Despite favorable thermodynamics, the high activation energy makes it difficult to degrade perchlorate (ClO₄^-) at the low concentrations typically encountered in the environment. The Oak Ridge National Laboratory recently developed a new methodology to degrade ClO₄^- in FeCl₃-HCl regenerant solutions using ferrous iron and/or non-toxic organic reducing agents (US Patent 6,358,396). Results indicate that a complete destruction of ClO₄^- can be achieved in less than 1-h residence time in the FeCl₃-HCl solution, and ClO₄^- ions are decomposed into chloride and water. While ClO₄^- is reduced, ferrous (Fe²⁺) ions are oxidized to Fe³⁺ ions, which replenish or "regenerate" the FeCl₃-HCl regenerant solution. Therefore the regenerant solution can be re-used for many cycles, and practically no waste regenerant solution (containing ClO₄^-) is produced!  The destruction of ClO₄^- can be operated in a flow-through reactor, and a nearly complete degradation of ClO₄^- is observed under a continuous flow-through mode. Because the FeCl₃-HCl solution has been successfully used in regenerating selective anion-exchange resins sorbed with ClO₄^-, this new methodology offers a cost-effective means to degrade ClO₄^- while not altering the chemical properties of the FeCl₃-HCl regenerant solution, so it can be reused to eliminate the production of secondary wastes.