Centralised systems are infrastructures such as drinking water or wastewater treatment plants, which treat large amounts of water from many households in one single spot. Centralised systems thus require either the collection of waste and wastewater from individual houses or the redistribution to the households (i.e. drinking water). Centralised systems thus imply the construction of a piping system (water distribution system or sewers) and / or other means of collection and distribution (e.g. cartage).