Inactivation of indicator micro‐organisms from various sources of faecal contamination in seawater and freshwater

Aim: The survival of indicator micro‐organisms in aquatic systems is affected by both biotic and abiotic factors. Much of the past research on this topic has been conducted using laboratory‐generated cultures of indicator bacteria. For this study, we used natural sources of faecal contamination as inoculants into environmental water samples, thereby representing the wide diversity of organisms likely to be found in faecal contamination. Methods and Results: Rates of inactivation of water quality indicators, total coliforms (TC), Escherichia coli, enterococci (EC) and F+‐specific coliphage were studied in three experiments using inoculants of sewage influent, sewage effluent and urban storm drain run‐off. Effects of temperature, nutrients, total suspended solids, bacterial load and solar irradiation were studied in fresh and seawater matrices. Results demonstrated that temperature and solar irradiation had significant effects upon rates of inactivation (anova, P