Ezra M. ORLOFSKY, Osnat GILLOR - Zuckerberg Inst of Water Research, Ben-Gurion University, Sde Boqer, Israel 84990

Karen SHAPIRO , Woutrina MILLER  - School of Veterinary Medicine Department of Pathology, Microbiology, and Immunology One Shields Avenue University of California Davis, CA 95616, USA

 Stefan WUERTZ - Department of Civil & Environmental Engineering, University of California Davis, One Shields Avenue Davis, CA 95616, USA

The reuse of wastewater, especially for non-potable purposes, is an economically and environmentally sustainable practice but needs to be managed with comprehensive safety guidelines. Among the concerns associated with recycling wastewater is the presence of disease-causing microorganisms such as pathogenic bacteria, protozoa and viruses that pose a serious risk to human health. Pathogenic microorganisms are rarely detected directly as the process is difficult and often expensive. Instead, the most common method for assessing the possibility of fecal contamination is the “fecal indicator method” which detects the presence of non-pathogenic organisms, mainly Escherichia coli. Although this approach holds major utility for protecting public health, numerous studies have raised concerns regarding the correlation between fecal indicators and pathogenic microorganisms. Due to the great variety of factors that can affect the persistence of pathogens in water, soil and crops, it is recommended that controlled field studies be implemented in the areas where treated wastewater is used for irrigation. The main goal of this project is to challenge the use of E. coli and FC as indicators to bacterial pathogens in water, soil and crops and to propose alternative, more reliable, means to assess pathogens’ threat in these matrixes. This study will assess the correlation between fecal indicator bacteria and pathogenic microorganisms that may be present in irrigation wastewater, soil and crops grown according to standard Israeli agricultural practice. In addition, the study will assess the correlation between the levels of pathogens in water, soil, and crops, as the levels of contamination are expected to vary between the matrices. A unique characteristic of this study is the quantification of pathogens with culture independent quantification methods (qPCR and DFA), that will minimize bias associated with difficult to culture pathogens. The study will provide important practical data relevant to farmers, health ministers and scientists regarding the use of fecal indicator bacteria for monitoring the safety of produce grown with wastewater effluent.

11th World Wide Workshop for Young Environmental Scientists WWW-YES-2011 Urban waters: resource or risks? Arcueil, France (5 - 10 June 2011)