Many new Steam-Assisted Gravity Drainage (SAGD) heavy oil recovery facilities have recently shifted from the use of warm or hot lime softening, filtration and weak acid cation (WAC) ion exchange to pretreat de-oiled produced water to an approach using falling film, mechanical vapour recompression evaporation to produce steam generator feedwater. This method of SAGD-produced water treatment is much simpler to operate, is more cost effective and results in significant increases in equipment reliability, on-stream availability and, ultimately, oil production. There are currently about 14 such evaporators operating, under construction, or in various stages of delivery in Alberta and overseas. Several of these evaporators produce feedwater for standard drum-type boilers rather than the traditional Once-Through Steam Generators (OTSG) due to the high level of water purity obtainable with the evaporative approach. This paper provides data from operational facilities, including evaporator distillate quality, heat transfer information, fouling rates, cleaning frequencies, energy and chemical consumption, and other technical and operational data. In conjunction with this evaporative produced water treatment process, some facilities have taken the additional step of recovering all liquid waste streams for re-use in the plant, resulting in zero liquid discharge (ZLD). Designing the facility for ZLD eliminates the need for deep well injection, minimizes make-up water requirements and simplifies the permitting process.