NOVELTY - The method comprises introducing waste (12) into a waste treatment plant at an inlet point (40, 42, 44), homogenizing the waste with an agitator (29), determining the consistency of the waste in the waste treatment plant, adding water or waste having a higher water content than the waste in the waste treatment plant if the water content of the waste in the waste treatment plant is too low, or removing water or adding waste having a lower water content if the water content of the waste is too high, transporting the introduced waste to an outlet point (64), and removing the waste.    USE - The method is useful for treating waste in a mechanical or mechanical-biological waste treatment plant, where the waste is municipal waste and household waste.    ADVANTAGE - The method allows rapid, safe and easy treatment of the waste in the mechanical or mechanical-biological waste treatment plant with less consumption of water and without emissions.    DETAILED DESCRIPTION - The method comprises introducing waste (12) into a waste treatment plant at an inlet point (40, 42, 44), homogenizing the waste with an agitator (29), determining the consistency of the waste in the waste treatment plant, adding water or waste having a higher water content than the waste in the waste treatment plant if the water content of the waste in the waste treatment plant is too low or removing water or adding waste having a lower water content if the water content of the waste is too high, transporting the introduced waste to an outlet point (64), and removing the waste, where the waste treatment plant is divided into two zones (15, 16, 17). An air space is supplied via a level of the waste air and/or an inert gas, and an exhaust air is removed. The treated waste water is supplied in regions in which the waste is loosened by agitator arms of and/or a unit for breaking clumping and/or caking of waste. The introduced waste is mixed/crushed by the agitator. A transport of the waste is carried out by a level mirror balance. A movement of the agitator supports the transport of the introduced waste, where a flow direction of the waste is not dependent on the direction of rotation of the agitator. The step of determining the consistency of the waste in the waste treatment plant is carried out via a camera and a power requirement of the agitator. An INDEPENDENT CLAIM is included for a device for a mechanical or mechanical-biological treatment of waste.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a waste treatment plant.    Waste (12)    Zones (15, 16, 17)    Agitator (29)    Inlet point (40, 42, 44)    Outlet point. (64)