Abstract
The compatibility of E. coli indicator measured by Colilert system and other indicator microorganisms for the environmental water was examined. The Colilert system indicated a good correlation with fecal indicators. The Colilert system detected higher values of coliforms especially in the upper reaches of a river. A newer Colilert18 system was compared with Colilert system. Risk assessment of river water was performed to determine the water quality suitable for bathing. The water quality suitable for bathing was expressed in terms of coliforms. This was compared with ongoing river water quality standard in Japan.
