Water supplies and water distribution systems have been identified as potential targets for contamination by bacterial biothreat agents. Since the 2001 Bacillus anthracis bioterrorist attacks, additional efforts have been aimed at research to characterize biothreat organisms in regards to their susceptibility to disinfectants and technologies currently in use for potable water. Here, we present a review of research relevant to disinfection of bacteria with the potential to pose a severe threat to public health and safety, and their potential surrogates. The efficacy of chlorine, monochloramine, chlorine dioxide, and ultraviolet light to inactivate each organism in suspension is described. The complexities of disinfection under varying water conditions and when the organisms are associated with biofilms in distribution systems are discussed.