Facet Vacuum Sewage Treatment Plants (VTP) for marine applications are designed for the treatment of black water (coming from W.C., urinals and hospital) and grey water (sinks, showers, laundry and galley) generated onboard ships. This treatment includes the purification and later disinfection of water in order to achieve a quality effluent meeting all necessary requirements. These plants treat sewage biologically, meaning they are of the active sludge, prolonged aeration, aerobic type.