Abstract: A method and system for the recuperation of the content of septic tank where the supernatant is returned to the septic tank after the recuperation of the sludge and of the scum is described herein. According to the method of the present invention, a major portion of the supernatant is advantageously recuperated from the top of the septic tank to the bottom thereof, and stored in a first reservoir of the system. The sludge, the remainder of the supernatant and the scum are then recuperated and stored in a second reservoir. The supernatant is filtered, either upon its recuperation or before its return to the septic tank. Finally, the filtered supernatant is returned to the septic tank.