Integrated Modeling for Source Characterization of Pathogenic Contamination in Watersheds

The US EPA’s regulatory framework for recreational waters has protected public health for decades. Pathogenic contamination of these waters, however, remains a frequent cause of impairment. Integrated modeling is being leveraged to advance the agency’s understanding of pathogen fate and transport processes in watersheds and improve its ability to predict the consequences of exposure. This paper describes integrated modeling research focusing on source characterization techniques for pathogen transport scenarios in watersheds. Source characterization is a hidden requirement of Quantitative Microbial Risk Assessment, a method for estimating infection risks being evaluated across several programs within the EPA. A hybrid source characterization approach is described and demonstrated that utilizes integrated and inverse modeling methodologies to determine pathogen source allocations.