Chemically oxidizing a wide range of targeted contaminants in soils, sludges, groundwater, process water, and wastewater and assisting in the eventual (over time) biological attenuation of the contaminants utilizing persulfates activated by trivalent metals, such as ferric iron. The use of trivalent metal activated persulfate results in a chemical oxidation process that yields degradation compounds which facilitate further attenuation via biological processes.