience examination of river as the process of identification of bacteria organisms in the river. The bacteria organisms are pathogenic to man when they drink it. Some of the causative agents are singella dysenterae, vibro cholera, Salmonella Typhi, , Salmonella Paratyphi. Etc.