Abstract: The invention relates to a wastewater treatment plant and method for treating wastewater, and to a wastewater treatment system having a plurality of filter layers disposed one under the other for purifying the wastewater, wherein at least one feeding device (200) for feeding wastewater to the filter layer (110) and at least one discharge device (300) for discharging the purified wastewater from the filter layer (110) is associated with each filter layer (110). The feeding device (200) for at least two of the filter layers (110) is directly fluidically connected to a wastewater feeding line (400) and the discharge device (300) is directly fluidically connected to an intermediate store (600), such that the unfiltered quantity of wastewater fed to each filter layer (110) can be filtered by said filter layer (110).