Abstract: A boiler blowdown recycle method and system for increasing recycle and water recovery percentages for steam generation units used in thermal hydrocarbon recovery processes such as SAGD and CSS methods. Blowdown from a steam generating unit is elevated to supercritical temperatures and pressures, and an oxidizing agent added, thereby oxidizing organic and inorganic compounds in the blowdown and simultaneously reducing solubility of inorganics within the blowdown allowing them to precipitate out or be more easily separated therefrom, leaving a purified stream.