The wastewater evaporator provides for effluent evaporation in a septic system to eliminate need for a drain field. The evaporator tank contains a plurality of evaporator trays in a vertical array. Solids settle in the septic tank, and liquid effluent flows from the septic tank to the evaporator tank and cascades sequentially from the uppermost to the lowermost tray. The multiple trays increase the surface area of liquid contained therein, thereby greatly enhancing evaporation. An above-surface air pump and vent may be provided for air flow through the evaporator tank. An ultrasonic generator may be installed in each tray to increase the surface area of the effluent to enhance evaporation. An additional intermediate pump tank may be provided between the septic tank and the evaporator tank to control effluent flow and delivery to the evaporator tank. A sump pump in the pump tank periodically delivers effluent to the evaporator tank.