Distribution of Enteric Pathogens in Wastewater Secondary Effluent and Safety Analysis for Urban Water Reuse

ABSTRACT Through a 1-year monitoring of enteroviruses and pathogenic bacteria in the secondary effluent using real-time polymerase chain reaction (real-time PCR), the pathogen removal requirement was evaluated for safeguarding the reclaimed water quality for urban reuse. The distribution of each pathogen in the secondary effluent was found to follow a log-normal relationship, although 50% cumulative concentrations differed much from each other (1.4 GEC/L of infectious enteroviruses, 3.1 × 102 CFU/L of Salmonella typhi, 1.0 × 103 CFU/L of Shigella, and 3.3 × 105 CFU/L of Escherichia coli). By exposure analysis regarding two reuse scenarios (golf course irrigation and recreational impoundment), risks were analyzed for pathogens in reused water based on monitoring data and dose–response relation. For enteroviruses and pathogenic bacteria, there were obvious differences in the relationship between the reliability and removal efficiency. Under an acceptable annual risk level (10–4/a), the pathogen removal requ...