The environmental fate of insensitive high explosive compound nitrotriazolone (NTO) has not been adequately studied in surface freshwater environments. The goal of this study was to evaluate and quantify removal and complete mineralization of NTO in distinct freshwater sediment systems. We conducted aquaria-scale experiments using four freshwater sediment types: low organic carbon (OC) river sand, low OC silt, high OC wetland sediment, high OC pond silt with and without submerged aquatic plants to investigate natural attenuation of NTO. Isotopically labeled NTO (