Abstract: A method of aseptic treatment of water which is produced continuously or discontinuously in an amount less than any momentary and maximum output of water. Produced water is supplied to a storage container. The recirculation is carried out from the bottom of the container up to the top thereof. A fresh supply of water and recirculated water is mixed in a mixing and flow deflector member at the top part and the water mixture is spread in a thin layer along the inside of the container above a temporary water level in the container.