They are not allowed to subcontract these services to specialised firms. The drinking water management system leaves the communes with the choice of relying on their own water supply sources (this is the case for 25 of the 116 communes in Luxembourg), of relying, through the communal syndicates, on water from the Esch-sur-Sure Syndicate (SEBES), or of having a mixed arrangement. Four inter-communal syndicates* and Luxembourg City are members of SEBES and deliver drinking water abstracted from the Esch-sur-Sure reservoir. For sewage, there are 11 syndicates, each covering several communes. Some communes manage their sewer networks and treatment plants on their own.