A composition for disinfecting contaminated drinking water. The composition can include a disinfecting agent for disinfecting or sanitizing the water and a masking agent for masking or minimizing undesired characteristics of the disinfecting agent, such as taste and odor. The disinfecting agent can be a halogen-based disinfecting agent, such as a chlorine-based disinfecting agent. The masking agent can be a chlorine-compatible masking agent or flavorant, such as a citrus fruit derived flavor. The composition can also include a substrate. The substrate can be a clay, zeolite, water-soluble carrier, water-insoluble carrier, or mixtures thereof. The flavorant can be loaded onto the substrate. The composition can include other components, such as a primary coagulant, a coagulant aid, a bridging flocculant, a polymeric material, an alkali agent, an autocatalytic oxidant, and mixtures thereof.