Produced water, for example from a steam assisted gravity drainage (SAGD) or cyclic steam stimulation (CSS) heavy oil recovery operation, is treated to recover water that is re-used to create steam. The produced water is treated in one or more thermal treatment devices such as an evaporator and a crystallizer. The thermal treatment produces a slurry comprising dispersed or dissolved salts and organic compounds. A water-miscible solvent for one or more of the organic compounds, for example methanol, is added to the slurry. The solids precipitate and are separated from the slurry. The solvent may be recovered for re-use in treating more slurry.