Spatiotemporal Patterns of Escherichia coli Impairment in Arid Environments: Implications for Environmental Management

Abstract:

Escherichia coli (E. coli) is a leading cause of impairment in streams throughout Arizona. Its presence in water bodies is indicative of human and/or animal waste contamination and is often associated with contamination from other pathogens. Mitigating risks from E. coli contamination in efforts to protect human health requires an understanding of the spatiotemporal drivers causing the contamination. While much research has focused on E. coli transport and occurrence in humid and temperate environments, there remains a significant gap in our understanding of E. coli occurrence, fate, and transport in arid and semiarid environments where streamflow is episodic. Using a database of E. coli concentrations across Arizona, we performed exploratory data analyses to investigate its occurrence patterns over time and space. We also compare E. coli data to sediment concentrations to evaluate whether this common approach to pathogen tracking in other environments can also be useful in arid settings. Outcomes of this work can help to identify sources and patterns in E. coli occurrence that will help create environmental management strategies to address human health risks.