Uranium is a naturally occurring element with complex geochemical behavior that is influenced by mineralogical, redox, and isotopic processes across surface and groundwater systems. This chapter critically reviews the occurrence, mobilization, and isotopic signatures of uranium in freshwater environments, emphasizing the environmental and health risks associated with uranium and fluoride contamination in drinking water sources. This study examines the geogenic and anthropogenic drivers of uranium release, alongside microbial and abiotic mechanisms that govern uranium reduction and oxidation. Particular attention has been given to recent advances in bioremediation strategies, nanotechnology applications, and managed aquifer recharge for mitigating uranium and fluoride exposure. By integrating geochemical, microbial, and hydrogeological perspectives, this chapter highlights the urgent need for sustainable groundwater management and outlines future directions for minimizing contaminant risks to ecosystems and human health.