Abstract: A method for dehalogenating contaminated ground water and/or soil where the contaminated area is contacted with a titanium carboxylic acid derivative such as titanium oxalate, titanium citrate or titanium nitriloacetate and a corrin or porphyrin catalyst preferably vitamin B12 compound. The result of contact with the contaminated source is that the compounds reductively dehalogenate the contaminates thereby making it less toxic. This is achieved by making use of the non-toxic reagents, namely the corrin or porphyrin catalyst such as vitamin B12 and the titanium carboxylic acid derivative.