Safety of drinking water supplies to suburban Paris: analysis and control of radioactivity at Choisy-le-Roi

In order to anticipate the nuclear power plant set up at Nogent/S/Seine 150 Km upstream the Choisy-le-Roi water treatment plant (800.000 cubic meter per day) and more generally to assume the safety of water distribution and cope with the risk of casual pollution the Syndicat des Eaux d'Ile de France and the Compagnie Generale des Eaux have undertaken several stringent actions - founding in 1985 a new laboratory branch for radioactivity measurement - adding new elements to the existing alarm network (automatic analysis of the raw water quality) - studies for the treatability of radioelements - using protected resources (ground water) - set up of a second treated water feeder between the river Seine and the river Marne areas. Other projects are under study, as the creation of a raw water reservoir and increasing the capacity of treated water stockage. (author)