TREATMENT OF WASTEWATER

The present invention provides a method of treating wastewater in a wastewater system. The wastewater system comprises a treatment plant comprising a treatment space and a sewer system comprising a sewer space. The treatment plant further comprises a treatment inlet for supplying wastewater to the treatment system from the sewer system. The method comprises the step of: providing a treatment parameter being significant for purification of wastewater in the treatment plant, determining an actual spare plant capacity indicating an amount of wastewater which can be supplied to the treatment space, and determining an actual spare wastewater storage volume indicating an amount of wastewater which can be retained in the sewer space. The amount of wastewater supplied through the treatment inlet to the treatment plant is varied based on the treatment parameter, the actual spare plant capacity, and the actual spare wastewater storage volume.