Abstract: A method has been invented for separating components of a wastewater stream, the stream containing water, oil (e.g. heavy oil and/or light oil), undesirable organic material (solid and/or liquid), and contaminating solids, the method including feeding a wastewater stream to a first pre-treatment unit producing a first pretreated stream, feeding the first pretreated stream to a first centrifuge for centrifugal separation, producing a first liquid centrifuged stream, and a second liquid stream, and feeding the first liquid centrifuged stream to a second centrifuge producing a resultant centrifuged stream of recoverable oil and a water phase centrifuged stream which can be treated further or fed back to a source for re-use. The source may be a facility from the group including refineries, chemical plants, paper mill plants, and oil and gas processing facilities.