Abstract: A method for economically creating useful thermal energy and decontaminating an aqueous stream containing dissolved organic pollutants which may be present in total concentration of 1 or 2 weight percent or as low as even less than 10 ppm. The stream of contaminated water is extracted with a once-through countercurrent stream of substantially water-immiscible, non-polar mixed C.sub.10 to C.sub.20 hydrocabons to dissolve and remove organic pollutants and create a treated water stream which meets environmental standardes for re-use or for discharge to a municipal treatment facility or to the environment. The contaminated mixed hydrocarbon stream is transferred to an on-site power or heat-generating facility where it and its contaminants are burned at a temperature of at least about 1000.degree. F. and a residence time of at least about 1 second to oxidize the contaminants and generate useful thermal energy, e.g.