Can treated wastewater mitigate water scarcity without compromising the ecological sustainability of arid rivers?

About This Grant

Communities in dry regions increasingly depend on treated wastewater to sustain streams and rivers as traditional water sources such as snowmelt, reservoir storage, and groundwater become less reliable. In these arid environments, a significant portion of river flow may originate from wastewater treatment facilities, particularly during extended dry periods. This project aims to improve understanding of how long-term treated wastewater inputs affect the ecological functioning and health of river systems. The research focuses on how biochemical processes in rivers respond to continuous exposure to treated effluent and their capacity to recover from disturbances. The Rio Grande River, which flows through a densely populated urban area near Albuquerque, New Mexico, and receives substantial treated effluent from a major facility, is an exemplary case study due to its representative conditions and scale. This project also contributes to environmental education by enhancing training in collecting and analyzing large ecological data sets and preparing future scientists and engineers with critical analytical skills. This project examines the long-term impacts of wastewater treatment plant effluent discharge on stream metabolism, resilience, and ecological sustainability in arid river systems. It quantifies atmospheric, hydrological, biogeochemical, and biological variables over multiple temporal scales, from short-term events to multiyear patterns, using semi-continuous monitoring across five strategically placed study sites along the Rio Grande River. Two upstream sites reflect natural, intermittent flow regimes, while three downstream sites capture the metabolic effects of chronic treated effluent exposure. The shared flow and atmospheric conditions across all sites establish a robust comparative framework for assessing the ecological consequences of anthropogenic loading. This research will identify patterns and ecological thresholds that signify resilience and vulnerability, informing the development of a mechanistic model that integrates terrestrial and aquatic ecosystem dynamics. This model aims to enhance predictive capabilities regarding the responses of watersheds to shifts in flow regimes and land use. Additionally, the project incorporates an educational component through a data-driven, problem-based hydrology course designed to equip students with foundational programming, modeling, and environmental data analysis skills, directly contributing to broader educational and societal benefits. 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.