Green infrastructure, including bioretention cells, is increasingly used as a more sustainable alternative to traditional urban drainage. While successfully employed in many aspects of stormwater management, there is as yet no real understanding of whether or how these systems provide public health services, such as controlling the spread of human pathogens. Concentrations of fecal indicator bacteria (FIB) in stormwater routinely exceed safe levels for human contact; however, FIBs are not good indicators of actual pathogens. This highlights the need to determine the abundance and diversity of actual disease-causing pathogens and to determine how bioretention reduces their contribution to downstream water bodies. This project will address this need by analyzing the microbiome of stormwater and evaluating the effectiveness of bioretention systems in reducing a range of microbial threats in stormwater to human health and environmental quality. <br/><br/>Past studies of the effectiveness of stormwater treatment technologies have been limited because conventional approaches and analytical methods only track limited bacterial species that are abundant and easy to culture, such as E. coli or coliforms. Using third generation sequencing to identify microbial species, the investigators will quantify abundance, diversity and antimicrobial resistance (AMR) genes to describe the microbiome of stormwater. The research is targeted to determine: (1) if conventional monitoring of subsets of bacteria (FIB) in stormwater is a sufficient proxy of the complete microbiome, including actual human pathogens, or if more extensive monitoring of the microbiome is warranted, and (2) if stormwater treatment technologies - in this case bioretention systems - can reduce pathogenic bacteria and AMR genes, as opposed to proxy subsets of these harmful pollutants as tracked by FIB. Through a Bioretention Design Challenge that includes field trips to the experimental watersheds, 7th and 8th grade students from Columbus City Schools will learn first-hand how to design bioretention systems and how to collect field and laboratory data to test hypotheses. Because more than 70% of Columbus City students are minorities, this will enhance the participation of underrepresented groups in STEM education. A significant societal benefit from this research will be the identification of design components that enhance stormwater pathogen reductions by green infrastructure.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.