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Dr. Manna’s research aims to advance our understanding of how water and contaminants move through the subsurface, from the vadose zone to groundwater systems and across groundwater–surface water interfaces. I investigate the processes controlling groundwater recharge, contaminant transport, and exchanges between groundwater and surface water in both porous and fractured environments. By integrating environmental and anthropogenic tracers, high-resolution hydraulic measurements, and numerical modeling, I develop innovative approaches to characterize complex groundwater flow systems and quantify water and contaminant fluxes across multiple spatial and temporal scales.

This fundamental understanding underpins Dr. Manna’s applied research, which addresses pressing environmental challenges, including the protection of drinking-water resources, the remediation of contaminated sites, and the sustainable management of groundwater under changing environmental conditions. He develops and applies methods to evaluate remediation performance, improves predictions of contaminant fate and transport, and identifies more effective and sustainable environmental management strategies. His research also investigates groundwater flow and water-resource challenges at complex mine sites, as well as the potential impacts of geothermal activities on groundwater quantity and quality.

By combining fundamental hydrogeological science with field-based investigations, advanced monitoring technologies, and predictive modeling, his research seeks to close critical knowledge gaps in how groundwater systems function and respond to natural processes and human activities.