Vacuum sewerage systems consist of a vacuum station, where the vacuum is generated; the vacuum pipeline system; collection chambers with collection sumps; and interface valve units. In contrast to conventional gravity sewerage systems with intermediate pumping stations, the pressure within the vacuum system is maintained below atmospheric pressure. Following the suction crated by the valve, batches of wastewater are forced to flow from the collection chambers towards the vacuum station. The valves are operated pneumatically and no electricity is needed. Vacuum sewerage is particularly advantageous where water is scarce; the natural slope is insufficient for gravity flow; in areas with poor subsoil conditions (e.g. rocky soil, high groundwater table); where operation is seasonal or water flow strongly intermittent; or in areas prone to flooding.