Collaborative Research: Assessing climate resilience of combined sewer systems and its impact on marginalized communities

Many U.S. cities experience combined sewer overflows (CSOs) during wet weather. The resulting release of sewage and stormwater can have negative environmental and health consequences. Of particular concern are marginalized communities residing historically in flood-prone zones, which face heightened susceptibility to CSO impacts. Current urban wastewater systems were designed to withstand peak flows derived from outdated precipitation records. With climate change producing more frequent and intense rainfall, cities face urgent challenges to manage and mitigate CSOs in an equitable manner. This project will directly address these challenges by developing a model of the Des Moines, IA combined sewer system using real-world data. This system is similar to that of many other major U.S. cities, and therefore provides a framework for researchers to study the resilience of wastewater systems. By prioritizing equity in the scientific approach and proactively integrating future climate conditions, this research bridges the gap in system-level resilience assessment for wastewater systems, and will provide insights into the vulnerability of marginalized communities to CSOs amid climate change. This research aims to analyze the resilience of combined sewer systems in response to climate change and assess potential CSO exposures and impacts on marginalized communities. An integrated modeling framework will be created enabled by cutting-edge development in below-ground drainage modeling and it will be coupled with a qualitative-quantitative survey method to perform relevant, local phenomena-based research. The project is expected to 1) advance data analytics and modeling methodologies for urban wastewater systems; 2) assess system-level resilience of the test-bed system (i.e., Des Moines, IA) to wet weather conditions under the influence of climate change; and 3) uncover the vulnerability of marginalized communities to future likely CSO incidents. This research aims to catalyze equitable solutions in the management and mitigation of CSOs, fostering enduring benefits for marginalized communities. In addition, it will provide unique opportunities for graduate and undergraduate students to work collaboratively across universities and directly with industry collaborators, enabling a pipeline for both personnel and research to move more rapidly in and out of academia. This project is funded jointly by the CBET Environmental Sustainability program and the CBET Environmental Engineering program. 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.