Impact of Moderate and High Severity Forest Fires on Metals Transformations and the Formation of Disinfection by Products

About This Grant

The frequency of wildfires has increased rapidly in recent decades and is projected to increase in the future. Among the many impacts of wildfires on society and the environment, there is growing evidence that wildfires alter forest vegetation and soil in ways that enhance the spread of debris and chemical contaminants in the environment. This leads to increased contamination of lakes, rivers, and groundwater. Unfortunately, when wildfire contaminants enter drinking water supplies, they can react with disinfectants used to treat drinking water and form harmful disinfection by-products (DPBs). The goal of this project is to address this gap in our understanding of how wildfire impacts the formation of DBPs through a combination of laboratory and field experiments. Researchers will characterize the organic and inorganic material present in forests during wildfires and assess how these compounds affect the formation of DBPs when released into water bodies. The successful completion of this research will benefit society by advancing fundamental knowledge about the impacts of wildfires on water disinfection processes and water quality. The findings of this research will be shared with stakeholders to implement effective mitigation strategies for wildfires. Further benefits to society will be achieved by training undergraduate and graduate students at the University of South Carolina to increase the STEM workforce. Combustion processes during wildfire alter the properties of organic matter and metals, leading to enhanced formation of DBPs during drinking water treatment of impacted waters. However, the relationships between the severity of wildfires and the transformation and mobility of metals, the levels and composition of dissolved organic matter (DOM), and enhanced formation of DBPs in drinking water sources remain unclear. To address these knowledge gaps, investigators will conduct a combined field and laboratory study to: (1) Characterize the wildfire-induced metal transformations in field-collected ashes, soils, and forest litter under laboratory-controlled experiments; (2) Determine the concentrations of metals and DOM levels and composition in simulated runoff and streams from the burned area; and (3) Investigate the formation of DBPs through controlled laboratory chlorination and chloramination of ash, soil, and water leachates. This research will improve the fundamental understanding of the real-world implications of wildfires by conducting planned moderate- and high-severity burns that allow for the collection of “before and after” fire samples. Both watershed-scale studies and laboratory experiments combining nontarget and target analysis of metals and organic matter will be used to create realistic predictions of real-world fires. Together, these results may facilitate the discovery of unexpected organic and inorganic compounds in the fire ash, soil, and water samples post wildfire events. 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.