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The overall objective of the proposed study is to understand similarities and differences in the occurrence, fate, and transport of key zoonotic pathogens and several indicator organisms in key hydrologic compartments (soil water, groundwater, and surface water) at the field-, farm-, and catchment-scales; and to provide a conceptual framework for the quantitative assessment of pathogen transport in the surface water - groundwater continuum. We will evaluate the environmental transmission of the zoonotic pathogens Cryptosporidium parvum, Campylobacter spp., E. coli O157:H7, and Salmonella, as well as the indicator organisms Enterococcus spp. and Bacteroidales in animal production areas and in cropping systems irrigated with waters containing animal and human waste. Our working hypothesis is that field reconnaissance with indicator organisms combined with thoughtfully conducted, quantitatively upscaled hydrologic modeling provides a useful framework to assess and evaluate the potential fate and transport of specific zoonotic pathogens in agricultural systems. <P>First, this project will provide a comparative longitudinal (temporal-dynamic) and cross-sectional (spatial mapping) characterization of the transmission of various pathogens and indicator organisms in farming systems where animal waste and municipal wastewater effluent are applied. Specifically, our goal is to characterize three characteristic endpoints in the microbial transmission pathway: A) Loading at the land surface (source). B) Occurrence in groundwater recharge (shallow groundwater) and field runoff (field-scale transmission). C) Occurrence at the point of use in domestic wells and irrigation canals (farm- and catchment-scale transmission leading to off-site export). <P>Second, the project will develop an integrated modeling framework for surface water, soil water, and groundwater transmission that accounts for spatio-temporal heterogeneity and that is capable of upscaling pathogen transport processes from the lab scale at which current process models are defined to the field- and farm-/catchment-scale. We plan to calibrate the microbial transport model against field data of conservative tracers and of a highly transmissive, frequently occurring, and long-living fecal microorganism (Enterococcus spp.). <P>Third, this project will evaluate and assess the applicability of the modeling framework by simulating field-scale occurrence of Salmonella, Campylobacter spp., E. coli O157, and C. parvum observed in the longitudinal and cross-sectional pathogen monitoring.
NON-TECHNICAL SUMMARY: The prevalence of some waterborne pathogens has prompted water districts, food safety agencies, and regulatory agencies to include animal agriculture and wastewater treatment plants in their list of possible adulterating water sources during outbreak investigations. This study is designed to understand similarities and differences in the occurrence, fate, and transport of key zoonotic pathogens and several indicator organisms in soil water, groundwater, and surface water at the field- and catchment-scale; and to provide a conceptual framework for the quantitative assessment of pathogen transport in the surface water groundwater continuum. We evaluate the environmental transmission of Cryptosporidium, Campylobacter, E. coli O157:H7, and Salmonella, as well as the indicator organisms Enterococcus spp. and Bacteroidales in animal production areas and in cropping systems irrigated with waters containing animal or human waste. This project begins to evaluate whether our current understanding of lab-scale processes can be scaled to the field- and catchment-scale. With multidisciplinary expertise in microbiology, veterinary medicine, and hydrology, the project team combines the strength of empirical work at various scales in agricultural systems with the need to understand transport processes based on first scientific principles. The knowledge gained will be critical to better assess and delineate the potential impacts of cattle grazing, confined animal agriculture (dairy), and municipal effluent application in cropping systems on surface water and groundwater quality. <P>
NON-TECHNICAL SUMMARY: The prevalence of some waterborne pathogens has prompted water districts, food safety agencies, and regulatory agencies to include animal agriculture and wastewater treatment plants in their list of possible adulterating water sources during outbreak investigations. This study is designed to understand similarities and differences in the occurrence, fate, and transport of key zoonotic pathogens and several indicator organisms in soil water, groundwater, and surface water at the field- and catchment-scale; and to provide a conceptual framework for the quantitative assessment of pathogen transport in the surface water groundwater continuum. We evaluate the environmental transmission of Cryptosporidium, Campylobacter, E. coli O157:H7, and Salmonella, as well as the indicator organisms Enterococcus spp. and Bacteroidales in animal production areas and in cropping systems irrigated with waters containing animal or human waste. This project begins to evaluate whether our current understanding of lab-scale processes can be scaled to the field- and catchment-scale. With multidisciplinary expertise in microbiology, veterinary medicine, and hydrology, the project team combines the strength of empirical work at various scales in agricultural systems with the need to understand transport processes based on first scientific principles. The knowledge gained will be critical to better assess and delineate the potential impacts of cattle grazing, confined animal agriculture (dairy), and municipal effluent application in cropping systems on surface water and groundwater quality.