A method for dehalogenation of aqueous compositions contaminated with halogenated aliphatic and alicyclic hydrocarbons is provided which comprises contacting an aqueous composition with an amount of a mixed metal composition effective to dehalogenate the halogenated aliphatic and alicyclic hydrocarbons at a temperature of at least 10° C., wherein the mixed metal composition comprises a second metal selected from the group consisting of copper, cobalt, nickel, molybdenum, bismuth, tin, lead, silver, chromium, palladium, platinum and gold deposited on an anchor metal consisting essentially of iron metal and wherein the amount of second metal in the mixed metal composition is an amount effective to increase the dehalogenation rate compared to use of iron alone, and the surface of the mixed metal composition has exposed iron metal.