Abstract: A process for treating produced water in heavy oil production comprises, providing an oil/water mixture gathered from an oil/water collection well, whereby oil from said oil/water mixture is separated to provide an oil product and a produced water product containing oil, dissolved gases and dissolved solutes. Said produced water product is then deoiled, and the deoiled water subsequently passes though a membrane system, resulting in permeate water and reject. The resulting permeate water is sent on to a boiler system for production of steam, and the reject is introduced into an evaporator to result in distillate water and blow down. Thereafter, the blow down may be charged into zero liquid discharge treatment; and the distillate water added to the membrane permeate.