There is disclosed a method and apparatus for treating produced water from a heavy oil thermal recovery unit to achieve water recovery and recycle levels of greater than 80% and as high as 100% to achieve zero discharge criteria. The method includes the initial steps of capturing the waste heat energy from the high pressure steam separator located downstream of the steam generators. Further, transferring the heat energy into a heated separator and reboiler exchanger to distill oil reservoir produced water and recover distilled water and a concentrated brine or solid product. The heated separator concentrated stream is circulated through the reboiler exchanger to maintain from 1% to about 50% mass vapour in the stream returning to the heated separator and prevent fouling and scaling. The apparatus includes a low pressure waste energy separator, heated separator and vapour compressor in combination with a forced circulation circuit to generate the distilled water.