An accurate understanding of pathogen concentrations in wastewater is important for developing criteria for wastewater treatment. This is particularly critical for wastewater that is used as a potable water source. This project assessed the feasibility of linking the wastewater concentrations of Cryptosporidium species, human norovirus, and human adenovirus to illness prevalence in communities. Project results were integrated into a model to predict wastewater concentrations given community prevalence and expected fecal shedding rates. Research partner: California State Water Resources Control Board. Published in 2021.