A method is provided of removing organic contaminants from an aqueous composition contaminated therewith. The method comprises contacting the aqueous composition with a sufficient amount of organoclay for a sufficient amount of time to absorb a substantial portion of the contaminant, and to form an aqueous organoclay admixture. The organoclay and aqueous composition are then separated from each other. The method is particularly useful for separating oily contaminants from water toxic substance precursors, e.g. humic acid and toxic organics (e.g. PCB) from water.