RAPID: Short- and mid-term dynamics of microplastic transport in urban drainage systems after Hurricane Debby

Past research has shown that hurricanes result in massive sewer overflows resulting in the release of pollutants to receiving waters. Such releases have the potential to create “hotspots” for microplastic release into the surrounding environment due to the high microplastic content in raw sewage. In August 2024, Hurricane Debby affected numerous urban population centers in the Florida Gulf, including Tallahassee, Florida. The processes affecting sewage overflows and runoff of accumulated microplastics from the land are poorly understood. The goal of this project is to assess the impact of hurricane-induced sewage overflows on microplastic release to the surrounding waters. Water samples obtained in a watershed impacted by sewage overflows from Hurricane Debby will be compared to those from systems that were not affected. These systems will be tracked over time to understand both short-term (days) and long-term (weeks) releases of microplastics following Hurricane Debby. The results will advance knowledge about the impact of hurricanes on microplastics release. More broadly, results will also help understand the impacts of hurricanes on water quality in urban drainage systems. Results from this study will inform efforts by urban water managers to prevent and mitigate releases from future hurricanes and other large flooding events. Hurricanes in urban watersheds can cause massive sewer overflows resulting in the release of pollutants. While research has demonstrated the importance of hurricane induced sewage overflows on pollutant release, comparatively little is known about how this process affects microplastics release. The specific objectives of this research project are to understand: i) how hurricanes affect the mass of microplastics released from urban drainage systems during sewage overflows, ii) how microplastics releases vary with space and time, and iii) whether hurricane induced sewage overflows create microplastics hotspots in urban water systems. Samples will be obtained from various locations in a watershed experiencing sewage overflows impacted by Hurricane Debby. Results will be compared to samples obtained from non-impacted waterbodies. State of the science FTIR techniques will be used to measure microplastics concentrations and composition. Successful completion of this research will help understand the impact of hurricane and other extreme event-induced flooding has on microplastics release. Results will benefit society by informing efforts to prevent and mitigate the impact of releases from urban flooding, as well as guiding future responses to hurricanes to prevent water contamination in urban areas. 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.