The Object is to provide the secondary treatment appropriate to the old existing facility to meet the conditions of discharge to normal area of an agglomeration of 300,000 equivalent inhabitants_x000D_ Various actions will be carried out on the existing pretreatment and a new biological treatment will be executed:_x000D_ -Remodelation of the two existing reactors and two of the secondary decanters are converted into biological reactors: biological reactors for MBBR treatment, with their corresponding aeration systems using perforated tubes and magnetic levitation blowers, submersible stirrers to keep the filling in suspension._x000D_ - Remodeling of existing storm tanks to house both tertiary treatment and the new storm treatment of relieved pretreated water_x000D_ - The expansion of the existing sludge treatment line is expected