Abstract: A flow distribution box for a wastewater treatment system includes an inlet into a back wall and outlets in the opposed outer side walls and front wall, the distribution box including a plurality of flow dividers therein to compartmentalize effluent within the flow distribution box. A flow director is disposed in the inlet into the flow distribution box for directing the flow into selected compartments within the distribution box. Each of the outlets in the box is in flow communication with a conduit leading into a selected area of a drain field.