Abstract: A system of waste treatment and disposal which receives and completely destroys waste solids biochemically and disposes of the effluent by total evaporation within a sealed dispersion reservoir surrounding a two stage tank assembly. Raw sewage is reduced in first and second stages of anaerobic digestion in upper and lower tank units of a double tank assembly. Liquid effluent is forced outwardly through discharge openings in the lower tank unit and upwardly through a rock bed in the dispersion reservoir under the pressure of a liquid column in the upper tank unit. The liquid effluent evaporates in the rock bed as a third stage of disposal, with the resulting vapors being filtered through a sand bed over the rock bed and dispersed to the atmosphere in a fourth and final stage.